xref: /openbmc/linux/Documentation/virt/kvm/api.rst (revision 79f382b9)
1.. SPDX-License-Identifier: GPL-2.0
2
3===================================================================
4The Definitive KVM (Kernel-based Virtual Machine) API Documentation
5===================================================================
6
71. General description
8======================
9
10The kvm API is a set of ioctls that are issued to control various aspects
11of a virtual machine.  The ioctls belong to the following classes:
12
13 - System ioctls: These query and set global attributes which affect the
14   whole kvm subsystem.  In addition a system ioctl is used to create
15   virtual machines.
16
17 - VM ioctls: These query and set attributes that affect an entire virtual
18   machine, for example memory layout.  In addition a VM ioctl is used to
19   create virtual cpus (vcpus) and devices.
20
21   VM ioctls must be issued from the same process (address space) that was
22   used to create the VM.
23
24 - vcpu ioctls: These query and set attributes that control the operation
25   of a single virtual cpu.
26
27   vcpu ioctls should be issued from the same thread that was used to create
28   the vcpu, except for asynchronous vcpu ioctl that are marked as such in
29   the documentation.  Otherwise, the first ioctl after switching threads
30   could see a performance impact.
31
32 - device ioctls: These query and set attributes that control the operation
33   of a single device.
34
35   device ioctls must be issued from the same process (address space) that
36   was used to create the VM.
37
382. File descriptors
39===================
40
41The kvm API is centered around file descriptors.  An initial
42open("/dev/kvm") obtains a handle to the kvm subsystem; this handle
43can be used to issue system ioctls.  A KVM_CREATE_VM ioctl on this
44handle will create a VM file descriptor which can be used to issue VM
45ioctls.  A KVM_CREATE_VCPU or KVM_CREATE_DEVICE ioctl on a VM fd will
46create a virtual cpu or device and return a file descriptor pointing to
47the new resource.  Finally, ioctls on a vcpu or device fd can be used
48to control the vcpu or device.  For vcpus, this includes the important
49task of actually running guest code.
50
51In general file descriptors can be migrated among processes by means
52of fork() and the SCM_RIGHTS facility of unix domain socket.  These
53kinds of tricks are explicitly not supported by kvm.  While they will
54not cause harm to the host, their actual behavior is not guaranteed by
55the API.  See "General description" for details on the ioctl usage
56model that is supported by KVM.
57
58It is important to note that althought VM ioctls may only be issued from
59the process that created the VM, a VM's lifecycle is associated with its
60file descriptor, not its creator (process).  In other words, the VM and
61its resources, *including the associated address space*, are not freed
62until the last reference to the VM's file descriptor has been released.
63For example, if fork() is issued after ioctl(KVM_CREATE_VM), the VM will
64not be freed until both the parent (original) process and its child have
65put their references to the VM's file descriptor.
66
67Because a VM's resources are not freed until the last reference to its
68file descriptor is released, creating additional references to a VM
69via fork(), dup(), etc... without careful consideration is strongly
70discouraged and may have unwanted side effects, e.g. memory allocated
71by and on behalf of the VM's process may not be freed/unaccounted when
72the VM is shut down.
73
74
753. Extensions
76=============
77
78As of Linux 2.6.22, the KVM ABI has been stabilized: no backward
79incompatible change are allowed.  However, there is an extension
80facility that allows backward-compatible extensions to the API to be
81queried and used.
82
83The extension mechanism is not based on the Linux version number.
84Instead, kvm defines extension identifiers and a facility to query
85whether a particular extension identifier is available.  If it is, a
86set of ioctls is available for application use.
87
88
894. API description
90==================
91
92This section describes ioctls that can be used to control kvm guests.
93For each ioctl, the following information is provided along with a
94description:
95
96  Capability:
97      which KVM extension provides this ioctl.  Can be 'basic',
98      which means that is will be provided by any kernel that supports
99      API version 12 (see section 4.1), a KVM_CAP_xyz constant, which
100      means availability needs to be checked with KVM_CHECK_EXTENSION
101      (see section 4.4), or 'none' which means that while not all kernels
102      support this ioctl, there's no capability bit to check its
103      availability: for kernels that don't support the ioctl,
104      the ioctl returns -ENOTTY.
105
106  Architectures:
107      which instruction set architectures provide this ioctl.
108      x86 includes both i386 and x86_64.
109
110  Type:
111      system, vm, or vcpu.
112
113  Parameters:
114      what parameters are accepted by the ioctl.
115
116  Returns:
117      the return value.  General error numbers (EBADF, ENOMEM, EINVAL)
118      are not detailed, but errors with specific meanings are.
119
120
1214.1 KVM_GET_API_VERSION
122-----------------------
123
124:Capability: basic
125:Architectures: all
126:Type: system ioctl
127:Parameters: none
128:Returns: the constant KVM_API_VERSION (=12)
129
130This identifies the API version as the stable kvm API. It is not
131expected that this number will change.  However, Linux 2.6.20 and
1322.6.21 report earlier versions; these are not documented and not
133supported.  Applications should refuse to run if KVM_GET_API_VERSION
134returns a value other than 12.  If this check passes, all ioctls
135described as 'basic' will be available.
136
137
1384.2 KVM_CREATE_VM
139-----------------
140
141:Capability: basic
142:Architectures: all
143:Type: system ioctl
144:Parameters: machine type identifier (KVM_VM_*)
145:Returns: a VM fd that can be used to control the new virtual machine.
146
147The new VM has no virtual cpus and no memory.
148You probably want to use 0 as machine type.
149
150In order to create user controlled virtual machines on S390, check
151KVM_CAP_S390_UCONTROL and use the flag KVM_VM_S390_UCONTROL as
152privileged user (CAP_SYS_ADMIN).
153
154To use hardware assisted virtualization on MIPS (VZ ASE) rather than
155the default trap & emulate implementation (which changes the virtual
156memory layout to fit in user mode), check KVM_CAP_MIPS_VZ and use the
157flag KVM_VM_MIPS_VZ.
158
159
160On arm64, the physical address size for a VM (IPA Size limit) is limited
161to 40bits by default. The limit can be configured if the host supports the
162extension KVM_CAP_ARM_VM_IPA_SIZE. When supported, use
163KVM_VM_TYPE_ARM_IPA_SIZE(IPA_Bits) to set the size in the machine type
164identifier, where IPA_Bits is the maximum width of any physical
165address used by the VM. The IPA_Bits is encoded in bits[7-0] of the
166machine type identifier.
167
168e.g, to configure a guest to use 48bit physical address size::
169
170    vm_fd = ioctl(dev_fd, KVM_CREATE_VM, KVM_VM_TYPE_ARM_IPA_SIZE(48));
171
172The requested size (IPA_Bits) must be:
173
174 ==   =========================================================
175  0   Implies default size, 40bits (for backward compatibility)
176  N   Implies N bits, where N is a positive integer such that,
177      32 <= N <= Host_IPA_Limit
178 ==   =========================================================
179
180Host_IPA_Limit is the maximum possible value for IPA_Bits on the host and
181is dependent on the CPU capability and the kernel configuration. The limit can
182be retrieved using KVM_CAP_ARM_VM_IPA_SIZE of the KVM_CHECK_EXTENSION
183ioctl() at run-time.
184
185Please note that configuring the IPA size does not affect the capability
186exposed by the guest CPUs in ID_AA64MMFR0_EL1[PARange]. It only affects
187size of the address translated by the stage2 level (guest physical to
188host physical address translations).
189
190
1914.3 KVM_GET_MSR_INDEX_LIST, KVM_GET_MSR_FEATURE_INDEX_LIST
192----------------------------------------------------------
193
194:Capability: basic, KVM_CAP_GET_MSR_FEATURES for KVM_GET_MSR_FEATURE_INDEX_LIST
195:Architectures: x86
196:Type: system ioctl
197:Parameters: struct kvm_msr_list (in/out)
198:Returns: 0 on success; -1 on error
199
200Errors:
201
202  ======     ============================================================
203  EFAULT     the msr index list cannot be read from or written to
204  E2BIG      the msr index list is to be to fit in the array specified by
205             the user.
206  ======     ============================================================
207
208::
209
210  struct kvm_msr_list {
211	__u32 nmsrs; /* number of msrs in entries */
212	__u32 indices[0];
213  };
214
215The user fills in the size of the indices array in nmsrs, and in return
216kvm adjusts nmsrs to reflect the actual number of msrs and fills in the
217indices array with their numbers.
218
219KVM_GET_MSR_INDEX_LIST returns the guest msrs that are supported.  The list
220varies by kvm version and host processor, but does not change otherwise.
221
222Note: if kvm indicates supports MCE (KVM_CAP_MCE), then the MCE bank MSRs are
223not returned in the MSR list, as different vcpus can have a different number
224of banks, as set via the KVM_X86_SETUP_MCE ioctl.
225
226KVM_GET_MSR_FEATURE_INDEX_LIST returns the list of MSRs that can be passed
227to the KVM_GET_MSRS system ioctl.  This lets userspace probe host capabilities
228and processor features that are exposed via MSRs (e.g., VMX capabilities).
229This list also varies by kvm version and host processor, but does not change
230otherwise.
231
232
2334.4 KVM_CHECK_EXTENSION
234-----------------------
235
236:Capability: basic, KVM_CAP_CHECK_EXTENSION_VM for vm ioctl
237:Architectures: all
238:Type: system ioctl, vm ioctl
239:Parameters: extension identifier (KVM_CAP_*)
240:Returns: 0 if unsupported; 1 (or some other positive integer) if supported
241
242The API allows the application to query about extensions to the core
243kvm API.  Userspace passes an extension identifier (an integer) and
244receives an integer that describes the extension availability.
245Generally 0 means no and 1 means yes, but some extensions may report
246additional information in the integer return value.
247
248Based on their initialization different VMs may have different capabilities.
249It is thus encouraged to use the vm ioctl to query for capabilities (available
250with KVM_CAP_CHECK_EXTENSION_VM on the vm fd)
251
2524.5 KVM_GET_VCPU_MMAP_SIZE
253--------------------------
254
255:Capability: basic
256:Architectures: all
257:Type: system ioctl
258:Parameters: none
259:Returns: size of vcpu mmap area, in bytes
260
261The KVM_RUN ioctl (cf.) communicates with userspace via a shared
262memory region.  This ioctl returns the size of that region.  See the
263KVM_RUN documentation for details.
264
265Besides the size of the KVM_RUN communication region, other areas of
266the VCPU file descriptor can be mmap-ed, including:
267
268- if KVM_CAP_COALESCED_MMIO is available, a page at
269  KVM_COALESCED_MMIO_PAGE_OFFSET * PAGE_SIZE; for historical reasons,
270  this page is included in the result of KVM_GET_VCPU_MMAP_SIZE.
271  KVM_CAP_COALESCED_MMIO is not documented yet.
272
273- if KVM_CAP_DIRTY_LOG_RING is available, a number of pages at
274  KVM_DIRTY_LOG_PAGE_OFFSET * PAGE_SIZE.  For more information on
275  KVM_CAP_DIRTY_LOG_RING, see section 8.3.
276
277
2784.6 KVM_SET_MEMORY_REGION
279-------------------------
280
281:Capability: basic
282:Architectures: all
283:Type: vm ioctl
284:Parameters: struct kvm_memory_region (in)
285:Returns: 0 on success, -1 on error
286
287This ioctl is obsolete and has been removed.
288
289
2904.7 KVM_CREATE_VCPU
291-------------------
292
293:Capability: basic
294:Architectures: all
295:Type: vm ioctl
296:Parameters: vcpu id (apic id on x86)
297:Returns: vcpu fd on success, -1 on error
298
299This API adds a vcpu to a virtual machine. No more than max_vcpus may be added.
300The vcpu id is an integer in the range [0, max_vcpu_id).
301
302The recommended max_vcpus value can be retrieved using the KVM_CAP_NR_VCPUS of
303the KVM_CHECK_EXTENSION ioctl() at run-time.
304The maximum possible value for max_vcpus can be retrieved using the
305KVM_CAP_MAX_VCPUS of the KVM_CHECK_EXTENSION ioctl() at run-time.
306
307If the KVM_CAP_NR_VCPUS does not exist, you should assume that max_vcpus is 4
308cpus max.
309If the KVM_CAP_MAX_VCPUS does not exist, you should assume that max_vcpus is
310same as the value returned from KVM_CAP_NR_VCPUS.
311
312The maximum possible value for max_vcpu_id can be retrieved using the
313KVM_CAP_MAX_VCPU_ID of the KVM_CHECK_EXTENSION ioctl() at run-time.
314
315If the KVM_CAP_MAX_VCPU_ID does not exist, you should assume that max_vcpu_id
316is the same as the value returned from KVM_CAP_MAX_VCPUS.
317
318On powerpc using book3s_hv mode, the vcpus are mapped onto virtual
319threads in one or more virtual CPU cores.  (This is because the
320hardware requires all the hardware threads in a CPU core to be in the
321same partition.)  The KVM_CAP_PPC_SMT capability indicates the number
322of vcpus per virtual core (vcore).  The vcore id is obtained by
323dividing the vcpu id by the number of vcpus per vcore.  The vcpus in a
324given vcore will always be in the same physical core as each other
325(though that might be a different physical core from time to time).
326Userspace can control the threading (SMT) mode of the guest by its
327allocation of vcpu ids.  For example, if userspace wants
328single-threaded guest vcpus, it should make all vcpu ids be a multiple
329of the number of vcpus per vcore.
330
331For virtual cpus that have been created with S390 user controlled virtual
332machines, the resulting vcpu fd can be memory mapped at page offset
333KVM_S390_SIE_PAGE_OFFSET in order to obtain a memory map of the virtual
334cpu's hardware control block.
335
336
3374.8 KVM_GET_DIRTY_LOG (vm ioctl)
338--------------------------------
339
340:Capability: basic
341:Architectures: all
342:Type: vm ioctl
343:Parameters: struct kvm_dirty_log (in/out)
344:Returns: 0 on success, -1 on error
345
346::
347
348  /* for KVM_GET_DIRTY_LOG */
349  struct kvm_dirty_log {
350	__u32 slot;
351	__u32 padding;
352	union {
353		void __user *dirty_bitmap; /* one bit per page */
354		__u64 padding;
355	};
356  };
357
358Given a memory slot, return a bitmap containing any pages dirtied
359since the last call to this ioctl.  Bit 0 is the first page in the
360memory slot.  Ensure the entire structure is cleared to avoid padding
361issues.
362
363If KVM_CAP_MULTI_ADDRESS_SPACE is available, bits 16-31 of slot field specifies
364the address space for which you want to return the dirty bitmap.  See
365KVM_SET_USER_MEMORY_REGION for details on the usage of slot field.
366
367The bits in the dirty bitmap are cleared before the ioctl returns, unless
368KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 is enabled.  For more information,
369see the description of the capability.
370
3714.9 KVM_SET_MEMORY_ALIAS
372------------------------
373
374:Capability: basic
375:Architectures: x86
376:Type: vm ioctl
377:Parameters: struct kvm_memory_alias (in)
378:Returns: 0 (success), -1 (error)
379
380This ioctl is obsolete and has been removed.
381
382
3834.10 KVM_RUN
384------------
385
386:Capability: basic
387:Architectures: all
388:Type: vcpu ioctl
389:Parameters: none
390:Returns: 0 on success, -1 on error
391
392Errors:
393
394  =======    ==============================================================
395  EINTR      an unmasked signal is pending
396  ENOEXEC    the vcpu hasn't been initialized or the guest tried to execute
397             instructions from device memory (arm64)
398  ENOSYS     data abort outside memslots with no syndrome info and
399             KVM_CAP_ARM_NISV_TO_USER not enabled (arm64)
400  EPERM      SVE feature set but not finalized (arm64)
401  =======    ==============================================================
402
403This ioctl is used to run a guest virtual cpu.  While there are no
404explicit parameters, there is an implicit parameter block that can be
405obtained by mmap()ing the vcpu fd at offset 0, with the size given by
406KVM_GET_VCPU_MMAP_SIZE.  The parameter block is formatted as a 'struct
407kvm_run' (see below).
408
409
4104.11 KVM_GET_REGS
411-----------------
412
413:Capability: basic
414:Architectures: all except ARM, arm64
415:Type: vcpu ioctl
416:Parameters: struct kvm_regs (out)
417:Returns: 0 on success, -1 on error
418
419Reads the general purpose registers from the vcpu.
420
421::
422
423  /* x86 */
424  struct kvm_regs {
425	/* out (KVM_GET_REGS) / in (KVM_SET_REGS) */
426	__u64 rax, rbx, rcx, rdx;
427	__u64 rsi, rdi, rsp, rbp;
428	__u64 r8,  r9,  r10, r11;
429	__u64 r12, r13, r14, r15;
430	__u64 rip, rflags;
431  };
432
433  /* mips */
434  struct kvm_regs {
435	/* out (KVM_GET_REGS) / in (KVM_SET_REGS) */
436	__u64 gpr[32];
437	__u64 hi;
438	__u64 lo;
439	__u64 pc;
440  };
441
442
4434.12 KVM_SET_REGS
444-----------------
445
446:Capability: basic
447:Architectures: all except ARM, arm64
448:Type: vcpu ioctl
449:Parameters: struct kvm_regs (in)
450:Returns: 0 on success, -1 on error
451
452Writes the general purpose registers into the vcpu.
453
454See KVM_GET_REGS for the data structure.
455
456
4574.13 KVM_GET_SREGS
458------------------
459
460:Capability: basic
461:Architectures: x86, ppc
462:Type: vcpu ioctl
463:Parameters: struct kvm_sregs (out)
464:Returns: 0 on success, -1 on error
465
466Reads special registers from the vcpu.
467
468::
469
470  /* x86 */
471  struct kvm_sregs {
472	struct kvm_segment cs, ds, es, fs, gs, ss;
473	struct kvm_segment tr, ldt;
474	struct kvm_dtable gdt, idt;
475	__u64 cr0, cr2, cr3, cr4, cr8;
476	__u64 efer;
477	__u64 apic_base;
478	__u64 interrupt_bitmap[(KVM_NR_INTERRUPTS + 63) / 64];
479  };
480
481  /* ppc -- see arch/powerpc/include/uapi/asm/kvm.h */
482
483interrupt_bitmap is a bitmap of pending external interrupts.  At most
484one bit may be set.  This interrupt has been acknowledged by the APIC
485but not yet injected into the cpu core.
486
487
4884.14 KVM_SET_SREGS
489------------------
490
491:Capability: basic
492:Architectures: x86, ppc
493:Type: vcpu ioctl
494:Parameters: struct kvm_sregs (in)
495:Returns: 0 on success, -1 on error
496
497Writes special registers into the vcpu.  See KVM_GET_SREGS for the
498data structures.
499
500
5014.15 KVM_TRANSLATE
502------------------
503
504:Capability: basic
505:Architectures: x86
506:Type: vcpu ioctl
507:Parameters: struct kvm_translation (in/out)
508:Returns: 0 on success, -1 on error
509
510Translates a virtual address according to the vcpu's current address
511translation mode.
512
513::
514
515  struct kvm_translation {
516	/* in */
517	__u64 linear_address;
518
519	/* out */
520	__u64 physical_address;
521	__u8  valid;
522	__u8  writeable;
523	__u8  usermode;
524	__u8  pad[5];
525  };
526
527
5284.16 KVM_INTERRUPT
529------------------
530
531:Capability: basic
532:Architectures: x86, ppc, mips
533:Type: vcpu ioctl
534:Parameters: struct kvm_interrupt (in)
535:Returns: 0 on success, negative on failure.
536
537Queues a hardware interrupt vector to be injected.
538
539::
540
541  /* for KVM_INTERRUPT */
542  struct kvm_interrupt {
543	/* in */
544	__u32 irq;
545  };
546
547X86:
548^^^^
549
550:Returns:
551
552	========= ===================================
553	  0       on success,
554	 -EEXIST  if an interrupt is already enqueued
555	 -EINVAL  the irq number is invalid
556	 -ENXIO   if the PIC is in the kernel
557	 -EFAULT  if the pointer is invalid
558	========= ===================================
559
560Note 'irq' is an interrupt vector, not an interrupt pin or line. This
561ioctl is useful if the in-kernel PIC is not used.
562
563PPC:
564^^^^
565
566Queues an external interrupt to be injected. This ioctl is overleaded
567with 3 different irq values:
568
569a) KVM_INTERRUPT_SET
570
571   This injects an edge type external interrupt into the guest once it's ready
572   to receive interrupts. When injected, the interrupt is done.
573
574b) KVM_INTERRUPT_UNSET
575
576   This unsets any pending interrupt.
577
578   Only available with KVM_CAP_PPC_UNSET_IRQ.
579
580c) KVM_INTERRUPT_SET_LEVEL
581
582   This injects a level type external interrupt into the guest context. The
583   interrupt stays pending until a specific ioctl with KVM_INTERRUPT_UNSET
584   is triggered.
585
586   Only available with KVM_CAP_PPC_IRQ_LEVEL.
587
588Note that any value for 'irq' other than the ones stated above is invalid
589and incurs unexpected behavior.
590
591This is an asynchronous vcpu ioctl and can be invoked from any thread.
592
593MIPS:
594^^^^^
595
596Queues an external interrupt to be injected into the virtual CPU. A negative
597interrupt number dequeues the interrupt.
598
599This is an asynchronous vcpu ioctl and can be invoked from any thread.
600
601
6024.17 KVM_DEBUG_GUEST
603--------------------
604
605:Capability: basic
606:Architectures: none
607:Type: vcpu ioctl
608:Parameters: none)
609:Returns: -1 on error
610
611Support for this has been removed.  Use KVM_SET_GUEST_DEBUG instead.
612
613
6144.18 KVM_GET_MSRS
615-----------------
616
617:Capability: basic (vcpu), KVM_CAP_GET_MSR_FEATURES (system)
618:Architectures: x86
619:Type: system ioctl, vcpu ioctl
620:Parameters: struct kvm_msrs (in/out)
621:Returns: number of msrs successfully returned;
622          -1 on error
623
624When used as a system ioctl:
625Reads the values of MSR-based features that are available for the VM.  This
626is similar to KVM_GET_SUPPORTED_CPUID, but it returns MSR indices and values.
627The list of msr-based features can be obtained using KVM_GET_MSR_FEATURE_INDEX_LIST
628in a system ioctl.
629
630When used as a vcpu ioctl:
631Reads model-specific registers from the vcpu.  Supported msr indices can
632be obtained using KVM_GET_MSR_INDEX_LIST in a system ioctl.
633
634::
635
636  struct kvm_msrs {
637	__u32 nmsrs; /* number of msrs in entries */
638	__u32 pad;
639
640	struct kvm_msr_entry entries[0];
641  };
642
643  struct kvm_msr_entry {
644	__u32 index;
645	__u32 reserved;
646	__u64 data;
647  };
648
649Application code should set the 'nmsrs' member (which indicates the
650size of the entries array) and the 'index' member of each array entry.
651kvm will fill in the 'data' member.
652
653
6544.19 KVM_SET_MSRS
655-----------------
656
657:Capability: basic
658:Architectures: x86
659:Type: vcpu ioctl
660:Parameters: struct kvm_msrs (in)
661:Returns: number of msrs successfully set (see below), -1 on error
662
663Writes model-specific registers to the vcpu.  See KVM_GET_MSRS for the
664data structures.
665
666Application code should set the 'nmsrs' member (which indicates the
667size of the entries array), and the 'index' and 'data' members of each
668array entry.
669
670It tries to set the MSRs in array entries[] one by one. If setting an MSR
671fails, e.g., due to setting reserved bits, the MSR isn't supported/emulated
672by KVM, etc..., it stops processing the MSR list and returns the number of
673MSRs that have been set successfully.
674
675
6764.20 KVM_SET_CPUID
677------------------
678
679:Capability: basic
680:Architectures: x86
681:Type: vcpu ioctl
682:Parameters: struct kvm_cpuid (in)
683:Returns: 0 on success, -1 on error
684
685Defines the vcpu responses to the cpuid instruction.  Applications
686should use the KVM_SET_CPUID2 ioctl if available.
687
688Note, when this IOCTL fails, KVM gives no guarantees that previous valid CPUID
689configuration (if there is) is not corrupted. Userspace can get a copy of the
690resulting CPUID configuration through KVM_GET_CPUID2 in case.
691
692::
693
694  struct kvm_cpuid_entry {
695	__u32 function;
696	__u32 eax;
697	__u32 ebx;
698	__u32 ecx;
699	__u32 edx;
700	__u32 padding;
701  };
702
703  /* for KVM_SET_CPUID */
704  struct kvm_cpuid {
705	__u32 nent;
706	__u32 padding;
707	struct kvm_cpuid_entry entries[0];
708  };
709
710
7114.21 KVM_SET_SIGNAL_MASK
712------------------------
713
714:Capability: basic
715:Architectures: all
716:Type: vcpu ioctl
717:Parameters: struct kvm_signal_mask (in)
718:Returns: 0 on success, -1 on error
719
720Defines which signals are blocked during execution of KVM_RUN.  This
721signal mask temporarily overrides the threads signal mask.  Any
722unblocked signal received (except SIGKILL and SIGSTOP, which retain
723their traditional behaviour) will cause KVM_RUN to return with -EINTR.
724
725Note the signal will only be delivered if not blocked by the original
726signal mask.
727
728::
729
730  /* for KVM_SET_SIGNAL_MASK */
731  struct kvm_signal_mask {
732	__u32 len;
733	__u8  sigset[0];
734  };
735
736
7374.22 KVM_GET_FPU
738----------------
739
740:Capability: basic
741:Architectures: x86
742:Type: vcpu ioctl
743:Parameters: struct kvm_fpu (out)
744:Returns: 0 on success, -1 on error
745
746Reads the floating point state from the vcpu.
747
748::
749
750  /* for KVM_GET_FPU and KVM_SET_FPU */
751  struct kvm_fpu {
752	__u8  fpr[8][16];
753	__u16 fcw;
754	__u16 fsw;
755	__u8  ftwx;  /* in fxsave format */
756	__u8  pad1;
757	__u16 last_opcode;
758	__u64 last_ip;
759	__u64 last_dp;
760	__u8  xmm[16][16];
761	__u32 mxcsr;
762	__u32 pad2;
763  };
764
765
7664.23 KVM_SET_FPU
767----------------
768
769:Capability: basic
770:Architectures: x86
771:Type: vcpu ioctl
772:Parameters: struct kvm_fpu (in)
773:Returns: 0 on success, -1 on error
774
775Writes the floating point state to the vcpu.
776
777::
778
779  /* for KVM_GET_FPU and KVM_SET_FPU */
780  struct kvm_fpu {
781	__u8  fpr[8][16];
782	__u16 fcw;
783	__u16 fsw;
784	__u8  ftwx;  /* in fxsave format */
785	__u8  pad1;
786	__u16 last_opcode;
787	__u64 last_ip;
788	__u64 last_dp;
789	__u8  xmm[16][16];
790	__u32 mxcsr;
791	__u32 pad2;
792  };
793
794
7954.24 KVM_CREATE_IRQCHIP
796-----------------------
797
798:Capability: KVM_CAP_IRQCHIP, KVM_CAP_S390_IRQCHIP (s390)
799:Architectures: x86, ARM, arm64, s390
800:Type: vm ioctl
801:Parameters: none
802:Returns: 0 on success, -1 on error
803
804Creates an interrupt controller model in the kernel.
805On x86, creates a virtual ioapic, a virtual PIC (two PICs, nested), and sets up
806future vcpus to have a local APIC.  IRQ routing for GSIs 0-15 is set to both
807PIC and IOAPIC; GSI 16-23 only go to the IOAPIC.
808On ARM/arm64, a GICv2 is created. Any other GIC versions require the usage of
809KVM_CREATE_DEVICE, which also supports creating a GICv2.  Using
810KVM_CREATE_DEVICE is preferred over KVM_CREATE_IRQCHIP for GICv2.
811On s390, a dummy irq routing table is created.
812
813Note that on s390 the KVM_CAP_S390_IRQCHIP vm capability needs to be enabled
814before KVM_CREATE_IRQCHIP can be used.
815
816
8174.25 KVM_IRQ_LINE
818-----------------
819
820:Capability: KVM_CAP_IRQCHIP
821:Architectures: x86, arm, arm64
822:Type: vm ioctl
823:Parameters: struct kvm_irq_level
824:Returns: 0 on success, -1 on error
825
826Sets the level of a GSI input to the interrupt controller model in the kernel.
827On some architectures it is required that an interrupt controller model has
828been previously created with KVM_CREATE_IRQCHIP.  Note that edge-triggered
829interrupts require the level to be set to 1 and then back to 0.
830
831On real hardware, interrupt pins can be active-low or active-high.  This
832does not matter for the level field of struct kvm_irq_level: 1 always
833means active (asserted), 0 means inactive (deasserted).
834
835x86 allows the operating system to program the interrupt polarity
836(active-low/active-high) for level-triggered interrupts, and KVM used
837to consider the polarity.  However, due to bitrot in the handling of
838active-low interrupts, the above convention is now valid on x86 too.
839This is signaled by KVM_CAP_X86_IOAPIC_POLARITY_IGNORED.  Userspace
840should not present interrupts to the guest as active-low unless this
841capability is present (or unless it is not using the in-kernel irqchip,
842of course).
843
844
845ARM/arm64 can signal an interrupt either at the CPU level, or at the
846in-kernel irqchip (GIC), and for in-kernel irqchip can tell the GIC to
847use PPIs designated for specific cpus.  The irq field is interpreted
848like this::
849
850  bits:  |  31 ... 28  | 27 ... 24 | 23  ... 16 | 15 ... 0 |
851  field: | vcpu2_index | irq_type  | vcpu_index |  irq_id  |
852
853The irq_type field has the following values:
854
855- irq_type[0]:
856	       out-of-kernel GIC: irq_id 0 is IRQ, irq_id 1 is FIQ
857- irq_type[1]:
858	       in-kernel GIC: SPI, irq_id between 32 and 1019 (incl.)
859               (the vcpu_index field is ignored)
860- irq_type[2]:
861	       in-kernel GIC: PPI, irq_id between 16 and 31 (incl.)
862
863(The irq_id field thus corresponds nicely to the IRQ ID in the ARM GIC specs)
864
865In both cases, level is used to assert/deassert the line.
866
867When KVM_CAP_ARM_IRQ_LINE_LAYOUT_2 is supported, the target vcpu is
868identified as (256 * vcpu2_index + vcpu_index). Otherwise, vcpu2_index
869must be zero.
870
871Note that on arm/arm64, the KVM_CAP_IRQCHIP capability only conditions
872injection of interrupts for the in-kernel irqchip. KVM_IRQ_LINE can always
873be used for a userspace interrupt controller.
874
875::
876
877  struct kvm_irq_level {
878	union {
879		__u32 irq;     /* GSI */
880		__s32 status;  /* not used for KVM_IRQ_LEVEL */
881	};
882	__u32 level;           /* 0 or 1 */
883  };
884
885
8864.26 KVM_GET_IRQCHIP
887--------------------
888
889:Capability: KVM_CAP_IRQCHIP
890:Architectures: x86
891:Type: vm ioctl
892:Parameters: struct kvm_irqchip (in/out)
893:Returns: 0 on success, -1 on error
894
895Reads the state of a kernel interrupt controller created with
896KVM_CREATE_IRQCHIP into a buffer provided by the caller.
897
898::
899
900  struct kvm_irqchip {
901	__u32 chip_id;  /* 0 = PIC1, 1 = PIC2, 2 = IOAPIC */
902	__u32 pad;
903        union {
904		char dummy[512];  /* reserving space */
905		struct kvm_pic_state pic;
906		struct kvm_ioapic_state ioapic;
907	} chip;
908  };
909
910
9114.27 KVM_SET_IRQCHIP
912--------------------
913
914:Capability: KVM_CAP_IRQCHIP
915:Architectures: x86
916:Type: vm ioctl
917:Parameters: struct kvm_irqchip (in)
918:Returns: 0 on success, -1 on error
919
920Sets the state of a kernel interrupt controller created with
921KVM_CREATE_IRQCHIP from a buffer provided by the caller.
922
923::
924
925  struct kvm_irqchip {
926	__u32 chip_id;  /* 0 = PIC1, 1 = PIC2, 2 = IOAPIC */
927	__u32 pad;
928        union {
929		char dummy[512];  /* reserving space */
930		struct kvm_pic_state pic;
931		struct kvm_ioapic_state ioapic;
932	} chip;
933  };
934
935
9364.28 KVM_XEN_HVM_CONFIG
937-----------------------
938
939:Capability: KVM_CAP_XEN_HVM
940:Architectures: x86
941:Type: vm ioctl
942:Parameters: struct kvm_xen_hvm_config (in)
943:Returns: 0 on success, -1 on error
944
945Sets the MSR that the Xen HVM guest uses to initialize its hypercall
946page, and provides the starting address and size of the hypercall
947blobs in userspace.  When the guest writes the MSR, kvm copies one
948page of a blob (32- or 64-bit, depending on the vcpu mode) to guest
949memory.
950
951::
952
953  struct kvm_xen_hvm_config {
954	__u32 flags;
955	__u32 msr;
956	__u64 blob_addr_32;
957	__u64 blob_addr_64;
958	__u8 blob_size_32;
959	__u8 blob_size_64;
960	__u8 pad2[30];
961  };
962
963If the KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL flag is returned from the
964KVM_CAP_XEN_HVM check, it may be set in the flags field of this ioctl.
965This requests KVM to generate the contents of the hypercall page
966automatically; hypercalls will be intercepted and passed to userspace
967through KVM_EXIT_XEN.  In this case, all of the blob size and address
968fields must be zero.
969
970No other flags are currently valid in the struct kvm_xen_hvm_config.
971
9724.29 KVM_GET_CLOCK
973------------------
974
975:Capability: KVM_CAP_ADJUST_CLOCK
976:Architectures: x86
977:Type: vm ioctl
978:Parameters: struct kvm_clock_data (out)
979:Returns: 0 on success, -1 on error
980
981Gets the current timestamp of kvmclock as seen by the current guest. In
982conjunction with KVM_SET_CLOCK, it is used to ensure monotonicity on scenarios
983such as migration.
984
985When KVM_CAP_ADJUST_CLOCK is passed to KVM_CHECK_EXTENSION, it returns the
986set of bits that KVM can return in struct kvm_clock_data's flag member.
987
988The only flag defined now is KVM_CLOCK_TSC_STABLE.  If set, the returned
989value is the exact kvmclock value seen by all VCPUs at the instant
990when KVM_GET_CLOCK was called.  If clear, the returned value is simply
991CLOCK_MONOTONIC plus a constant offset; the offset can be modified
992with KVM_SET_CLOCK.  KVM will try to make all VCPUs follow this clock,
993but the exact value read by each VCPU could differ, because the host
994TSC is not stable.
995
996::
997
998  struct kvm_clock_data {
999	__u64 clock;  /* kvmclock current value */
1000	__u32 flags;
1001	__u32 pad[9];
1002  };
1003
1004
10054.30 KVM_SET_CLOCK
1006------------------
1007
1008:Capability: KVM_CAP_ADJUST_CLOCK
1009:Architectures: x86
1010:Type: vm ioctl
1011:Parameters: struct kvm_clock_data (in)
1012:Returns: 0 on success, -1 on error
1013
1014Sets the current timestamp of kvmclock to the value specified in its parameter.
1015In conjunction with KVM_GET_CLOCK, it is used to ensure monotonicity on scenarios
1016such as migration.
1017
1018::
1019
1020  struct kvm_clock_data {
1021	__u64 clock;  /* kvmclock current value */
1022	__u32 flags;
1023	__u32 pad[9];
1024  };
1025
1026
10274.31 KVM_GET_VCPU_EVENTS
1028------------------------
1029
1030:Capability: KVM_CAP_VCPU_EVENTS
1031:Extended by: KVM_CAP_INTR_SHADOW
1032:Architectures: x86, arm, arm64
1033:Type: vcpu ioctl
1034:Parameters: struct kvm_vcpu_event (out)
1035:Returns: 0 on success, -1 on error
1036
1037X86:
1038^^^^
1039
1040Gets currently pending exceptions, interrupts, and NMIs as well as related
1041states of the vcpu.
1042
1043::
1044
1045  struct kvm_vcpu_events {
1046	struct {
1047		__u8 injected;
1048		__u8 nr;
1049		__u8 has_error_code;
1050		__u8 pending;
1051		__u32 error_code;
1052	} exception;
1053	struct {
1054		__u8 injected;
1055		__u8 nr;
1056		__u8 soft;
1057		__u8 shadow;
1058	} interrupt;
1059	struct {
1060		__u8 injected;
1061		__u8 pending;
1062		__u8 masked;
1063		__u8 pad;
1064	} nmi;
1065	__u32 sipi_vector;
1066	__u32 flags;
1067	struct {
1068		__u8 smm;
1069		__u8 pending;
1070		__u8 smm_inside_nmi;
1071		__u8 latched_init;
1072	} smi;
1073	__u8 reserved[27];
1074	__u8 exception_has_payload;
1075	__u64 exception_payload;
1076  };
1077
1078The following bits are defined in the flags field:
1079
1080- KVM_VCPUEVENT_VALID_SHADOW may be set to signal that
1081  interrupt.shadow contains a valid state.
1082
1083- KVM_VCPUEVENT_VALID_SMM may be set to signal that smi contains a
1084  valid state.
1085
1086- KVM_VCPUEVENT_VALID_PAYLOAD may be set to signal that the
1087  exception_has_payload, exception_payload, and exception.pending
1088  fields contain a valid state. This bit will be set whenever
1089  KVM_CAP_EXCEPTION_PAYLOAD is enabled.
1090
1091ARM/ARM64:
1092^^^^^^^^^^
1093
1094If the guest accesses a device that is being emulated by the host kernel in
1095such a way that a real device would generate a physical SError, KVM may make
1096a virtual SError pending for that VCPU. This system error interrupt remains
1097pending until the guest takes the exception by unmasking PSTATE.A.
1098
1099Running the VCPU may cause it to take a pending SError, or make an access that
1100causes an SError to become pending. The event's description is only valid while
1101the VPCU is not running.
1102
1103This API provides a way to read and write the pending 'event' state that is not
1104visible to the guest. To save, restore or migrate a VCPU the struct representing
1105the state can be read then written using this GET/SET API, along with the other
1106guest-visible registers. It is not possible to 'cancel' an SError that has been
1107made pending.
1108
1109A device being emulated in user-space may also wish to generate an SError. To do
1110this the events structure can be populated by user-space. The current state
1111should be read first, to ensure no existing SError is pending. If an existing
1112SError is pending, the architecture's 'Multiple SError interrupts' rules should
1113be followed. (2.5.3 of DDI0587.a "ARM Reliability, Availability, and
1114Serviceability (RAS) Specification").
1115
1116SError exceptions always have an ESR value. Some CPUs have the ability to
1117specify what the virtual SError's ESR value should be. These systems will
1118advertise KVM_CAP_ARM_INJECT_SERROR_ESR. In this case exception.has_esr will
1119always have a non-zero value when read, and the agent making an SError pending
1120should specify the ISS field in the lower 24 bits of exception.serror_esr. If
1121the system supports KVM_CAP_ARM_INJECT_SERROR_ESR, but user-space sets the events
1122with exception.has_esr as zero, KVM will choose an ESR.
1123
1124Specifying exception.has_esr on a system that does not support it will return
1125-EINVAL. Setting anything other than the lower 24bits of exception.serror_esr
1126will return -EINVAL.
1127
1128It is not possible to read back a pending external abort (injected via
1129KVM_SET_VCPU_EVENTS or otherwise) because such an exception is always delivered
1130directly to the virtual CPU).
1131
1132::
1133
1134  struct kvm_vcpu_events {
1135	struct {
1136		__u8 serror_pending;
1137		__u8 serror_has_esr;
1138		__u8 ext_dabt_pending;
1139		/* Align it to 8 bytes */
1140		__u8 pad[5];
1141		__u64 serror_esr;
1142	} exception;
1143	__u32 reserved[12];
1144  };
1145
11464.32 KVM_SET_VCPU_EVENTS
1147------------------------
1148
1149:Capability: KVM_CAP_VCPU_EVENTS
1150:Extended by: KVM_CAP_INTR_SHADOW
1151:Architectures: x86, arm, arm64
1152:Type: vcpu ioctl
1153:Parameters: struct kvm_vcpu_event (in)
1154:Returns: 0 on success, -1 on error
1155
1156X86:
1157^^^^
1158
1159Set pending exceptions, interrupts, and NMIs as well as related states of the
1160vcpu.
1161
1162See KVM_GET_VCPU_EVENTS for the data structure.
1163
1164Fields that may be modified asynchronously by running VCPUs can be excluded
1165from the update. These fields are nmi.pending, sipi_vector, smi.smm,
1166smi.pending. Keep the corresponding bits in the flags field cleared to
1167suppress overwriting the current in-kernel state. The bits are:
1168
1169===============================  ==================================
1170KVM_VCPUEVENT_VALID_NMI_PENDING  transfer nmi.pending to the kernel
1171KVM_VCPUEVENT_VALID_SIPI_VECTOR  transfer sipi_vector
1172KVM_VCPUEVENT_VALID_SMM          transfer the smi sub-struct.
1173===============================  ==================================
1174
1175If KVM_CAP_INTR_SHADOW is available, KVM_VCPUEVENT_VALID_SHADOW can be set in
1176the flags field to signal that interrupt.shadow contains a valid state and
1177shall be written into the VCPU.
1178
1179KVM_VCPUEVENT_VALID_SMM can only be set if KVM_CAP_X86_SMM is available.
1180
1181If KVM_CAP_EXCEPTION_PAYLOAD is enabled, KVM_VCPUEVENT_VALID_PAYLOAD
1182can be set in the flags field to signal that the
1183exception_has_payload, exception_payload, and exception.pending fields
1184contain a valid state and shall be written into the VCPU.
1185
1186ARM/ARM64:
1187^^^^^^^^^^
1188
1189User space may need to inject several types of events to the guest.
1190
1191Set the pending SError exception state for this VCPU. It is not possible to
1192'cancel' an Serror that has been made pending.
1193
1194If the guest performed an access to I/O memory which could not be handled by
1195userspace, for example because of missing instruction syndrome decode
1196information or because there is no device mapped at the accessed IPA, then
1197userspace can ask the kernel to inject an external abort using the address
1198from the exiting fault on the VCPU. It is a programming error to set
1199ext_dabt_pending after an exit which was not either KVM_EXIT_MMIO or
1200KVM_EXIT_ARM_NISV. This feature is only available if the system supports
1201KVM_CAP_ARM_INJECT_EXT_DABT. This is a helper which provides commonality in
1202how userspace reports accesses for the above cases to guests, across different
1203userspace implementations. Nevertheless, userspace can still emulate all Arm
1204exceptions by manipulating individual registers using the KVM_SET_ONE_REG API.
1205
1206See KVM_GET_VCPU_EVENTS for the data structure.
1207
1208
12094.33 KVM_GET_DEBUGREGS
1210----------------------
1211
1212:Capability: KVM_CAP_DEBUGREGS
1213:Architectures: x86
1214:Type: vm ioctl
1215:Parameters: struct kvm_debugregs (out)
1216:Returns: 0 on success, -1 on error
1217
1218Reads debug registers from the vcpu.
1219
1220::
1221
1222  struct kvm_debugregs {
1223	__u64 db[4];
1224	__u64 dr6;
1225	__u64 dr7;
1226	__u64 flags;
1227	__u64 reserved[9];
1228  };
1229
1230
12314.34 KVM_SET_DEBUGREGS
1232----------------------
1233
1234:Capability: KVM_CAP_DEBUGREGS
1235:Architectures: x86
1236:Type: vm ioctl
1237:Parameters: struct kvm_debugregs (in)
1238:Returns: 0 on success, -1 on error
1239
1240Writes debug registers into the vcpu.
1241
1242See KVM_GET_DEBUGREGS for the data structure. The flags field is unused
1243yet and must be cleared on entry.
1244
1245
12464.35 KVM_SET_USER_MEMORY_REGION
1247-------------------------------
1248
1249:Capability: KVM_CAP_USER_MEMORY
1250:Architectures: all
1251:Type: vm ioctl
1252:Parameters: struct kvm_userspace_memory_region (in)
1253:Returns: 0 on success, -1 on error
1254
1255::
1256
1257  struct kvm_userspace_memory_region {
1258	__u32 slot;
1259	__u32 flags;
1260	__u64 guest_phys_addr;
1261	__u64 memory_size; /* bytes */
1262	__u64 userspace_addr; /* start of the userspace allocated memory */
1263  };
1264
1265  /* for kvm_memory_region::flags */
1266  #define KVM_MEM_LOG_DIRTY_PAGES	(1UL << 0)
1267  #define KVM_MEM_READONLY	(1UL << 1)
1268
1269This ioctl allows the user to create, modify or delete a guest physical
1270memory slot.  Bits 0-15 of "slot" specify the slot id and this value
1271should be less than the maximum number of user memory slots supported per
1272VM.  The maximum allowed slots can be queried using KVM_CAP_NR_MEMSLOTS.
1273Slots may not overlap in guest physical address space.
1274
1275If KVM_CAP_MULTI_ADDRESS_SPACE is available, bits 16-31 of "slot"
1276specifies the address space which is being modified.  They must be
1277less than the value that KVM_CHECK_EXTENSION returns for the
1278KVM_CAP_MULTI_ADDRESS_SPACE capability.  Slots in separate address spaces
1279are unrelated; the restriction on overlapping slots only applies within
1280each address space.
1281
1282Deleting a slot is done by passing zero for memory_size.  When changing
1283an existing slot, it may be moved in the guest physical memory space,
1284or its flags may be modified, but it may not be resized.
1285
1286Memory for the region is taken starting at the address denoted by the
1287field userspace_addr, which must point at user addressable memory for
1288the entire memory slot size.  Any object may back this memory, including
1289anonymous memory, ordinary files, and hugetlbfs.
1290
1291On architectures that support a form of address tagging, userspace_addr must
1292be an untagged address.
1293
1294It is recommended that the lower 21 bits of guest_phys_addr and userspace_addr
1295be identical.  This allows large pages in the guest to be backed by large
1296pages in the host.
1297
1298The flags field supports two flags: KVM_MEM_LOG_DIRTY_PAGES and
1299KVM_MEM_READONLY.  The former can be set to instruct KVM to keep track of
1300writes to memory within the slot.  See KVM_GET_DIRTY_LOG ioctl to know how to
1301use it.  The latter can be set, if KVM_CAP_READONLY_MEM capability allows it,
1302to make a new slot read-only.  In this case, writes to this memory will be
1303posted to userspace as KVM_EXIT_MMIO exits.
1304
1305When the KVM_CAP_SYNC_MMU capability is available, changes in the backing of
1306the memory region are automatically reflected into the guest.  For example, an
1307mmap() that affects the region will be made visible immediately.  Another
1308example is madvise(MADV_DROP).
1309
1310It is recommended to use this API instead of the KVM_SET_MEMORY_REGION ioctl.
1311The KVM_SET_MEMORY_REGION does not allow fine grained control over memory
1312allocation and is deprecated.
1313
1314
13154.36 KVM_SET_TSS_ADDR
1316---------------------
1317
1318:Capability: KVM_CAP_SET_TSS_ADDR
1319:Architectures: x86
1320:Type: vm ioctl
1321:Parameters: unsigned long tss_address (in)
1322:Returns: 0 on success, -1 on error
1323
1324This ioctl defines the physical address of a three-page region in the guest
1325physical address space.  The region must be within the first 4GB of the
1326guest physical address space and must not conflict with any memory slot
1327or any mmio address.  The guest may malfunction if it accesses this memory
1328region.
1329
1330This ioctl is required on Intel-based hosts.  This is needed on Intel hardware
1331because of a quirk in the virtualization implementation (see the internals
1332documentation when it pops into existence).
1333
1334
13354.37 KVM_ENABLE_CAP
1336-------------------
1337
1338:Capability: KVM_CAP_ENABLE_CAP
1339:Architectures: mips, ppc, s390
1340:Type: vcpu ioctl
1341:Parameters: struct kvm_enable_cap (in)
1342:Returns: 0 on success; -1 on error
1343
1344:Capability: KVM_CAP_ENABLE_CAP_VM
1345:Architectures: all
1346:Type: vm ioctl
1347:Parameters: struct kvm_enable_cap (in)
1348:Returns: 0 on success; -1 on error
1349
1350.. note::
1351
1352   Not all extensions are enabled by default. Using this ioctl the application
1353   can enable an extension, making it available to the guest.
1354
1355On systems that do not support this ioctl, it always fails. On systems that
1356do support it, it only works for extensions that are supported for enablement.
1357
1358To check if a capability can be enabled, the KVM_CHECK_EXTENSION ioctl should
1359be used.
1360
1361::
1362
1363  struct kvm_enable_cap {
1364       /* in */
1365       __u32 cap;
1366
1367The capability that is supposed to get enabled.
1368
1369::
1370
1371       __u32 flags;
1372
1373A bitfield indicating future enhancements. Has to be 0 for now.
1374
1375::
1376
1377       __u64 args[4];
1378
1379Arguments for enabling a feature. If a feature needs initial values to
1380function properly, this is the place to put them.
1381
1382::
1383
1384       __u8  pad[64];
1385  };
1386
1387The vcpu ioctl should be used for vcpu-specific capabilities, the vm ioctl
1388for vm-wide capabilities.
1389
13904.38 KVM_GET_MP_STATE
1391---------------------
1392
1393:Capability: KVM_CAP_MP_STATE
1394:Architectures: x86, s390, arm, arm64
1395:Type: vcpu ioctl
1396:Parameters: struct kvm_mp_state (out)
1397:Returns: 0 on success; -1 on error
1398
1399::
1400
1401  struct kvm_mp_state {
1402	__u32 mp_state;
1403  };
1404
1405Returns the vcpu's current "multiprocessing state" (though also valid on
1406uniprocessor guests).
1407
1408Possible values are:
1409
1410   ==========================    ===============================================
1411   KVM_MP_STATE_RUNNABLE         the vcpu is currently running [x86,arm/arm64]
1412   KVM_MP_STATE_UNINITIALIZED    the vcpu is an application processor (AP)
1413                                 which has not yet received an INIT signal [x86]
1414   KVM_MP_STATE_INIT_RECEIVED    the vcpu has received an INIT signal, and is
1415                                 now ready for a SIPI [x86]
1416   KVM_MP_STATE_HALTED           the vcpu has executed a HLT instruction and
1417                                 is waiting for an interrupt [x86]
1418   KVM_MP_STATE_SIPI_RECEIVED    the vcpu has just received a SIPI (vector
1419                                 accessible via KVM_GET_VCPU_EVENTS) [x86]
1420   KVM_MP_STATE_STOPPED          the vcpu is stopped [s390,arm/arm64]
1421   KVM_MP_STATE_CHECK_STOP       the vcpu is in a special error state [s390]
1422   KVM_MP_STATE_OPERATING        the vcpu is operating (running or halted)
1423                                 [s390]
1424   KVM_MP_STATE_LOAD             the vcpu is in a special load/startup state
1425                                 [s390]
1426   ==========================    ===============================================
1427
1428On x86, this ioctl is only useful after KVM_CREATE_IRQCHIP. Without an
1429in-kernel irqchip, the multiprocessing state must be maintained by userspace on
1430these architectures.
1431
1432For arm/arm64:
1433^^^^^^^^^^^^^^
1434
1435The only states that are valid are KVM_MP_STATE_STOPPED and
1436KVM_MP_STATE_RUNNABLE which reflect if the vcpu is paused or not.
1437
14384.39 KVM_SET_MP_STATE
1439---------------------
1440
1441:Capability: KVM_CAP_MP_STATE
1442:Architectures: x86, s390, arm, arm64
1443:Type: vcpu ioctl
1444:Parameters: struct kvm_mp_state (in)
1445:Returns: 0 on success; -1 on error
1446
1447Sets the vcpu's current "multiprocessing state"; see KVM_GET_MP_STATE for
1448arguments.
1449
1450On x86, this ioctl is only useful after KVM_CREATE_IRQCHIP. Without an
1451in-kernel irqchip, the multiprocessing state must be maintained by userspace on
1452these architectures.
1453
1454For arm/arm64:
1455^^^^^^^^^^^^^^
1456
1457The only states that are valid are KVM_MP_STATE_STOPPED and
1458KVM_MP_STATE_RUNNABLE which reflect if the vcpu should be paused or not.
1459
14604.40 KVM_SET_IDENTITY_MAP_ADDR
1461------------------------------
1462
1463:Capability: KVM_CAP_SET_IDENTITY_MAP_ADDR
1464:Architectures: x86
1465:Type: vm ioctl
1466:Parameters: unsigned long identity (in)
1467:Returns: 0 on success, -1 on error
1468
1469This ioctl defines the physical address of a one-page region in the guest
1470physical address space.  The region must be within the first 4GB of the
1471guest physical address space and must not conflict with any memory slot
1472or any mmio address.  The guest may malfunction if it accesses this memory
1473region.
1474
1475Setting the address to 0 will result in resetting the address to its default
1476(0xfffbc000).
1477
1478This ioctl is required on Intel-based hosts.  This is needed on Intel hardware
1479because of a quirk in the virtualization implementation (see the internals
1480documentation when it pops into existence).
1481
1482Fails if any VCPU has already been created.
1483
14844.41 KVM_SET_BOOT_CPU_ID
1485------------------------
1486
1487:Capability: KVM_CAP_SET_BOOT_CPU_ID
1488:Architectures: x86
1489:Type: vm ioctl
1490:Parameters: unsigned long vcpu_id
1491:Returns: 0 on success, -1 on error
1492
1493Define which vcpu is the Bootstrap Processor (BSP).  Values are the same
1494as the vcpu id in KVM_CREATE_VCPU.  If this ioctl is not called, the default
1495is vcpu 0.
1496
1497
14984.42 KVM_GET_XSAVE
1499------------------
1500
1501:Capability: KVM_CAP_XSAVE
1502:Architectures: x86
1503:Type: vcpu ioctl
1504:Parameters: struct kvm_xsave (out)
1505:Returns: 0 on success, -1 on error
1506
1507
1508::
1509
1510  struct kvm_xsave {
1511	__u32 region[1024];
1512  };
1513
1514This ioctl would copy current vcpu's xsave struct to the userspace.
1515
1516
15174.43 KVM_SET_XSAVE
1518------------------
1519
1520:Capability: KVM_CAP_XSAVE
1521:Architectures: x86
1522:Type: vcpu ioctl
1523:Parameters: struct kvm_xsave (in)
1524:Returns: 0 on success, -1 on error
1525
1526::
1527
1528
1529  struct kvm_xsave {
1530	__u32 region[1024];
1531  };
1532
1533This ioctl would copy userspace's xsave struct to the kernel.
1534
1535
15364.44 KVM_GET_XCRS
1537-----------------
1538
1539:Capability: KVM_CAP_XCRS
1540:Architectures: x86
1541:Type: vcpu ioctl
1542:Parameters: struct kvm_xcrs (out)
1543:Returns: 0 on success, -1 on error
1544
1545::
1546
1547  struct kvm_xcr {
1548	__u32 xcr;
1549	__u32 reserved;
1550	__u64 value;
1551  };
1552
1553  struct kvm_xcrs {
1554	__u32 nr_xcrs;
1555	__u32 flags;
1556	struct kvm_xcr xcrs[KVM_MAX_XCRS];
1557	__u64 padding[16];
1558  };
1559
1560This ioctl would copy current vcpu's xcrs to the userspace.
1561
1562
15634.45 KVM_SET_XCRS
1564-----------------
1565
1566:Capability: KVM_CAP_XCRS
1567:Architectures: x86
1568:Type: vcpu ioctl
1569:Parameters: struct kvm_xcrs (in)
1570:Returns: 0 on success, -1 on error
1571
1572::
1573
1574  struct kvm_xcr {
1575	__u32 xcr;
1576	__u32 reserved;
1577	__u64 value;
1578  };
1579
1580  struct kvm_xcrs {
1581	__u32 nr_xcrs;
1582	__u32 flags;
1583	struct kvm_xcr xcrs[KVM_MAX_XCRS];
1584	__u64 padding[16];
1585  };
1586
1587This ioctl would set vcpu's xcr to the value userspace specified.
1588
1589
15904.46 KVM_GET_SUPPORTED_CPUID
1591----------------------------
1592
1593:Capability: KVM_CAP_EXT_CPUID
1594:Architectures: x86
1595:Type: system ioctl
1596:Parameters: struct kvm_cpuid2 (in/out)
1597:Returns: 0 on success, -1 on error
1598
1599::
1600
1601  struct kvm_cpuid2 {
1602	__u32 nent;
1603	__u32 padding;
1604	struct kvm_cpuid_entry2 entries[0];
1605  };
1606
1607  #define KVM_CPUID_FLAG_SIGNIFCANT_INDEX		BIT(0)
1608  #define KVM_CPUID_FLAG_STATEFUL_FUNC		BIT(1) /* deprecated */
1609  #define KVM_CPUID_FLAG_STATE_READ_NEXT		BIT(2) /* deprecated */
1610
1611  struct kvm_cpuid_entry2 {
1612	__u32 function;
1613	__u32 index;
1614	__u32 flags;
1615	__u32 eax;
1616	__u32 ebx;
1617	__u32 ecx;
1618	__u32 edx;
1619	__u32 padding[3];
1620  };
1621
1622This ioctl returns x86 cpuid features which are supported by both the
1623hardware and kvm in its default configuration.  Userspace can use the
1624information returned by this ioctl to construct cpuid information (for
1625KVM_SET_CPUID2) that is consistent with hardware, kernel, and
1626userspace capabilities, and with user requirements (for example, the
1627user may wish to constrain cpuid to emulate older hardware, or for
1628feature consistency across a cluster).
1629
1630Note that certain capabilities, such as KVM_CAP_X86_DISABLE_EXITS, may
1631expose cpuid features (e.g. MONITOR) which are not supported by kvm in
1632its default configuration. If userspace enables such capabilities, it
1633is responsible for modifying the results of this ioctl appropriately.
1634
1635Userspace invokes KVM_GET_SUPPORTED_CPUID by passing a kvm_cpuid2 structure
1636with the 'nent' field indicating the number of entries in the variable-size
1637array 'entries'.  If the number of entries is too low to describe the cpu
1638capabilities, an error (E2BIG) is returned.  If the number is too high,
1639the 'nent' field is adjusted and an error (ENOMEM) is returned.  If the
1640number is just right, the 'nent' field is adjusted to the number of valid
1641entries in the 'entries' array, which is then filled.
1642
1643The entries returned are the host cpuid as returned by the cpuid instruction,
1644with unknown or unsupported features masked out.  Some features (for example,
1645x2apic), may not be present in the host cpu, but are exposed by kvm if it can
1646emulate them efficiently. The fields in each entry are defined as follows:
1647
1648  function:
1649         the eax value used to obtain the entry
1650
1651  index:
1652         the ecx value used to obtain the entry (for entries that are
1653         affected by ecx)
1654
1655  flags:
1656     an OR of zero or more of the following:
1657
1658        KVM_CPUID_FLAG_SIGNIFCANT_INDEX:
1659           if the index field is valid
1660
1661   eax, ebx, ecx, edx:
1662         the values returned by the cpuid instruction for
1663         this function/index combination
1664
1665The TSC deadline timer feature (CPUID leaf 1, ecx[24]) is always returned
1666as false, since the feature depends on KVM_CREATE_IRQCHIP for local APIC
1667support.  Instead it is reported via::
1668
1669  ioctl(KVM_CHECK_EXTENSION, KVM_CAP_TSC_DEADLINE_TIMER)
1670
1671if that returns true and you use KVM_CREATE_IRQCHIP, or if you emulate the
1672feature in userspace, then you can enable the feature for KVM_SET_CPUID2.
1673
1674
16754.47 KVM_PPC_GET_PVINFO
1676-----------------------
1677
1678:Capability: KVM_CAP_PPC_GET_PVINFO
1679:Architectures: ppc
1680:Type: vm ioctl
1681:Parameters: struct kvm_ppc_pvinfo (out)
1682:Returns: 0 on success, !0 on error
1683
1684::
1685
1686  struct kvm_ppc_pvinfo {
1687	__u32 flags;
1688	__u32 hcall[4];
1689	__u8  pad[108];
1690  };
1691
1692This ioctl fetches PV specific information that need to be passed to the guest
1693using the device tree or other means from vm context.
1694
1695The hcall array defines 4 instructions that make up a hypercall.
1696
1697If any additional field gets added to this structure later on, a bit for that
1698additional piece of information will be set in the flags bitmap.
1699
1700The flags bitmap is defined as::
1701
1702   /* the host supports the ePAPR idle hcall
1703   #define KVM_PPC_PVINFO_FLAGS_EV_IDLE   (1<<0)
1704
17054.52 KVM_SET_GSI_ROUTING
1706------------------------
1707
1708:Capability: KVM_CAP_IRQ_ROUTING
1709:Architectures: x86 s390 arm arm64
1710:Type: vm ioctl
1711:Parameters: struct kvm_irq_routing (in)
1712:Returns: 0 on success, -1 on error
1713
1714Sets the GSI routing table entries, overwriting any previously set entries.
1715
1716On arm/arm64, GSI routing has the following limitation:
1717
1718- GSI routing does not apply to KVM_IRQ_LINE but only to KVM_IRQFD.
1719
1720::
1721
1722  struct kvm_irq_routing {
1723	__u32 nr;
1724	__u32 flags;
1725	struct kvm_irq_routing_entry entries[0];
1726  };
1727
1728No flags are specified so far, the corresponding field must be set to zero.
1729
1730::
1731
1732  struct kvm_irq_routing_entry {
1733	__u32 gsi;
1734	__u32 type;
1735	__u32 flags;
1736	__u32 pad;
1737	union {
1738		struct kvm_irq_routing_irqchip irqchip;
1739		struct kvm_irq_routing_msi msi;
1740		struct kvm_irq_routing_s390_adapter adapter;
1741		struct kvm_irq_routing_hv_sint hv_sint;
1742		__u32 pad[8];
1743	} u;
1744  };
1745
1746  /* gsi routing entry types */
1747  #define KVM_IRQ_ROUTING_IRQCHIP 1
1748  #define KVM_IRQ_ROUTING_MSI 2
1749  #define KVM_IRQ_ROUTING_S390_ADAPTER 3
1750  #define KVM_IRQ_ROUTING_HV_SINT 4
1751
1752flags:
1753
1754- KVM_MSI_VALID_DEVID: used along with KVM_IRQ_ROUTING_MSI routing entry
1755  type, specifies that the devid field contains a valid value.  The per-VM
1756  KVM_CAP_MSI_DEVID capability advertises the requirement to provide
1757  the device ID.  If this capability is not available, userspace should
1758  never set the KVM_MSI_VALID_DEVID flag as the ioctl might fail.
1759- zero otherwise
1760
1761::
1762
1763  struct kvm_irq_routing_irqchip {
1764	__u32 irqchip;
1765	__u32 pin;
1766  };
1767
1768  struct kvm_irq_routing_msi {
1769	__u32 address_lo;
1770	__u32 address_hi;
1771	__u32 data;
1772	union {
1773		__u32 pad;
1774		__u32 devid;
1775	};
1776  };
1777
1778If KVM_MSI_VALID_DEVID is set, devid contains a unique device identifier
1779for the device that wrote the MSI message.  For PCI, this is usually a
1780BFD identifier in the lower 16 bits.
1781
1782On x86, address_hi is ignored unless the KVM_X2APIC_API_USE_32BIT_IDS
1783feature of KVM_CAP_X2APIC_API capability is enabled.  If it is enabled,
1784address_hi bits 31-8 provide bits 31-8 of the destination id.  Bits 7-0 of
1785address_hi must be zero.
1786
1787::
1788
1789  struct kvm_irq_routing_s390_adapter {
1790	__u64 ind_addr;
1791	__u64 summary_addr;
1792	__u64 ind_offset;
1793	__u32 summary_offset;
1794	__u32 adapter_id;
1795  };
1796
1797  struct kvm_irq_routing_hv_sint {
1798	__u32 vcpu;
1799	__u32 sint;
1800  };
1801
1802
18034.55 KVM_SET_TSC_KHZ
1804--------------------
1805
1806:Capability: KVM_CAP_TSC_CONTROL
1807:Architectures: x86
1808:Type: vcpu ioctl
1809:Parameters: virtual tsc_khz
1810:Returns: 0 on success, -1 on error
1811
1812Specifies the tsc frequency for the virtual machine. The unit of the
1813frequency is KHz.
1814
1815
18164.56 KVM_GET_TSC_KHZ
1817--------------------
1818
1819:Capability: KVM_CAP_GET_TSC_KHZ
1820:Architectures: x86
1821:Type: vcpu ioctl
1822:Parameters: none
1823:Returns: virtual tsc-khz on success, negative value on error
1824
1825Returns the tsc frequency of the guest. The unit of the return value is
1826KHz. If the host has unstable tsc this ioctl returns -EIO instead as an
1827error.
1828
1829
18304.57 KVM_GET_LAPIC
1831------------------
1832
1833:Capability: KVM_CAP_IRQCHIP
1834:Architectures: x86
1835:Type: vcpu ioctl
1836:Parameters: struct kvm_lapic_state (out)
1837:Returns: 0 on success, -1 on error
1838
1839::
1840
1841  #define KVM_APIC_REG_SIZE 0x400
1842  struct kvm_lapic_state {
1843	char regs[KVM_APIC_REG_SIZE];
1844  };
1845
1846Reads the Local APIC registers and copies them into the input argument.  The
1847data format and layout are the same as documented in the architecture manual.
1848
1849If KVM_X2APIC_API_USE_32BIT_IDS feature of KVM_CAP_X2APIC_API is
1850enabled, then the format of APIC_ID register depends on the APIC mode
1851(reported by MSR_IA32_APICBASE) of its VCPU.  x2APIC stores APIC ID in
1852the APIC_ID register (bytes 32-35).  xAPIC only allows an 8-bit APIC ID
1853which is stored in bits 31-24 of the APIC register, or equivalently in
1854byte 35 of struct kvm_lapic_state's regs field.  KVM_GET_LAPIC must then
1855be called after MSR_IA32_APICBASE has been set with KVM_SET_MSR.
1856
1857If KVM_X2APIC_API_USE_32BIT_IDS feature is disabled, struct kvm_lapic_state
1858always uses xAPIC format.
1859
1860
18614.58 KVM_SET_LAPIC
1862------------------
1863
1864:Capability: KVM_CAP_IRQCHIP
1865:Architectures: x86
1866:Type: vcpu ioctl
1867:Parameters: struct kvm_lapic_state (in)
1868:Returns: 0 on success, -1 on error
1869
1870::
1871
1872  #define KVM_APIC_REG_SIZE 0x400
1873  struct kvm_lapic_state {
1874	char regs[KVM_APIC_REG_SIZE];
1875  };
1876
1877Copies the input argument into the Local APIC registers.  The data format
1878and layout are the same as documented in the architecture manual.
1879
1880The format of the APIC ID register (bytes 32-35 of struct kvm_lapic_state's
1881regs field) depends on the state of the KVM_CAP_X2APIC_API capability.
1882See the note in KVM_GET_LAPIC.
1883
1884
18854.59 KVM_IOEVENTFD
1886------------------
1887
1888:Capability: KVM_CAP_IOEVENTFD
1889:Architectures: all
1890:Type: vm ioctl
1891:Parameters: struct kvm_ioeventfd (in)
1892:Returns: 0 on success, !0 on error
1893
1894This ioctl attaches or detaches an ioeventfd to a legal pio/mmio address
1895within the guest.  A guest write in the registered address will signal the
1896provided event instead of triggering an exit.
1897
1898::
1899
1900  struct kvm_ioeventfd {
1901	__u64 datamatch;
1902	__u64 addr;        /* legal pio/mmio address */
1903	__u32 len;         /* 0, 1, 2, 4, or 8 bytes    */
1904	__s32 fd;
1905	__u32 flags;
1906	__u8  pad[36];
1907  };
1908
1909For the special case of virtio-ccw devices on s390, the ioevent is matched
1910to a subchannel/virtqueue tuple instead.
1911
1912The following flags are defined::
1913
1914  #define KVM_IOEVENTFD_FLAG_DATAMATCH (1 << kvm_ioeventfd_flag_nr_datamatch)
1915  #define KVM_IOEVENTFD_FLAG_PIO       (1 << kvm_ioeventfd_flag_nr_pio)
1916  #define KVM_IOEVENTFD_FLAG_DEASSIGN  (1 << kvm_ioeventfd_flag_nr_deassign)
1917  #define KVM_IOEVENTFD_FLAG_VIRTIO_CCW_NOTIFY \
1918	(1 << kvm_ioeventfd_flag_nr_virtio_ccw_notify)
1919
1920If datamatch flag is set, the event will be signaled only if the written value
1921to the registered address is equal to datamatch in struct kvm_ioeventfd.
1922
1923For virtio-ccw devices, addr contains the subchannel id and datamatch the
1924virtqueue index.
1925
1926With KVM_CAP_IOEVENTFD_ANY_LENGTH, a zero length ioeventfd is allowed, and
1927the kernel will ignore the length of guest write and may get a faster vmexit.
1928The speedup may only apply to specific architectures, but the ioeventfd will
1929work anyway.
1930
19314.60 KVM_DIRTY_TLB
1932------------------
1933
1934:Capability: KVM_CAP_SW_TLB
1935:Architectures: ppc
1936:Type: vcpu ioctl
1937:Parameters: struct kvm_dirty_tlb (in)
1938:Returns: 0 on success, -1 on error
1939
1940::
1941
1942  struct kvm_dirty_tlb {
1943	__u64 bitmap;
1944	__u32 num_dirty;
1945  };
1946
1947This must be called whenever userspace has changed an entry in the shared
1948TLB, prior to calling KVM_RUN on the associated vcpu.
1949
1950The "bitmap" field is the userspace address of an array.  This array
1951consists of a number of bits, equal to the total number of TLB entries as
1952determined by the last successful call to KVM_CONFIG_TLB, rounded up to the
1953nearest multiple of 64.
1954
1955Each bit corresponds to one TLB entry, ordered the same as in the shared TLB
1956array.
1957
1958The array is little-endian: the bit 0 is the least significant bit of the
1959first byte, bit 8 is the least significant bit of the second byte, etc.
1960This avoids any complications with differing word sizes.
1961
1962The "num_dirty" field is a performance hint for KVM to determine whether it
1963should skip processing the bitmap and just invalidate everything.  It must
1964be set to the number of set bits in the bitmap.
1965
1966
19674.62 KVM_CREATE_SPAPR_TCE
1968-------------------------
1969
1970:Capability: KVM_CAP_SPAPR_TCE
1971:Architectures: powerpc
1972:Type: vm ioctl
1973:Parameters: struct kvm_create_spapr_tce (in)
1974:Returns: file descriptor for manipulating the created TCE table
1975
1976This creates a virtual TCE (translation control entry) table, which
1977is an IOMMU for PAPR-style virtual I/O.  It is used to translate
1978logical addresses used in virtual I/O into guest physical addresses,
1979and provides a scatter/gather capability for PAPR virtual I/O.
1980
1981::
1982
1983  /* for KVM_CAP_SPAPR_TCE */
1984  struct kvm_create_spapr_tce {
1985	__u64 liobn;
1986	__u32 window_size;
1987  };
1988
1989The liobn field gives the logical IO bus number for which to create a
1990TCE table.  The window_size field specifies the size of the DMA window
1991which this TCE table will translate - the table will contain one 64
1992bit TCE entry for every 4kiB of the DMA window.
1993
1994When the guest issues an H_PUT_TCE hcall on a liobn for which a TCE
1995table has been created using this ioctl(), the kernel will handle it
1996in real mode, updating the TCE table.  H_PUT_TCE calls for other
1997liobns will cause a vm exit and must be handled by userspace.
1998
1999The return value is a file descriptor which can be passed to mmap(2)
2000to map the created TCE table into userspace.  This lets userspace read
2001the entries written by kernel-handled H_PUT_TCE calls, and also lets
2002userspace update the TCE table directly which is useful in some
2003circumstances.
2004
2005
20064.63 KVM_ALLOCATE_RMA
2007---------------------
2008
2009:Capability: KVM_CAP_PPC_RMA
2010:Architectures: powerpc
2011:Type: vm ioctl
2012:Parameters: struct kvm_allocate_rma (out)
2013:Returns: file descriptor for mapping the allocated RMA
2014
2015This allocates a Real Mode Area (RMA) from the pool allocated at boot
2016time by the kernel.  An RMA is a physically-contiguous, aligned region
2017of memory used on older POWER processors to provide the memory which
2018will be accessed by real-mode (MMU off) accesses in a KVM guest.
2019POWER processors support a set of sizes for the RMA that usually
2020includes 64MB, 128MB, 256MB and some larger powers of two.
2021
2022::
2023
2024  /* for KVM_ALLOCATE_RMA */
2025  struct kvm_allocate_rma {
2026	__u64 rma_size;
2027  };
2028
2029The return value is a file descriptor which can be passed to mmap(2)
2030to map the allocated RMA into userspace.  The mapped area can then be
2031passed to the KVM_SET_USER_MEMORY_REGION ioctl to establish it as the
2032RMA for a virtual machine.  The size of the RMA in bytes (which is
2033fixed at host kernel boot time) is returned in the rma_size field of
2034the argument structure.
2035
2036The KVM_CAP_PPC_RMA capability is 1 or 2 if the KVM_ALLOCATE_RMA ioctl
2037is supported; 2 if the processor requires all virtual machines to have
2038an RMA, or 1 if the processor can use an RMA but doesn't require it,
2039because it supports the Virtual RMA (VRMA) facility.
2040
2041
20424.64 KVM_NMI
2043------------
2044
2045:Capability: KVM_CAP_USER_NMI
2046:Architectures: x86
2047:Type: vcpu ioctl
2048:Parameters: none
2049:Returns: 0 on success, -1 on error
2050
2051Queues an NMI on the thread's vcpu.  Note this is well defined only
2052when KVM_CREATE_IRQCHIP has not been called, since this is an interface
2053between the virtual cpu core and virtual local APIC.  After KVM_CREATE_IRQCHIP
2054has been called, this interface is completely emulated within the kernel.
2055
2056To use this to emulate the LINT1 input with KVM_CREATE_IRQCHIP, use the
2057following algorithm:
2058
2059  - pause the vcpu
2060  - read the local APIC's state (KVM_GET_LAPIC)
2061  - check whether changing LINT1 will queue an NMI (see the LVT entry for LINT1)
2062  - if so, issue KVM_NMI
2063  - resume the vcpu
2064
2065Some guests configure the LINT1 NMI input to cause a panic, aiding in
2066debugging.
2067
2068
20694.65 KVM_S390_UCAS_MAP
2070----------------------
2071
2072:Capability: KVM_CAP_S390_UCONTROL
2073:Architectures: s390
2074:Type: vcpu ioctl
2075:Parameters: struct kvm_s390_ucas_mapping (in)
2076:Returns: 0 in case of success
2077
2078The parameter is defined like this::
2079
2080	struct kvm_s390_ucas_mapping {
2081		__u64 user_addr;
2082		__u64 vcpu_addr;
2083		__u64 length;
2084	};
2085
2086This ioctl maps the memory at "user_addr" with the length "length" to
2087the vcpu's address space starting at "vcpu_addr". All parameters need to
2088be aligned by 1 megabyte.
2089
2090
20914.66 KVM_S390_UCAS_UNMAP
2092------------------------
2093
2094:Capability: KVM_CAP_S390_UCONTROL
2095:Architectures: s390
2096:Type: vcpu ioctl
2097:Parameters: struct kvm_s390_ucas_mapping (in)
2098:Returns: 0 in case of success
2099
2100The parameter is defined like this::
2101
2102	struct kvm_s390_ucas_mapping {
2103		__u64 user_addr;
2104		__u64 vcpu_addr;
2105		__u64 length;
2106	};
2107
2108This ioctl unmaps the memory in the vcpu's address space starting at
2109"vcpu_addr" with the length "length". The field "user_addr" is ignored.
2110All parameters need to be aligned by 1 megabyte.
2111
2112
21134.67 KVM_S390_VCPU_FAULT
2114------------------------
2115
2116:Capability: KVM_CAP_S390_UCONTROL
2117:Architectures: s390
2118:Type: vcpu ioctl
2119:Parameters: vcpu absolute address (in)
2120:Returns: 0 in case of success
2121
2122This call creates a page table entry on the virtual cpu's address space
2123(for user controlled virtual machines) or the virtual machine's address
2124space (for regular virtual machines). This only works for minor faults,
2125thus it's recommended to access subject memory page via the user page
2126table upfront. This is useful to handle validity intercepts for user
2127controlled virtual machines to fault in the virtual cpu's lowcore pages
2128prior to calling the KVM_RUN ioctl.
2129
2130
21314.68 KVM_SET_ONE_REG
2132--------------------
2133
2134:Capability: KVM_CAP_ONE_REG
2135:Architectures: all
2136:Type: vcpu ioctl
2137:Parameters: struct kvm_one_reg (in)
2138:Returns: 0 on success, negative value on failure
2139
2140Errors:
2141
2142  ======   ============================================================
2143  ENOENT   no such register
2144  EINVAL   invalid register ID, or no such register or used with VMs in
2145           protected virtualization mode on s390
2146  EPERM    (arm64) register access not allowed before vcpu finalization
2147  ======   ============================================================
2148
2149(These error codes are indicative only: do not rely on a specific error
2150code being returned in a specific situation.)
2151
2152::
2153
2154  struct kvm_one_reg {
2155       __u64 id;
2156       __u64 addr;
2157 };
2158
2159Using this ioctl, a single vcpu register can be set to a specific value
2160defined by user space with the passed in struct kvm_one_reg, where id
2161refers to the register identifier as described below and addr is a pointer
2162to a variable with the respective size. There can be architecture agnostic
2163and architecture specific registers. Each have their own range of operation
2164and their own constants and width. To keep track of the implemented
2165registers, find a list below:
2166
2167  ======= =============================== ============
2168  Arch              Register              Width (bits)
2169  ======= =============================== ============
2170  PPC     KVM_REG_PPC_HIOR                64
2171  PPC     KVM_REG_PPC_IAC1                64
2172  PPC     KVM_REG_PPC_IAC2                64
2173  PPC     KVM_REG_PPC_IAC3                64
2174  PPC     KVM_REG_PPC_IAC4                64
2175  PPC     KVM_REG_PPC_DAC1                64
2176  PPC     KVM_REG_PPC_DAC2                64
2177  PPC     KVM_REG_PPC_DABR                64
2178  PPC     KVM_REG_PPC_DSCR                64
2179  PPC     KVM_REG_PPC_PURR                64
2180  PPC     KVM_REG_PPC_SPURR               64
2181  PPC     KVM_REG_PPC_DAR                 64
2182  PPC     KVM_REG_PPC_DSISR               32
2183  PPC     KVM_REG_PPC_AMR                 64
2184  PPC     KVM_REG_PPC_UAMOR               64
2185  PPC     KVM_REG_PPC_MMCR0               64
2186  PPC     KVM_REG_PPC_MMCR1               64
2187  PPC     KVM_REG_PPC_MMCRA               64
2188  PPC     KVM_REG_PPC_MMCR2               64
2189  PPC     KVM_REG_PPC_MMCRS               64
2190  PPC     KVM_REG_PPC_MMCR3               64
2191  PPC     KVM_REG_PPC_SIAR                64
2192  PPC     KVM_REG_PPC_SDAR                64
2193  PPC     KVM_REG_PPC_SIER                64
2194  PPC     KVM_REG_PPC_SIER2               64
2195  PPC     KVM_REG_PPC_SIER3               64
2196  PPC     KVM_REG_PPC_PMC1                32
2197  PPC     KVM_REG_PPC_PMC2                32
2198  PPC     KVM_REG_PPC_PMC3                32
2199  PPC     KVM_REG_PPC_PMC4                32
2200  PPC     KVM_REG_PPC_PMC5                32
2201  PPC     KVM_REG_PPC_PMC6                32
2202  PPC     KVM_REG_PPC_PMC7                32
2203  PPC     KVM_REG_PPC_PMC8                32
2204  PPC     KVM_REG_PPC_FPR0                64
2205  ...
2206  PPC     KVM_REG_PPC_FPR31               64
2207  PPC     KVM_REG_PPC_VR0                 128
2208  ...
2209  PPC     KVM_REG_PPC_VR31                128
2210  PPC     KVM_REG_PPC_VSR0                128
2211  ...
2212  PPC     KVM_REG_PPC_VSR31               128
2213  PPC     KVM_REG_PPC_FPSCR               64
2214  PPC     KVM_REG_PPC_VSCR                32
2215  PPC     KVM_REG_PPC_VPA_ADDR            64
2216  PPC     KVM_REG_PPC_VPA_SLB             128
2217  PPC     KVM_REG_PPC_VPA_DTL             128
2218  PPC     KVM_REG_PPC_EPCR                32
2219  PPC     KVM_REG_PPC_EPR                 32
2220  PPC     KVM_REG_PPC_TCR                 32
2221  PPC     KVM_REG_PPC_TSR                 32
2222  PPC     KVM_REG_PPC_OR_TSR              32
2223  PPC     KVM_REG_PPC_CLEAR_TSR           32
2224  PPC     KVM_REG_PPC_MAS0                32
2225  PPC     KVM_REG_PPC_MAS1                32
2226  PPC     KVM_REG_PPC_MAS2                64
2227  PPC     KVM_REG_PPC_MAS7_3              64
2228  PPC     KVM_REG_PPC_MAS4                32
2229  PPC     KVM_REG_PPC_MAS6                32
2230  PPC     KVM_REG_PPC_MMUCFG              32
2231  PPC     KVM_REG_PPC_TLB0CFG             32
2232  PPC     KVM_REG_PPC_TLB1CFG             32
2233  PPC     KVM_REG_PPC_TLB2CFG             32
2234  PPC     KVM_REG_PPC_TLB3CFG             32
2235  PPC     KVM_REG_PPC_TLB0PS              32
2236  PPC     KVM_REG_PPC_TLB1PS              32
2237  PPC     KVM_REG_PPC_TLB2PS              32
2238  PPC     KVM_REG_PPC_TLB3PS              32
2239  PPC     KVM_REG_PPC_EPTCFG              32
2240  PPC     KVM_REG_PPC_ICP_STATE           64
2241  PPC     KVM_REG_PPC_VP_STATE            128
2242  PPC     KVM_REG_PPC_TB_OFFSET           64
2243  PPC     KVM_REG_PPC_SPMC1               32
2244  PPC     KVM_REG_PPC_SPMC2               32
2245  PPC     KVM_REG_PPC_IAMR                64
2246  PPC     KVM_REG_PPC_TFHAR               64
2247  PPC     KVM_REG_PPC_TFIAR               64
2248  PPC     KVM_REG_PPC_TEXASR              64
2249  PPC     KVM_REG_PPC_FSCR                64
2250  PPC     KVM_REG_PPC_PSPB                32
2251  PPC     KVM_REG_PPC_EBBHR               64
2252  PPC     KVM_REG_PPC_EBBRR               64
2253  PPC     KVM_REG_PPC_BESCR               64
2254  PPC     KVM_REG_PPC_TAR                 64
2255  PPC     KVM_REG_PPC_DPDES               64
2256  PPC     KVM_REG_PPC_DAWR                64
2257  PPC     KVM_REG_PPC_DAWRX               64
2258  PPC     KVM_REG_PPC_CIABR               64
2259  PPC     KVM_REG_PPC_IC                  64
2260  PPC     KVM_REG_PPC_VTB                 64
2261  PPC     KVM_REG_PPC_CSIGR               64
2262  PPC     KVM_REG_PPC_TACR                64
2263  PPC     KVM_REG_PPC_TCSCR               64
2264  PPC     KVM_REG_PPC_PID                 64
2265  PPC     KVM_REG_PPC_ACOP                64
2266  PPC     KVM_REG_PPC_VRSAVE              32
2267  PPC     KVM_REG_PPC_LPCR                32
2268  PPC     KVM_REG_PPC_LPCR_64             64
2269  PPC     KVM_REG_PPC_PPR                 64
2270  PPC     KVM_REG_PPC_ARCH_COMPAT         32
2271  PPC     KVM_REG_PPC_DABRX               32
2272  PPC     KVM_REG_PPC_WORT                64
2273  PPC	  KVM_REG_PPC_SPRG9               64
2274  PPC	  KVM_REG_PPC_DBSR                32
2275  PPC     KVM_REG_PPC_TIDR                64
2276  PPC     KVM_REG_PPC_PSSCR               64
2277  PPC     KVM_REG_PPC_DEC_EXPIRY          64
2278  PPC     KVM_REG_PPC_PTCR                64
2279  PPC     KVM_REG_PPC_DAWR1               64
2280  PPC     KVM_REG_PPC_DAWRX1              64
2281  PPC     KVM_REG_PPC_TM_GPR0             64
2282  ...
2283  PPC     KVM_REG_PPC_TM_GPR31            64
2284  PPC     KVM_REG_PPC_TM_VSR0             128
2285  ...
2286  PPC     KVM_REG_PPC_TM_VSR63            128
2287  PPC     KVM_REG_PPC_TM_CR               64
2288  PPC     KVM_REG_PPC_TM_LR               64
2289  PPC     KVM_REG_PPC_TM_CTR              64
2290  PPC     KVM_REG_PPC_TM_FPSCR            64
2291  PPC     KVM_REG_PPC_TM_AMR              64
2292  PPC     KVM_REG_PPC_TM_PPR              64
2293  PPC     KVM_REG_PPC_TM_VRSAVE           64
2294  PPC     KVM_REG_PPC_TM_VSCR             32
2295  PPC     KVM_REG_PPC_TM_DSCR             64
2296  PPC     KVM_REG_PPC_TM_TAR              64
2297  PPC     KVM_REG_PPC_TM_XER              64
2298
2299  MIPS    KVM_REG_MIPS_R0                 64
2300  ...
2301  MIPS    KVM_REG_MIPS_R31                64
2302  MIPS    KVM_REG_MIPS_HI                 64
2303  MIPS    KVM_REG_MIPS_LO                 64
2304  MIPS    KVM_REG_MIPS_PC                 64
2305  MIPS    KVM_REG_MIPS_CP0_INDEX          32
2306  MIPS    KVM_REG_MIPS_CP0_ENTRYLO0       64
2307  MIPS    KVM_REG_MIPS_CP0_ENTRYLO1       64
2308  MIPS    KVM_REG_MIPS_CP0_CONTEXT        64
2309  MIPS    KVM_REG_MIPS_CP0_CONTEXTCONFIG  32
2310  MIPS    KVM_REG_MIPS_CP0_USERLOCAL      64
2311  MIPS    KVM_REG_MIPS_CP0_XCONTEXTCONFIG 64
2312  MIPS    KVM_REG_MIPS_CP0_PAGEMASK       32
2313  MIPS    KVM_REG_MIPS_CP0_PAGEGRAIN      32
2314  MIPS    KVM_REG_MIPS_CP0_SEGCTL0        64
2315  MIPS    KVM_REG_MIPS_CP0_SEGCTL1        64
2316  MIPS    KVM_REG_MIPS_CP0_SEGCTL2        64
2317  MIPS    KVM_REG_MIPS_CP0_PWBASE         64
2318  MIPS    KVM_REG_MIPS_CP0_PWFIELD        64
2319  MIPS    KVM_REG_MIPS_CP0_PWSIZE         64
2320  MIPS    KVM_REG_MIPS_CP0_WIRED          32
2321  MIPS    KVM_REG_MIPS_CP0_PWCTL          32
2322  MIPS    KVM_REG_MIPS_CP0_HWRENA         32
2323  MIPS    KVM_REG_MIPS_CP0_BADVADDR       64
2324  MIPS    KVM_REG_MIPS_CP0_BADINSTR       32
2325  MIPS    KVM_REG_MIPS_CP0_BADINSTRP      32
2326  MIPS    KVM_REG_MIPS_CP0_COUNT          32
2327  MIPS    KVM_REG_MIPS_CP0_ENTRYHI        64
2328  MIPS    KVM_REG_MIPS_CP0_COMPARE        32
2329  MIPS    KVM_REG_MIPS_CP0_STATUS         32
2330  MIPS    KVM_REG_MIPS_CP0_INTCTL         32
2331  MIPS    KVM_REG_MIPS_CP0_CAUSE          32
2332  MIPS    KVM_REG_MIPS_CP0_EPC            64
2333  MIPS    KVM_REG_MIPS_CP0_PRID           32
2334  MIPS    KVM_REG_MIPS_CP0_EBASE          64
2335  MIPS    KVM_REG_MIPS_CP0_CONFIG         32
2336  MIPS    KVM_REG_MIPS_CP0_CONFIG1        32
2337  MIPS    KVM_REG_MIPS_CP0_CONFIG2        32
2338  MIPS    KVM_REG_MIPS_CP0_CONFIG3        32
2339  MIPS    KVM_REG_MIPS_CP0_CONFIG4        32
2340  MIPS    KVM_REG_MIPS_CP0_CONFIG5        32
2341  MIPS    KVM_REG_MIPS_CP0_CONFIG7        32
2342  MIPS    KVM_REG_MIPS_CP0_XCONTEXT       64
2343  MIPS    KVM_REG_MIPS_CP0_ERROREPC       64
2344  MIPS    KVM_REG_MIPS_CP0_KSCRATCH1      64
2345  MIPS    KVM_REG_MIPS_CP0_KSCRATCH2      64
2346  MIPS    KVM_REG_MIPS_CP0_KSCRATCH3      64
2347  MIPS    KVM_REG_MIPS_CP0_KSCRATCH4      64
2348  MIPS    KVM_REG_MIPS_CP0_KSCRATCH5      64
2349  MIPS    KVM_REG_MIPS_CP0_KSCRATCH6      64
2350  MIPS    KVM_REG_MIPS_CP0_MAAR(0..63)    64
2351  MIPS    KVM_REG_MIPS_COUNT_CTL          64
2352  MIPS    KVM_REG_MIPS_COUNT_RESUME       64
2353  MIPS    KVM_REG_MIPS_COUNT_HZ           64
2354  MIPS    KVM_REG_MIPS_FPR_32(0..31)      32
2355  MIPS    KVM_REG_MIPS_FPR_64(0..31)      64
2356  MIPS    KVM_REG_MIPS_VEC_128(0..31)     128
2357  MIPS    KVM_REG_MIPS_FCR_IR             32
2358  MIPS    KVM_REG_MIPS_FCR_CSR            32
2359  MIPS    KVM_REG_MIPS_MSA_IR             32
2360  MIPS    KVM_REG_MIPS_MSA_CSR            32
2361  ======= =============================== ============
2362
2363ARM registers are mapped using the lower 32 bits.  The upper 16 of that
2364is the register group type, or coprocessor number:
2365
2366ARM core registers have the following id bit patterns::
2367
2368  0x4020 0000 0010 <index into the kvm_regs struct:16>
2369
2370ARM 32-bit CP15 registers have the following id bit patterns::
2371
2372  0x4020 0000 000F <zero:1> <crn:4> <crm:4> <opc1:4> <opc2:3>
2373
2374ARM 64-bit CP15 registers have the following id bit patterns::
2375
2376  0x4030 0000 000F <zero:1> <zero:4> <crm:4> <opc1:4> <zero:3>
2377
2378ARM CCSIDR registers are demultiplexed by CSSELR value::
2379
2380  0x4020 0000 0011 00 <csselr:8>
2381
2382ARM 32-bit VFP control registers have the following id bit patterns::
2383
2384  0x4020 0000 0012 1 <regno:12>
2385
2386ARM 64-bit FP registers have the following id bit patterns::
2387
2388  0x4030 0000 0012 0 <regno:12>
2389
2390ARM firmware pseudo-registers have the following bit pattern::
2391
2392  0x4030 0000 0014 <regno:16>
2393
2394
2395arm64 registers are mapped using the lower 32 bits. The upper 16 of
2396that is the register group type, or coprocessor number:
2397
2398arm64 core/FP-SIMD registers have the following id bit patterns. Note
2399that the size of the access is variable, as the kvm_regs structure
2400contains elements ranging from 32 to 128 bits. The index is a 32bit
2401value in the kvm_regs structure seen as a 32bit array::
2402
2403  0x60x0 0000 0010 <index into the kvm_regs struct:16>
2404
2405Specifically:
2406
2407======================= ========= ===== =======================================
2408    Encoding            Register  Bits  kvm_regs member
2409======================= ========= ===== =======================================
2410  0x6030 0000 0010 0000 X0          64  regs.regs[0]
2411  0x6030 0000 0010 0002 X1          64  regs.regs[1]
2412  ...
2413  0x6030 0000 0010 003c X30         64  regs.regs[30]
2414  0x6030 0000 0010 003e SP          64  regs.sp
2415  0x6030 0000 0010 0040 PC          64  regs.pc
2416  0x6030 0000 0010 0042 PSTATE      64  regs.pstate
2417  0x6030 0000 0010 0044 SP_EL1      64  sp_el1
2418  0x6030 0000 0010 0046 ELR_EL1     64  elr_el1
2419  0x6030 0000 0010 0048 SPSR_EL1    64  spsr[KVM_SPSR_EL1] (alias SPSR_SVC)
2420  0x6030 0000 0010 004a SPSR_ABT    64  spsr[KVM_SPSR_ABT]
2421  0x6030 0000 0010 004c SPSR_UND    64  spsr[KVM_SPSR_UND]
2422  0x6030 0000 0010 004e SPSR_IRQ    64  spsr[KVM_SPSR_IRQ]
2423  0x6060 0000 0010 0050 SPSR_FIQ    64  spsr[KVM_SPSR_FIQ]
2424  0x6040 0000 0010 0054 V0         128  fp_regs.vregs[0]    [1]_
2425  0x6040 0000 0010 0058 V1         128  fp_regs.vregs[1]    [1]_
2426  ...
2427  0x6040 0000 0010 00d0 V31        128  fp_regs.vregs[31]   [1]_
2428  0x6020 0000 0010 00d4 FPSR        32  fp_regs.fpsr
2429  0x6020 0000 0010 00d5 FPCR        32  fp_regs.fpcr
2430======================= ========= ===== =======================================
2431
2432.. [1] These encodings are not accepted for SVE-enabled vcpus.  See
2433       KVM_ARM_VCPU_INIT.
2434
2435       The equivalent register content can be accessed via bits [127:0] of
2436       the corresponding SVE Zn registers instead for vcpus that have SVE
2437       enabled (see below).
2438
2439arm64 CCSIDR registers are demultiplexed by CSSELR value::
2440
2441  0x6020 0000 0011 00 <csselr:8>
2442
2443arm64 system registers have the following id bit patterns::
2444
2445  0x6030 0000 0013 <op0:2> <op1:3> <crn:4> <crm:4> <op2:3>
2446
2447.. warning::
2448
2449     Two system register IDs do not follow the specified pattern.  These
2450     are KVM_REG_ARM_TIMER_CVAL and KVM_REG_ARM_TIMER_CNT, which map to
2451     system registers CNTV_CVAL_EL0 and CNTVCT_EL0 respectively.  These
2452     two had their values accidentally swapped, which means TIMER_CVAL is
2453     derived from the register encoding for CNTVCT_EL0 and TIMER_CNT is
2454     derived from the register encoding for CNTV_CVAL_EL0.  As this is
2455     API, it must remain this way.
2456
2457arm64 firmware pseudo-registers have the following bit pattern::
2458
2459  0x6030 0000 0014 <regno:16>
2460
2461arm64 SVE registers have the following bit patterns::
2462
2463  0x6080 0000 0015 00 <n:5> <slice:5>   Zn bits[2048*slice + 2047 : 2048*slice]
2464  0x6050 0000 0015 04 <n:4> <slice:5>   Pn bits[256*slice + 255 : 256*slice]
2465  0x6050 0000 0015 060 <slice:5>        FFR bits[256*slice + 255 : 256*slice]
2466  0x6060 0000 0015 ffff                 KVM_REG_ARM64_SVE_VLS pseudo-register
2467
2468Access to register IDs where 2048 * slice >= 128 * max_vq will fail with
2469ENOENT.  max_vq is the vcpu's maximum supported vector length in 128-bit
2470quadwords: see [2]_ below.
2471
2472These registers are only accessible on vcpus for which SVE is enabled.
2473See KVM_ARM_VCPU_INIT for details.
2474
2475In addition, except for KVM_REG_ARM64_SVE_VLS, these registers are not
2476accessible until the vcpu's SVE configuration has been finalized
2477using KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE).  See KVM_ARM_VCPU_INIT
2478and KVM_ARM_VCPU_FINALIZE for more information about this procedure.
2479
2480KVM_REG_ARM64_SVE_VLS is a pseudo-register that allows the set of vector
2481lengths supported by the vcpu to be discovered and configured by
2482userspace.  When transferred to or from user memory via KVM_GET_ONE_REG
2483or KVM_SET_ONE_REG, the value of this register is of type
2484__u64[KVM_ARM64_SVE_VLS_WORDS], and encodes the set of vector lengths as
2485follows::
2486
2487  __u64 vector_lengths[KVM_ARM64_SVE_VLS_WORDS];
2488
2489  if (vq >= SVE_VQ_MIN && vq <= SVE_VQ_MAX &&
2490      ((vector_lengths[(vq - KVM_ARM64_SVE_VQ_MIN) / 64] >>
2491		((vq - KVM_ARM64_SVE_VQ_MIN) % 64)) & 1))
2492	/* Vector length vq * 16 bytes supported */
2493  else
2494	/* Vector length vq * 16 bytes not supported */
2495
2496.. [2] The maximum value vq for which the above condition is true is
2497       max_vq.  This is the maximum vector length available to the guest on
2498       this vcpu, and determines which register slices are visible through
2499       this ioctl interface.
2500
2501(See Documentation/arm64/sve.rst for an explanation of the "vq"
2502nomenclature.)
2503
2504KVM_REG_ARM64_SVE_VLS is only accessible after KVM_ARM_VCPU_INIT.
2505KVM_ARM_VCPU_INIT initialises it to the best set of vector lengths that
2506the host supports.
2507
2508Userspace may subsequently modify it if desired until the vcpu's SVE
2509configuration is finalized using KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE).
2510
2511Apart from simply removing all vector lengths from the host set that
2512exceed some value, support for arbitrarily chosen sets of vector lengths
2513is hardware-dependent and may not be available.  Attempting to configure
2514an invalid set of vector lengths via KVM_SET_ONE_REG will fail with
2515EINVAL.
2516
2517After the vcpu's SVE configuration is finalized, further attempts to
2518write this register will fail with EPERM.
2519
2520
2521MIPS registers are mapped using the lower 32 bits.  The upper 16 of that is
2522the register group type:
2523
2524MIPS core registers (see above) have the following id bit patterns::
2525
2526  0x7030 0000 0000 <reg:16>
2527
2528MIPS CP0 registers (see KVM_REG_MIPS_CP0_* above) have the following id bit
2529patterns depending on whether they're 32-bit or 64-bit registers::
2530
2531  0x7020 0000 0001 00 <reg:5> <sel:3>   (32-bit)
2532  0x7030 0000 0001 00 <reg:5> <sel:3>   (64-bit)
2533
2534Note: KVM_REG_MIPS_CP0_ENTRYLO0 and KVM_REG_MIPS_CP0_ENTRYLO1 are the MIPS64
2535versions of the EntryLo registers regardless of the word size of the host
2536hardware, host kernel, guest, and whether XPA is present in the guest, i.e.
2537with the RI and XI bits (if they exist) in bits 63 and 62 respectively, and
2538the PFNX field starting at bit 30.
2539
2540MIPS MAARs (see KVM_REG_MIPS_CP0_MAAR(*) above) have the following id bit
2541patterns::
2542
2543  0x7030 0000 0001 01 <reg:8>
2544
2545MIPS KVM control registers (see above) have the following id bit patterns::
2546
2547  0x7030 0000 0002 <reg:16>
2548
2549MIPS FPU registers (see KVM_REG_MIPS_FPR_{32,64}() above) have the following
2550id bit patterns depending on the size of the register being accessed. They are
2551always accessed according to the current guest FPU mode (Status.FR and
2552Config5.FRE), i.e. as the guest would see them, and they become unpredictable
2553if the guest FPU mode is changed. MIPS SIMD Architecture (MSA) vector
2554registers (see KVM_REG_MIPS_VEC_128() above) have similar patterns as they
2555overlap the FPU registers::
2556
2557  0x7020 0000 0003 00 <0:3> <reg:5> (32-bit FPU registers)
2558  0x7030 0000 0003 00 <0:3> <reg:5> (64-bit FPU registers)
2559  0x7040 0000 0003 00 <0:3> <reg:5> (128-bit MSA vector registers)
2560
2561MIPS FPU control registers (see KVM_REG_MIPS_FCR_{IR,CSR} above) have the
2562following id bit patterns::
2563
2564  0x7020 0000 0003 01 <0:3> <reg:5>
2565
2566MIPS MSA control registers (see KVM_REG_MIPS_MSA_{IR,CSR} above) have the
2567following id bit patterns::
2568
2569  0x7020 0000 0003 02 <0:3> <reg:5>
2570
2571
25724.69 KVM_GET_ONE_REG
2573--------------------
2574
2575:Capability: KVM_CAP_ONE_REG
2576:Architectures: all
2577:Type: vcpu ioctl
2578:Parameters: struct kvm_one_reg (in and out)
2579:Returns: 0 on success, negative value on failure
2580
2581Errors include:
2582
2583  ======== ============================================================
2584  ENOENT   no such register
2585  EINVAL   invalid register ID, or no such register or used with VMs in
2586           protected virtualization mode on s390
2587  EPERM    (arm64) register access not allowed before vcpu finalization
2588  ======== ============================================================
2589
2590(These error codes are indicative only: do not rely on a specific error
2591code being returned in a specific situation.)
2592
2593This ioctl allows to receive the value of a single register implemented
2594in a vcpu. The register to read is indicated by the "id" field of the
2595kvm_one_reg struct passed in. On success, the register value can be found
2596at the memory location pointed to by "addr".
2597
2598The list of registers accessible using this interface is identical to the
2599list in 4.68.
2600
2601
26024.70 KVM_KVMCLOCK_CTRL
2603----------------------
2604
2605:Capability: KVM_CAP_KVMCLOCK_CTRL
2606:Architectures: Any that implement pvclocks (currently x86 only)
2607:Type: vcpu ioctl
2608:Parameters: None
2609:Returns: 0 on success, -1 on error
2610
2611This ioctl sets a flag accessible to the guest indicating that the specified
2612vCPU has been paused by the host userspace.
2613
2614The host will set a flag in the pvclock structure that is checked from the
2615soft lockup watchdog.  The flag is part of the pvclock structure that is
2616shared between guest and host, specifically the second bit of the flags
2617field of the pvclock_vcpu_time_info structure.  It will be set exclusively by
2618the host and read/cleared exclusively by the guest.  The guest operation of
2619checking and clearing the flag must be an atomic operation so
2620load-link/store-conditional, or equivalent must be used.  There are two cases
2621where the guest will clear the flag: when the soft lockup watchdog timer resets
2622itself or when a soft lockup is detected.  This ioctl can be called any time
2623after pausing the vcpu, but before it is resumed.
2624
2625
26264.71 KVM_SIGNAL_MSI
2627-------------------
2628
2629:Capability: KVM_CAP_SIGNAL_MSI
2630:Architectures: x86 arm arm64
2631:Type: vm ioctl
2632:Parameters: struct kvm_msi (in)
2633:Returns: >0 on delivery, 0 if guest blocked the MSI, and -1 on error
2634
2635Directly inject a MSI message. Only valid with in-kernel irqchip that handles
2636MSI messages.
2637
2638::
2639
2640  struct kvm_msi {
2641	__u32 address_lo;
2642	__u32 address_hi;
2643	__u32 data;
2644	__u32 flags;
2645	__u32 devid;
2646	__u8  pad[12];
2647  };
2648
2649flags:
2650  KVM_MSI_VALID_DEVID: devid contains a valid value.  The per-VM
2651  KVM_CAP_MSI_DEVID capability advertises the requirement to provide
2652  the device ID.  If this capability is not available, userspace
2653  should never set the KVM_MSI_VALID_DEVID flag as the ioctl might fail.
2654
2655If KVM_MSI_VALID_DEVID is set, devid contains a unique device identifier
2656for the device that wrote the MSI message.  For PCI, this is usually a
2657BFD identifier in the lower 16 bits.
2658
2659On x86, address_hi is ignored unless the KVM_X2APIC_API_USE_32BIT_IDS
2660feature of KVM_CAP_X2APIC_API capability is enabled.  If it is enabled,
2661address_hi bits 31-8 provide bits 31-8 of the destination id.  Bits 7-0 of
2662address_hi must be zero.
2663
2664
26654.71 KVM_CREATE_PIT2
2666--------------------
2667
2668:Capability: KVM_CAP_PIT2
2669:Architectures: x86
2670:Type: vm ioctl
2671:Parameters: struct kvm_pit_config (in)
2672:Returns: 0 on success, -1 on error
2673
2674Creates an in-kernel device model for the i8254 PIT. This call is only valid
2675after enabling in-kernel irqchip support via KVM_CREATE_IRQCHIP. The following
2676parameters have to be passed::
2677
2678  struct kvm_pit_config {
2679	__u32 flags;
2680	__u32 pad[15];
2681  };
2682
2683Valid flags are::
2684
2685  #define KVM_PIT_SPEAKER_DUMMY     1 /* emulate speaker port stub */
2686
2687PIT timer interrupts may use a per-VM kernel thread for injection. If it
2688exists, this thread will have a name of the following pattern::
2689
2690  kvm-pit/<owner-process-pid>
2691
2692When running a guest with elevated priorities, the scheduling parameters of
2693this thread may have to be adjusted accordingly.
2694
2695This IOCTL replaces the obsolete KVM_CREATE_PIT.
2696
2697
26984.72 KVM_GET_PIT2
2699-----------------
2700
2701:Capability: KVM_CAP_PIT_STATE2
2702:Architectures: x86
2703:Type: vm ioctl
2704:Parameters: struct kvm_pit_state2 (out)
2705:Returns: 0 on success, -1 on error
2706
2707Retrieves the state of the in-kernel PIT model. Only valid after
2708KVM_CREATE_PIT2. The state is returned in the following structure::
2709
2710  struct kvm_pit_state2 {
2711	struct kvm_pit_channel_state channels[3];
2712	__u32 flags;
2713	__u32 reserved[9];
2714  };
2715
2716Valid flags are::
2717
2718  /* disable PIT in HPET legacy mode */
2719  #define KVM_PIT_FLAGS_HPET_LEGACY  0x00000001
2720
2721This IOCTL replaces the obsolete KVM_GET_PIT.
2722
2723
27244.73 KVM_SET_PIT2
2725-----------------
2726
2727:Capability: KVM_CAP_PIT_STATE2
2728:Architectures: x86
2729:Type: vm ioctl
2730:Parameters: struct kvm_pit_state2 (in)
2731:Returns: 0 on success, -1 on error
2732
2733Sets the state of the in-kernel PIT model. Only valid after KVM_CREATE_PIT2.
2734See KVM_GET_PIT2 for details on struct kvm_pit_state2.
2735
2736This IOCTL replaces the obsolete KVM_SET_PIT.
2737
2738
27394.74 KVM_PPC_GET_SMMU_INFO
2740--------------------------
2741
2742:Capability: KVM_CAP_PPC_GET_SMMU_INFO
2743:Architectures: powerpc
2744:Type: vm ioctl
2745:Parameters: None
2746:Returns: 0 on success, -1 on error
2747
2748This populates and returns a structure describing the features of
2749the "Server" class MMU emulation supported by KVM.
2750This can in turn be used by userspace to generate the appropriate
2751device-tree properties for the guest operating system.
2752
2753The structure contains some global information, followed by an
2754array of supported segment page sizes::
2755
2756      struct kvm_ppc_smmu_info {
2757	     __u64 flags;
2758	     __u32 slb_size;
2759	     __u32 pad;
2760	     struct kvm_ppc_one_seg_page_size sps[KVM_PPC_PAGE_SIZES_MAX_SZ];
2761      };
2762
2763The supported flags are:
2764
2765    - KVM_PPC_PAGE_SIZES_REAL:
2766        When that flag is set, guest page sizes must "fit" the backing
2767        store page sizes. When not set, any page size in the list can
2768        be used regardless of how they are backed by userspace.
2769
2770    - KVM_PPC_1T_SEGMENTS
2771        The emulated MMU supports 1T segments in addition to the
2772        standard 256M ones.
2773
2774    - KVM_PPC_NO_HASH
2775	This flag indicates that HPT guests are not supported by KVM,
2776	thus all guests must use radix MMU mode.
2777
2778The "slb_size" field indicates how many SLB entries are supported
2779
2780The "sps" array contains 8 entries indicating the supported base
2781page sizes for a segment in increasing order. Each entry is defined
2782as follow::
2783
2784   struct kvm_ppc_one_seg_page_size {
2785	__u32 page_shift;	/* Base page shift of segment (or 0) */
2786	__u32 slb_enc;		/* SLB encoding for BookS */
2787	struct kvm_ppc_one_page_size enc[KVM_PPC_PAGE_SIZES_MAX_SZ];
2788   };
2789
2790An entry with a "page_shift" of 0 is unused. Because the array is
2791organized in increasing order, a lookup can stop when encoutering
2792such an entry.
2793
2794The "slb_enc" field provides the encoding to use in the SLB for the
2795page size. The bits are in positions such as the value can directly
2796be OR'ed into the "vsid" argument of the slbmte instruction.
2797
2798The "enc" array is a list which for each of those segment base page
2799size provides the list of supported actual page sizes (which can be
2800only larger or equal to the base page size), along with the
2801corresponding encoding in the hash PTE. Similarly, the array is
28028 entries sorted by increasing sizes and an entry with a "0" shift
2803is an empty entry and a terminator::
2804
2805   struct kvm_ppc_one_page_size {
2806	__u32 page_shift;	/* Page shift (or 0) */
2807	__u32 pte_enc;		/* Encoding in the HPTE (>>12) */
2808   };
2809
2810The "pte_enc" field provides a value that can OR'ed into the hash
2811PTE's RPN field (ie, it needs to be shifted left by 12 to OR it
2812into the hash PTE second double word).
2813
28144.75 KVM_IRQFD
2815--------------
2816
2817:Capability: KVM_CAP_IRQFD
2818:Architectures: x86 s390 arm arm64
2819:Type: vm ioctl
2820:Parameters: struct kvm_irqfd (in)
2821:Returns: 0 on success, -1 on error
2822
2823Allows setting an eventfd to directly trigger a guest interrupt.
2824kvm_irqfd.fd specifies the file descriptor to use as the eventfd and
2825kvm_irqfd.gsi specifies the irqchip pin toggled by this event.  When
2826an event is triggered on the eventfd, an interrupt is injected into
2827the guest using the specified gsi pin.  The irqfd is removed using
2828the KVM_IRQFD_FLAG_DEASSIGN flag, specifying both kvm_irqfd.fd
2829and kvm_irqfd.gsi.
2830
2831With KVM_CAP_IRQFD_RESAMPLE, KVM_IRQFD supports a de-assert and notify
2832mechanism allowing emulation of level-triggered, irqfd-based
2833interrupts.  When KVM_IRQFD_FLAG_RESAMPLE is set the user must pass an
2834additional eventfd in the kvm_irqfd.resamplefd field.  When operating
2835in resample mode, posting of an interrupt through kvm_irq.fd asserts
2836the specified gsi in the irqchip.  When the irqchip is resampled, such
2837as from an EOI, the gsi is de-asserted and the user is notified via
2838kvm_irqfd.resamplefd.  It is the user's responsibility to re-queue
2839the interrupt if the device making use of it still requires service.
2840Note that closing the resamplefd is not sufficient to disable the
2841irqfd.  The KVM_IRQFD_FLAG_RESAMPLE is only necessary on assignment
2842and need not be specified with KVM_IRQFD_FLAG_DEASSIGN.
2843
2844On arm/arm64, gsi routing being supported, the following can happen:
2845
2846- in case no routing entry is associated to this gsi, injection fails
2847- in case the gsi is associated to an irqchip routing entry,
2848  irqchip.pin + 32 corresponds to the injected SPI ID.
2849- in case the gsi is associated to an MSI routing entry, the MSI
2850  message and device ID are translated into an LPI (support restricted
2851  to GICv3 ITS in-kernel emulation).
2852
28534.76 KVM_PPC_ALLOCATE_HTAB
2854--------------------------
2855
2856:Capability: KVM_CAP_PPC_ALLOC_HTAB
2857:Architectures: powerpc
2858:Type: vm ioctl
2859:Parameters: Pointer to u32 containing hash table order (in/out)
2860:Returns: 0 on success, -1 on error
2861
2862This requests the host kernel to allocate an MMU hash table for a
2863guest using the PAPR paravirtualization interface.  This only does
2864anything if the kernel is configured to use the Book 3S HV style of
2865virtualization.  Otherwise the capability doesn't exist and the ioctl
2866returns an ENOTTY error.  The rest of this description assumes Book 3S
2867HV.
2868
2869There must be no vcpus running when this ioctl is called; if there
2870are, it will do nothing and return an EBUSY error.
2871
2872The parameter is a pointer to a 32-bit unsigned integer variable
2873containing the order (log base 2) of the desired size of the hash
2874table, which must be between 18 and 46.  On successful return from the
2875ioctl, the value will not be changed by the kernel.
2876
2877If no hash table has been allocated when any vcpu is asked to run
2878(with the KVM_RUN ioctl), the host kernel will allocate a
2879default-sized hash table (16 MB).
2880
2881If this ioctl is called when a hash table has already been allocated,
2882with a different order from the existing hash table, the existing hash
2883table will be freed and a new one allocated.  If this is ioctl is
2884called when a hash table has already been allocated of the same order
2885as specified, the kernel will clear out the existing hash table (zero
2886all HPTEs).  In either case, if the guest is using the virtualized
2887real-mode area (VRMA) facility, the kernel will re-create the VMRA
2888HPTEs on the next KVM_RUN of any vcpu.
2889
28904.77 KVM_S390_INTERRUPT
2891-----------------------
2892
2893:Capability: basic
2894:Architectures: s390
2895:Type: vm ioctl, vcpu ioctl
2896:Parameters: struct kvm_s390_interrupt (in)
2897:Returns: 0 on success, -1 on error
2898
2899Allows to inject an interrupt to the guest. Interrupts can be floating
2900(vm ioctl) or per cpu (vcpu ioctl), depending on the interrupt type.
2901
2902Interrupt parameters are passed via kvm_s390_interrupt::
2903
2904  struct kvm_s390_interrupt {
2905	__u32 type;
2906	__u32 parm;
2907	__u64 parm64;
2908  };
2909
2910type can be one of the following:
2911
2912KVM_S390_SIGP_STOP (vcpu)
2913    - sigp stop; optional flags in parm
2914KVM_S390_PROGRAM_INT (vcpu)
2915    - program check; code in parm
2916KVM_S390_SIGP_SET_PREFIX (vcpu)
2917    - sigp set prefix; prefix address in parm
2918KVM_S390_RESTART (vcpu)
2919    - restart
2920KVM_S390_INT_CLOCK_COMP (vcpu)
2921    - clock comparator interrupt
2922KVM_S390_INT_CPU_TIMER (vcpu)
2923    - CPU timer interrupt
2924KVM_S390_INT_VIRTIO (vm)
2925    - virtio external interrupt; external interrupt
2926      parameters in parm and parm64
2927KVM_S390_INT_SERVICE (vm)
2928    - sclp external interrupt; sclp parameter in parm
2929KVM_S390_INT_EMERGENCY (vcpu)
2930    - sigp emergency; source cpu in parm
2931KVM_S390_INT_EXTERNAL_CALL (vcpu)
2932    - sigp external call; source cpu in parm
2933KVM_S390_INT_IO(ai,cssid,ssid,schid) (vm)
2934    - compound value to indicate an
2935      I/O interrupt (ai - adapter interrupt; cssid,ssid,schid - subchannel);
2936      I/O interruption parameters in parm (subchannel) and parm64 (intparm,
2937      interruption subclass)
2938KVM_S390_MCHK (vm, vcpu)
2939    - machine check interrupt; cr 14 bits in parm, machine check interrupt
2940      code in parm64 (note that machine checks needing further payload are not
2941      supported by this ioctl)
2942
2943This is an asynchronous vcpu ioctl and can be invoked from any thread.
2944
29454.78 KVM_PPC_GET_HTAB_FD
2946------------------------
2947
2948:Capability: KVM_CAP_PPC_HTAB_FD
2949:Architectures: powerpc
2950:Type: vm ioctl
2951:Parameters: Pointer to struct kvm_get_htab_fd (in)
2952:Returns: file descriptor number (>= 0) on success, -1 on error
2953
2954This returns a file descriptor that can be used either to read out the
2955entries in the guest's hashed page table (HPT), or to write entries to
2956initialize the HPT.  The returned fd can only be written to if the
2957KVM_GET_HTAB_WRITE bit is set in the flags field of the argument, and
2958can only be read if that bit is clear.  The argument struct looks like
2959this::
2960
2961  /* For KVM_PPC_GET_HTAB_FD */
2962  struct kvm_get_htab_fd {
2963	__u64	flags;
2964	__u64	start_index;
2965	__u64	reserved[2];
2966  };
2967
2968  /* Values for kvm_get_htab_fd.flags */
2969  #define KVM_GET_HTAB_BOLTED_ONLY	((__u64)0x1)
2970  #define KVM_GET_HTAB_WRITE		((__u64)0x2)
2971
2972The 'start_index' field gives the index in the HPT of the entry at
2973which to start reading.  It is ignored when writing.
2974
2975Reads on the fd will initially supply information about all
2976"interesting" HPT entries.  Interesting entries are those with the
2977bolted bit set, if the KVM_GET_HTAB_BOLTED_ONLY bit is set, otherwise
2978all entries.  When the end of the HPT is reached, the read() will
2979return.  If read() is called again on the fd, it will start again from
2980the beginning of the HPT, but will only return HPT entries that have
2981changed since they were last read.
2982
2983Data read or written is structured as a header (8 bytes) followed by a
2984series of valid HPT entries (16 bytes) each.  The header indicates how
2985many valid HPT entries there are and how many invalid entries follow
2986the valid entries.  The invalid entries are not represented explicitly
2987in the stream.  The header format is::
2988
2989  struct kvm_get_htab_header {
2990	__u32	index;
2991	__u16	n_valid;
2992	__u16	n_invalid;
2993  };
2994
2995Writes to the fd create HPT entries starting at the index given in the
2996header; first 'n_valid' valid entries with contents from the data
2997written, then 'n_invalid' invalid entries, invalidating any previously
2998valid entries found.
2999
30004.79 KVM_CREATE_DEVICE
3001----------------------
3002
3003:Capability: KVM_CAP_DEVICE_CTRL
3004:Type: vm ioctl
3005:Parameters: struct kvm_create_device (in/out)
3006:Returns: 0 on success, -1 on error
3007
3008Errors:
3009
3010  ======  =======================================================
3011  ENODEV  The device type is unknown or unsupported
3012  EEXIST  Device already created, and this type of device may not
3013          be instantiated multiple times
3014  ======  =======================================================
3015
3016  Other error conditions may be defined by individual device types or
3017  have their standard meanings.
3018
3019Creates an emulated device in the kernel.  The file descriptor returned
3020in fd can be used with KVM_SET/GET/HAS_DEVICE_ATTR.
3021
3022If the KVM_CREATE_DEVICE_TEST flag is set, only test whether the
3023device type is supported (not necessarily whether it can be created
3024in the current vm).
3025
3026Individual devices should not define flags.  Attributes should be used
3027for specifying any behavior that is not implied by the device type
3028number.
3029
3030::
3031
3032  struct kvm_create_device {
3033	__u32	type;	/* in: KVM_DEV_TYPE_xxx */
3034	__u32	fd;	/* out: device handle */
3035	__u32	flags;	/* in: KVM_CREATE_DEVICE_xxx */
3036  };
3037
30384.80 KVM_SET_DEVICE_ATTR/KVM_GET_DEVICE_ATTR
3039--------------------------------------------
3040
3041:Capability: KVM_CAP_DEVICE_CTRL, KVM_CAP_VM_ATTRIBUTES for vm device,
3042             KVM_CAP_VCPU_ATTRIBUTES for vcpu device
3043:Type: device ioctl, vm ioctl, vcpu ioctl
3044:Parameters: struct kvm_device_attr
3045:Returns: 0 on success, -1 on error
3046
3047Errors:
3048
3049  =====   =============================================================
3050  ENXIO   The group or attribute is unknown/unsupported for this device
3051          or hardware support is missing.
3052  EPERM   The attribute cannot (currently) be accessed this way
3053          (e.g. read-only attribute, or attribute that only makes
3054          sense when the device is in a different state)
3055  =====   =============================================================
3056
3057  Other error conditions may be defined by individual device types.
3058
3059Gets/sets a specified piece of device configuration and/or state.  The
3060semantics are device-specific.  See individual device documentation in
3061the "devices" directory.  As with ONE_REG, the size of the data
3062transferred is defined by the particular attribute.
3063
3064::
3065
3066  struct kvm_device_attr {
3067	__u32	flags;		/* no flags currently defined */
3068	__u32	group;		/* device-defined */
3069	__u64	attr;		/* group-defined */
3070	__u64	addr;		/* userspace address of attr data */
3071  };
3072
30734.81 KVM_HAS_DEVICE_ATTR
3074------------------------
3075
3076:Capability: KVM_CAP_DEVICE_CTRL, KVM_CAP_VM_ATTRIBUTES for vm device,
3077	     KVM_CAP_VCPU_ATTRIBUTES for vcpu device
3078:Type: device ioctl, vm ioctl, vcpu ioctl
3079:Parameters: struct kvm_device_attr
3080:Returns: 0 on success, -1 on error
3081
3082Errors:
3083
3084  =====   =============================================================
3085  ENXIO   The group or attribute is unknown/unsupported for this device
3086          or hardware support is missing.
3087  =====   =============================================================
3088
3089Tests whether a device supports a particular attribute.  A successful
3090return indicates the attribute is implemented.  It does not necessarily
3091indicate that the attribute can be read or written in the device's
3092current state.  "addr" is ignored.
3093
30944.82 KVM_ARM_VCPU_INIT
3095----------------------
3096
3097:Capability: basic
3098:Architectures: arm, arm64
3099:Type: vcpu ioctl
3100:Parameters: struct kvm_vcpu_init (in)
3101:Returns: 0 on success; -1 on error
3102
3103Errors:
3104
3105  ======     =================================================================
3106  EINVAL     the target is unknown, or the combination of features is invalid.
3107  ENOENT     a features bit specified is unknown.
3108  ======     =================================================================
3109
3110This tells KVM what type of CPU to present to the guest, and what
3111optional features it should have.  This will cause a reset of the cpu
3112registers to their initial values.  If this is not called, KVM_RUN will
3113return ENOEXEC for that vcpu.
3114
3115Note that because some registers reflect machine topology, all vcpus
3116should be created before this ioctl is invoked.
3117
3118Userspace can call this function multiple times for a given vcpu, including
3119after the vcpu has been run. This will reset the vcpu to its initial
3120state. All calls to this function after the initial call must use the same
3121target and same set of feature flags, otherwise EINVAL will be returned.
3122
3123Possible features:
3124
3125	- KVM_ARM_VCPU_POWER_OFF: Starts the CPU in a power-off state.
3126	  Depends on KVM_CAP_ARM_PSCI.  If not set, the CPU will be powered on
3127	  and execute guest code when KVM_RUN is called.
3128	- KVM_ARM_VCPU_EL1_32BIT: Starts the CPU in a 32bit mode.
3129	  Depends on KVM_CAP_ARM_EL1_32BIT (arm64 only).
3130	- KVM_ARM_VCPU_PSCI_0_2: Emulate PSCI v0.2 (or a future revision
3131          backward compatible with v0.2) for the CPU.
3132	  Depends on KVM_CAP_ARM_PSCI_0_2.
3133	- KVM_ARM_VCPU_PMU_V3: Emulate PMUv3 for the CPU.
3134	  Depends on KVM_CAP_ARM_PMU_V3.
3135
3136	- KVM_ARM_VCPU_PTRAUTH_ADDRESS: Enables Address Pointer authentication
3137	  for arm64 only.
3138	  Depends on KVM_CAP_ARM_PTRAUTH_ADDRESS.
3139	  If KVM_CAP_ARM_PTRAUTH_ADDRESS and KVM_CAP_ARM_PTRAUTH_GENERIC are
3140	  both present, then both KVM_ARM_VCPU_PTRAUTH_ADDRESS and
3141	  KVM_ARM_VCPU_PTRAUTH_GENERIC must be requested or neither must be
3142	  requested.
3143
3144	- KVM_ARM_VCPU_PTRAUTH_GENERIC: Enables Generic Pointer authentication
3145	  for arm64 only.
3146	  Depends on KVM_CAP_ARM_PTRAUTH_GENERIC.
3147	  If KVM_CAP_ARM_PTRAUTH_ADDRESS and KVM_CAP_ARM_PTRAUTH_GENERIC are
3148	  both present, then both KVM_ARM_VCPU_PTRAUTH_ADDRESS and
3149	  KVM_ARM_VCPU_PTRAUTH_GENERIC must be requested or neither must be
3150	  requested.
3151
3152	- KVM_ARM_VCPU_SVE: Enables SVE for the CPU (arm64 only).
3153	  Depends on KVM_CAP_ARM_SVE.
3154	  Requires KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE):
3155
3156	   * After KVM_ARM_VCPU_INIT:
3157
3158	      - KVM_REG_ARM64_SVE_VLS may be read using KVM_GET_ONE_REG: the
3159	        initial value of this pseudo-register indicates the best set of
3160	        vector lengths possible for a vcpu on this host.
3161
3162	   * Before KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE):
3163
3164	      - KVM_RUN and KVM_GET_REG_LIST are not available;
3165
3166	      - KVM_GET_ONE_REG and KVM_SET_ONE_REG cannot be used to access
3167	        the scalable archietctural SVE registers
3168	        KVM_REG_ARM64_SVE_ZREG(), KVM_REG_ARM64_SVE_PREG() or
3169	        KVM_REG_ARM64_SVE_FFR;
3170
3171	      - KVM_REG_ARM64_SVE_VLS may optionally be written using
3172	        KVM_SET_ONE_REG, to modify the set of vector lengths available
3173	        for the vcpu.
3174
3175	   * After KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE):
3176
3177	      - the KVM_REG_ARM64_SVE_VLS pseudo-register is immutable, and can
3178	        no longer be written using KVM_SET_ONE_REG.
3179
31804.83 KVM_ARM_PREFERRED_TARGET
3181-----------------------------
3182
3183:Capability: basic
3184:Architectures: arm, arm64
3185:Type: vm ioctl
3186:Parameters: struct kvm_vcpu_init (out)
3187:Returns: 0 on success; -1 on error
3188
3189Errors:
3190
3191  ======     ==========================================
3192  ENODEV     no preferred target available for the host
3193  ======     ==========================================
3194
3195This queries KVM for preferred CPU target type which can be emulated
3196by KVM on underlying host.
3197
3198The ioctl returns struct kvm_vcpu_init instance containing information
3199about preferred CPU target type and recommended features for it.  The
3200kvm_vcpu_init->features bitmap returned will have feature bits set if
3201the preferred target recommends setting these features, but this is
3202not mandatory.
3203
3204The information returned by this ioctl can be used to prepare an instance
3205of struct kvm_vcpu_init for KVM_ARM_VCPU_INIT ioctl which will result in
3206VCPU matching underlying host.
3207
3208
32094.84 KVM_GET_REG_LIST
3210---------------------
3211
3212:Capability: basic
3213:Architectures: arm, arm64, mips
3214:Type: vcpu ioctl
3215:Parameters: struct kvm_reg_list (in/out)
3216:Returns: 0 on success; -1 on error
3217
3218Errors:
3219
3220  =====      ==============================================================
3221  E2BIG      the reg index list is too big to fit in the array specified by
3222             the user (the number required will be written into n).
3223  =====      ==============================================================
3224
3225::
3226
3227  struct kvm_reg_list {
3228	__u64 n; /* number of registers in reg[] */
3229	__u64 reg[0];
3230  };
3231
3232This ioctl returns the guest registers that are supported for the
3233KVM_GET_ONE_REG/KVM_SET_ONE_REG calls.
3234
3235
32364.85 KVM_ARM_SET_DEVICE_ADDR (deprecated)
3237-----------------------------------------
3238
3239:Capability: KVM_CAP_ARM_SET_DEVICE_ADDR
3240:Architectures: arm, arm64
3241:Type: vm ioctl
3242:Parameters: struct kvm_arm_device_address (in)
3243:Returns: 0 on success, -1 on error
3244
3245Errors:
3246
3247  ======  ============================================
3248  ENODEV  The device id is unknown
3249  ENXIO   Device not supported on current system
3250  EEXIST  Address already set
3251  E2BIG   Address outside guest physical address space
3252  EBUSY   Address overlaps with other device range
3253  ======  ============================================
3254
3255::
3256
3257  struct kvm_arm_device_addr {
3258	__u64 id;
3259	__u64 addr;
3260  };
3261
3262Specify a device address in the guest's physical address space where guests
3263can access emulated or directly exposed devices, which the host kernel needs
3264to know about. The id field is an architecture specific identifier for a
3265specific device.
3266
3267ARM/arm64 divides the id field into two parts, a device id and an
3268address type id specific to the individual device::
3269
3270  bits:  | 63        ...       32 | 31    ...    16 | 15    ...    0 |
3271  field: |        0x00000000      |     device id   |  addr type id  |
3272
3273ARM/arm64 currently only require this when using the in-kernel GIC
3274support for the hardware VGIC features, using KVM_ARM_DEVICE_VGIC_V2
3275as the device id.  When setting the base address for the guest's
3276mapping of the VGIC virtual CPU and distributor interface, the ioctl
3277must be called after calling KVM_CREATE_IRQCHIP, but before calling
3278KVM_RUN on any of the VCPUs.  Calling this ioctl twice for any of the
3279base addresses will return -EEXIST.
3280
3281Note, this IOCTL is deprecated and the more flexible SET/GET_DEVICE_ATTR API
3282should be used instead.
3283
3284
32854.86 KVM_PPC_RTAS_DEFINE_TOKEN
3286------------------------------
3287
3288:Capability: KVM_CAP_PPC_RTAS
3289:Architectures: ppc
3290:Type: vm ioctl
3291:Parameters: struct kvm_rtas_token_args
3292:Returns: 0 on success, -1 on error
3293
3294Defines a token value for a RTAS (Run Time Abstraction Services)
3295service in order to allow it to be handled in the kernel.  The
3296argument struct gives the name of the service, which must be the name
3297of a service that has a kernel-side implementation.  If the token
3298value is non-zero, it will be associated with that service, and
3299subsequent RTAS calls by the guest specifying that token will be
3300handled by the kernel.  If the token value is 0, then any token
3301associated with the service will be forgotten, and subsequent RTAS
3302calls by the guest for that service will be passed to userspace to be
3303handled.
3304
33054.87 KVM_SET_GUEST_DEBUG
3306------------------------
3307
3308:Capability: KVM_CAP_SET_GUEST_DEBUG
3309:Architectures: x86, s390, ppc, arm64
3310:Type: vcpu ioctl
3311:Parameters: struct kvm_guest_debug (in)
3312:Returns: 0 on success; -1 on error
3313
3314::
3315
3316  struct kvm_guest_debug {
3317       __u32 control;
3318       __u32 pad;
3319       struct kvm_guest_debug_arch arch;
3320  };
3321
3322Set up the processor specific debug registers and configure vcpu for
3323handling guest debug events. There are two parts to the structure, the
3324first a control bitfield indicates the type of debug events to handle
3325when running. Common control bits are:
3326
3327  - KVM_GUESTDBG_ENABLE:        guest debugging is enabled
3328  - KVM_GUESTDBG_SINGLESTEP:    the next run should single-step
3329
3330The top 16 bits of the control field are architecture specific control
3331flags which can include the following:
3332
3333  - KVM_GUESTDBG_USE_SW_BP:     using software breakpoints [x86, arm64]
3334  - KVM_GUESTDBG_USE_HW_BP:     using hardware breakpoints [x86, s390, arm64]
3335  - KVM_GUESTDBG_INJECT_DB:     inject DB type exception [x86]
3336  - KVM_GUESTDBG_INJECT_BP:     inject BP type exception [x86]
3337  - KVM_GUESTDBG_EXIT_PENDING:  trigger an immediate guest exit [s390]
3338
3339For example KVM_GUESTDBG_USE_SW_BP indicates that software breakpoints
3340are enabled in memory so we need to ensure breakpoint exceptions are
3341correctly trapped and the KVM run loop exits at the breakpoint and not
3342running off into the normal guest vector. For KVM_GUESTDBG_USE_HW_BP
3343we need to ensure the guest vCPUs architecture specific registers are
3344updated to the correct (supplied) values.
3345
3346The second part of the structure is architecture specific and
3347typically contains a set of debug registers.
3348
3349For arm64 the number of debug registers is implementation defined and
3350can be determined by querying the KVM_CAP_GUEST_DEBUG_HW_BPS and
3351KVM_CAP_GUEST_DEBUG_HW_WPS capabilities which return a positive number
3352indicating the number of supported registers.
3353
3354For ppc, the KVM_CAP_PPC_GUEST_DEBUG_SSTEP capability indicates whether
3355the single-step debug event (KVM_GUESTDBG_SINGLESTEP) is supported.
3356
3357When debug events exit the main run loop with the reason
3358KVM_EXIT_DEBUG with the kvm_debug_exit_arch part of the kvm_run
3359structure containing architecture specific debug information.
3360
33614.88 KVM_GET_EMULATED_CPUID
3362---------------------------
3363
3364:Capability: KVM_CAP_EXT_EMUL_CPUID
3365:Architectures: x86
3366:Type: system ioctl
3367:Parameters: struct kvm_cpuid2 (in/out)
3368:Returns: 0 on success, -1 on error
3369
3370::
3371
3372  struct kvm_cpuid2 {
3373	__u32 nent;
3374	__u32 flags;
3375	struct kvm_cpuid_entry2 entries[0];
3376  };
3377
3378The member 'flags' is used for passing flags from userspace.
3379
3380::
3381
3382  #define KVM_CPUID_FLAG_SIGNIFCANT_INDEX		BIT(0)
3383  #define KVM_CPUID_FLAG_STATEFUL_FUNC		BIT(1) /* deprecated */
3384  #define KVM_CPUID_FLAG_STATE_READ_NEXT		BIT(2) /* deprecated */
3385
3386  struct kvm_cpuid_entry2 {
3387	__u32 function;
3388	__u32 index;
3389	__u32 flags;
3390	__u32 eax;
3391	__u32 ebx;
3392	__u32 ecx;
3393	__u32 edx;
3394	__u32 padding[3];
3395  };
3396
3397This ioctl returns x86 cpuid features which are emulated by
3398kvm.Userspace can use the information returned by this ioctl to query
3399which features are emulated by kvm instead of being present natively.
3400
3401Userspace invokes KVM_GET_EMULATED_CPUID by passing a kvm_cpuid2
3402structure with the 'nent' field indicating the number of entries in
3403the variable-size array 'entries'. If the number of entries is too low
3404to describe the cpu capabilities, an error (E2BIG) is returned. If the
3405number is too high, the 'nent' field is adjusted and an error (ENOMEM)
3406is returned. If the number is just right, the 'nent' field is adjusted
3407to the number of valid entries in the 'entries' array, which is then
3408filled.
3409
3410The entries returned are the set CPUID bits of the respective features
3411which kvm emulates, as returned by the CPUID instruction, with unknown
3412or unsupported feature bits cleared.
3413
3414Features like x2apic, for example, may not be present in the host cpu
3415but are exposed by kvm in KVM_GET_SUPPORTED_CPUID because they can be
3416emulated efficiently and thus not included here.
3417
3418The fields in each entry are defined as follows:
3419
3420  function:
3421	 the eax value used to obtain the entry
3422  index:
3423	 the ecx value used to obtain the entry (for entries that are
3424         affected by ecx)
3425  flags:
3426    an OR of zero or more of the following:
3427
3428        KVM_CPUID_FLAG_SIGNIFCANT_INDEX:
3429           if the index field is valid
3430
3431   eax, ebx, ecx, edx:
3432
3433         the values returned by the cpuid instruction for
3434         this function/index combination
3435
34364.89 KVM_S390_MEM_OP
3437--------------------
3438
3439:Capability: KVM_CAP_S390_MEM_OP
3440:Architectures: s390
3441:Type: vcpu ioctl
3442:Parameters: struct kvm_s390_mem_op (in)
3443:Returns: = 0 on success,
3444          < 0 on generic error (e.g. -EFAULT or -ENOMEM),
3445          > 0 if an exception occurred while walking the page tables
3446
3447Read or write data from/to the logical (virtual) memory of a VCPU.
3448
3449Parameters are specified via the following structure::
3450
3451  struct kvm_s390_mem_op {
3452	__u64 gaddr;		/* the guest address */
3453	__u64 flags;		/* flags */
3454	__u32 size;		/* amount of bytes */
3455	__u32 op;		/* type of operation */
3456	__u64 buf;		/* buffer in userspace */
3457	__u8 ar;		/* the access register number */
3458	__u8 reserved[31];	/* should be set to 0 */
3459  };
3460
3461The type of operation is specified in the "op" field. It is either
3462KVM_S390_MEMOP_LOGICAL_READ for reading from logical memory space or
3463KVM_S390_MEMOP_LOGICAL_WRITE for writing to logical memory space. The
3464KVM_S390_MEMOP_F_CHECK_ONLY flag can be set in the "flags" field to check
3465whether the corresponding memory access would create an access exception
3466(without touching the data in the memory at the destination). In case an
3467access exception occurred while walking the MMU tables of the guest, the
3468ioctl returns a positive error number to indicate the type of exception.
3469This exception is also raised directly at the corresponding VCPU if the
3470flag KVM_S390_MEMOP_F_INJECT_EXCEPTION is set in the "flags" field.
3471
3472The start address of the memory region has to be specified in the "gaddr"
3473field, and the length of the region in the "size" field (which must not
3474be 0). The maximum value for "size" can be obtained by checking the
3475KVM_CAP_S390_MEM_OP capability. "buf" is the buffer supplied by the
3476userspace application where the read data should be written to for
3477KVM_S390_MEMOP_LOGICAL_READ, or where the data that should be written is
3478stored for a KVM_S390_MEMOP_LOGICAL_WRITE. When KVM_S390_MEMOP_F_CHECK_ONLY
3479is specified, "buf" is unused and can be NULL. "ar" designates the access
3480register number to be used; the valid range is 0..15.
3481
3482The "reserved" field is meant for future extensions. It is not used by
3483KVM with the currently defined set of flags.
3484
34854.90 KVM_S390_GET_SKEYS
3486-----------------------
3487
3488:Capability: KVM_CAP_S390_SKEYS
3489:Architectures: s390
3490:Type: vm ioctl
3491:Parameters: struct kvm_s390_skeys
3492:Returns: 0 on success, KVM_S390_GET_KEYS_NONE if guest is not using storage
3493          keys, negative value on error
3494
3495This ioctl is used to get guest storage key values on the s390
3496architecture. The ioctl takes parameters via the kvm_s390_skeys struct::
3497
3498  struct kvm_s390_skeys {
3499	__u64 start_gfn;
3500	__u64 count;
3501	__u64 skeydata_addr;
3502	__u32 flags;
3503	__u32 reserved[9];
3504  };
3505
3506The start_gfn field is the number of the first guest frame whose storage keys
3507you want to get.
3508
3509The count field is the number of consecutive frames (starting from start_gfn)
3510whose storage keys to get. The count field must be at least 1 and the maximum
3511allowed value is defined as KVM_S390_SKEYS_ALLOC_MAX. Values outside this range
3512will cause the ioctl to return -EINVAL.
3513
3514The skeydata_addr field is the address to a buffer large enough to hold count
3515bytes. This buffer will be filled with storage key data by the ioctl.
3516
35174.91 KVM_S390_SET_SKEYS
3518-----------------------
3519
3520:Capability: KVM_CAP_S390_SKEYS
3521:Architectures: s390
3522:Type: vm ioctl
3523:Parameters: struct kvm_s390_skeys
3524:Returns: 0 on success, negative value on error
3525
3526This ioctl is used to set guest storage key values on the s390
3527architecture. The ioctl takes parameters via the kvm_s390_skeys struct.
3528See section on KVM_S390_GET_SKEYS for struct definition.
3529
3530The start_gfn field is the number of the first guest frame whose storage keys
3531you want to set.
3532
3533The count field is the number of consecutive frames (starting from start_gfn)
3534whose storage keys to get. The count field must be at least 1 and the maximum
3535allowed value is defined as KVM_S390_SKEYS_ALLOC_MAX. Values outside this range
3536will cause the ioctl to return -EINVAL.
3537
3538The skeydata_addr field is the address to a buffer containing count bytes of
3539storage keys. Each byte in the buffer will be set as the storage key for a
3540single frame starting at start_gfn for count frames.
3541
3542Note: If any architecturally invalid key value is found in the given data then
3543the ioctl will return -EINVAL.
3544
35454.92 KVM_S390_IRQ
3546-----------------
3547
3548:Capability: KVM_CAP_S390_INJECT_IRQ
3549:Architectures: s390
3550:Type: vcpu ioctl
3551:Parameters: struct kvm_s390_irq (in)
3552:Returns: 0 on success, -1 on error
3553
3554Errors:
3555
3556
3557  ======  =================================================================
3558  EINVAL  interrupt type is invalid
3559          type is KVM_S390_SIGP_STOP and flag parameter is invalid value,
3560          type is KVM_S390_INT_EXTERNAL_CALL and code is bigger
3561          than the maximum of VCPUs
3562  EBUSY   type is KVM_S390_SIGP_SET_PREFIX and vcpu is not stopped,
3563          type is KVM_S390_SIGP_STOP and a stop irq is already pending,
3564          type is KVM_S390_INT_EXTERNAL_CALL and an external call interrupt
3565          is already pending
3566  ======  =================================================================
3567
3568Allows to inject an interrupt to the guest.
3569
3570Using struct kvm_s390_irq as a parameter allows
3571to inject additional payload which is not
3572possible via KVM_S390_INTERRUPT.
3573
3574Interrupt parameters are passed via kvm_s390_irq::
3575
3576  struct kvm_s390_irq {
3577	__u64 type;
3578	union {
3579		struct kvm_s390_io_info io;
3580		struct kvm_s390_ext_info ext;
3581		struct kvm_s390_pgm_info pgm;
3582		struct kvm_s390_emerg_info emerg;
3583		struct kvm_s390_extcall_info extcall;
3584		struct kvm_s390_prefix_info prefix;
3585		struct kvm_s390_stop_info stop;
3586		struct kvm_s390_mchk_info mchk;
3587		char reserved[64];
3588	} u;
3589  };
3590
3591type can be one of the following:
3592
3593- KVM_S390_SIGP_STOP - sigp stop; parameter in .stop
3594- KVM_S390_PROGRAM_INT - program check; parameters in .pgm
3595- KVM_S390_SIGP_SET_PREFIX - sigp set prefix; parameters in .prefix
3596- KVM_S390_RESTART - restart; no parameters
3597- KVM_S390_INT_CLOCK_COMP - clock comparator interrupt; no parameters
3598- KVM_S390_INT_CPU_TIMER - CPU timer interrupt; no parameters
3599- KVM_S390_INT_EMERGENCY - sigp emergency; parameters in .emerg
3600- KVM_S390_INT_EXTERNAL_CALL - sigp external call; parameters in .extcall
3601- KVM_S390_MCHK - machine check interrupt; parameters in .mchk
3602
3603This is an asynchronous vcpu ioctl and can be invoked from any thread.
3604
36054.94 KVM_S390_GET_IRQ_STATE
3606---------------------------
3607
3608:Capability: KVM_CAP_S390_IRQ_STATE
3609:Architectures: s390
3610:Type: vcpu ioctl
3611:Parameters: struct kvm_s390_irq_state (out)
3612:Returns: >= number of bytes copied into buffer,
3613          -EINVAL if buffer size is 0,
3614          -ENOBUFS if buffer size is too small to fit all pending interrupts,
3615          -EFAULT if the buffer address was invalid
3616
3617This ioctl allows userspace to retrieve the complete state of all currently
3618pending interrupts in a single buffer. Use cases include migration
3619and introspection. The parameter structure contains the address of a
3620userspace buffer and its length::
3621
3622  struct kvm_s390_irq_state {
3623	__u64 buf;
3624	__u32 flags;        /* will stay unused for compatibility reasons */
3625	__u32 len;
3626	__u32 reserved[4];  /* will stay unused for compatibility reasons */
3627  };
3628
3629Userspace passes in the above struct and for each pending interrupt a
3630struct kvm_s390_irq is copied to the provided buffer.
3631
3632The structure contains a flags and a reserved field for future extensions. As
3633the kernel never checked for flags == 0 and QEMU never pre-zeroed flags and
3634reserved, these fields can not be used in the future without breaking
3635compatibility.
3636
3637If -ENOBUFS is returned the buffer provided was too small and userspace
3638may retry with a bigger buffer.
3639
36404.95 KVM_S390_SET_IRQ_STATE
3641---------------------------
3642
3643:Capability: KVM_CAP_S390_IRQ_STATE
3644:Architectures: s390
3645:Type: vcpu ioctl
3646:Parameters: struct kvm_s390_irq_state (in)
3647:Returns: 0 on success,
3648          -EFAULT if the buffer address was invalid,
3649          -EINVAL for an invalid buffer length (see below),
3650          -EBUSY if there were already interrupts pending,
3651          errors occurring when actually injecting the
3652          interrupt. See KVM_S390_IRQ.
3653
3654This ioctl allows userspace to set the complete state of all cpu-local
3655interrupts currently pending for the vcpu. It is intended for restoring
3656interrupt state after a migration. The input parameter is a userspace buffer
3657containing a struct kvm_s390_irq_state::
3658
3659  struct kvm_s390_irq_state {
3660	__u64 buf;
3661	__u32 flags;        /* will stay unused for compatibility reasons */
3662	__u32 len;
3663	__u32 reserved[4];  /* will stay unused for compatibility reasons */
3664  };
3665
3666The restrictions for flags and reserved apply as well.
3667(see KVM_S390_GET_IRQ_STATE)
3668
3669The userspace memory referenced by buf contains a struct kvm_s390_irq
3670for each interrupt to be injected into the guest.
3671If one of the interrupts could not be injected for some reason the
3672ioctl aborts.
3673
3674len must be a multiple of sizeof(struct kvm_s390_irq). It must be > 0
3675and it must not exceed (max_vcpus + 32) * sizeof(struct kvm_s390_irq),
3676which is the maximum number of possibly pending cpu-local interrupts.
3677
36784.96 KVM_SMI
3679------------
3680
3681:Capability: KVM_CAP_X86_SMM
3682:Architectures: x86
3683:Type: vcpu ioctl
3684:Parameters: none
3685:Returns: 0 on success, -1 on error
3686
3687Queues an SMI on the thread's vcpu.
3688
36894.97 KVM_CAP_PPC_MULTITCE
3690-------------------------
3691
3692:Capability: KVM_CAP_PPC_MULTITCE
3693:Architectures: ppc
3694:Type: vm
3695
3696This capability means the kernel is capable of handling hypercalls
3697H_PUT_TCE_INDIRECT and H_STUFF_TCE without passing those into the user
3698space. This significantly accelerates DMA operations for PPC KVM guests.
3699User space should expect that its handlers for these hypercalls
3700are not going to be called if user space previously registered LIOBN
3701in KVM (via KVM_CREATE_SPAPR_TCE or similar calls).
3702
3703In order to enable H_PUT_TCE_INDIRECT and H_STUFF_TCE use in the guest,
3704user space might have to advertise it for the guest. For example,
3705IBM pSeries (sPAPR) guest starts using them if "hcall-multi-tce" is
3706present in the "ibm,hypertas-functions" device-tree property.
3707
3708The hypercalls mentioned above may or may not be processed successfully
3709in the kernel based fast path. If they can not be handled by the kernel,
3710they will get passed on to user space. So user space still has to have
3711an implementation for these despite the in kernel acceleration.
3712
3713This capability is always enabled.
3714
37154.98 KVM_CREATE_SPAPR_TCE_64
3716----------------------------
3717
3718:Capability: KVM_CAP_SPAPR_TCE_64
3719:Architectures: powerpc
3720:Type: vm ioctl
3721:Parameters: struct kvm_create_spapr_tce_64 (in)
3722:Returns: file descriptor for manipulating the created TCE table
3723
3724This is an extension for KVM_CAP_SPAPR_TCE which only supports 32bit
3725windows, described in 4.62 KVM_CREATE_SPAPR_TCE
3726
3727This capability uses extended struct in ioctl interface::
3728
3729  /* for KVM_CAP_SPAPR_TCE_64 */
3730  struct kvm_create_spapr_tce_64 {
3731	__u64 liobn;
3732	__u32 page_shift;
3733	__u32 flags;
3734	__u64 offset;	/* in pages */
3735	__u64 size; 	/* in pages */
3736  };
3737
3738The aim of extension is to support an additional bigger DMA window with
3739a variable page size.
3740KVM_CREATE_SPAPR_TCE_64 receives a 64bit window size, an IOMMU page shift and
3741a bus offset of the corresponding DMA window, @size and @offset are numbers
3742of IOMMU pages.
3743
3744@flags are not used at the moment.
3745
3746The rest of functionality is identical to KVM_CREATE_SPAPR_TCE.
3747
37484.99 KVM_REINJECT_CONTROL
3749-------------------------
3750
3751:Capability: KVM_CAP_REINJECT_CONTROL
3752:Architectures: x86
3753:Type: vm ioctl
3754:Parameters: struct kvm_reinject_control (in)
3755:Returns: 0 on success,
3756         -EFAULT if struct kvm_reinject_control cannot be read,
3757         -ENXIO if KVM_CREATE_PIT or KVM_CREATE_PIT2 didn't succeed earlier.
3758
3759i8254 (PIT) has two modes, reinject and !reinject.  The default is reinject,
3760where KVM queues elapsed i8254 ticks and monitors completion of interrupt from
3761vector(s) that i8254 injects.  Reinject mode dequeues a tick and injects its
3762interrupt whenever there isn't a pending interrupt from i8254.
3763!reinject mode injects an interrupt as soon as a tick arrives.
3764
3765::
3766
3767  struct kvm_reinject_control {
3768	__u8 pit_reinject;
3769	__u8 reserved[31];
3770  };
3771
3772pit_reinject = 0 (!reinject mode) is recommended, unless running an old
3773operating system that uses the PIT for timing (e.g. Linux 2.4.x).
3774
37754.100 KVM_PPC_CONFIGURE_V3_MMU
3776------------------------------
3777
3778:Capability: KVM_CAP_PPC_RADIX_MMU or KVM_CAP_PPC_HASH_MMU_V3
3779:Architectures: ppc
3780:Type: vm ioctl
3781:Parameters: struct kvm_ppc_mmuv3_cfg (in)
3782:Returns: 0 on success,
3783         -EFAULT if struct kvm_ppc_mmuv3_cfg cannot be read,
3784         -EINVAL if the configuration is invalid
3785
3786This ioctl controls whether the guest will use radix or HPT (hashed
3787page table) translation, and sets the pointer to the process table for
3788the guest.
3789
3790::
3791
3792  struct kvm_ppc_mmuv3_cfg {
3793	__u64	flags;
3794	__u64	process_table;
3795  };
3796
3797There are two bits that can be set in flags; KVM_PPC_MMUV3_RADIX and
3798KVM_PPC_MMUV3_GTSE.  KVM_PPC_MMUV3_RADIX, if set, configures the guest
3799to use radix tree translation, and if clear, to use HPT translation.
3800KVM_PPC_MMUV3_GTSE, if set and if KVM permits it, configures the guest
3801to be able to use the global TLB and SLB invalidation instructions;
3802if clear, the guest may not use these instructions.
3803
3804The process_table field specifies the address and size of the guest
3805process table, which is in the guest's space.  This field is formatted
3806as the second doubleword of the partition table entry, as defined in
3807the Power ISA V3.00, Book III section 5.7.6.1.
3808
38094.101 KVM_PPC_GET_RMMU_INFO
3810---------------------------
3811
3812:Capability: KVM_CAP_PPC_RADIX_MMU
3813:Architectures: ppc
3814:Type: vm ioctl
3815:Parameters: struct kvm_ppc_rmmu_info (out)
3816:Returns: 0 on success,
3817	 -EFAULT if struct kvm_ppc_rmmu_info cannot be written,
3818	 -EINVAL if no useful information can be returned
3819
3820This ioctl returns a structure containing two things: (a) a list
3821containing supported radix tree geometries, and (b) a list that maps
3822page sizes to put in the "AP" (actual page size) field for the tlbie
3823(TLB invalidate entry) instruction.
3824
3825::
3826
3827  struct kvm_ppc_rmmu_info {
3828	struct kvm_ppc_radix_geom {
3829		__u8	page_shift;
3830		__u8	level_bits[4];
3831		__u8	pad[3];
3832	}	geometries[8];
3833	__u32	ap_encodings[8];
3834  };
3835
3836The geometries[] field gives up to 8 supported geometries for the
3837radix page table, in terms of the log base 2 of the smallest page
3838size, and the number of bits indexed at each level of the tree, from
3839the PTE level up to the PGD level in that order.  Any unused entries
3840will have 0 in the page_shift field.
3841
3842The ap_encodings gives the supported page sizes and their AP field
3843encodings, encoded with the AP value in the top 3 bits and the log
3844base 2 of the page size in the bottom 6 bits.
3845
38464.102 KVM_PPC_RESIZE_HPT_PREPARE
3847--------------------------------
3848
3849:Capability: KVM_CAP_SPAPR_RESIZE_HPT
3850:Architectures: powerpc
3851:Type: vm ioctl
3852:Parameters: struct kvm_ppc_resize_hpt (in)
3853:Returns: 0 on successful completion,
3854	 >0 if a new HPT is being prepared, the value is an estimated
3855         number of milliseconds until preparation is complete,
3856         -EFAULT if struct kvm_reinject_control cannot be read,
3857	 -EINVAL if the supplied shift or flags are invalid,
3858	 -ENOMEM if unable to allocate the new HPT,
3859
3860Used to implement the PAPR extension for runtime resizing of a guest's
3861Hashed Page Table (HPT).  Specifically this starts, stops or monitors
3862the preparation of a new potential HPT for the guest, essentially
3863implementing the H_RESIZE_HPT_PREPARE hypercall.
3864
3865::
3866
3867  struct kvm_ppc_resize_hpt {
3868	__u64 flags;
3869	__u32 shift;
3870	__u32 pad;
3871  };
3872
3873If called with shift > 0 when there is no pending HPT for the guest,
3874this begins preparation of a new pending HPT of size 2^(shift) bytes.
3875It then returns a positive integer with the estimated number of
3876milliseconds until preparation is complete.
3877
3878If called when there is a pending HPT whose size does not match that
3879requested in the parameters, discards the existing pending HPT and
3880creates a new one as above.
3881
3882If called when there is a pending HPT of the size requested, will:
3883
3884  * If preparation of the pending HPT is already complete, return 0
3885  * If preparation of the pending HPT has failed, return an error
3886    code, then discard the pending HPT.
3887  * If preparation of the pending HPT is still in progress, return an
3888    estimated number of milliseconds until preparation is complete.
3889
3890If called with shift == 0, discards any currently pending HPT and
3891returns 0 (i.e. cancels any in-progress preparation).
3892
3893flags is reserved for future expansion, currently setting any bits in
3894flags will result in an -EINVAL.
3895
3896Normally this will be called repeatedly with the same parameters until
3897it returns <= 0.  The first call will initiate preparation, subsequent
3898ones will monitor preparation until it completes or fails.
3899
39004.103 KVM_PPC_RESIZE_HPT_COMMIT
3901-------------------------------
3902
3903:Capability: KVM_CAP_SPAPR_RESIZE_HPT
3904:Architectures: powerpc
3905:Type: vm ioctl
3906:Parameters: struct kvm_ppc_resize_hpt (in)
3907:Returns: 0 on successful completion,
3908         -EFAULT if struct kvm_reinject_control cannot be read,
3909	 -EINVAL if the supplied shift or flags are invalid,
3910	 -ENXIO is there is no pending HPT, or the pending HPT doesn't
3911         have the requested size,
3912	 -EBUSY if the pending HPT is not fully prepared,
3913	 -ENOSPC if there was a hash collision when moving existing
3914         HPT entries to the new HPT,
3915	 -EIO on other error conditions
3916
3917Used to implement the PAPR extension for runtime resizing of a guest's
3918Hashed Page Table (HPT).  Specifically this requests that the guest be
3919transferred to working with the new HPT, essentially implementing the
3920H_RESIZE_HPT_COMMIT hypercall.
3921
3922::
3923
3924  struct kvm_ppc_resize_hpt {
3925	__u64 flags;
3926	__u32 shift;
3927	__u32 pad;
3928  };
3929
3930This should only be called after KVM_PPC_RESIZE_HPT_PREPARE has
3931returned 0 with the same parameters.  In other cases
3932KVM_PPC_RESIZE_HPT_COMMIT will return an error (usually -ENXIO or
3933-EBUSY, though others may be possible if the preparation was started,
3934but failed).
3935
3936This will have undefined effects on the guest if it has not already
3937placed itself in a quiescent state where no vcpu will make MMU enabled
3938memory accesses.
3939
3940On succsful completion, the pending HPT will become the guest's active
3941HPT and the previous HPT will be discarded.
3942
3943On failure, the guest will still be operating on its previous HPT.
3944
39454.104 KVM_X86_GET_MCE_CAP_SUPPORTED
3946-----------------------------------
3947
3948:Capability: KVM_CAP_MCE
3949:Architectures: x86
3950:Type: system ioctl
3951:Parameters: u64 mce_cap (out)
3952:Returns: 0 on success, -1 on error
3953
3954Returns supported MCE capabilities. The u64 mce_cap parameter
3955has the same format as the MSR_IA32_MCG_CAP register. Supported
3956capabilities will have the corresponding bits set.
3957
39584.105 KVM_X86_SETUP_MCE
3959-----------------------
3960
3961:Capability: KVM_CAP_MCE
3962:Architectures: x86
3963:Type: vcpu ioctl
3964:Parameters: u64 mcg_cap (in)
3965:Returns: 0 on success,
3966         -EFAULT if u64 mcg_cap cannot be read,
3967         -EINVAL if the requested number of banks is invalid,
3968         -EINVAL if requested MCE capability is not supported.
3969
3970Initializes MCE support for use. The u64 mcg_cap parameter
3971has the same format as the MSR_IA32_MCG_CAP register and
3972specifies which capabilities should be enabled. The maximum
3973supported number of error-reporting banks can be retrieved when
3974checking for KVM_CAP_MCE. The supported capabilities can be
3975retrieved with KVM_X86_GET_MCE_CAP_SUPPORTED.
3976
39774.106 KVM_X86_SET_MCE
3978---------------------
3979
3980:Capability: KVM_CAP_MCE
3981:Architectures: x86
3982:Type: vcpu ioctl
3983:Parameters: struct kvm_x86_mce (in)
3984:Returns: 0 on success,
3985         -EFAULT if struct kvm_x86_mce cannot be read,
3986         -EINVAL if the bank number is invalid,
3987         -EINVAL if VAL bit is not set in status field.
3988
3989Inject a machine check error (MCE) into the guest. The input
3990parameter is::
3991
3992  struct kvm_x86_mce {
3993	__u64 status;
3994	__u64 addr;
3995	__u64 misc;
3996	__u64 mcg_status;
3997	__u8 bank;
3998	__u8 pad1[7];
3999	__u64 pad2[3];
4000  };
4001
4002If the MCE being reported is an uncorrected error, KVM will
4003inject it as an MCE exception into the guest. If the guest
4004MCG_STATUS register reports that an MCE is in progress, KVM
4005causes an KVM_EXIT_SHUTDOWN vmexit.
4006
4007Otherwise, if the MCE is a corrected error, KVM will just
4008store it in the corresponding bank (provided this bank is
4009not holding a previously reported uncorrected error).
4010
40114.107 KVM_S390_GET_CMMA_BITS
4012----------------------------
4013
4014:Capability: KVM_CAP_S390_CMMA_MIGRATION
4015:Architectures: s390
4016:Type: vm ioctl
4017:Parameters: struct kvm_s390_cmma_log (in, out)
4018:Returns: 0 on success, a negative value on error
4019
4020This ioctl is used to get the values of the CMMA bits on the s390
4021architecture. It is meant to be used in two scenarios:
4022
4023- During live migration to save the CMMA values. Live migration needs
4024  to be enabled via the KVM_REQ_START_MIGRATION VM property.
4025- To non-destructively peek at the CMMA values, with the flag
4026  KVM_S390_CMMA_PEEK set.
4027
4028The ioctl takes parameters via the kvm_s390_cmma_log struct. The desired
4029values are written to a buffer whose location is indicated via the "values"
4030member in the kvm_s390_cmma_log struct.  The values in the input struct are
4031also updated as needed.
4032
4033Each CMMA value takes up one byte.
4034
4035::
4036
4037  struct kvm_s390_cmma_log {
4038	__u64 start_gfn;
4039	__u32 count;
4040	__u32 flags;
4041	union {
4042		__u64 remaining;
4043		__u64 mask;
4044	};
4045	__u64 values;
4046  };
4047
4048start_gfn is the number of the first guest frame whose CMMA values are
4049to be retrieved,
4050
4051count is the length of the buffer in bytes,
4052
4053values points to the buffer where the result will be written to.
4054
4055If count is greater than KVM_S390_SKEYS_MAX, then it is considered to be
4056KVM_S390_SKEYS_MAX. KVM_S390_SKEYS_MAX is re-used for consistency with
4057other ioctls.
4058
4059The result is written in the buffer pointed to by the field values, and
4060the values of the input parameter are updated as follows.
4061
4062Depending on the flags, different actions are performed. The only
4063supported flag so far is KVM_S390_CMMA_PEEK.
4064
4065The default behaviour if KVM_S390_CMMA_PEEK is not set is:
4066start_gfn will indicate the first page frame whose CMMA bits were dirty.
4067It is not necessarily the same as the one passed as input, as clean pages
4068are skipped.
4069
4070count will indicate the number of bytes actually written in the buffer.
4071It can (and very often will) be smaller than the input value, since the
4072buffer is only filled until 16 bytes of clean values are found (which
4073are then not copied in the buffer). Since a CMMA migration block needs
4074the base address and the length, for a total of 16 bytes, we will send
4075back some clean data if there is some dirty data afterwards, as long as
4076the size of the clean data does not exceed the size of the header. This
4077allows to minimize the amount of data to be saved or transferred over
4078the network at the expense of more roundtrips to userspace. The next
4079invocation of the ioctl will skip over all the clean values, saving
4080potentially more than just the 16 bytes we found.
4081
4082If KVM_S390_CMMA_PEEK is set:
4083the existing storage attributes are read even when not in migration
4084mode, and no other action is performed;
4085
4086the output start_gfn will be equal to the input start_gfn,
4087
4088the output count will be equal to the input count, except if the end of
4089memory has been reached.
4090
4091In both cases:
4092the field "remaining" will indicate the total number of dirty CMMA values
4093still remaining, or 0 if KVM_S390_CMMA_PEEK is set and migration mode is
4094not enabled.
4095
4096mask is unused.
4097
4098values points to the userspace buffer where the result will be stored.
4099
4100This ioctl can fail with -ENOMEM if not enough memory can be allocated to
4101complete the task, with -ENXIO if CMMA is not enabled, with -EINVAL if
4102KVM_S390_CMMA_PEEK is not set but migration mode was not enabled, with
4103-EFAULT if the userspace address is invalid or if no page table is
4104present for the addresses (e.g. when using hugepages).
4105
41064.108 KVM_S390_SET_CMMA_BITS
4107----------------------------
4108
4109:Capability: KVM_CAP_S390_CMMA_MIGRATION
4110:Architectures: s390
4111:Type: vm ioctl
4112:Parameters: struct kvm_s390_cmma_log (in)
4113:Returns: 0 on success, a negative value on error
4114
4115This ioctl is used to set the values of the CMMA bits on the s390
4116architecture. It is meant to be used during live migration to restore
4117the CMMA values, but there are no restrictions on its use.
4118The ioctl takes parameters via the kvm_s390_cmma_values struct.
4119Each CMMA value takes up one byte.
4120
4121::
4122
4123  struct kvm_s390_cmma_log {
4124	__u64 start_gfn;
4125	__u32 count;
4126	__u32 flags;
4127	union {
4128		__u64 remaining;
4129		__u64 mask;
4130 	};
4131	__u64 values;
4132  };
4133
4134start_gfn indicates the starting guest frame number,
4135
4136count indicates how many values are to be considered in the buffer,
4137
4138flags is not used and must be 0.
4139
4140mask indicates which PGSTE bits are to be considered.
4141
4142remaining is not used.
4143
4144values points to the buffer in userspace where to store the values.
4145
4146This ioctl can fail with -ENOMEM if not enough memory can be allocated to
4147complete the task, with -ENXIO if CMMA is not enabled, with -EINVAL if
4148the count field is too large (e.g. more than KVM_S390_CMMA_SIZE_MAX) or
4149if the flags field was not 0, with -EFAULT if the userspace address is
4150invalid, if invalid pages are written to (e.g. after the end of memory)
4151or if no page table is present for the addresses (e.g. when using
4152hugepages).
4153
41544.109 KVM_PPC_GET_CPU_CHAR
4155--------------------------
4156
4157:Capability: KVM_CAP_PPC_GET_CPU_CHAR
4158:Architectures: powerpc
4159:Type: vm ioctl
4160:Parameters: struct kvm_ppc_cpu_char (out)
4161:Returns: 0 on successful completion,
4162	 -EFAULT if struct kvm_ppc_cpu_char cannot be written
4163
4164This ioctl gives userspace information about certain characteristics
4165of the CPU relating to speculative execution of instructions and
4166possible information leakage resulting from speculative execution (see
4167CVE-2017-5715, CVE-2017-5753 and CVE-2017-5754).  The information is
4168returned in struct kvm_ppc_cpu_char, which looks like this::
4169
4170  struct kvm_ppc_cpu_char {
4171	__u64	character;		/* characteristics of the CPU */
4172	__u64	behaviour;		/* recommended software behaviour */
4173	__u64	character_mask;		/* valid bits in character */
4174	__u64	behaviour_mask;		/* valid bits in behaviour */
4175  };
4176
4177For extensibility, the character_mask and behaviour_mask fields
4178indicate which bits of character and behaviour have been filled in by
4179the kernel.  If the set of defined bits is extended in future then
4180userspace will be able to tell whether it is running on a kernel that
4181knows about the new bits.
4182
4183The character field describes attributes of the CPU which can help
4184with preventing inadvertent information disclosure - specifically,
4185whether there is an instruction to flash-invalidate the L1 data cache
4186(ori 30,30,0 or mtspr SPRN_TRIG2,rN), whether the L1 data cache is set
4187to a mode where entries can only be used by the thread that created
4188them, whether the bcctr[l] instruction prevents speculation, and
4189whether a speculation barrier instruction (ori 31,31,0) is provided.
4190
4191The behaviour field describes actions that software should take to
4192prevent inadvertent information disclosure, and thus describes which
4193vulnerabilities the hardware is subject to; specifically whether the
4194L1 data cache should be flushed when returning to user mode from the
4195kernel, and whether a speculation barrier should be placed between an
4196array bounds check and the array access.
4197
4198These fields use the same bit definitions as the new
4199H_GET_CPU_CHARACTERISTICS hypercall.
4200
42014.110 KVM_MEMORY_ENCRYPT_OP
4202---------------------------
4203
4204:Capability: basic
4205:Architectures: x86
4206:Type: vm
4207:Parameters: an opaque platform specific structure (in/out)
4208:Returns: 0 on success; -1 on error
4209
4210If the platform supports creating encrypted VMs then this ioctl can be used
4211for issuing platform-specific memory encryption commands to manage those
4212encrypted VMs.
4213
4214Currently, this ioctl is used for issuing Secure Encrypted Virtualization
4215(SEV) commands on AMD Processors. The SEV commands are defined in
4216Documentation/virt/kvm/amd-memory-encryption.rst.
4217
42184.111 KVM_MEMORY_ENCRYPT_REG_REGION
4219-----------------------------------
4220
4221:Capability: basic
4222:Architectures: x86
4223:Type: system
4224:Parameters: struct kvm_enc_region (in)
4225:Returns: 0 on success; -1 on error
4226
4227This ioctl can be used to register a guest memory region which may
4228contain encrypted data (e.g. guest RAM, SMRAM etc).
4229
4230It is used in the SEV-enabled guest. When encryption is enabled, a guest
4231memory region may contain encrypted data. The SEV memory encryption
4232engine uses a tweak such that two identical plaintext pages, each at
4233different locations will have differing ciphertexts. So swapping or
4234moving ciphertext of those pages will not result in plaintext being
4235swapped. So relocating (or migrating) physical backing pages for the SEV
4236guest will require some additional steps.
4237
4238Note: The current SEV key management spec does not provide commands to
4239swap or migrate (move) ciphertext pages. Hence, for now we pin the guest
4240memory region registered with the ioctl.
4241
42424.112 KVM_MEMORY_ENCRYPT_UNREG_REGION
4243-------------------------------------
4244
4245:Capability: basic
4246:Architectures: x86
4247:Type: system
4248:Parameters: struct kvm_enc_region (in)
4249:Returns: 0 on success; -1 on error
4250
4251This ioctl can be used to unregister the guest memory region registered
4252with KVM_MEMORY_ENCRYPT_REG_REGION ioctl above.
4253
42544.113 KVM_HYPERV_EVENTFD
4255------------------------
4256
4257:Capability: KVM_CAP_HYPERV_EVENTFD
4258:Architectures: x86
4259:Type: vm ioctl
4260:Parameters: struct kvm_hyperv_eventfd (in)
4261
4262This ioctl (un)registers an eventfd to receive notifications from the guest on
4263the specified Hyper-V connection id through the SIGNAL_EVENT hypercall, without
4264causing a user exit.  SIGNAL_EVENT hypercall with non-zero event flag number
4265(bits 24-31) still triggers a KVM_EXIT_HYPERV_HCALL user exit.
4266
4267::
4268
4269  struct kvm_hyperv_eventfd {
4270	__u32 conn_id;
4271	__s32 fd;
4272	__u32 flags;
4273	__u32 padding[3];
4274  };
4275
4276The conn_id field should fit within 24 bits::
4277
4278  #define KVM_HYPERV_CONN_ID_MASK		0x00ffffff
4279
4280The acceptable values for the flags field are::
4281
4282  #define KVM_HYPERV_EVENTFD_DEASSIGN	(1 << 0)
4283
4284:Returns: 0 on success,
4285 	  -EINVAL if conn_id or flags is outside the allowed range,
4286	  -ENOENT on deassign if the conn_id isn't registered,
4287	  -EEXIST on assign if the conn_id is already registered
4288
42894.114 KVM_GET_NESTED_STATE
4290--------------------------
4291
4292:Capability: KVM_CAP_NESTED_STATE
4293:Architectures: x86
4294:Type: vcpu ioctl
4295:Parameters: struct kvm_nested_state (in/out)
4296:Returns: 0 on success, -1 on error
4297
4298Errors:
4299
4300  =====      =============================================================
4301  E2BIG      the total state size exceeds the value of 'size' specified by
4302             the user; the size required will be written into size.
4303  =====      =============================================================
4304
4305::
4306
4307  struct kvm_nested_state {
4308	__u16 flags;
4309	__u16 format;
4310	__u32 size;
4311
4312	union {
4313		struct kvm_vmx_nested_state_hdr vmx;
4314		struct kvm_svm_nested_state_hdr svm;
4315
4316		/* Pad the header to 128 bytes.  */
4317		__u8 pad[120];
4318	} hdr;
4319
4320	union {
4321		struct kvm_vmx_nested_state_data vmx[0];
4322		struct kvm_svm_nested_state_data svm[0];
4323	} data;
4324  };
4325
4326  #define KVM_STATE_NESTED_GUEST_MODE		0x00000001
4327  #define KVM_STATE_NESTED_RUN_PENDING		0x00000002
4328  #define KVM_STATE_NESTED_EVMCS		0x00000004
4329
4330  #define KVM_STATE_NESTED_FORMAT_VMX		0
4331  #define KVM_STATE_NESTED_FORMAT_SVM		1
4332
4333  #define KVM_STATE_NESTED_VMX_VMCS_SIZE	0x1000
4334
4335  #define KVM_STATE_NESTED_VMX_SMM_GUEST_MODE	0x00000001
4336  #define KVM_STATE_NESTED_VMX_SMM_VMXON	0x00000002
4337
4338  #define KVM_STATE_VMX_PREEMPTION_TIMER_DEADLINE 0x00000001
4339
4340  struct kvm_vmx_nested_state_hdr {
4341	__u64 vmxon_pa;
4342	__u64 vmcs12_pa;
4343
4344	struct {
4345		__u16 flags;
4346	} smm;
4347
4348	__u32 flags;
4349	__u64 preemption_timer_deadline;
4350  };
4351
4352  struct kvm_vmx_nested_state_data {
4353	__u8 vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE];
4354	__u8 shadow_vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE];
4355  };
4356
4357This ioctl copies the vcpu's nested virtualization state from the kernel to
4358userspace.
4359
4360The maximum size of the state can be retrieved by passing KVM_CAP_NESTED_STATE
4361to the KVM_CHECK_EXTENSION ioctl().
4362
43634.115 KVM_SET_NESTED_STATE
4364--------------------------
4365
4366:Capability: KVM_CAP_NESTED_STATE
4367:Architectures: x86
4368:Type: vcpu ioctl
4369:Parameters: struct kvm_nested_state (in)
4370:Returns: 0 on success, -1 on error
4371
4372This copies the vcpu's kvm_nested_state struct from userspace to the kernel.
4373For the definition of struct kvm_nested_state, see KVM_GET_NESTED_STATE.
4374
43754.116 KVM_(UN)REGISTER_COALESCED_MMIO
4376-------------------------------------
4377
4378:Capability: KVM_CAP_COALESCED_MMIO (for coalesced mmio)
4379	     KVM_CAP_COALESCED_PIO (for coalesced pio)
4380:Architectures: all
4381:Type: vm ioctl
4382:Parameters: struct kvm_coalesced_mmio_zone
4383:Returns: 0 on success, < 0 on error
4384
4385Coalesced I/O is a performance optimization that defers hardware
4386register write emulation so that userspace exits are avoided.  It is
4387typically used to reduce the overhead of emulating frequently accessed
4388hardware registers.
4389
4390When a hardware register is configured for coalesced I/O, write accesses
4391do not exit to userspace and their value is recorded in a ring buffer
4392that is shared between kernel and userspace.
4393
4394Coalesced I/O is used if one or more write accesses to a hardware
4395register can be deferred until a read or a write to another hardware
4396register on the same device.  This last access will cause a vmexit and
4397userspace will process accesses from the ring buffer before emulating
4398it. That will avoid exiting to userspace on repeated writes.
4399
4400Coalesced pio is based on coalesced mmio. There is little difference
4401between coalesced mmio and pio except that coalesced pio records accesses
4402to I/O ports.
4403
44044.117 KVM_CLEAR_DIRTY_LOG (vm ioctl)
4405------------------------------------
4406
4407:Capability: KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2
4408:Architectures: x86, arm, arm64, mips
4409:Type: vm ioctl
4410:Parameters: struct kvm_clear_dirty_log (in)
4411:Returns: 0 on success, -1 on error
4412
4413::
4414
4415  /* for KVM_CLEAR_DIRTY_LOG */
4416  struct kvm_clear_dirty_log {
4417	__u32 slot;
4418	__u32 num_pages;
4419	__u64 first_page;
4420	union {
4421		void __user *dirty_bitmap; /* one bit per page */
4422		__u64 padding;
4423	};
4424  };
4425
4426The ioctl clears the dirty status of pages in a memory slot, according to
4427the bitmap that is passed in struct kvm_clear_dirty_log's dirty_bitmap
4428field.  Bit 0 of the bitmap corresponds to page "first_page" in the
4429memory slot, and num_pages is the size in bits of the input bitmap.
4430first_page must be a multiple of 64; num_pages must also be a multiple of
443164 unless first_page + num_pages is the size of the memory slot.  For each
4432bit that is set in the input bitmap, the corresponding page is marked "clean"
4433in KVM's dirty bitmap, and dirty tracking is re-enabled for that page
4434(for example via write-protection, or by clearing the dirty bit in
4435a page table entry).
4436
4437If KVM_CAP_MULTI_ADDRESS_SPACE is available, bits 16-31 of slot field specifies
4438the address space for which you want to clear the dirty status.  See
4439KVM_SET_USER_MEMORY_REGION for details on the usage of slot field.
4440
4441This ioctl is mostly useful when KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2
4442is enabled; for more information, see the description of the capability.
4443However, it can always be used as long as KVM_CHECK_EXTENSION confirms
4444that KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 is present.
4445
44464.118 KVM_GET_SUPPORTED_HV_CPUID
4447--------------------------------
4448
4449:Capability: KVM_CAP_HYPERV_CPUID (vcpu), KVM_CAP_SYS_HYPERV_CPUID (system)
4450:Architectures: x86
4451:Type: system ioctl, vcpu ioctl
4452:Parameters: struct kvm_cpuid2 (in/out)
4453:Returns: 0 on success, -1 on error
4454
4455::
4456
4457  struct kvm_cpuid2 {
4458	__u32 nent;
4459	__u32 padding;
4460	struct kvm_cpuid_entry2 entries[0];
4461  };
4462
4463  struct kvm_cpuid_entry2 {
4464	__u32 function;
4465	__u32 index;
4466	__u32 flags;
4467	__u32 eax;
4468	__u32 ebx;
4469	__u32 ecx;
4470	__u32 edx;
4471	__u32 padding[3];
4472  };
4473
4474This ioctl returns x86 cpuid features leaves related to Hyper-V emulation in
4475KVM.  Userspace can use the information returned by this ioctl to construct
4476cpuid information presented to guests consuming Hyper-V enlightenments (e.g.
4477Windows or Hyper-V guests).
4478
4479CPUID feature leaves returned by this ioctl are defined by Hyper-V Top Level
4480Functional Specification (TLFS). These leaves can't be obtained with
4481KVM_GET_SUPPORTED_CPUID ioctl because some of them intersect with KVM feature
4482leaves (0x40000000, 0x40000001).
4483
4484Currently, the following list of CPUID leaves are returned:
4485
4486 - HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS
4487 - HYPERV_CPUID_INTERFACE
4488 - HYPERV_CPUID_VERSION
4489 - HYPERV_CPUID_FEATURES
4490 - HYPERV_CPUID_ENLIGHTMENT_INFO
4491 - HYPERV_CPUID_IMPLEMENT_LIMITS
4492 - HYPERV_CPUID_NESTED_FEATURES
4493 - HYPERV_CPUID_SYNDBG_VENDOR_AND_MAX_FUNCTIONS
4494 - HYPERV_CPUID_SYNDBG_INTERFACE
4495 - HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES
4496
4497Userspace invokes KVM_GET_SUPPORTED_HV_CPUID by passing a kvm_cpuid2 structure
4498with the 'nent' field indicating the number of entries in the variable-size
4499array 'entries'.  If the number of entries is too low to describe all Hyper-V
4500feature leaves, an error (E2BIG) is returned. If the number is more or equal
4501to the number of Hyper-V feature leaves, the 'nent' field is adjusted to the
4502number of valid entries in the 'entries' array, which is then filled.
4503
4504'index' and 'flags' fields in 'struct kvm_cpuid_entry2' are currently reserved,
4505userspace should not expect to get any particular value there.
4506
4507Note, vcpu version of KVM_GET_SUPPORTED_HV_CPUID is currently deprecated. Unlike
4508system ioctl which exposes all supported feature bits unconditionally, vcpu
4509version has the following quirks:
4510
4511- HYPERV_CPUID_NESTED_FEATURES leaf and HV_X64_ENLIGHTENED_VMCS_RECOMMENDED
4512  feature bit are only exposed when Enlightened VMCS was previously enabled
4513  on the corresponding vCPU (KVM_CAP_HYPERV_ENLIGHTENED_VMCS).
4514- HV_STIMER_DIRECT_MODE_AVAILABLE bit is only exposed with in-kernel LAPIC.
4515  (presumes KVM_CREATE_IRQCHIP has already been called).
4516
45174.119 KVM_ARM_VCPU_FINALIZE
4518---------------------------
4519
4520:Architectures: arm, arm64
4521:Type: vcpu ioctl
4522:Parameters: int feature (in)
4523:Returns: 0 on success, -1 on error
4524
4525Errors:
4526
4527  ======     ==============================================================
4528  EPERM      feature not enabled, needs configuration, or already finalized
4529  EINVAL     feature unknown or not present
4530  ======     ==============================================================
4531
4532Recognised values for feature:
4533
4534  =====      ===========================================
4535  arm64      KVM_ARM_VCPU_SVE (requires KVM_CAP_ARM_SVE)
4536  =====      ===========================================
4537
4538Finalizes the configuration of the specified vcpu feature.
4539
4540The vcpu must already have been initialised, enabling the affected feature, by
4541means of a successful KVM_ARM_VCPU_INIT call with the appropriate flag set in
4542features[].
4543
4544For affected vcpu features, this is a mandatory step that must be performed
4545before the vcpu is fully usable.
4546
4547Between KVM_ARM_VCPU_INIT and KVM_ARM_VCPU_FINALIZE, the feature may be
4548configured by use of ioctls such as KVM_SET_ONE_REG.  The exact configuration
4549that should be performaned and how to do it are feature-dependent.
4550
4551Other calls that depend on a particular feature being finalized, such as
4552KVM_RUN, KVM_GET_REG_LIST, KVM_GET_ONE_REG and KVM_SET_ONE_REG, will fail with
4553-EPERM unless the feature has already been finalized by means of a
4554KVM_ARM_VCPU_FINALIZE call.
4555
4556See KVM_ARM_VCPU_INIT for details of vcpu features that require finalization
4557using this ioctl.
4558
45594.120 KVM_SET_PMU_EVENT_FILTER
4560------------------------------
4561
4562:Capability: KVM_CAP_PMU_EVENT_FILTER
4563:Architectures: x86
4564:Type: vm ioctl
4565:Parameters: struct kvm_pmu_event_filter (in)
4566:Returns: 0 on success, -1 on error
4567
4568::
4569
4570  struct kvm_pmu_event_filter {
4571	__u32 action;
4572	__u32 nevents;
4573	__u32 fixed_counter_bitmap;
4574	__u32 flags;
4575	__u32 pad[4];
4576	__u64 events[0];
4577  };
4578
4579This ioctl restricts the set of PMU events that the guest can program.
4580The argument holds a list of events which will be allowed or denied.
4581The eventsel+umask of each event the guest attempts to program is compared
4582against the events field to determine whether the guest should have access.
4583The events field only controls general purpose counters; fixed purpose
4584counters are controlled by the fixed_counter_bitmap.
4585
4586No flags are defined yet, the field must be zero.
4587
4588Valid values for 'action'::
4589
4590  #define KVM_PMU_EVENT_ALLOW 0
4591  #define KVM_PMU_EVENT_DENY 1
4592
45934.121 KVM_PPC_SVM_OFF
4594---------------------
4595
4596:Capability: basic
4597:Architectures: powerpc
4598:Type: vm ioctl
4599:Parameters: none
4600:Returns: 0 on successful completion,
4601
4602Errors:
4603
4604  ======     ================================================================
4605  EINVAL     if ultravisor failed to terminate the secure guest
4606  ENOMEM     if hypervisor failed to allocate new radix page tables for guest
4607  ======     ================================================================
4608
4609This ioctl is used to turn off the secure mode of the guest or transition
4610the guest from secure mode to normal mode. This is invoked when the guest
4611is reset. This has no effect if called for a normal guest.
4612
4613This ioctl issues an ultravisor call to terminate the secure guest,
4614unpins the VPA pages and releases all the device pages that are used to
4615track the secure pages by hypervisor.
4616
46174.122 KVM_S390_NORMAL_RESET
4618---------------------------
4619
4620:Capability: KVM_CAP_S390_VCPU_RESETS
4621:Architectures: s390
4622:Type: vcpu ioctl
4623:Parameters: none
4624:Returns: 0
4625
4626This ioctl resets VCPU registers and control structures according to
4627the cpu reset definition in the POP (Principles Of Operation).
4628
46294.123 KVM_S390_INITIAL_RESET
4630----------------------------
4631
4632:Capability: none
4633:Architectures: s390
4634:Type: vcpu ioctl
4635:Parameters: none
4636:Returns: 0
4637
4638This ioctl resets VCPU registers and control structures according to
4639the initial cpu reset definition in the POP. However, the cpu is not
4640put into ESA mode. This reset is a superset of the normal reset.
4641
46424.124 KVM_S390_CLEAR_RESET
4643--------------------------
4644
4645:Capability: KVM_CAP_S390_VCPU_RESETS
4646:Architectures: s390
4647:Type: vcpu ioctl
4648:Parameters: none
4649:Returns: 0
4650
4651This ioctl resets VCPU registers and control structures according to
4652the clear cpu reset definition in the POP. However, the cpu is not put
4653into ESA mode. This reset is a superset of the initial reset.
4654
4655
46564.125 KVM_S390_PV_COMMAND
4657-------------------------
4658
4659:Capability: KVM_CAP_S390_PROTECTED
4660:Architectures: s390
4661:Type: vm ioctl
4662:Parameters: struct kvm_pv_cmd
4663:Returns: 0 on success, < 0 on error
4664
4665::
4666
4667  struct kvm_pv_cmd {
4668	__u32 cmd;	/* Command to be executed */
4669	__u16 rc;	/* Ultravisor return code */
4670	__u16 rrc;	/* Ultravisor return reason code */
4671	__u64 data;	/* Data or address */
4672	__u32 flags;    /* flags for future extensions. Must be 0 for now */
4673	__u32 reserved[3];
4674  };
4675
4676cmd values:
4677
4678KVM_PV_ENABLE
4679  Allocate memory and register the VM with the Ultravisor, thereby
4680  donating memory to the Ultravisor that will become inaccessible to
4681  KVM. All existing CPUs are converted to protected ones. After this
4682  command has succeeded, any CPU added via hotplug will become
4683  protected during its creation as well.
4684
4685  Errors:
4686
4687  =====      =============================
4688  EINTR      an unmasked signal is pending
4689  =====      =============================
4690
4691KVM_PV_DISABLE
4692
4693  Deregister the VM from the Ultravisor and reclaim the memory that
4694  had been donated to the Ultravisor, making it usable by the kernel
4695  again.  All registered VCPUs are converted back to non-protected
4696  ones.
4697
4698KVM_PV_VM_SET_SEC_PARMS
4699  Pass the image header from VM memory to the Ultravisor in
4700  preparation of image unpacking and verification.
4701
4702KVM_PV_VM_UNPACK
4703  Unpack (protect and decrypt) a page of the encrypted boot image.
4704
4705KVM_PV_VM_VERIFY
4706  Verify the integrity of the unpacked image. Only if this succeeds,
4707  KVM is allowed to start protected VCPUs.
4708
47094.126 KVM_X86_SET_MSR_FILTER
4710----------------------------
4711
4712:Capability: KVM_X86_SET_MSR_FILTER
4713:Architectures: x86
4714:Type: vm ioctl
4715:Parameters: struct kvm_msr_filter
4716:Returns: 0 on success, < 0 on error
4717
4718::
4719
4720  struct kvm_msr_filter_range {
4721  #define KVM_MSR_FILTER_READ  (1 << 0)
4722  #define KVM_MSR_FILTER_WRITE (1 << 1)
4723	__u32 flags;
4724	__u32 nmsrs; /* number of msrs in bitmap */
4725	__u32 base;  /* MSR index the bitmap starts at */
4726	__u8 *bitmap; /* a 1 bit allows the operations in flags, 0 denies */
4727  };
4728
4729  #define KVM_MSR_FILTER_MAX_RANGES 16
4730  struct kvm_msr_filter {
4731  #define KVM_MSR_FILTER_DEFAULT_ALLOW (0 << 0)
4732  #define KVM_MSR_FILTER_DEFAULT_DENY  (1 << 0)
4733	__u32 flags;
4734	struct kvm_msr_filter_range ranges[KVM_MSR_FILTER_MAX_RANGES];
4735  };
4736
4737flags values for ``struct kvm_msr_filter_range``:
4738
4739``KVM_MSR_FILTER_READ``
4740
4741  Filter read accesses to MSRs using the given bitmap. A 0 in the bitmap
4742  indicates that a read should immediately fail, while a 1 indicates that
4743  a read for a particular MSR should be handled regardless of the default
4744  filter action.
4745
4746``KVM_MSR_FILTER_WRITE``
4747
4748  Filter write accesses to MSRs using the given bitmap. A 0 in the bitmap
4749  indicates that a write should immediately fail, while a 1 indicates that
4750  a write for a particular MSR should be handled regardless of the default
4751  filter action.
4752
4753``KVM_MSR_FILTER_READ | KVM_MSR_FILTER_WRITE``
4754
4755  Filter both read and write accesses to MSRs using the given bitmap. A 0
4756  in the bitmap indicates that both reads and writes should immediately fail,
4757  while a 1 indicates that reads and writes for a particular MSR are not
4758  filtered by this range.
4759
4760flags values for ``struct kvm_msr_filter``:
4761
4762``KVM_MSR_FILTER_DEFAULT_ALLOW``
4763
4764  If no filter range matches an MSR index that is getting accessed, KVM will
4765  fall back to allowing access to the MSR.
4766
4767``KVM_MSR_FILTER_DEFAULT_DENY``
4768
4769  If no filter range matches an MSR index that is getting accessed, KVM will
4770  fall back to rejecting access to the MSR. In this mode, all MSRs that should
4771  be processed by KVM need to explicitly be marked as allowed in the bitmaps.
4772
4773This ioctl allows user space to define up to 16 bitmaps of MSR ranges to
4774specify whether a certain MSR access should be explicitly filtered for or not.
4775
4776If this ioctl has never been invoked, MSR accesses are not guarded and the
4777default KVM in-kernel emulation behavior is fully preserved.
4778
4779Calling this ioctl with an empty set of ranges (all nmsrs == 0) disables MSR
4780filtering. In that mode, ``KVM_MSR_FILTER_DEFAULT_DENY`` is invalid and causes
4781an error.
4782
4783As soon as the filtering is in place, every MSR access is processed through
4784the filtering except for accesses to the x2APIC MSRs (from 0x800 to 0x8ff);
4785x2APIC MSRs are always allowed, independent of the ``default_allow`` setting,
4786and their behavior depends on the ``X2APIC_ENABLE`` bit of the APIC base
4787register.
4788
4789If a bit is within one of the defined ranges, read and write accesses are
4790guarded by the bitmap's value for the MSR index if the kind of access
4791is included in the ``struct kvm_msr_filter_range`` flags.  If no range
4792cover this particular access, the behavior is determined by the flags
4793field in the kvm_msr_filter struct: ``KVM_MSR_FILTER_DEFAULT_ALLOW``
4794and ``KVM_MSR_FILTER_DEFAULT_DENY``.
4795
4796Each bitmap range specifies a range of MSRs to potentially allow access on.
4797The range goes from MSR index [base .. base+nmsrs]. The flags field
4798indicates whether reads, writes or both reads and writes are filtered
4799by setting a 1 bit in the bitmap for the corresponding MSR index.
4800
4801If an MSR access is not permitted through the filtering, it generates a
4802#GP inside the guest. When combined with KVM_CAP_X86_USER_SPACE_MSR, that
4803allows user space to deflect and potentially handle various MSR accesses
4804into user space.
4805
4806If a vCPU is in running state while this ioctl is invoked, the vCPU may
4807experience inconsistent filtering behavior on MSR accesses.
4808
48094.127 KVM_XEN_HVM_SET_ATTR
4810--------------------------
4811
4812:Capability: KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_SHARED_INFO
4813:Architectures: x86
4814:Type: vm ioctl
4815:Parameters: struct kvm_xen_hvm_attr
4816:Returns: 0 on success, < 0 on error
4817
4818::
4819
4820  struct kvm_xen_hvm_attr {
4821	__u16 type;
4822	__u16 pad[3];
4823	union {
4824		__u8 long_mode;
4825		__u8 vector;
4826		struct {
4827			__u64 gfn;
4828		} shared_info;
4829		__u64 pad[4];
4830	} u;
4831  };
4832
4833type values:
4834
4835KVM_XEN_ATTR_TYPE_LONG_MODE
4836  Sets the ABI mode of the VM to 32-bit or 64-bit (long mode). This
4837  determines the layout of the shared info pages exposed to the VM.
4838
4839KVM_XEN_ATTR_TYPE_SHARED_INFO
4840  Sets the guest physical frame number at which the Xen "shared info"
4841  page resides. Note that although Xen places vcpu_info for the first
4842  32 vCPUs in the shared_info page, KVM does not automatically do so
4843  and instead requires that KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO be used
4844  explicitly even when the vcpu_info for a given vCPU resides at the
4845  "default" location in the shared_info page. This is because KVM is
4846  not aware of the Xen CPU id which is used as the index into the
4847  vcpu_info[] array, so cannot know the correct default location.
4848
4849KVM_XEN_ATTR_TYPE_UPCALL_VECTOR
4850  Sets the exception vector used to deliver Xen event channel upcalls.
4851
48524.128 KVM_XEN_HVM_GET_ATTR
4853--------------------------
4854
4855:Capability: KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_SHARED_INFO
4856:Architectures: x86
4857:Type: vm ioctl
4858:Parameters: struct kvm_xen_hvm_attr
4859:Returns: 0 on success, < 0 on error
4860
4861Allows Xen VM attributes to be read. For the structure and types,
4862see KVM_XEN_HVM_SET_ATTR above.
4863
48644.129 KVM_XEN_VCPU_SET_ATTR
4865---------------------------
4866
4867:Capability: KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_SHARED_INFO
4868:Architectures: x86
4869:Type: vcpu ioctl
4870:Parameters: struct kvm_xen_vcpu_attr
4871:Returns: 0 on success, < 0 on error
4872
4873::
4874
4875  struct kvm_xen_vcpu_attr {
4876	__u16 type;
4877	__u16 pad[3];
4878	union {
4879		__u64 gpa;
4880		__u64 pad[4];
4881		struct {
4882			__u64 state;
4883			__u64 state_entry_time;
4884			__u64 time_running;
4885			__u64 time_runnable;
4886			__u64 time_blocked;
4887			__u64 time_offline;
4888		} runstate;
4889	} u;
4890  };
4891
4892type values:
4893
4894KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO
4895  Sets the guest physical address of the vcpu_info for a given vCPU.
4896
4897KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO
4898  Sets the guest physical address of an additional pvclock structure
4899  for a given vCPU. This is typically used for guest vsyscall support.
4900
4901KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADDR
4902  Sets the guest physical address of the vcpu_runstate_info for a given
4903  vCPU. This is how a Xen guest tracks CPU state such as steal time.
4904
4905KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_CURRENT
4906  Sets the runstate (RUNSTATE_running/_runnable/_blocked/_offline) of
4907  the given vCPU from the .u.runstate.state member of the structure.
4908  KVM automatically accounts running and runnable time but blocked
4909  and offline states are only entered explicitly.
4910
4911KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_DATA
4912  Sets all fields of the vCPU runstate data from the .u.runstate member
4913  of the structure, including the current runstate. The state_entry_time
4914  must equal the sum of the other four times.
4915
4916KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADJUST
4917  This *adds* the contents of the .u.runstate members of the structure
4918  to the corresponding members of the given vCPU's runstate data, thus
4919  permitting atomic adjustments to the runstate times. The adjustment
4920  to the state_entry_time must equal the sum of the adjustments to the
4921  other four times. The state field must be set to -1, or to a valid
4922  runstate value (RUNSTATE_running, RUNSTATE_runnable, RUNSTATE_blocked
4923  or RUNSTATE_offline) to set the current accounted state as of the
4924  adjusted state_entry_time.
4925
49264.130 KVM_XEN_VCPU_GET_ATTR
4927---------------------------
4928
4929:Capability: KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_SHARED_INFO
4930:Architectures: x86
4931:Type: vcpu ioctl
4932:Parameters: struct kvm_xen_vcpu_attr
4933:Returns: 0 on success, < 0 on error
4934
4935Allows Xen vCPU attributes to be read. For the structure and types,
4936see KVM_XEN_VCPU_SET_ATTR above.
4937
4938The KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADJUST type may not be used
4939with the KVM_XEN_VCPU_GET_ATTR ioctl.
4940
49415. The kvm_run structure
4942========================
4943
4944Application code obtains a pointer to the kvm_run structure by
4945mmap()ing a vcpu fd.  From that point, application code can control
4946execution by changing fields in kvm_run prior to calling the KVM_RUN
4947ioctl, and obtain information about the reason KVM_RUN returned by
4948looking up structure members.
4949
4950::
4951
4952  struct kvm_run {
4953	/* in */
4954	__u8 request_interrupt_window;
4955
4956Request that KVM_RUN return when it becomes possible to inject external
4957interrupts into the guest.  Useful in conjunction with KVM_INTERRUPT.
4958
4959::
4960
4961	__u8 immediate_exit;
4962
4963This field is polled once when KVM_RUN starts; if non-zero, KVM_RUN
4964exits immediately, returning -EINTR.  In the common scenario where a
4965signal is used to "kick" a VCPU out of KVM_RUN, this field can be used
4966to avoid usage of KVM_SET_SIGNAL_MASK, which has worse scalability.
4967Rather than blocking the signal outside KVM_RUN, userspace can set up
4968a signal handler that sets run->immediate_exit to a non-zero value.
4969
4970This field is ignored if KVM_CAP_IMMEDIATE_EXIT is not available.
4971
4972::
4973
4974	__u8 padding1[6];
4975
4976	/* out */
4977	__u32 exit_reason;
4978
4979When KVM_RUN has returned successfully (return value 0), this informs
4980application code why KVM_RUN has returned.  Allowable values for this
4981field are detailed below.
4982
4983::
4984
4985	__u8 ready_for_interrupt_injection;
4986
4987If request_interrupt_window has been specified, this field indicates
4988an interrupt can be injected now with KVM_INTERRUPT.
4989
4990::
4991
4992	__u8 if_flag;
4993
4994The value of the current interrupt flag.  Only valid if in-kernel
4995local APIC is not used.
4996
4997::
4998
4999	__u16 flags;
5000
5001More architecture-specific flags detailing state of the VCPU that may
5002affect the device's behavior. Current defined flags::
5003
5004  /* x86, set if the VCPU is in system management mode */
5005  #define KVM_RUN_X86_SMM     (1 << 0)
5006  /* x86, set if bus lock detected in VM */
5007  #define KVM_RUN_BUS_LOCK    (1 << 1)
5008
5009::
5010
5011	/* in (pre_kvm_run), out (post_kvm_run) */
5012	__u64 cr8;
5013
5014The value of the cr8 register.  Only valid if in-kernel local APIC is
5015not used.  Both input and output.
5016
5017::
5018
5019	__u64 apic_base;
5020
5021The value of the APIC BASE msr.  Only valid if in-kernel local
5022APIC is not used.  Both input and output.
5023
5024::
5025
5026	union {
5027		/* KVM_EXIT_UNKNOWN */
5028		struct {
5029			__u64 hardware_exit_reason;
5030		} hw;
5031
5032If exit_reason is KVM_EXIT_UNKNOWN, the vcpu has exited due to unknown
5033reasons.  Further architecture-specific information is available in
5034hardware_exit_reason.
5035
5036::
5037
5038		/* KVM_EXIT_FAIL_ENTRY */
5039		struct {
5040			__u64 hardware_entry_failure_reason;
5041			__u32 cpu; /* if KVM_LAST_CPU */
5042		} fail_entry;
5043
5044If exit_reason is KVM_EXIT_FAIL_ENTRY, the vcpu could not be run due
5045to unknown reasons.  Further architecture-specific information is
5046available in hardware_entry_failure_reason.
5047
5048::
5049
5050		/* KVM_EXIT_EXCEPTION */
5051		struct {
5052			__u32 exception;
5053			__u32 error_code;
5054		} ex;
5055
5056Unused.
5057
5058::
5059
5060		/* KVM_EXIT_IO */
5061		struct {
5062  #define KVM_EXIT_IO_IN  0
5063  #define KVM_EXIT_IO_OUT 1
5064			__u8 direction;
5065			__u8 size; /* bytes */
5066			__u16 port;
5067			__u32 count;
5068			__u64 data_offset; /* relative to kvm_run start */
5069		} io;
5070
5071If exit_reason is KVM_EXIT_IO, then the vcpu has
5072executed a port I/O instruction which could not be satisfied by kvm.
5073data_offset describes where the data is located (KVM_EXIT_IO_OUT) or
5074where kvm expects application code to place the data for the next
5075KVM_RUN invocation (KVM_EXIT_IO_IN).  Data format is a packed array.
5076
5077::
5078
5079		/* KVM_EXIT_DEBUG */
5080		struct {
5081			struct kvm_debug_exit_arch arch;
5082		} debug;
5083
5084If the exit_reason is KVM_EXIT_DEBUG, then a vcpu is processing a debug event
5085for which architecture specific information is returned.
5086
5087::
5088
5089		/* KVM_EXIT_MMIO */
5090		struct {
5091			__u64 phys_addr;
5092			__u8  data[8];
5093			__u32 len;
5094			__u8  is_write;
5095		} mmio;
5096
5097If exit_reason is KVM_EXIT_MMIO, then the vcpu has
5098executed a memory-mapped I/O instruction which could not be satisfied
5099by kvm.  The 'data' member contains the written data if 'is_write' is
5100true, and should be filled by application code otherwise.
5101
5102The 'data' member contains, in its first 'len' bytes, the value as it would
5103appear if the VCPU performed a load or store of the appropriate width directly
5104to the byte array.
5105
5106.. note::
5107
5108      For KVM_EXIT_IO, KVM_EXIT_MMIO, KVM_EXIT_OSI, KVM_EXIT_PAPR, KVM_EXIT_XEN,
5109      KVM_EXIT_EPR, KVM_EXIT_X86_RDMSR and KVM_EXIT_X86_WRMSR the corresponding
5110      operations are complete (and guest state is consistent) only after userspace
5111      has re-entered the kernel with KVM_RUN.  The kernel side will first finish
5112      incomplete operations and then check for pending signals.
5113
5114      The pending state of the operation is not preserved in state which is
5115      visible to userspace, thus userspace should ensure that the operation is
5116      completed before performing a live migration.  Userspace can re-enter the
5117      guest with an unmasked signal pending or with the immediate_exit field set
5118      to complete pending operations without allowing any further instructions
5119      to be executed.
5120
5121::
5122
5123		/* KVM_EXIT_HYPERCALL */
5124		struct {
5125			__u64 nr;
5126			__u64 args[6];
5127			__u64 ret;
5128			__u32 longmode;
5129			__u32 pad;
5130		} hypercall;
5131
5132Unused.  This was once used for 'hypercall to userspace'.  To implement
5133such functionality, use KVM_EXIT_IO (x86) or KVM_EXIT_MMIO (all except s390).
5134
5135.. note:: KVM_EXIT_IO is significantly faster than KVM_EXIT_MMIO.
5136
5137::
5138
5139		/* KVM_EXIT_TPR_ACCESS */
5140		struct {
5141			__u64 rip;
5142			__u32 is_write;
5143			__u32 pad;
5144		} tpr_access;
5145
5146To be documented (KVM_TPR_ACCESS_REPORTING).
5147
5148::
5149
5150		/* KVM_EXIT_S390_SIEIC */
5151		struct {
5152			__u8 icptcode;
5153			__u64 mask; /* psw upper half */
5154			__u64 addr; /* psw lower half */
5155			__u16 ipa;
5156			__u32 ipb;
5157		} s390_sieic;
5158
5159s390 specific.
5160
5161::
5162
5163		/* KVM_EXIT_S390_RESET */
5164  #define KVM_S390_RESET_POR       1
5165  #define KVM_S390_RESET_CLEAR     2
5166  #define KVM_S390_RESET_SUBSYSTEM 4
5167  #define KVM_S390_RESET_CPU_INIT  8
5168  #define KVM_S390_RESET_IPL       16
5169		__u64 s390_reset_flags;
5170
5171s390 specific.
5172
5173::
5174
5175		/* KVM_EXIT_S390_UCONTROL */
5176		struct {
5177			__u64 trans_exc_code;
5178			__u32 pgm_code;
5179		} s390_ucontrol;
5180
5181s390 specific. A page fault has occurred for a user controlled virtual
5182machine (KVM_VM_S390_UNCONTROL) on it's host page table that cannot be
5183resolved by the kernel.
5184The program code and the translation exception code that were placed
5185in the cpu's lowcore are presented here as defined by the z Architecture
5186Principles of Operation Book in the Chapter for Dynamic Address Translation
5187(DAT)
5188
5189::
5190
5191		/* KVM_EXIT_DCR */
5192		struct {
5193			__u32 dcrn;
5194			__u32 data;
5195			__u8  is_write;
5196		} dcr;
5197
5198Deprecated - was used for 440 KVM.
5199
5200::
5201
5202		/* KVM_EXIT_OSI */
5203		struct {
5204			__u64 gprs[32];
5205		} osi;
5206
5207MOL uses a special hypercall interface it calls 'OSI'. To enable it, we catch
5208hypercalls and exit with this exit struct that contains all the guest gprs.
5209
5210If exit_reason is KVM_EXIT_OSI, then the vcpu has triggered such a hypercall.
5211Userspace can now handle the hypercall and when it's done modify the gprs as
5212necessary. Upon guest entry all guest GPRs will then be replaced by the values
5213in this struct.
5214
5215::
5216
5217		/* KVM_EXIT_PAPR_HCALL */
5218		struct {
5219			__u64 nr;
5220			__u64 ret;
5221			__u64 args[9];
5222		} papr_hcall;
5223
5224This is used on 64-bit PowerPC when emulating a pSeries partition,
5225e.g. with the 'pseries' machine type in qemu.  It occurs when the
5226guest does a hypercall using the 'sc 1' instruction.  The 'nr' field
5227contains the hypercall number (from the guest R3), and 'args' contains
5228the arguments (from the guest R4 - R12).  Userspace should put the
5229return code in 'ret' and any extra returned values in args[].
5230The possible hypercalls are defined in the Power Architecture Platform
5231Requirements (PAPR) document available from www.power.org (free
5232developer registration required to access it).
5233
5234::
5235
5236		/* KVM_EXIT_S390_TSCH */
5237		struct {
5238			__u16 subchannel_id;
5239			__u16 subchannel_nr;
5240			__u32 io_int_parm;
5241			__u32 io_int_word;
5242			__u32 ipb;
5243			__u8 dequeued;
5244		} s390_tsch;
5245
5246s390 specific. This exit occurs when KVM_CAP_S390_CSS_SUPPORT has been enabled
5247and TEST SUBCHANNEL was intercepted. If dequeued is set, a pending I/O
5248interrupt for the target subchannel has been dequeued and subchannel_id,
5249subchannel_nr, io_int_parm and io_int_word contain the parameters for that
5250interrupt. ipb is needed for instruction parameter decoding.
5251
5252::
5253
5254		/* KVM_EXIT_EPR */
5255		struct {
5256			__u32 epr;
5257		} epr;
5258
5259On FSL BookE PowerPC chips, the interrupt controller has a fast patch
5260interrupt acknowledge path to the core. When the core successfully
5261delivers an interrupt, it automatically populates the EPR register with
5262the interrupt vector number and acknowledges the interrupt inside
5263the interrupt controller.
5264
5265In case the interrupt controller lives in user space, we need to do
5266the interrupt acknowledge cycle through it to fetch the next to be
5267delivered interrupt vector using this exit.
5268
5269It gets triggered whenever both KVM_CAP_PPC_EPR are enabled and an
5270external interrupt has just been delivered into the guest. User space
5271should put the acknowledged interrupt vector into the 'epr' field.
5272
5273::
5274
5275		/* KVM_EXIT_SYSTEM_EVENT */
5276		struct {
5277  #define KVM_SYSTEM_EVENT_SHUTDOWN       1
5278  #define KVM_SYSTEM_EVENT_RESET          2
5279  #define KVM_SYSTEM_EVENT_CRASH          3
5280			__u32 type;
5281			__u64 flags;
5282		} system_event;
5283
5284If exit_reason is KVM_EXIT_SYSTEM_EVENT then the vcpu has triggered
5285a system-level event using some architecture specific mechanism (hypercall
5286or some special instruction). In case of ARM/ARM64, this is triggered using
5287HVC instruction based PSCI call from the vcpu. The 'type' field describes
5288the system-level event type. The 'flags' field describes architecture
5289specific flags for the system-level event.
5290
5291Valid values for 'type' are:
5292
5293 - KVM_SYSTEM_EVENT_SHUTDOWN -- the guest has requested a shutdown of the
5294   VM. Userspace is not obliged to honour this, and if it does honour
5295   this does not need to destroy the VM synchronously (ie it may call
5296   KVM_RUN again before shutdown finally occurs).
5297 - KVM_SYSTEM_EVENT_RESET -- the guest has requested a reset of the VM.
5298   As with SHUTDOWN, userspace can choose to ignore the request, or
5299   to schedule the reset to occur in the future and may call KVM_RUN again.
5300 - KVM_SYSTEM_EVENT_CRASH -- the guest crash occurred and the guest
5301   has requested a crash condition maintenance. Userspace can choose
5302   to ignore the request, or to gather VM memory core dump and/or
5303   reset/shutdown of the VM.
5304
5305::
5306
5307		/* KVM_EXIT_IOAPIC_EOI */
5308		struct {
5309			__u8 vector;
5310		} eoi;
5311
5312Indicates that the VCPU's in-kernel local APIC received an EOI for a
5313level-triggered IOAPIC interrupt.  This exit only triggers when the
5314IOAPIC is implemented in userspace (i.e. KVM_CAP_SPLIT_IRQCHIP is enabled);
5315the userspace IOAPIC should process the EOI and retrigger the interrupt if
5316it is still asserted.  Vector is the LAPIC interrupt vector for which the
5317EOI was received.
5318
5319::
5320
5321		struct kvm_hyperv_exit {
5322  #define KVM_EXIT_HYPERV_SYNIC          1
5323  #define KVM_EXIT_HYPERV_HCALL          2
5324  #define KVM_EXIT_HYPERV_SYNDBG         3
5325			__u32 type;
5326			__u32 pad1;
5327			union {
5328				struct {
5329					__u32 msr;
5330					__u32 pad2;
5331					__u64 control;
5332					__u64 evt_page;
5333					__u64 msg_page;
5334				} synic;
5335				struct {
5336					__u64 input;
5337					__u64 result;
5338					__u64 params[2];
5339				} hcall;
5340				struct {
5341					__u32 msr;
5342					__u32 pad2;
5343					__u64 control;
5344					__u64 status;
5345					__u64 send_page;
5346					__u64 recv_page;
5347					__u64 pending_page;
5348				} syndbg;
5349			} u;
5350		};
5351		/* KVM_EXIT_HYPERV */
5352                struct kvm_hyperv_exit hyperv;
5353
5354Indicates that the VCPU exits into userspace to process some tasks
5355related to Hyper-V emulation.
5356
5357Valid values for 'type' are:
5358
5359	- KVM_EXIT_HYPERV_SYNIC -- synchronously notify user-space about
5360
5361Hyper-V SynIC state change. Notification is used to remap SynIC
5362event/message pages and to enable/disable SynIC messages/events processing
5363in userspace.
5364
5365	- KVM_EXIT_HYPERV_SYNDBG -- synchronously notify user-space about
5366
5367Hyper-V Synthetic debugger state change. Notification is used to either update
5368the pending_page location or to send a control command (send the buffer located
5369in send_page or recv a buffer to recv_page).
5370
5371::
5372
5373		/* KVM_EXIT_ARM_NISV */
5374		struct {
5375			__u64 esr_iss;
5376			__u64 fault_ipa;
5377		} arm_nisv;
5378
5379Used on arm and arm64 systems. If a guest accesses memory not in a memslot,
5380KVM will typically return to userspace and ask it to do MMIO emulation on its
5381behalf. However, for certain classes of instructions, no instruction decode
5382(direction, length of memory access) is provided, and fetching and decoding
5383the instruction from the VM is overly complicated to live in the kernel.
5384
5385Historically, when this situation occurred, KVM would print a warning and kill
5386the VM. KVM assumed that if the guest accessed non-memslot memory, it was
5387trying to do I/O, which just couldn't be emulated, and the warning message was
5388phrased accordingly. However, what happened more often was that a guest bug
5389caused access outside the guest memory areas which should lead to a more
5390meaningful warning message and an external abort in the guest, if the access
5391did not fall within an I/O window.
5392
5393Userspace implementations can query for KVM_CAP_ARM_NISV_TO_USER, and enable
5394this capability at VM creation. Once this is done, these types of errors will
5395instead return to userspace with KVM_EXIT_ARM_NISV, with the valid bits from
5396the HSR (arm) and ESR_EL2 (arm64) in the esr_iss field, and the faulting IPA
5397in the fault_ipa field. Userspace can either fix up the access if it's
5398actually an I/O access by decoding the instruction from guest memory (if it's
5399very brave) and continue executing the guest, or it can decide to suspend,
5400dump, or restart the guest.
5401
5402Note that KVM does not skip the faulting instruction as it does for
5403KVM_EXIT_MMIO, but userspace has to emulate any change to the processing state
5404if it decides to decode and emulate the instruction.
5405
5406::
5407
5408		/* KVM_EXIT_X86_RDMSR / KVM_EXIT_X86_WRMSR */
5409		struct {
5410			__u8 error; /* user -> kernel */
5411			__u8 pad[7];
5412			__u32 reason; /* kernel -> user */
5413			__u32 index; /* kernel -> user */
5414			__u64 data; /* kernel <-> user */
5415		} msr;
5416
5417Used on x86 systems. When the VM capability KVM_CAP_X86_USER_SPACE_MSR is
5418enabled, MSR accesses to registers that would invoke a #GP by KVM kernel code
5419will instead trigger a KVM_EXIT_X86_RDMSR exit for reads and KVM_EXIT_X86_WRMSR
5420exit for writes.
5421
5422The "reason" field specifies why the MSR trap occurred. User space will only
5423receive MSR exit traps when a particular reason was requested during through
5424ENABLE_CAP. Currently valid exit reasons are:
5425
5426	KVM_MSR_EXIT_REASON_UNKNOWN - access to MSR that is unknown to KVM
5427	KVM_MSR_EXIT_REASON_INVAL - access to invalid MSRs or reserved bits
5428	KVM_MSR_EXIT_REASON_FILTER - access blocked by KVM_X86_SET_MSR_FILTER
5429
5430For KVM_EXIT_X86_RDMSR, the "index" field tells user space which MSR the guest
5431wants to read. To respond to this request with a successful read, user space
5432writes the respective data into the "data" field and must continue guest
5433execution to ensure the read data is transferred into guest register state.
5434
5435If the RDMSR request was unsuccessful, user space indicates that with a "1" in
5436the "error" field. This will inject a #GP into the guest when the VCPU is
5437executed again.
5438
5439For KVM_EXIT_X86_WRMSR, the "index" field tells user space which MSR the guest
5440wants to write. Once finished processing the event, user space must continue
5441vCPU execution. If the MSR write was unsuccessful, user space also sets the
5442"error" field to "1".
5443
5444::
5445
5446
5447		struct kvm_xen_exit {
5448  #define KVM_EXIT_XEN_HCALL          1
5449			__u32 type;
5450			union {
5451				struct {
5452					__u32 longmode;
5453					__u32 cpl;
5454					__u64 input;
5455					__u64 result;
5456					__u64 params[6];
5457				} hcall;
5458			} u;
5459		};
5460		/* KVM_EXIT_XEN */
5461                struct kvm_hyperv_exit xen;
5462
5463Indicates that the VCPU exits into userspace to process some tasks
5464related to Xen emulation.
5465
5466Valid values for 'type' are:
5467
5468  - KVM_EXIT_XEN_HCALL -- synchronously notify user-space about Xen hypercall.
5469    Userspace is expected to place the hypercall result into the appropriate
5470    field before invoking KVM_RUN again.
5471
5472::
5473
5474		/* Fix the size of the union. */
5475		char padding[256];
5476	};
5477
5478	/*
5479	 * shared registers between kvm and userspace.
5480	 * kvm_valid_regs specifies the register classes set by the host
5481	 * kvm_dirty_regs specified the register classes dirtied by userspace
5482	 * struct kvm_sync_regs is architecture specific, as well as the
5483	 * bits for kvm_valid_regs and kvm_dirty_regs
5484	 */
5485	__u64 kvm_valid_regs;
5486	__u64 kvm_dirty_regs;
5487	union {
5488		struct kvm_sync_regs regs;
5489		char padding[SYNC_REGS_SIZE_BYTES];
5490	} s;
5491
5492If KVM_CAP_SYNC_REGS is defined, these fields allow userspace to access
5493certain guest registers without having to call SET/GET_*REGS. Thus we can
5494avoid some system call overhead if userspace has to handle the exit.
5495Userspace can query the validity of the structure by checking
5496kvm_valid_regs for specific bits. These bits are architecture specific
5497and usually define the validity of a groups of registers. (e.g. one bit
5498for general purpose registers)
5499
5500Please note that the kernel is allowed to use the kvm_run structure as the
5501primary storage for certain register types. Therefore, the kernel may use the
5502values in kvm_run even if the corresponding bit in kvm_dirty_regs is not set.
5503
5504::
5505
5506  };
5507
5508
5509
55106. Capabilities that can be enabled on vCPUs
5511============================================
5512
5513There are certain capabilities that change the behavior of the virtual CPU or
5514the virtual machine when enabled. To enable them, please see section 4.37.
5515Below you can find a list of capabilities and what their effect on the vCPU or
5516the virtual machine is when enabling them.
5517
5518The following information is provided along with the description:
5519
5520  Architectures:
5521      which instruction set architectures provide this ioctl.
5522      x86 includes both i386 and x86_64.
5523
5524  Target:
5525      whether this is a per-vcpu or per-vm capability.
5526
5527  Parameters:
5528      what parameters are accepted by the capability.
5529
5530  Returns:
5531      the return value.  General error numbers (EBADF, ENOMEM, EINVAL)
5532      are not detailed, but errors with specific meanings are.
5533
5534
55356.1 KVM_CAP_PPC_OSI
5536-------------------
5537
5538:Architectures: ppc
5539:Target: vcpu
5540:Parameters: none
5541:Returns: 0 on success; -1 on error
5542
5543This capability enables interception of OSI hypercalls that otherwise would
5544be treated as normal system calls to be injected into the guest. OSI hypercalls
5545were invented by Mac-on-Linux to have a standardized communication mechanism
5546between the guest and the host.
5547
5548When this capability is enabled, KVM_EXIT_OSI can occur.
5549
5550
55516.2 KVM_CAP_PPC_PAPR
5552--------------------
5553
5554:Architectures: ppc
5555:Target: vcpu
5556:Parameters: none
5557:Returns: 0 on success; -1 on error
5558
5559This capability enables interception of PAPR hypercalls. PAPR hypercalls are
5560done using the hypercall instruction "sc 1".
5561
5562It also sets the guest privilege level to "supervisor" mode. Usually the guest
5563runs in "hypervisor" privilege mode with a few missing features.
5564
5565In addition to the above, it changes the semantics of SDR1. In this mode, the
5566HTAB address part of SDR1 contains an HVA instead of a GPA, as PAPR keeps the
5567HTAB invisible to the guest.
5568
5569When this capability is enabled, KVM_EXIT_PAPR_HCALL can occur.
5570
5571
55726.3 KVM_CAP_SW_TLB
5573------------------
5574
5575:Architectures: ppc
5576:Target: vcpu
5577:Parameters: args[0] is the address of a struct kvm_config_tlb
5578:Returns: 0 on success; -1 on error
5579
5580::
5581
5582  struct kvm_config_tlb {
5583	__u64 params;
5584	__u64 array;
5585	__u32 mmu_type;
5586	__u32 array_len;
5587  };
5588
5589Configures the virtual CPU's TLB array, establishing a shared memory area
5590between userspace and KVM.  The "params" and "array" fields are userspace
5591addresses of mmu-type-specific data structures.  The "array_len" field is an
5592safety mechanism, and should be set to the size in bytes of the memory that
5593userspace has reserved for the array.  It must be at least the size dictated
5594by "mmu_type" and "params".
5595
5596While KVM_RUN is active, the shared region is under control of KVM.  Its
5597contents are undefined, and any modification by userspace results in
5598boundedly undefined behavior.
5599
5600On return from KVM_RUN, the shared region will reflect the current state of
5601the guest's TLB.  If userspace makes any changes, it must call KVM_DIRTY_TLB
5602to tell KVM which entries have been changed, prior to calling KVM_RUN again
5603on this vcpu.
5604
5605For mmu types KVM_MMU_FSL_BOOKE_NOHV and KVM_MMU_FSL_BOOKE_HV:
5606
5607 - The "params" field is of type "struct kvm_book3e_206_tlb_params".
5608 - The "array" field points to an array of type "struct
5609   kvm_book3e_206_tlb_entry".
5610 - The array consists of all entries in the first TLB, followed by all
5611   entries in the second TLB.
5612 - Within a TLB, entries are ordered first by increasing set number.  Within a
5613   set, entries are ordered by way (increasing ESEL).
5614 - The hash for determining set number in TLB0 is: (MAS2 >> 12) & (num_sets - 1)
5615   where "num_sets" is the tlb_sizes[] value divided by the tlb_ways[] value.
5616 - The tsize field of mas1 shall be set to 4K on TLB0, even though the
5617   hardware ignores this value for TLB0.
5618
56196.4 KVM_CAP_S390_CSS_SUPPORT
5620----------------------------
5621
5622:Architectures: s390
5623:Target: vcpu
5624:Parameters: none
5625:Returns: 0 on success; -1 on error
5626
5627This capability enables support for handling of channel I/O instructions.
5628
5629TEST PENDING INTERRUPTION and the interrupt portion of TEST SUBCHANNEL are
5630handled in-kernel, while the other I/O instructions are passed to userspace.
5631
5632When this capability is enabled, KVM_EXIT_S390_TSCH will occur on TEST
5633SUBCHANNEL intercepts.
5634
5635Note that even though this capability is enabled per-vcpu, the complete
5636virtual machine is affected.
5637
56386.5 KVM_CAP_PPC_EPR
5639-------------------
5640
5641:Architectures: ppc
5642:Target: vcpu
5643:Parameters: args[0] defines whether the proxy facility is active
5644:Returns: 0 on success; -1 on error
5645
5646This capability enables or disables the delivery of interrupts through the
5647external proxy facility.
5648
5649When enabled (args[0] != 0), every time the guest gets an external interrupt
5650delivered, it automatically exits into user space with a KVM_EXIT_EPR exit
5651to receive the topmost interrupt vector.
5652
5653When disabled (args[0] == 0), behavior is as if this facility is unsupported.
5654
5655When this capability is enabled, KVM_EXIT_EPR can occur.
5656
56576.6 KVM_CAP_IRQ_MPIC
5658--------------------
5659
5660:Architectures: ppc
5661:Parameters: args[0] is the MPIC device fd;
5662             args[1] is the MPIC CPU number for this vcpu
5663
5664This capability connects the vcpu to an in-kernel MPIC device.
5665
56666.7 KVM_CAP_IRQ_XICS
5667--------------------
5668
5669:Architectures: ppc
5670:Target: vcpu
5671:Parameters: args[0] is the XICS device fd;
5672             args[1] is the XICS CPU number (server ID) for this vcpu
5673
5674This capability connects the vcpu to an in-kernel XICS device.
5675
56766.8 KVM_CAP_S390_IRQCHIP
5677------------------------
5678
5679:Architectures: s390
5680:Target: vm
5681:Parameters: none
5682
5683This capability enables the in-kernel irqchip for s390. Please refer to
5684"4.24 KVM_CREATE_IRQCHIP" for details.
5685
56866.9 KVM_CAP_MIPS_FPU
5687--------------------
5688
5689:Architectures: mips
5690:Target: vcpu
5691:Parameters: args[0] is reserved for future use (should be 0).
5692
5693This capability allows the use of the host Floating Point Unit by the guest. It
5694allows the Config1.FP bit to be set to enable the FPU in the guest. Once this is
5695done the ``KVM_REG_MIPS_FPR_*`` and ``KVM_REG_MIPS_FCR_*`` registers can be
5696accessed (depending on the current guest FPU register mode), and the Status.FR,
5697Config5.FRE bits are accessible via the KVM API and also from the guest,
5698depending on them being supported by the FPU.
5699
57006.10 KVM_CAP_MIPS_MSA
5701---------------------
5702
5703:Architectures: mips
5704:Target: vcpu
5705:Parameters: args[0] is reserved for future use (should be 0).
5706
5707This capability allows the use of the MIPS SIMD Architecture (MSA) by the guest.
5708It allows the Config3.MSAP bit to be set to enable the use of MSA by the guest.
5709Once this is done the ``KVM_REG_MIPS_VEC_*`` and ``KVM_REG_MIPS_MSA_*``
5710registers can be accessed, and the Config5.MSAEn bit is accessible via the
5711KVM API and also from the guest.
5712
57136.74 KVM_CAP_SYNC_REGS
5714----------------------
5715
5716:Architectures: s390, x86
5717:Target: s390: always enabled, x86: vcpu
5718:Parameters: none
5719:Returns: x86: KVM_CHECK_EXTENSION returns a bit-array indicating which register
5720          sets are supported
5721          (bitfields defined in arch/x86/include/uapi/asm/kvm.h).
5722
5723As described above in the kvm_sync_regs struct info in section 5 (kvm_run):
5724KVM_CAP_SYNC_REGS "allow[s] userspace to access certain guest registers
5725without having to call SET/GET_*REGS". This reduces overhead by eliminating
5726repeated ioctl calls for setting and/or getting register values. This is
5727particularly important when userspace is making synchronous guest state
5728modifications, e.g. when emulating and/or intercepting instructions in
5729userspace.
5730
5731For s390 specifics, please refer to the source code.
5732
5733For x86:
5734
5735- the register sets to be copied out to kvm_run are selectable
5736  by userspace (rather that all sets being copied out for every exit).
5737- vcpu_events are available in addition to regs and sregs.
5738
5739For x86, the 'kvm_valid_regs' field of struct kvm_run is overloaded to
5740function as an input bit-array field set by userspace to indicate the
5741specific register sets to be copied out on the next exit.
5742
5743To indicate when userspace has modified values that should be copied into
5744the vCPU, the all architecture bitarray field, 'kvm_dirty_regs' must be set.
5745This is done using the same bitflags as for the 'kvm_valid_regs' field.
5746If the dirty bit is not set, then the register set values will not be copied
5747into the vCPU even if they've been modified.
5748
5749Unused bitfields in the bitarrays must be set to zero.
5750
5751::
5752
5753  struct kvm_sync_regs {
5754        struct kvm_regs regs;
5755        struct kvm_sregs sregs;
5756        struct kvm_vcpu_events events;
5757  };
5758
57596.75 KVM_CAP_PPC_IRQ_XIVE
5760-------------------------
5761
5762:Architectures: ppc
5763:Target: vcpu
5764:Parameters: args[0] is the XIVE device fd;
5765             args[1] is the XIVE CPU number (server ID) for this vcpu
5766
5767This capability connects the vcpu to an in-kernel XIVE device.
5768
57697. Capabilities that can be enabled on VMs
5770==========================================
5771
5772There are certain capabilities that change the behavior of the virtual
5773machine when enabled. To enable them, please see section 4.37. Below
5774you can find a list of capabilities and what their effect on the VM
5775is when enabling them.
5776
5777The following information is provided along with the description:
5778
5779  Architectures:
5780      which instruction set architectures provide this ioctl.
5781      x86 includes both i386 and x86_64.
5782
5783  Parameters:
5784      what parameters are accepted by the capability.
5785
5786  Returns:
5787      the return value.  General error numbers (EBADF, ENOMEM, EINVAL)
5788      are not detailed, but errors with specific meanings are.
5789
5790
57917.1 KVM_CAP_PPC_ENABLE_HCALL
5792----------------------------
5793
5794:Architectures: ppc
5795:Parameters: args[0] is the sPAPR hcall number;
5796	     args[1] is 0 to disable, 1 to enable in-kernel handling
5797
5798This capability controls whether individual sPAPR hypercalls (hcalls)
5799get handled by the kernel or not.  Enabling or disabling in-kernel
5800handling of an hcall is effective across the VM.  On creation, an
5801initial set of hcalls are enabled for in-kernel handling, which
5802consists of those hcalls for which in-kernel handlers were implemented
5803before this capability was implemented.  If disabled, the kernel will
5804not to attempt to handle the hcall, but will always exit to userspace
5805to handle it.  Note that it may not make sense to enable some and
5806disable others of a group of related hcalls, but KVM does not prevent
5807userspace from doing that.
5808
5809If the hcall number specified is not one that has an in-kernel
5810implementation, the KVM_ENABLE_CAP ioctl will fail with an EINVAL
5811error.
5812
58137.2 KVM_CAP_S390_USER_SIGP
5814--------------------------
5815
5816:Architectures: s390
5817:Parameters: none
5818
5819This capability controls which SIGP orders will be handled completely in user
5820space. With this capability enabled, all fast orders will be handled completely
5821in the kernel:
5822
5823- SENSE
5824- SENSE RUNNING
5825- EXTERNAL CALL
5826- EMERGENCY SIGNAL
5827- CONDITIONAL EMERGENCY SIGNAL
5828
5829All other orders will be handled completely in user space.
5830
5831Only privileged operation exceptions will be checked for in the kernel (or even
5832in the hardware prior to interception). If this capability is not enabled, the
5833old way of handling SIGP orders is used (partially in kernel and user space).
5834
58357.3 KVM_CAP_S390_VECTOR_REGISTERS
5836---------------------------------
5837
5838:Architectures: s390
5839:Parameters: none
5840:Returns: 0 on success, negative value on error
5841
5842Allows use of the vector registers introduced with z13 processor, and
5843provides for the synchronization between host and user space.  Will
5844return -EINVAL if the machine does not support vectors.
5845
58467.4 KVM_CAP_S390_USER_STSI
5847--------------------------
5848
5849:Architectures: s390
5850:Parameters: none
5851
5852This capability allows post-handlers for the STSI instruction. After
5853initial handling in the kernel, KVM exits to user space with
5854KVM_EXIT_S390_STSI to allow user space to insert further data.
5855
5856Before exiting to userspace, kvm handlers should fill in s390_stsi field of
5857vcpu->run::
5858
5859  struct {
5860	__u64 addr;
5861	__u8 ar;
5862	__u8 reserved;
5863	__u8 fc;
5864	__u8 sel1;
5865	__u16 sel2;
5866  } s390_stsi;
5867
5868  @addr - guest address of STSI SYSIB
5869  @fc   - function code
5870  @sel1 - selector 1
5871  @sel2 - selector 2
5872  @ar   - access register number
5873
5874KVM handlers should exit to userspace with rc = -EREMOTE.
5875
58767.5 KVM_CAP_SPLIT_IRQCHIP
5877-------------------------
5878
5879:Architectures: x86
5880:Parameters: args[0] - number of routes reserved for userspace IOAPICs
5881:Returns: 0 on success, -1 on error
5882
5883Create a local apic for each processor in the kernel. This can be used
5884instead of KVM_CREATE_IRQCHIP if the userspace VMM wishes to emulate the
5885IOAPIC and PIC (and also the PIT, even though this has to be enabled
5886separately).
5887
5888This capability also enables in kernel routing of interrupt requests;
5889when KVM_CAP_SPLIT_IRQCHIP only routes of KVM_IRQ_ROUTING_MSI type are
5890used in the IRQ routing table.  The first args[0] MSI routes are reserved
5891for the IOAPIC pins.  Whenever the LAPIC receives an EOI for these routes,
5892a KVM_EXIT_IOAPIC_EOI vmexit will be reported to userspace.
5893
5894Fails if VCPU has already been created, or if the irqchip is already in the
5895kernel (i.e. KVM_CREATE_IRQCHIP has already been called).
5896
58977.6 KVM_CAP_S390_RI
5898-------------------
5899
5900:Architectures: s390
5901:Parameters: none
5902
5903Allows use of runtime-instrumentation introduced with zEC12 processor.
5904Will return -EINVAL if the machine does not support runtime-instrumentation.
5905Will return -EBUSY if a VCPU has already been created.
5906
59077.7 KVM_CAP_X2APIC_API
5908----------------------
5909
5910:Architectures: x86
5911:Parameters: args[0] - features that should be enabled
5912:Returns: 0 on success, -EINVAL when args[0] contains invalid features
5913
5914Valid feature flags in args[0] are::
5915
5916  #define KVM_X2APIC_API_USE_32BIT_IDS            (1ULL << 0)
5917  #define KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK  (1ULL << 1)
5918
5919Enabling KVM_X2APIC_API_USE_32BIT_IDS changes the behavior of
5920KVM_SET_GSI_ROUTING, KVM_SIGNAL_MSI, KVM_SET_LAPIC, and KVM_GET_LAPIC,
5921allowing the use of 32-bit APIC IDs.  See KVM_CAP_X2APIC_API in their
5922respective sections.
5923
5924KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK must be enabled for x2APIC to work
5925in logical mode or with more than 255 VCPUs.  Otherwise, KVM treats 0xff
5926as a broadcast even in x2APIC mode in order to support physical x2APIC
5927without interrupt remapping.  This is undesirable in logical mode,
5928where 0xff represents CPUs 0-7 in cluster 0.
5929
59307.8 KVM_CAP_S390_USER_INSTR0
5931----------------------------
5932
5933:Architectures: s390
5934:Parameters: none
5935
5936With this capability enabled, all illegal instructions 0x0000 (2 bytes) will
5937be intercepted and forwarded to user space. User space can use this
5938mechanism e.g. to realize 2-byte software breakpoints. The kernel will
5939not inject an operating exception for these instructions, user space has
5940to take care of that.
5941
5942This capability can be enabled dynamically even if VCPUs were already
5943created and are running.
5944
59457.9 KVM_CAP_S390_GS
5946-------------------
5947
5948:Architectures: s390
5949:Parameters: none
5950:Returns: 0 on success; -EINVAL if the machine does not support
5951          guarded storage; -EBUSY if a VCPU has already been created.
5952
5953Allows use of guarded storage for the KVM guest.
5954
59557.10 KVM_CAP_S390_AIS
5956---------------------
5957
5958:Architectures: s390
5959:Parameters: none
5960
5961Allow use of adapter-interruption suppression.
5962:Returns: 0 on success; -EBUSY if a VCPU has already been created.
5963
59647.11 KVM_CAP_PPC_SMT
5965--------------------
5966
5967:Architectures: ppc
5968:Parameters: vsmt_mode, flags
5969
5970Enabling this capability on a VM provides userspace with a way to set
5971the desired virtual SMT mode (i.e. the number of virtual CPUs per
5972virtual core).  The virtual SMT mode, vsmt_mode, must be a power of 2
5973between 1 and 8.  On POWER8, vsmt_mode must also be no greater than
5974the number of threads per subcore for the host.  Currently flags must
5975be 0.  A successful call to enable this capability will result in
5976vsmt_mode being returned when the KVM_CAP_PPC_SMT capability is
5977subsequently queried for the VM.  This capability is only supported by
5978HV KVM, and can only be set before any VCPUs have been created.
5979The KVM_CAP_PPC_SMT_POSSIBLE capability indicates which virtual SMT
5980modes are available.
5981
59827.12 KVM_CAP_PPC_FWNMI
5983----------------------
5984
5985:Architectures: ppc
5986:Parameters: none
5987
5988With this capability a machine check exception in the guest address
5989space will cause KVM to exit the guest with NMI exit reason. This
5990enables QEMU to build error log and branch to guest kernel registered
5991machine check handling routine. Without this capability KVM will
5992branch to guests' 0x200 interrupt vector.
5993
59947.13 KVM_CAP_X86_DISABLE_EXITS
5995------------------------------
5996
5997:Architectures: x86
5998:Parameters: args[0] defines which exits are disabled
5999:Returns: 0 on success, -EINVAL when args[0] contains invalid exits
6000
6001Valid bits in args[0] are::
6002
6003  #define KVM_X86_DISABLE_EXITS_MWAIT            (1 << 0)
6004  #define KVM_X86_DISABLE_EXITS_HLT              (1 << 1)
6005  #define KVM_X86_DISABLE_EXITS_PAUSE            (1 << 2)
6006  #define KVM_X86_DISABLE_EXITS_CSTATE           (1 << 3)
6007
6008Enabling this capability on a VM provides userspace with a way to no
6009longer intercept some instructions for improved latency in some
6010workloads, and is suggested when vCPUs are associated to dedicated
6011physical CPUs.  More bits can be added in the future; userspace can
6012just pass the KVM_CHECK_EXTENSION result to KVM_ENABLE_CAP to disable
6013all such vmexits.
6014
6015Do not enable KVM_FEATURE_PV_UNHALT if you disable HLT exits.
6016
60177.14 KVM_CAP_S390_HPAGE_1M
6018--------------------------
6019
6020:Architectures: s390
6021:Parameters: none
6022:Returns: 0 on success, -EINVAL if hpage module parameter was not set
6023	  or cmma is enabled, or the VM has the KVM_VM_S390_UCONTROL
6024	  flag set
6025
6026With this capability the KVM support for memory backing with 1m pages
6027through hugetlbfs can be enabled for a VM. After the capability is
6028enabled, cmma can't be enabled anymore and pfmfi and the storage key
6029interpretation are disabled. If cmma has already been enabled or the
6030hpage module parameter is not set to 1, -EINVAL is returned.
6031
6032While it is generally possible to create a huge page backed VM without
6033this capability, the VM will not be able to run.
6034
60357.15 KVM_CAP_MSR_PLATFORM_INFO
6036------------------------------
6037
6038:Architectures: x86
6039:Parameters: args[0] whether feature should be enabled or not
6040
6041With this capability, a guest may read the MSR_PLATFORM_INFO MSR. Otherwise,
6042a #GP would be raised when the guest tries to access. Currently, this
6043capability does not enable write permissions of this MSR for the guest.
6044
60457.16 KVM_CAP_PPC_NESTED_HV
6046--------------------------
6047
6048:Architectures: ppc
6049:Parameters: none
6050:Returns: 0 on success, -EINVAL when the implementation doesn't support
6051	  nested-HV virtualization.
6052
6053HV-KVM on POWER9 and later systems allows for "nested-HV"
6054virtualization, which provides a way for a guest VM to run guests that
6055can run using the CPU's supervisor mode (privileged non-hypervisor
6056state).  Enabling this capability on a VM depends on the CPU having
6057the necessary functionality and on the facility being enabled with a
6058kvm-hv module parameter.
6059
60607.17 KVM_CAP_EXCEPTION_PAYLOAD
6061------------------------------
6062
6063:Architectures: x86
6064:Parameters: args[0] whether feature should be enabled or not
6065
6066With this capability enabled, CR2 will not be modified prior to the
6067emulated VM-exit when L1 intercepts a #PF exception that occurs in
6068L2. Similarly, for kvm-intel only, DR6 will not be modified prior to
6069the emulated VM-exit when L1 intercepts a #DB exception that occurs in
6070L2. As a result, when KVM_GET_VCPU_EVENTS reports a pending #PF (or
6071#DB) exception for L2, exception.has_payload will be set and the
6072faulting address (or the new DR6 bits*) will be reported in the
6073exception_payload field. Similarly, when userspace injects a #PF (or
6074#DB) into L2 using KVM_SET_VCPU_EVENTS, it is expected to set
6075exception.has_payload and to put the faulting address - or the new DR6
6076bits\ [#]_ - in the exception_payload field.
6077
6078This capability also enables exception.pending in struct
6079kvm_vcpu_events, which allows userspace to distinguish between pending
6080and injected exceptions.
6081
6082
6083.. [#] For the new DR6 bits, note that bit 16 is set iff the #DB exception
6084       will clear DR6.RTM.
6085
60867.18 KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2
6087
6088:Architectures: x86, arm, arm64, mips
6089:Parameters: args[0] whether feature should be enabled or not
6090
6091Valid flags are::
6092
6093  #define KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE   (1 << 0)
6094  #define KVM_DIRTY_LOG_INITIALLY_SET           (1 << 1)
6095
6096With KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE is set, KVM_GET_DIRTY_LOG will not
6097automatically clear and write-protect all pages that are returned as dirty.
6098Rather, userspace will have to do this operation separately using
6099KVM_CLEAR_DIRTY_LOG.
6100
6101At the cost of a slightly more complicated operation, this provides better
6102scalability and responsiveness for two reasons.  First,
6103KVM_CLEAR_DIRTY_LOG ioctl can operate on a 64-page granularity rather
6104than requiring to sync a full memslot; this ensures that KVM does not
6105take spinlocks for an extended period of time.  Second, in some cases a
6106large amount of time can pass between a call to KVM_GET_DIRTY_LOG and
6107userspace actually using the data in the page.  Pages can be modified
6108during this time, which is inefficient for both the guest and userspace:
6109the guest will incur a higher penalty due to write protection faults,
6110while userspace can see false reports of dirty pages.  Manual reprotection
6111helps reducing this time, improving guest performance and reducing the
6112number of dirty log false positives.
6113
6114With KVM_DIRTY_LOG_INITIALLY_SET set, all the bits of the dirty bitmap
6115will be initialized to 1 when created.  This also improves performance because
6116dirty logging can be enabled gradually in small chunks on the first call
6117to KVM_CLEAR_DIRTY_LOG.  KVM_DIRTY_LOG_INITIALLY_SET depends on
6118KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE (it is also only available on
6119x86 and arm64 for now).
6120
6121KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 was previously available under the name
6122KVM_CAP_MANUAL_DIRTY_LOG_PROTECT, but the implementation had bugs that make
6123it hard or impossible to use it correctly.  The availability of
6124KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 signals that those bugs are fixed.
6125Userspace should not try to use KVM_CAP_MANUAL_DIRTY_LOG_PROTECT.
6126
61277.19 KVM_CAP_PPC_SECURE_GUEST
6128------------------------------
6129
6130:Architectures: ppc
6131
6132This capability indicates that KVM is running on a host that has
6133ultravisor firmware and thus can support a secure guest.  On such a
6134system, a guest can ask the ultravisor to make it a secure guest,
6135one whose memory is inaccessible to the host except for pages which
6136are explicitly requested to be shared with the host.  The ultravisor
6137notifies KVM when a guest requests to become a secure guest, and KVM
6138has the opportunity to veto the transition.
6139
6140If present, this capability can be enabled for a VM, meaning that KVM
6141will allow the transition to secure guest mode.  Otherwise KVM will
6142veto the transition.
6143
61447.20 KVM_CAP_HALT_POLL
6145----------------------
6146
6147:Architectures: all
6148:Target: VM
6149:Parameters: args[0] is the maximum poll time in nanoseconds
6150:Returns: 0 on success; -1 on error
6151
6152This capability overrides the kvm module parameter halt_poll_ns for the
6153target VM.
6154
6155VCPU polling allows a VCPU to poll for wakeup events instead of immediately
6156scheduling during guest halts. The maximum time a VCPU can spend polling is
6157controlled by the kvm module parameter halt_poll_ns. This capability allows
6158the maximum halt time to specified on a per-VM basis, effectively overriding
6159the module parameter for the target VM.
6160
61617.21 KVM_CAP_X86_USER_SPACE_MSR
6162-------------------------------
6163
6164:Architectures: x86
6165:Target: VM
6166:Parameters: args[0] contains the mask of KVM_MSR_EXIT_REASON_* events to report
6167:Returns: 0 on success; -1 on error
6168
6169This capability enables trapping of #GP invoking RDMSR and WRMSR instructions
6170into user space.
6171
6172When a guest requests to read or write an MSR, KVM may not implement all MSRs
6173that are relevant to a respective system. It also does not differentiate by
6174CPU type.
6175
6176To allow more fine grained control over MSR handling, user space may enable
6177this capability. With it enabled, MSR accesses that match the mask specified in
6178args[0] and trigger a #GP event inside the guest by KVM will instead trigger
6179KVM_EXIT_X86_RDMSR and KVM_EXIT_X86_WRMSR exit notifications which user space
6180can then handle to implement model specific MSR handling and/or user notifications
6181to inform a user that an MSR was not handled.
6182
61837.22 KVM_CAP_X86_BUS_LOCK_EXIT
6184-------------------------------
6185
6186:Architectures: x86
6187:Target: VM
6188:Parameters: args[0] defines the policy used when bus locks detected in guest
6189:Returns: 0 on success, -EINVAL when args[0] contains invalid bits
6190
6191Valid bits in args[0] are::
6192
6193  #define KVM_BUS_LOCK_DETECTION_OFF      (1 << 0)
6194  #define KVM_BUS_LOCK_DETECTION_EXIT     (1 << 1)
6195
6196Enabling this capability on a VM provides userspace with a way to select
6197a policy to handle the bus locks detected in guest. Userspace can obtain
6198the supported modes from the result of KVM_CHECK_EXTENSION and define it
6199through the KVM_ENABLE_CAP.
6200
6201KVM_BUS_LOCK_DETECTION_OFF and KVM_BUS_LOCK_DETECTION_EXIT are supported
6202currently and mutually exclusive with each other. More bits can be added in
6203the future.
6204
6205With KVM_BUS_LOCK_DETECTION_OFF set, bus locks in guest will not cause vm exits
6206so that no additional actions are needed. This is the default mode.
6207
6208With KVM_BUS_LOCK_DETECTION_EXIT set, vm exits happen when bus lock detected
6209in VM. KVM just exits to userspace when handling them. Userspace can enforce
6210its own throttling or other policy based mitigations.
6211
6212This capability is aimed to address the thread that VM can exploit bus locks to
6213degree the performance of the whole system. Once the userspace enable this
6214capability and select the KVM_BUS_LOCK_DETECTION_EXIT mode, KVM will set the
6215KVM_RUN_BUS_LOCK flag in vcpu-run->flags field and exit to userspace. Concerning
6216the bus lock vm exit can be preempted by a higher priority VM exit, the exit
6217notifications to userspace can be KVM_EXIT_BUS_LOCK or other reasons.
6218KVM_RUN_BUS_LOCK flag is used to distinguish between them.
6219
62207.23 KVM_CAP_PPC_DAWR1
6221----------------------
6222
6223:Architectures: ppc
6224:Parameters: none
6225:Returns: 0 on success, -EINVAL when CPU doesn't support 2nd DAWR
6226
6227This capability can be used to check / enable 2nd DAWR feature provided
6228by POWER10 processor.
6229
62308. Other capabilities.
6231======================
6232
6233This section lists capabilities that give information about other
6234features of the KVM implementation.
6235
62368.1 KVM_CAP_PPC_HWRNG
6237---------------------
6238
6239:Architectures: ppc
6240
6241This capability, if KVM_CHECK_EXTENSION indicates that it is
6242available, means that the kernel has an implementation of the
6243H_RANDOM hypercall backed by a hardware random-number generator.
6244If present, the kernel H_RANDOM handler can be enabled for guest use
6245with the KVM_CAP_PPC_ENABLE_HCALL capability.
6246
62478.2 KVM_CAP_HYPERV_SYNIC
6248------------------------
6249
6250:Architectures: x86
6251
6252This capability, if KVM_CHECK_EXTENSION indicates that it is
6253available, means that the kernel has an implementation of the
6254Hyper-V Synthetic interrupt controller(SynIC). Hyper-V SynIC is
6255used to support Windows Hyper-V based guest paravirt drivers(VMBus).
6256
6257In order to use SynIC, it has to be activated by setting this
6258capability via KVM_ENABLE_CAP ioctl on the vcpu fd. Note that this
6259will disable the use of APIC hardware virtualization even if supported
6260by the CPU, as it's incompatible with SynIC auto-EOI behavior.
6261
62628.3 KVM_CAP_PPC_RADIX_MMU
6263-------------------------
6264
6265:Architectures: ppc
6266
6267This capability, if KVM_CHECK_EXTENSION indicates that it is
6268available, means that the kernel can support guests using the
6269radix MMU defined in Power ISA V3.00 (as implemented in the POWER9
6270processor).
6271
62728.4 KVM_CAP_PPC_HASH_MMU_V3
6273---------------------------
6274
6275:Architectures: ppc
6276
6277This capability, if KVM_CHECK_EXTENSION indicates that it is
6278available, means that the kernel can support guests using the
6279hashed page table MMU defined in Power ISA V3.00 (as implemented in
6280the POWER9 processor), including in-memory segment tables.
6281
62828.5 KVM_CAP_MIPS_VZ
6283-------------------
6284
6285:Architectures: mips
6286
6287This capability, if KVM_CHECK_EXTENSION on the main kvm handle indicates that
6288it is available, means that full hardware assisted virtualization capabilities
6289of the hardware are available for use through KVM. An appropriate
6290KVM_VM_MIPS_* type must be passed to KVM_CREATE_VM to create a VM which
6291utilises it.
6292
6293If KVM_CHECK_EXTENSION on a kvm VM handle indicates that this capability is
6294available, it means that the VM is using full hardware assisted virtualization
6295capabilities of the hardware. This is useful to check after creating a VM with
6296KVM_VM_MIPS_DEFAULT.
6297
6298The value returned by KVM_CHECK_EXTENSION should be compared against known
6299values (see below). All other values are reserved. This is to allow for the
6300possibility of other hardware assisted virtualization implementations which
6301may be incompatible with the MIPS VZ ASE.
6302
6303==  ==========================================================================
6304 0  The trap & emulate implementation is in use to run guest code in user
6305    mode. Guest virtual memory segments are rearranged to fit the guest in the
6306    user mode address space.
6307
6308 1  The MIPS VZ ASE is in use, providing full hardware assisted
6309    virtualization, including standard guest virtual memory segments.
6310==  ==========================================================================
6311
63128.6 KVM_CAP_MIPS_TE
6313-------------------
6314
6315:Architectures: mips
6316
6317This capability, if KVM_CHECK_EXTENSION on the main kvm handle indicates that
6318it is available, means that the trap & emulate implementation is available to
6319run guest code in user mode, even if KVM_CAP_MIPS_VZ indicates that hardware
6320assisted virtualisation is also available. KVM_VM_MIPS_TE (0) must be passed
6321to KVM_CREATE_VM to create a VM which utilises it.
6322
6323If KVM_CHECK_EXTENSION on a kvm VM handle indicates that this capability is
6324available, it means that the VM is using trap & emulate.
6325
63268.7 KVM_CAP_MIPS_64BIT
6327----------------------
6328
6329:Architectures: mips
6330
6331This capability indicates the supported architecture type of the guest, i.e. the
6332supported register and address width.
6333
6334The values returned when this capability is checked by KVM_CHECK_EXTENSION on a
6335kvm VM handle correspond roughly to the CP0_Config.AT register field, and should
6336be checked specifically against known values (see below). All other values are
6337reserved.
6338
6339==  ========================================================================
6340 0  MIPS32 or microMIPS32.
6341    Both registers and addresses are 32-bits wide.
6342    It will only be possible to run 32-bit guest code.
6343
6344 1  MIPS64 or microMIPS64 with access only to 32-bit compatibility segments.
6345    Registers are 64-bits wide, but addresses are 32-bits wide.
6346    64-bit guest code may run but cannot access MIPS64 memory segments.
6347    It will also be possible to run 32-bit guest code.
6348
6349 2  MIPS64 or microMIPS64 with access to all address segments.
6350    Both registers and addresses are 64-bits wide.
6351    It will be possible to run 64-bit or 32-bit guest code.
6352==  ========================================================================
6353
63548.9 KVM_CAP_ARM_USER_IRQ
6355------------------------
6356
6357:Architectures: arm, arm64
6358
6359This capability, if KVM_CHECK_EXTENSION indicates that it is available, means
6360that if userspace creates a VM without an in-kernel interrupt controller, it
6361will be notified of changes to the output level of in-kernel emulated devices,
6362which can generate virtual interrupts, presented to the VM.
6363For such VMs, on every return to userspace, the kernel
6364updates the vcpu's run->s.regs.device_irq_level field to represent the actual
6365output level of the device.
6366
6367Whenever kvm detects a change in the device output level, kvm guarantees at
6368least one return to userspace before running the VM.  This exit could either
6369be a KVM_EXIT_INTR or any other exit event, like KVM_EXIT_MMIO. This way,
6370userspace can always sample the device output level and re-compute the state of
6371the userspace interrupt controller.  Userspace should always check the state
6372of run->s.regs.device_irq_level on every kvm exit.
6373The value in run->s.regs.device_irq_level can represent both level and edge
6374triggered interrupt signals, depending on the device.  Edge triggered interrupt
6375signals will exit to userspace with the bit in run->s.regs.device_irq_level
6376set exactly once per edge signal.
6377
6378The field run->s.regs.device_irq_level is available independent of
6379run->kvm_valid_regs or run->kvm_dirty_regs bits.
6380
6381If KVM_CAP_ARM_USER_IRQ is supported, the KVM_CHECK_EXTENSION ioctl returns a
6382number larger than 0 indicating the version of this capability is implemented
6383and thereby which bits in run->s.regs.device_irq_level can signal values.
6384
6385Currently the following bits are defined for the device_irq_level bitmap::
6386
6387  KVM_CAP_ARM_USER_IRQ >= 1:
6388
6389    KVM_ARM_DEV_EL1_VTIMER -  EL1 virtual timer
6390    KVM_ARM_DEV_EL1_PTIMER -  EL1 physical timer
6391    KVM_ARM_DEV_PMU        -  ARM PMU overflow interrupt signal
6392
6393Future versions of kvm may implement additional events. These will get
6394indicated by returning a higher number from KVM_CHECK_EXTENSION and will be
6395listed above.
6396
63978.10 KVM_CAP_PPC_SMT_POSSIBLE
6398-----------------------------
6399
6400:Architectures: ppc
6401
6402Querying this capability returns a bitmap indicating the possible
6403virtual SMT modes that can be set using KVM_CAP_PPC_SMT.  If bit N
6404(counting from the right) is set, then a virtual SMT mode of 2^N is
6405available.
6406
64078.11 KVM_CAP_HYPERV_SYNIC2
6408--------------------------
6409
6410:Architectures: x86
6411
6412This capability enables a newer version of Hyper-V Synthetic interrupt
6413controller (SynIC).  The only difference with KVM_CAP_HYPERV_SYNIC is that KVM
6414doesn't clear SynIC message and event flags pages when they are enabled by
6415writing to the respective MSRs.
6416
64178.12 KVM_CAP_HYPERV_VP_INDEX
6418----------------------------
6419
6420:Architectures: x86
6421
6422This capability indicates that userspace can load HV_X64_MSR_VP_INDEX msr.  Its
6423value is used to denote the target vcpu for a SynIC interrupt.  For
6424compatibilty, KVM initializes this msr to KVM's internal vcpu index.  When this
6425capability is absent, userspace can still query this msr's value.
6426
64278.13 KVM_CAP_S390_AIS_MIGRATION
6428-------------------------------
6429
6430:Architectures: s390
6431:Parameters: none
6432
6433This capability indicates if the flic device will be able to get/set the
6434AIS states for migration via the KVM_DEV_FLIC_AISM_ALL attribute and allows
6435to discover this without having to create a flic device.
6436
64378.14 KVM_CAP_S390_PSW
6438---------------------
6439
6440:Architectures: s390
6441
6442This capability indicates that the PSW is exposed via the kvm_run structure.
6443
64448.15 KVM_CAP_S390_GMAP
6445----------------------
6446
6447:Architectures: s390
6448
6449This capability indicates that the user space memory used as guest mapping can
6450be anywhere in the user memory address space, as long as the memory slots are
6451aligned and sized to a segment (1MB) boundary.
6452
64538.16 KVM_CAP_S390_COW
6454---------------------
6455
6456:Architectures: s390
6457
6458This capability indicates that the user space memory used as guest mapping can
6459use copy-on-write semantics as well as dirty pages tracking via read-only page
6460tables.
6461
64628.17 KVM_CAP_S390_BPB
6463---------------------
6464
6465:Architectures: s390
6466
6467This capability indicates that kvm will implement the interfaces to handle
6468reset, migration and nested KVM for branch prediction blocking. The stfle
6469facility 82 should not be provided to the guest without this capability.
6470
64718.18 KVM_CAP_HYPERV_TLBFLUSH
6472----------------------------
6473
6474:Architectures: x86
6475
6476This capability indicates that KVM supports paravirtualized Hyper-V TLB Flush
6477hypercalls:
6478HvFlushVirtualAddressSpace, HvFlushVirtualAddressSpaceEx,
6479HvFlushVirtualAddressList, HvFlushVirtualAddressListEx.
6480
64818.19 KVM_CAP_ARM_INJECT_SERROR_ESR
6482----------------------------------
6483
6484:Architectures: arm, arm64
6485
6486This capability indicates that userspace can specify (via the
6487KVM_SET_VCPU_EVENTS ioctl) the syndrome value reported to the guest when it
6488takes a virtual SError interrupt exception.
6489If KVM advertises this capability, userspace can only specify the ISS field for
6490the ESR syndrome. Other parts of the ESR, such as the EC are generated by the
6491CPU when the exception is taken. If this virtual SError is taken to EL1 using
6492AArch64, this value will be reported in the ISS field of ESR_ELx.
6493
6494See KVM_CAP_VCPU_EVENTS for more details.
6495
64968.20 KVM_CAP_HYPERV_SEND_IPI
6497----------------------------
6498
6499:Architectures: x86
6500
6501This capability indicates that KVM supports paravirtualized Hyper-V IPI send
6502hypercalls:
6503HvCallSendSyntheticClusterIpi, HvCallSendSyntheticClusterIpiEx.
6504
65058.21 KVM_CAP_HYPERV_DIRECT_TLBFLUSH
6506-----------------------------------
6507
6508:Architectures: x86
6509
6510This capability indicates that KVM running on top of Hyper-V hypervisor
6511enables Direct TLB flush for its guests meaning that TLB flush
6512hypercalls are handled by Level 0 hypervisor (Hyper-V) bypassing KVM.
6513Due to the different ABI for hypercall parameters between Hyper-V and
6514KVM, enabling this capability effectively disables all hypercall
6515handling by KVM (as some KVM hypercall may be mistakenly treated as TLB
6516flush hypercalls by Hyper-V) so userspace should disable KVM identification
6517in CPUID and only exposes Hyper-V identification. In this case, guest
6518thinks it's running on Hyper-V and only use Hyper-V hypercalls.
6519
65208.22 KVM_CAP_S390_VCPU_RESETS
6521-----------------------------
6522
6523:Architectures: s390
6524
6525This capability indicates that the KVM_S390_NORMAL_RESET and
6526KVM_S390_CLEAR_RESET ioctls are available.
6527
65288.23 KVM_CAP_S390_PROTECTED
6529---------------------------
6530
6531:Architectures: s390
6532
6533This capability indicates that the Ultravisor has been initialized and
6534KVM can therefore start protected VMs.
6535This capability governs the KVM_S390_PV_COMMAND ioctl and the
6536KVM_MP_STATE_LOAD MP_STATE. KVM_SET_MP_STATE can fail for protected
6537guests when the state change is invalid.
6538
65398.24 KVM_CAP_STEAL_TIME
6540-----------------------
6541
6542:Architectures: arm64, x86
6543
6544This capability indicates that KVM supports steal time accounting.
6545When steal time accounting is supported it may be enabled with
6546architecture-specific interfaces.  This capability and the architecture-
6547specific interfaces must be consistent, i.e. if one says the feature
6548is supported, than the other should as well and vice versa.  For arm64
6549see Documentation/virt/kvm/devices/vcpu.rst "KVM_ARM_VCPU_PVTIME_CTRL".
6550For x86 see Documentation/virt/kvm/msr.rst "MSR_KVM_STEAL_TIME".
6551
65528.25 KVM_CAP_S390_DIAG318
6553-------------------------
6554
6555:Architectures: s390
6556
6557This capability enables a guest to set information about its control program
6558(i.e. guest kernel type and version). The information is helpful during
6559system/firmware service events, providing additional data about the guest
6560environments running on the machine.
6561
6562The information is associated with the DIAGNOSE 0x318 instruction, which sets
6563an 8-byte value consisting of a one-byte Control Program Name Code (CPNC) and
6564a 7-byte Control Program Version Code (CPVC). The CPNC determines what
6565environment the control program is running in (e.g. Linux, z/VM...), and the
6566CPVC is used for information specific to OS (e.g. Linux version, Linux
6567distribution...)
6568
6569If this capability is available, then the CPNC and CPVC can be synchronized
6570between KVM and userspace via the sync regs mechanism (KVM_SYNC_DIAG318).
6571
65728.26 KVM_CAP_X86_USER_SPACE_MSR
6573-------------------------------
6574
6575:Architectures: x86
6576
6577This capability indicates that KVM supports deflection of MSR reads and
6578writes to user space. It can be enabled on a VM level. If enabled, MSR
6579accesses that would usually trigger a #GP by KVM into the guest will
6580instead get bounced to user space through the KVM_EXIT_X86_RDMSR and
6581KVM_EXIT_X86_WRMSR exit notifications.
6582
65838.27 KVM_X86_SET_MSR_FILTER
6584---------------------------
6585
6586:Architectures: x86
6587
6588This capability indicates that KVM supports that accesses to user defined MSRs
6589may be rejected. With this capability exposed, KVM exports new VM ioctl
6590KVM_X86_SET_MSR_FILTER which user space can call to specify bitmaps of MSR
6591ranges that KVM should reject access to.
6592
6593In combination with KVM_CAP_X86_USER_SPACE_MSR, this allows user space to
6594trap and emulate MSRs that are outside of the scope of KVM as well as
6595limit the attack surface on KVM's MSR emulation code.
6596
65978.28 KVM_CAP_ENFORCE_PV_CPUID
6598-----------------------------
6599
6600Architectures: x86
6601
6602When enabled, KVM will disable paravirtual features provided to the
6603guest according to the bits in the KVM_CPUID_FEATURES CPUID leaf
6604(0x40000001). Otherwise, a guest may use the paravirtual features
6605regardless of what has actually been exposed through the CPUID leaf.
6606
66078.29 KVM_CAP_DIRTY_LOG_RING
6608---------------------------
6609
6610:Architectures: x86
6611:Parameters: args[0] - size of the dirty log ring
6612
6613KVM is capable of tracking dirty memory using ring buffers that are
6614mmaped into userspace; there is one dirty ring per vcpu.
6615
6616The dirty ring is available to userspace as an array of
6617``struct kvm_dirty_gfn``.  Each dirty entry it's defined as::
6618
6619  struct kvm_dirty_gfn {
6620          __u32 flags;
6621          __u32 slot; /* as_id | slot_id */
6622          __u64 offset;
6623  };
6624
6625The following values are defined for the flags field to define the
6626current state of the entry::
6627
6628  #define KVM_DIRTY_GFN_F_DIRTY           BIT(0)
6629  #define KVM_DIRTY_GFN_F_RESET           BIT(1)
6630  #define KVM_DIRTY_GFN_F_MASK            0x3
6631
6632Userspace should call KVM_ENABLE_CAP ioctl right after KVM_CREATE_VM
6633ioctl to enable this capability for the new guest and set the size of
6634the rings.  Enabling the capability is only allowed before creating any
6635vCPU, and the size of the ring must be a power of two.  The larger the
6636ring buffer, the less likely the ring is full and the VM is forced to
6637exit to userspace. The optimal size depends on the workload, but it is
6638recommended that it be at least 64 KiB (4096 entries).
6639
6640Just like for dirty page bitmaps, the buffer tracks writes to
6641all user memory regions for which the KVM_MEM_LOG_DIRTY_PAGES flag was
6642set in KVM_SET_USER_MEMORY_REGION.  Once a memory region is registered
6643with the flag set, userspace can start harvesting dirty pages from the
6644ring buffer.
6645
6646An entry in the ring buffer can be unused (flag bits ``00``),
6647dirty (flag bits ``01``) or harvested (flag bits ``1X``).  The
6648state machine for the entry is as follows::
6649
6650          dirtied         harvested        reset
6651     00 -----------> 01 -------------> 1X -------+
6652      ^                                          |
6653      |                                          |
6654      +------------------------------------------+
6655
6656To harvest the dirty pages, userspace accesses the mmaped ring buffer
6657to read the dirty GFNs.  If the flags has the DIRTY bit set (at this stage
6658the RESET bit must be cleared), then it means this GFN is a dirty GFN.
6659The userspace should harvest this GFN and mark the flags from state
6660``01b`` to ``1Xb`` (bit 0 will be ignored by KVM, but bit 1 must be set
6661to show that this GFN is harvested and waiting for a reset), and move
6662on to the next GFN.  The userspace should continue to do this until the
6663flags of a GFN have the DIRTY bit cleared, meaning that it has harvested
6664all the dirty GFNs that were available.
6665
6666It's not necessary for userspace to harvest the all dirty GFNs at once.
6667However it must collect the dirty GFNs in sequence, i.e., the userspace
6668program cannot skip one dirty GFN to collect the one next to it.
6669
6670After processing one or more entries in the ring buffer, userspace
6671calls the VM ioctl KVM_RESET_DIRTY_RINGS to notify the kernel about
6672it, so that the kernel will reprotect those collected GFNs.
6673Therefore, the ioctl must be called *before* reading the content of
6674the dirty pages.
6675
6676The dirty ring can get full.  When it happens, the KVM_RUN of the
6677vcpu will return with exit reason KVM_EXIT_DIRTY_LOG_FULL.
6678
6679The dirty ring interface has a major difference comparing to the
6680KVM_GET_DIRTY_LOG interface in that, when reading the dirty ring from
6681userspace, it's still possible that the kernel has not yet flushed the
6682processor's dirty page buffers into the kernel buffer (with dirty bitmaps, the
6683flushing is done by the KVM_GET_DIRTY_LOG ioctl).  To achieve that, one
6684needs to kick the vcpu out of KVM_RUN using a signal.  The resulting
6685vmexit ensures that all dirty GFNs are flushed to the dirty rings.
6686
6687NOTE: the capability KVM_CAP_DIRTY_LOG_RING and the corresponding
6688ioctl KVM_RESET_DIRTY_RINGS are mutual exclusive to the existing ioctls
6689KVM_GET_DIRTY_LOG and KVM_CLEAR_DIRTY_LOG.  After enabling
6690KVM_CAP_DIRTY_LOG_RING with an acceptable dirty ring size, the virtual
6691machine will switch to ring-buffer dirty page tracking and further
6692KVM_GET_DIRTY_LOG or KVM_CLEAR_DIRTY_LOG ioctls will fail.
6693
66948.30 KVM_CAP_XEN_HVM
6695--------------------
6696
6697:Architectures: x86
6698
6699This capability indicates the features that Xen supports for hosting Xen
6700PVHVM guests. Valid flags are::
6701
6702  #define KVM_XEN_HVM_CONFIG_HYPERCALL_MSR	(1 << 0)
6703  #define KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL	(1 << 1)
6704  #define KVM_XEN_HVM_CONFIG_SHARED_INFO	(1 << 2)
6705  #define KVM_XEN_HVM_CONFIG_RUNSTATE		(1 << 2)
6706
6707The KVM_XEN_HVM_CONFIG_HYPERCALL_MSR flag indicates that the KVM_XEN_HVM_CONFIG
6708ioctl is available, for the guest to set its hypercall page.
6709
6710If KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL is also set, the same flag may also be
6711provided in the flags to KVM_XEN_HVM_CONFIG, without providing hypercall page
6712contents, to request that KVM generate hypercall page content automatically
6713and also enable interception of guest hypercalls with KVM_EXIT_XEN.
6714
6715The KVM_XEN_HVM_CONFIG_SHARED_INFO flag indicates the availability of the
6716KVM_XEN_HVM_SET_ATTR, KVM_XEN_HVM_GET_ATTR, KVM_XEN_VCPU_SET_ATTR and
6717KVM_XEN_VCPU_GET_ATTR ioctls, as well as the delivery of exception vectors
6718for event channel upcalls when the evtchn_upcall_pending field of a vcpu's
6719vcpu_info is set.
6720
6721The KVM_XEN_HVM_CONFIG_RUNSTATE flag indicates that the runstate-related
6722features KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADDR/_CURRENT/_DATA/_ADJUST are
6723supported by the KVM_XEN_VCPU_SET_ATTR/KVM_XEN_VCPU_GET_ATTR ioctls.
6724