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 }; 962 963 9644.29 KVM_GET_CLOCK 965------------------ 966 967:Capability: KVM_CAP_ADJUST_CLOCK 968:Architectures: x86 969:Type: vm ioctl 970:Parameters: struct kvm_clock_data (out) 971:Returns: 0 on success, -1 on error 972 973Gets the current timestamp of kvmclock as seen by the current guest. In 974conjunction with KVM_SET_CLOCK, it is used to ensure monotonicity on scenarios 975such as migration. 976 977When KVM_CAP_ADJUST_CLOCK is passed to KVM_CHECK_EXTENSION, it returns the 978set of bits that KVM can return in struct kvm_clock_data's flag member. 979 980The only flag defined now is KVM_CLOCK_TSC_STABLE. If set, the returned 981value is the exact kvmclock value seen by all VCPUs at the instant 982when KVM_GET_CLOCK was called. If clear, the returned value is simply 983CLOCK_MONOTONIC plus a constant offset; the offset can be modified 984with KVM_SET_CLOCK. KVM will try to make all VCPUs follow this clock, 985but the exact value read by each VCPU could differ, because the host 986TSC is not stable. 987 988:: 989 990 struct kvm_clock_data { 991 __u64 clock; /* kvmclock current value */ 992 __u32 flags; 993 __u32 pad[9]; 994 }; 995 996 9974.30 KVM_SET_CLOCK 998------------------ 999 1000:Capability: KVM_CAP_ADJUST_CLOCK 1001:Architectures: x86 1002:Type: vm ioctl 1003:Parameters: struct kvm_clock_data (in) 1004:Returns: 0 on success, -1 on error 1005 1006Sets the current timestamp of kvmclock to the value specified in its parameter. 1007In conjunction with KVM_GET_CLOCK, it is used to ensure monotonicity on scenarios 1008such as migration. 1009 1010:: 1011 1012 struct kvm_clock_data { 1013 __u64 clock; /* kvmclock current value */ 1014 __u32 flags; 1015 __u32 pad[9]; 1016 }; 1017 1018 10194.31 KVM_GET_VCPU_EVENTS 1020------------------------ 1021 1022:Capability: KVM_CAP_VCPU_EVENTS 1023:Extended by: KVM_CAP_INTR_SHADOW 1024:Architectures: x86, arm, arm64 1025:Type: vcpu ioctl 1026:Parameters: struct kvm_vcpu_event (out) 1027:Returns: 0 on success, -1 on error 1028 1029X86: 1030^^^^ 1031 1032Gets currently pending exceptions, interrupts, and NMIs as well as related 1033states of the vcpu. 1034 1035:: 1036 1037 struct kvm_vcpu_events { 1038 struct { 1039 __u8 injected; 1040 __u8 nr; 1041 __u8 has_error_code; 1042 __u8 pending; 1043 __u32 error_code; 1044 } exception; 1045 struct { 1046 __u8 injected; 1047 __u8 nr; 1048 __u8 soft; 1049 __u8 shadow; 1050 } interrupt; 1051 struct { 1052 __u8 injected; 1053 __u8 pending; 1054 __u8 masked; 1055 __u8 pad; 1056 } nmi; 1057 __u32 sipi_vector; 1058 __u32 flags; 1059 struct { 1060 __u8 smm; 1061 __u8 pending; 1062 __u8 smm_inside_nmi; 1063 __u8 latched_init; 1064 } smi; 1065 __u8 reserved[27]; 1066 __u8 exception_has_payload; 1067 __u64 exception_payload; 1068 }; 1069 1070The following bits are defined in the flags field: 1071 1072- KVM_VCPUEVENT_VALID_SHADOW may be set to signal that 1073 interrupt.shadow contains a valid state. 1074 1075- KVM_VCPUEVENT_VALID_SMM may be set to signal that smi contains a 1076 valid state. 1077 1078- KVM_VCPUEVENT_VALID_PAYLOAD may be set to signal that the 1079 exception_has_payload, exception_payload, and exception.pending 1080 fields contain a valid state. This bit will be set whenever 1081 KVM_CAP_EXCEPTION_PAYLOAD is enabled. 1082 1083ARM/ARM64: 1084^^^^^^^^^^ 1085 1086If the guest accesses a device that is being emulated by the host kernel in 1087such a way that a real device would generate a physical SError, KVM may make 1088a virtual SError pending for that VCPU. This system error interrupt remains 1089pending until the guest takes the exception by unmasking PSTATE.A. 1090 1091Running the VCPU may cause it to take a pending SError, or make an access that 1092causes an SError to become pending. The event's description is only valid while 1093the VPCU is not running. 1094 1095This API provides a way to read and write the pending 'event' state that is not 1096visible to the guest. To save, restore or migrate a VCPU the struct representing 1097the state can be read then written using this GET/SET API, along with the other 1098guest-visible registers. It is not possible to 'cancel' an SError that has been 1099made pending. 1100 1101A device being emulated in user-space may also wish to generate an SError. To do 1102this the events structure can be populated by user-space. The current state 1103should be read first, to ensure no existing SError is pending. If an existing 1104SError is pending, the architecture's 'Multiple SError interrupts' rules should 1105be followed. (2.5.3 of DDI0587.a "ARM Reliability, Availability, and 1106Serviceability (RAS) Specification"). 1107 1108SError exceptions always have an ESR value. Some CPUs have the ability to 1109specify what the virtual SError's ESR value should be. These systems will 1110advertise KVM_CAP_ARM_INJECT_SERROR_ESR. In this case exception.has_esr will 1111always have a non-zero value when read, and the agent making an SError pending 1112should specify the ISS field in the lower 24 bits of exception.serror_esr. If 1113the system supports KVM_CAP_ARM_INJECT_SERROR_ESR, but user-space sets the events 1114with exception.has_esr as zero, KVM will choose an ESR. 1115 1116Specifying exception.has_esr on a system that does not support it will return 1117-EINVAL. Setting anything other than the lower 24bits of exception.serror_esr 1118will return -EINVAL. 1119 1120It is not possible to read back a pending external abort (injected via 1121KVM_SET_VCPU_EVENTS or otherwise) because such an exception is always delivered 1122directly to the virtual CPU). 1123 1124:: 1125 1126 struct kvm_vcpu_events { 1127 struct { 1128 __u8 serror_pending; 1129 __u8 serror_has_esr; 1130 __u8 ext_dabt_pending; 1131 /* Align it to 8 bytes */ 1132 __u8 pad[5]; 1133 __u64 serror_esr; 1134 } exception; 1135 __u32 reserved[12]; 1136 }; 1137 11384.32 KVM_SET_VCPU_EVENTS 1139------------------------ 1140 1141:Capability: KVM_CAP_VCPU_EVENTS 1142:Extended by: KVM_CAP_INTR_SHADOW 1143:Architectures: x86, arm, arm64 1144:Type: vcpu ioctl 1145:Parameters: struct kvm_vcpu_event (in) 1146:Returns: 0 on success, -1 on error 1147 1148X86: 1149^^^^ 1150 1151Set pending exceptions, interrupts, and NMIs as well as related states of the 1152vcpu. 1153 1154See KVM_GET_VCPU_EVENTS for the data structure. 1155 1156Fields that may be modified asynchronously by running VCPUs can be excluded 1157from the update. These fields are nmi.pending, sipi_vector, smi.smm, 1158smi.pending. Keep the corresponding bits in the flags field cleared to 1159suppress overwriting the current in-kernel state. The bits are: 1160 1161=============================== ================================== 1162KVM_VCPUEVENT_VALID_NMI_PENDING transfer nmi.pending to the kernel 1163KVM_VCPUEVENT_VALID_SIPI_VECTOR transfer sipi_vector 1164KVM_VCPUEVENT_VALID_SMM transfer the smi sub-struct. 1165=============================== ================================== 1166 1167If KVM_CAP_INTR_SHADOW is available, KVM_VCPUEVENT_VALID_SHADOW can be set in 1168the flags field to signal that interrupt.shadow contains a valid state and 1169shall be written into the VCPU. 1170 1171KVM_VCPUEVENT_VALID_SMM can only be set if KVM_CAP_X86_SMM is available. 1172 1173If KVM_CAP_EXCEPTION_PAYLOAD is enabled, KVM_VCPUEVENT_VALID_PAYLOAD 1174can be set in the flags field to signal that the 1175exception_has_payload, exception_payload, and exception.pending fields 1176contain a valid state and shall be written into the VCPU. 1177 1178ARM/ARM64: 1179^^^^^^^^^^ 1180 1181User space may need to inject several types of events to the guest. 1182 1183Set the pending SError exception state for this VCPU. It is not possible to 1184'cancel' an Serror that has been made pending. 1185 1186If the guest performed an access to I/O memory which could not be handled by 1187userspace, for example because of missing instruction syndrome decode 1188information or because there is no device mapped at the accessed IPA, then 1189userspace can ask the kernel to inject an external abort using the address 1190from the exiting fault on the VCPU. It is a programming error to set 1191ext_dabt_pending after an exit which was not either KVM_EXIT_MMIO or 1192KVM_EXIT_ARM_NISV. This feature is only available if the system supports 1193KVM_CAP_ARM_INJECT_EXT_DABT. This is a helper which provides commonality in 1194how userspace reports accesses for the above cases to guests, across different 1195userspace implementations. Nevertheless, userspace can still emulate all Arm 1196exceptions by manipulating individual registers using the KVM_SET_ONE_REG API. 1197 1198See KVM_GET_VCPU_EVENTS for the data structure. 1199 1200 12014.33 KVM_GET_DEBUGREGS 1202---------------------- 1203 1204:Capability: KVM_CAP_DEBUGREGS 1205:Architectures: x86 1206:Type: vm ioctl 1207:Parameters: struct kvm_debugregs (out) 1208:Returns: 0 on success, -1 on error 1209 1210Reads debug registers from the vcpu. 1211 1212:: 1213 1214 struct kvm_debugregs { 1215 __u64 db[4]; 1216 __u64 dr6; 1217 __u64 dr7; 1218 __u64 flags; 1219 __u64 reserved[9]; 1220 }; 1221 1222 12234.34 KVM_SET_DEBUGREGS 1224---------------------- 1225 1226:Capability: KVM_CAP_DEBUGREGS 1227:Architectures: x86 1228:Type: vm ioctl 1229:Parameters: struct kvm_debugregs (in) 1230:Returns: 0 on success, -1 on error 1231 1232Writes debug registers into the vcpu. 1233 1234See KVM_GET_DEBUGREGS for the data structure. The flags field is unused 1235yet and must be cleared on entry. 1236 1237 12384.35 KVM_SET_USER_MEMORY_REGION 1239------------------------------- 1240 1241:Capability: KVM_CAP_USER_MEMORY 1242:Architectures: all 1243:Type: vm ioctl 1244:Parameters: struct kvm_userspace_memory_region (in) 1245:Returns: 0 on success, -1 on error 1246 1247:: 1248 1249 struct kvm_userspace_memory_region { 1250 __u32 slot; 1251 __u32 flags; 1252 __u64 guest_phys_addr; 1253 __u64 memory_size; /* bytes */ 1254 __u64 userspace_addr; /* start of the userspace allocated memory */ 1255 }; 1256 1257 /* for kvm_memory_region::flags */ 1258 #define KVM_MEM_LOG_DIRTY_PAGES (1UL << 0) 1259 #define KVM_MEM_READONLY (1UL << 1) 1260 1261This ioctl allows the user to create, modify or delete a guest physical 1262memory slot. Bits 0-15 of "slot" specify the slot id and this value 1263should be less than the maximum number of user memory slots supported per 1264VM. The maximum allowed slots can be queried using KVM_CAP_NR_MEMSLOTS. 1265Slots may not overlap in guest physical address space. 1266 1267If KVM_CAP_MULTI_ADDRESS_SPACE is available, bits 16-31 of "slot" 1268specifies the address space which is being modified. They must be 1269less than the value that KVM_CHECK_EXTENSION returns for the 1270KVM_CAP_MULTI_ADDRESS_SPACE capability. Slots in separate address spaces 1271are unrelated; the restriction on overlapping slots only applies within 1272each address space. 1273 1274Deleting a slot is done by passing zero for memory_size. When changing 1275an existing slot, it may be moved in the guest physical memory space, 1276or its flags may be modified, but it may not be resized. 1277 1278Memory for the region is taken starting at the address denoted by the 1279field userspace_addr, which must point at user addressable memory for 1280the entire memory slot size. Any object may back this memory, including 1281anonymous memory, ordinary files, and hugetlbfs. 1282 1283On architectures that support a form of address tagging, userspace_addr must 1284be an untagged address. 1285 1286It is recommended that the lower 21 bits of guest_phys_addr and userspace_addr 1287be identical. This allows large pages in the guest to be backed by large 1288pages in the host. 1289 1290The flags field supports two flags: KVM_MEM_LOG_DIRTY_PAGES and 1291KVM_MEM_READONLY. The former can be set to instruct KVM to keep track of 1292writes to memory within the slot. See KVM_GET_DIRTY_LOG ioctl to know how to 1293use it. The latter can be set, if KVM_CAP_READONLY_MEM capability allows it, 1294to make a new slot read-only. In this case, writes to this memory will be 1295posted to userspace as KVM_EXIT_MMIO exits. 1296 1297When the KVM_CAP_SYNC_MMU capability is available, changes in the backing of 1298the memory region are automatically reflected into the guest. For example, an 1299mmap() that affects the region will be made visible immediately. Another 1300example is madvise(MADV_DROP). 1301 1302It is recommended to use this API instead of the KVM_SET_MEMORY_REGION ioctl. 1303The KVM_SET_MEMORY_REGION does not allow fine grained control over memory 1304allocation and is deprecated. 1305 1306 13074.36 KVM_SET_TSS_ADDR 1308--------------------- 1309 1310:Capability: KVM_CAP_SET_TSS_ADDR 1311:Architectures: x86 1312:Type: vm ioctl 1313:Parameters: unsigned long tss_address (in) 1314:Returns: 0 on success, -1 on error 1315 1316This ioctl defines the physical address of a three-page region in the guest 1317physical address space. The region must be within the first 4GB of the 1318guest physical address space and must not conflict with any memory slot 1319or any mmio address. The guest may malfunction if it accesses this memory 1320region. 1321 1322This ioctl is required on Intel-based hosts. This is needed on Intel hardware 1323because of a quirk in the virtualization implementation (see the internals 1324documentation when it pops into existence). 1325 1326 13274.37 KVM_ENABLE_CAP 1328------------------- 1329 1330:Capability: KVM_CAP_ENABLE_CAP 1331:Architectures: mips, ppc, s390 1332:Type: vcpu ioctl 1333:Parameters: struct kvm_enable_cap (in) 1334:Returns: 0 on success; -1 on error 1335 1336:Capability: KVM_CAP_ENABLE_CAP_VM 1337:Architectures: all 1338:Type: vm ioctl 1339:Parameters: struct kvm_enable_cap (in) 1340:Returns: 0 on success; -1 on error 1341 1342.. note:: 1343 1344 Not all extensions are enabled by default. Using this ioctl the application 1345 can enable an extension, making it available to the guest. 1346 1347On systems that do not support this ioctl, it always fails. On systems that 1348do support it, it only works for extensions that are supported for enablement. 1349 1350To check if a capability can be enabled, the KVM_CHECK_EXTENSION ioctl should 1351be used. 1352 1353:: 1354 1355 struct kvm_enable_cap { 1356 /* in */ 1357 __u32 cap; 1358 1359The capability that is supposed to get enabled. 1360 1361:: 1362 1363 __u32 flags; 1364 1365A bitfield indicating future enhancements. Has to be 0 for now. 1366 1367:: 1368 1369 __u64 args[4]; 1370 1371Arguments for enabling a feature. If a feature needs initial values to 1372function properly, this is the place to put them. 1373 1374:: 1375 1376 __u8 pad[64]; 1377 }; 1378 1379The vcpu ioctl should be used for vcpu-specific capabilities, the vm ioctl 1380for vm-wide capabilities. 1381 13824.38 KVM_GET_MP_STATE 1383--------------------- 1384 1385:Capability: KVM_CAP_MP_STATE 1386:Architectures: x86, s390, arm, arm64 1387:Type: vcpu ioctl 1388:Parameters: struct kvm_mp_state (out) 1389:Returns: 0 on success; -1 on error 1390 1391:: 1392 1393 struct kvm_mp_state { 1394 __u32 mp_state; 1395 }; 1396 1397Returns the vcpu's current "multiprocessing state" (though also valid on 1398uniprocessor guests). 1399 1400Possible values are: 1401 1402 ========================== =============================================== 1403 KVM_MP_STATE_RUNNABLE the vcpu is currently running [x86,arm/arm64] 1404 KVM_MP_STATE_UNINITIALIZED the vcpu is an application processor (AP) 1405 which has not yet received an INIT signal [x86] 1406 KVM_MP_STATE_INIT_RECEIVED the vcpu has received an INIT signal, and is 1407 now ready for a SIPI [x86] 1408 KVM_MP_STATE_HALTED the vcpu has executed a HLT instruction and 1409 is waiting for an interrupt [x86] 1410 KVM_MP_STATE_SIPI_RECEIVED the vcpu has just received a SIPI (vector 1411 accessible via KVM_GET_VCPU_EVENTS) [x86] 1412 KVM_MP_STATE_STOPPED the vcpu is stopped [s390,arm/arm64] 1413 KVM_MP_STATE_CHECK_STOP the vcpu is in a special error state [s390] 1414 KVM_MP_STATE_OPERATING the vcpu is operating (running or halted) 1415 [s390] 1416 KVM_MP_STATE_LOAD the vcpu is in a special load/startup state 1417 [s390] 1418 ========================== =============================================== 1419 1420On x86, this ioctl is only useful after KVM_CREATE_IRQCHIP. Without an 1421in-kernel irqchip, the multiprocessing state must be maintained by userspace on 1422these architectures. 1423 1424For arm/arm64: 1425^^^^^^^^^^^^^^ 1426 1427The only states that are valid are KVM_MP_STATE_STOPPED and 1428KVM_MP_STATE_RUNNABLE which reflect if the vcpu is paused or not. 1429 14304.39 KVM_SET_MP_STATE 1431--------------------- 1432 1433:Capability: KVM_CAP_MP_STATE 1434:Architectures: x86, s390, arm, arm64 1435:Type: vcpu ioctl 1436:Parameters: struct kvm_mp_state (in) 1437:Returns: 0 on success; -1 on error 1438 1439Sets the vcpu's current "multiprocessing state"; see KVM_GET_MP_STATE for 1440arguments. 1441 1442On x86, this ioctl is only useful after KVM_CREATE_IRQCHIP. Without an 1443in-kernel irqchip, the multiprocessing state must be maintained by userspace on 1444these architectures. 1445 1446For arm/arm64: 1447^^^^^^^^^^^^^^ 1448 1449The only states that are valid are KVM_MP_STATE_STOPPED and 1450KVM_MP_STATE_RUNNABLE which reflect if the vcpu should be paused or not. 1451 14524.40 KVM_SET_IDENTITY_MAP_ADDR 1453------------------------------ 1454 1455:Capability: KVM_CAP_SET_IDENTITY_MAP_ADDR 1456:Architectures: x86 1457:Type: vm ioctl 1458:Parameters: unsigned long identity (in) 1459:Returns: 0 on success, -1 on error 1460 1461This ioctl defines the physical address of a one-page region in the guest 1462physical address space. The region must be within the first 4GB of the 1463guest physical address space and must not conflict with any memory slot 1464or any mmio address. The guest may malfunction if it accesses this memory 1465region. 1466 1467Setting the address to 0 will result in resetting the address to its default 1468(0xfffbc000). 1469 1470This ioctl is required on Intel-based hosts. This is needed on Intel hardware 1471because of a quirk in the virtualization implementation (see the internals 1472documentation when it pops into existence). 1473 1474Fails if any VCPU has already been created. 1475 14764.41 KVM_SET_BOOT_CPU_ID 1477------------------------ 1478 1479:Capability: KVM_CAP_SET_BOOT_CPU_ID 1480:Architectures: x86 1481:Type: vm ioctl 1482:Parameters: unsigned long vcpu_id 1483:Returns: 0 on success, -1 on error 1484 1485Define which vcpu is the Bootstrap Processor (BSP). Values are the same 1486as the vcpu id in KVM_CREATE_VCPU. If this ioctl is not called, the default 1487is vcpu 0. 1488 1489 14904.42 KVM_GET_XSAVE 1491------------------ 1492 1493:Capability: KVM_CAP_XSAVE 1494:Architectures: x86 1495:Type: vcpu ioctl 1496:Parameters: struct kvm_xsave (out) 1497:Returns: 0 on success, -1 on error 1498 1499 1500:: 1501 1502 struct kvm_xsave { 1503 __u32 region[1024]; 1504 }; 1505 1506This ioctl would copy current vcpu's xsave struct to the userspace. 1507 1508 15094.43 KVM_SET_XSAVE 1510------------------ 1511 1512:Capability: KVM_CAP_XSAVE 1513:Architectures: x86 1514:Type: vcpu ioctl 1515:Parameters: struct kvm_xsave (in) 1516:Returns: 0 on success, -1 on error 1517 1518:: 1519 1520 1521 struct kvm_xsave { 1522 __u32 region[1024]; 1523 }; 1524 1525This ioctl would copy userspace's xsave struct to the kernel. 1526 1527 15284.44 KVM_GET_XCRS 1529----------------- 1530 1531:Capability: KVM_CAP_XCRS 1532:Architectures: x86 1533:Type: vcpu ioctl 1534:Parameters: struct kvm_xcrs (out) 1535:Returns: 0 on success, -1 on error 1536 1537:: 1538 1539 struct kvm_xcr { 1540 __u32 xcr; 1541 __u32 reserved; 1542 __u64 value; 1543 }; 1544 1545 struct kvm_xcrs { 1546 __u32 nr_xcrs; 1547 __u32 flags; 1548 struct kvm_xcr xcrs[KVM_MAX_XCRS]; 1549 __u64 padding[16]; 1550 }; 1551 1552This ioctl would copy current vcpu's xcrs to the userspace. 1553 1554 15554.45 KVM_SET_XCRS 1556----------------- 1557 1558:Capability: KVM_CAP_XCRS 1559:Architectures: x86 1560:Type: vcpu ioctl 1561:Parameters: struct kvm_xcrs (in) 1562:Returns: 0 on success, -1 on error 1563 1564:: 1565 1566 struct kvm_xcr { 1567 __u32 xcr; 1568 __u32 reserved; 1569 __u64 value; 1570 }; 1571 1572 struct kvm_xcrs { 1573 __u32 nr_xcrs; 1574 __u32 flags; 1575 struct kvm_xcr xcrs[KVM_MAX_XCRS]; 1576 __u64 padding[16]; 1577 }; 1578 1579This ioctl would set vcpu's xcr to the value userspace specified. 1580 1581 15824.46 KVM_GET_SUPPORTED_CPUID 1583---------------------------- 1584 1585:Capability: KVM_CAP_EXT_CPUID 1586:Architectures: x86 1587:Type: system ioctl 1588:Parameters: struct kvm_cpuid2 (in/out) 1589:Returns: 0 on success, -1 on error 1590 1591:: 1592 1593 struct kvm_cpuid2 { 1594 __u32 nent; 1595 __u32 padding; 1596 struct kvm_cpuid_entry2 entries[0]; 1597 }; 1598 1599 #define KVM_CPUID_FLAG_SIGNIFCANT_INDEX BIT(0) 1600 #define KVM_CPUID_FLAG_STATEFUL_FUNC BIT(1) /* deprecated */ 1601 #define KVM_CPUID_FLAG_STATE_READ_NEXT BIT(2) /* deprecated */ 1602 1603 struct kvm_cpuid_entry2 { 1604 __u32 function; 1605 __u32 index; 1606 __u32 flags; 1607 __u32 eax; 1608 __u32 ebx; 1609 __u32 ecx; 1610 __u32 edx; 1611 __u32 padding[3]; 1612 }; 1613 1614This ioctl returns x86 cpuid features which are supported by both the 1615hardware and kvm in its default configuration. Userspace can use the 1616information returned by this ioctl to construct cpuid information (for 1617KVM_SET_CPUID2) that is consistent with hardware, kernel, and 1618userspace capabilities, and with user requirements (for example, the 1619user may wish to constrain cpuid to emulate older hardware, or for 1620feature consistency across a cluster). 1621 1622Note that certain capabilities, such as KVM_CAP_X86_DISABLE_EXITS, may 1623expose cpuid features (e.g. MONITOR) which are not supported by kvm in 1624its default configuration. If userspace enables such capabilities, it 1625is responsible for modifying the results of this ioctl appropriately. 1626 1627Userspace invokes KVM_GET_SUPPORTED_CPUID by passing a kvm_cpuid2 structure 1628with the 'nent' field indicating the number of entries in the variable-size 1629array 'entries'. If the number of entries is too low to describe the cpu 1630capabilities, an error (E2BIG) is returned. If the number is too high, 1631the 'nent' field is adjusted and an error (ENOMEM) is returned. If the 1632number is just right, the 'nent' field is adjusted to the number of valid 1633entries in the 'entries' array, which is then filled. 1634 1635The entries returned are the host cpuid as returned by the cpuid instruction, 1636with unknown or unsupported features masked out. Some features (for example, 1637x2apic), may not be present in the host cpu, but are exposed by kvm if it can 1638emulate them efficiently. The fields in each entry are defined as follows: 1639 1640 function: 1641 the eax value used to obtain the entry 1642 1643 index: 1644 the ecx value used to obtain the entry (for entries that are 1645 affected by ecx) 1646 1647 flags: 1648 an OR of zero or more of the following: 1649 1650 KVM_CPUID_FLAG_SIGNIFCANT_INDEX: 1651 if the index field is valid 1652 1653 eax, ebx, ecx, edx: 1654 the values returned by the cpuid instruction for 1655 this function/index combination 1656 1657The TSC deadline timer feature (CPUID leaf 1, ecx[24]) is always returned 1658as false, since the feature depends on KVM_CREATE_IRQCHIP for local APIC 1659support. Instead it is reported via:: 1660 1661 ioctl(KVM_CHECK_EXTENSION, KVM_CAP_TSC_DEADLINE_TIMER) 1662 1663if that returns true and you use KVM_CREATE_IRQCHIP, or if you emulate the 1664feature in userspace, then you can enable the feature for KVM_SET_CPUID2. 1665 1666 16674.47 KVM_PPC_GET_PVINFO 1668----------------------- 1669 1670:Capability: KVM_CAP_PPC_GET_PVINFO 1671:Architectures: ppc 1672:Type: vm ioctl 1673:Parameters: struct kvm_ppc_pvinfo (out) 1674:Returns: 0 on success, !0 on error 1675 1676:: 1677 1678 struct kvm_ppc_pvinfo { 1679 __u32 flags; 1680 __u32 hcall[4]; 1681 __u8 pad[108]; 1682 }; 1683 1684This ioctl fetches PV specific information that need to be passed to the guest 1685using the device tree or other means from vm context. 1686 1687The hcall array defines 4 instructions that make up a hypercall. 1688 1689If any additional field gets added to this structure later on, a bit for that 1690additional piece of information will be set in the flags bitmap. 1691 1692The flags bitmap is defined as:: 1693 1694 /* the host supports the ePAPR idle hcall 1695 #define KVM_PPC_PVINFO_FLAGS_EV_IDLE (1<<0) 1696 16974.52 KVM_SET_GSI_ROUTING 1698------------------------ 1699 1700:Capability: KVM_CAP_IRQ_ROUTING 1701:Architectures: x86 s390 arm arm64 1702:Type: vm ioctl 1703:Parameters: struct kvm_irq_routing (in) 1704:Returns: 0 on success, -1 on error 1705 1706Sets the GSI routing table entries, overwriting any previously set entries. 1707 1708On arm/arm64, GSI routing has the following limitation: 1709 1710- GSI routing does not apply to KVM_IRQ_LINE but only to KVM_IRQFD. 1711 1712:: 1713 1714 struct kvm_irq_routing { 1715 __u32 nr; 1716 __u32 flags; 1717 struct kvm_irq_routing_entry entries[0]; 1718 }; 1719 1720No flags are specified so far, the corresponding field must be set to zero. 1721 1722:: 1723 1724 struct kvm_irq_routing_entry { 1725 __u32 gsi; 1726 __u32 type; 1727 __u32 flags; 1728 __u32 pad; 1729 union { 1730 struct kvm_irq_routing_irqchip irqchip; 1731 struct kvm_irq_routing_msi msi; 1732 struct kvm_irq_routing_s390_adapter adapter; 1733 struct kvm_irq_routing_hv_sint hv_sint; 1734 __u32 pad[8]; 1735 } u; 1736 }; 1737 1738 /* gsi routing entry types */ 1739 #define KVM_IRQ_ROUTING_IRQCHIP 1 1740 #define KVM_IRQ_ROUTING_MSI 2 1741 #define KVM_IRQ_ROUTING_S390_ADAPTER 3 1742 #define KVM_IRQ_ROUTING_HV_SINT 4 1743 1744flags: 1745 1746- KVM_MSI_VALID_DEVID: used along with KVM_IRQ_ROUTING_MSI routing entry 1747 type, specifies that the devid field contains a valid value. The per-VM 1748 KVM_CAP_MSI_DEVID capability advertises the requirement to provide 1749 the device ID. If this capability is not available, userspace should 1750 never set the KVM_MSI_VALID_DEVID flag as the ioctl might fail. 1751- zero otherwise 1752 1753:: 1754 1755 struct kvm_irq_routing_irqchip { 1756 __u32 irqchip; 1757 __u32 pin; 1758 }; 1759 1760 struct kvm_irq_routing_msi { 1761 __u32 address_lo; 1762 __u32 address_hi; 1763 __u32 data; 1764 union { 1765 __u32 pad; 1766 __u32 devid; 1767 }; 1768 }; 1769 1770If KVM_MSI_VALID_DEVID is set, devid contains a unique device identifier 1771for the device that wrote the MSI message. For PCI, this is usually a 1772BFD identifier in the lower 16 bits. 1773 1774On x86, address_hi is ignored unless the KVM_X2APIC_API_USE_32BIT_IDS 1775feature of KVM_CAP_X2APIC_API capability is enabled. If it is enabled, 1776address_hi bits 31-8 provide bits 31-8 of the destination id. Bits 7-0 of 1777address_hi must be zero. 1778 1779:: 1780 1781 struct kvm_irq_routing_s390_adapter { 1782 __u64 ind_addr; 1783 __u64 summary_addr; 1784 __u64 ind_offset; 1785 __u32 summary_offset; 1786 __u32 adapter_id; 1787 }; 1788 1789 struct kvm_irq_routing_hv_sint { 1790 __u32 vcpu; 1791 __u32 sint; 1792 }; 1793 1794 17954.55 KVM_SET_TSC_KHZ 1796-------------------- 1797 1798:Capability: KVM_CAP_TSC_CONTROL 1799:Architectures: x86 1800:Type: vcpu ioctl 1801:Parameters: virtual tsc_khz 1802:Returns: 0 on success, -1 on error 1803 1804Specifies the tsc frequency for the virtual machine. The unit of the 1805frequency is KHz. 1806 1807 18084.56 KVM_GET_TSC_KHZ 1809-------------------- 1810 1811:Capability: KVM_CAP_GET_TSC_KHZ 1812:Architectures: x86 1813:Type: vcpu ioctl 1814:Parameters: none 1815:Returns: virtual tsc-khz on success, negative value on error 1816 1817Returns the tsc frequency of the guest. The unit of the return value is 1818KHz. If the host has unstable tsc this ioctl returns -EIO instead as an 1819error. 1820 1821 18224.57 KVM_GET_LAPIC 1823------------------ 1824 1825:Capability: KVM_CAP_IRQCHIP 1826:Architectures: x86 1827:Type: vcpu ioctl 1828:Parameters: struct kvm_lapic_state (out) 1829:Returns: 0 on success, -1 on error 1830 1831:: 1832 1833 #define KVM_APIC_REG_SIZE 0x400 1834 struct kvm_lapic_state { 1835 char regs[KVM_APIC_REG_SIZE]; 1836 }; 1837 1838Reads the Local APIC registers and copies them into the input argument. The 1839data format and layout are the same as documented in the architecture manual. 1840 1841If KVM_X2APIC_API_USE_32BIT_IDS feature of KVM_CAP_X2APIC_API is 1842enabled, then the format of APIC_ID register depends on the APIC mode 1843(reported by MSR_IA32_APICBASE) of its VCPU. x2APIC stores APIC ID in 1844the APIC_ID register (bytes 32-35). xAPIC only allows an 8-bit APIC ID 1845which is stored in bits 31-24 of the APIC register, or equivalently in 1846byte 35 of struct kvm_lapic_state's regs field. KVM_GET_LAPIC must then 1847be called after MSR_IA32_APICBASE has been set with KVM_SET_MSR. 1848 1849If KVM_X2APIC_API_USE_32BIT_IDS feature is disabled, struct kvm_lapic_state 1850always uses xAPIC format. 1851 1852 18534.58 KVM_SET_LAPIC 1854------------------ 1855 1856:Capability: KVM_CAP_IRQCHIP 1857:Architectures: x86 1858:Type: vcpu ioctl 1859:Parameters: struct kvm_lapic_state (in) 1860:Returns: 0 on success, -1 on error 1861 1862:: 1863 1864 #define KVM_APIC_REG_SIZE 0x400 1865 struct kvm_lapic_state { 1866 char regs[KVM_APIC_REG_SIZE]; 1867 }; 1868 1869Copies the input argument into the Local APIC registers. The data format 1870and layout are the same as documented in the architecture manual. 1871 1872The format of the APIC ID register (bytes 32-35 of struct kvm_lapic_state's 1873regs field) depends on the state of the KVM_CAP_X2APIC_API capability. 1874See the note in KVM_GET_LAPIC. 1875 1876 18774.59 KVM_IOEVENTFD 1878------------------ 1879 1880:Capability: KVM_CAP_IOEVENTFD 1881:Architectures: all 1882:Type: vm ioctl 1883:Parameters: struct kvm_ioeventfd (in) 1884:Returns: 0 on success, !0 on error 1885 1886This ioctl attaches or detaches an ioeventfd to a legal pio/mmio address 1887within the guest. A guest write in the registered address will signal the 1888provided event instead of triggering an exit. 1889 1890:: 1891 1892 struct kvm_ioeventfd { 1893 __u64 datamatch; 1894 __u64 addr; /* legal pio/mmio address */ 1895 __u32 len; /* 0, 1, 2, 4, or 8 bytes */ 1896 __s32 fd; 1897 __u32 flags; 1898 __u8 pad[36]; 1899 }; 1900 1901For the special case of virtio-ccw devices on s390, the ioevent is matched 1902to a subchannel/virtqueue tuple instead. 1903 1904The following flags are defined:: 1905 1906 #define KVM_IOEVENTFD_FLAG_DATAMATCH (1 << kvm_ioeventfd_flag_nr_datamatch) 1907 #define KVM_IOEVENTFD_FLAG_PIO (1 << kvm_ioeventfd_flag_nr_pio) 1908 #define KVM_IOEVENTFD_FLAG_DEASSIGN (1 << kvm_ioeventfd_flag_nr_deassign) 1909 #define KVM_IOEVENTFD_FLAG_VIRTIO_CCW_NOTIFY \ 1910 (1 << kvm_ioeventfd_flag_nr_virtio_ccw_notify) 1911 1912If datamatch flag is set, the event will be signaled only if the written value 1913to the registered address is equal to datamatch in struct kvm_ioeventfd. 1914 1915For virtio-ccw devices, addr contains the subchannel id and datamatch the 1916virtqueue index. 1917 1918With KVM_CAP_IOEVENTFD_ANY_LENGTH, a zero length ioeventfd is allowed, and 1919the kernel will ignore the length of guest write and may get a faster vmexit. 1920The speedup may only apply to specific architectures, but the ioeventfd will 1921work anyway. 1922 19234.60 KVM_DIRTY_TLB 1924------------------ 1925 1926:Capability: KVM_CAP_SW_TLB 1927:Architectures: ppc 1928:Type: vcpu ioctl 1929:Parameters: struct kvm_dirty_tlb (in) 1930:Returns: 0 on success, -1 on error 1931 1932:: 1933 1934 struct kvm_dirty_tlb { 1935 __u64 bitmap; 1936 __u32 num_dirty; 1937 }; 1938 1939This must be called whenever userspace has changed an entry in the shared 1940TLB, prior to calling KVM_RUN on the associated vcpu. 1941 1942The "bitmap" field is the userspace address of an array. This array 1943consists of a number of bits, equal to the total number of TLB entries as 1944determined by the last successful call to KVM_CONFIG_TLB, rounded up to the 1945nearest multiple of 64. 1946 1947Each bit corresponds to one TLB entry, ordered the same as in the shared TLB 1948array. 1949 1950The array is little-endian: the bit 0 is the least significant bit of the 1951first byte, bit 8 is the least significant bit of the second byte, etc. 1952This avoids any complications with differing word sizes. 1953 1954The "num_dirty" field is a performance hint for KVM to determine whether it 1955should skip processing the bitmap and just invalidate everything. It must 1956be set to the number of set bits in the bitmap. 1957 1958 19594.62 KVM_CREATE_SPAPR_TCE 1960------------------------- 1961 1962:Capability: KVM_CAP_SPAPR_TCE 1963:Architectures: powerpc 1964:Type: vm ioctl 1965:Parameters: struct kvm_create_spapr_tce (in) 1966:Returns: file descriptor for manipulating the created TCE table 1967 1968This creates a virtual TCE (translation control entry) table, which 1969is an IOMMU for PAPR-style virtual I/O. It is used to translate 1970logical addresses used in virtual I/O into guest physical addresses, 1971and provides a scatter/gather capability for PAPR virtual I/O. 1972 1973:: 1974 1975 /* for KVM_CAP_SPAPR_TCE */ 1976 struct kvm_create_spapr_tce { 1977 __u64 liobn; 1978 __u32 window_size; 1979 }; 1980 1981The liobn field gives the logical IO bus number for which to create a 1982TCE table. The window_size field specifies the size of the DMA window 1983which this TCE table will translate - the table will contain one 64 1984bit TCE entry for every 4kiB of the DMA window. 1985 1986When the guest issues an H_PUT_TCE hcall on a liobn for which a TCE 1987table has been created using this ioctl(), the kernel will handle it 1988in real mode, updating the TCE table. H_PUT_TCE calls for other 1989liobns will cause a vm exit and must be handled by userspace. 1990 1991The return value is a file descriptor which can be passed to mmap(2) 1992to map the created TCE table into userspace. This lets userspace read 1993the entries written by kernel-handled H_PUT_TCE calls, and also lets 1994userspace update the TCE table directly which is useful in some 1995circumstances. 1996 1997 19984.63 KVM_ALLOCATE_RMA 1999--------------------- 2000 2001:Capability: KVM_CAP_PPC_RMA 2002:Architectures: powerpc 2003:Type: vm ioctl 2004:Parameters: struct kvm_allocate_rma (out) 2005:Returns: file descriptor for mapping the allocated RMA 2006 2007This allocates a Real Mode Area (RMA) from the pool allocated at boot 2008time by the kernel. An RMA is a physically-contiguous, aligned region 2009of memory used on older POWER processors to provide the memory which 2010will be accessed by real-mode (MMU off) accesses in a KVM guest. 2011POWER processors support a set of sizes for the RMA that usually 2012includes 64MB, 128MB, 256MB and some larger powers of two. 2013 2014:: 2015 2016 /* for KVM_ALLOCATE_RMA */ 2017 struct kvm_allocate_rma { 2018 __u64 rma_size; 2019 }; 2020 2021The return value is a file descriptor which can be passed to mmap(2) 2022to map the allocated RMA into userspace. The mapped area can then be 2023passed to the KVM_SET_USER_MEMORY_REGION ioctl to establish it as the 2024RMA for a virtual machine. The size of the RMA in bytes (which is 2025fixed at host kernel boot time) is returned in the rma_size field of 2026the argument structure. 2027 2028The KVM_CAP_PPC_RMA capability is 1 or 2 if the KVM_ALLOCATE_RMA ioctl 2029is supported; 2 if the processor requires all virtual machines to have 2030an RMA, or 1 if the processor can use an RMA but doesn't require it, 2031because it supports the Virtual RMA (VRMA) facility. 2032 2033 20344.64 KVM_NMI 2035------------ 2036 2037:Capability: KVM_CAP_USER_NMI 2038:Architectures: x86 2039:Type: vcpu ioctl 2040:Parameters: none 2041:Returns: 0 on success, -1 on error 2042 2043Queues an NMI on the thread's vcpu. Note this is well defined only 2044when KVM_CREATE_IRQCHIP has not been called, since this is an interface 2045between the virtual cpu core and virtual local APIC. After KVM_CREATE_IRQCHIP 2046has been called, this interface is completely emulated within the kernel. 2047 2048To use this to emulate the LINT1 input with KVM_CREATE_IRQCHIP, use the 2049following algorithm: 2050 2051 - pause the vcpu 2052 - read the local APIC's state (KVM_GET_LAPIC) 2053 - check whether changing LINT1 will queue an NMI (see the LVT entry for LINT1) 2054 - if so, issue KVM_NMI 2055 - resume the vcpu 2056 2057Some guests configure the LINT1 NMI input to cause a panic, aiding in 2058debugging. 2059 2060 20614.65 KVM_S390_UCAS_MAP 2062---------------------- 2063 2064:Capability: KVM_CAP_S390_UCONTROL 2065:Architectures: s390 2066:Type: vcpu ioctl 2067:Parameters: struct kvm_s390_ucas_mapping (in) 2068:Returns: 0 in case of success 2069 2070The parameter is defined like this:: 2071 2072 struct kvm_s390_ucas_mapping { 2073 __u64 user_addr; 2074 __u64 vcpu_addr; 2075 __u64 length; 2076 }; 2077 2078This ioctl maps the memory at "user_addr" with the length "length" to 2079the vcpu's address space starting at "vcpu_addr". All parameters need to 2080be aligned by 1 megabyte. 2081 2082 20834.66 KVM_S390_UCAS_UNMAP 2084------------------------ 2085 2086:Capability: KVM_CAP_S390_UCONTROL 2087:Architectures: s390 2088:Type: vcpu ioctl 2089:Parameters: struct kvm_s390_ucas_mapping (in) 2090:Returns: 0 in case of success 2091 2092The parameter is defined like this:: 2093 2094 struct kvm_s390_ucas_mapping { 2095 __u64 user_addr; 2096 __u64 vcpu_addr; 2097 __u64 length; 2098 }; 2099 2100This ioctl unmaps the memory in the vcpu's address space starting at 2101"vcpu_addr" with the length "length". The field "user_addr" is ignored. 2102All parameters need to be aligned by 1 megabyte. 2103 2104 21054.67 KVM_S390_VCPU_FAULT 2106------------------------ 2107 2108:Capability: KVM_CAP_S390_UCONTROL 2109:Architectures: s390 2110:Type: vcpu ioctl 2111:Parameters: vcpu absolute address (in) 2112:Returns: 0 in case of success 2113 2114This call creates a page table entry on the virtual cpu's address space 2115(for user controlled virtual machines) or the virtual machine's address 2116space (for regular virtual machines). This only works for minor faults, 2117thus it's recommended to access subject memory page via the user page 2118table upfront. This is useful to handle validity intercepts for user 2119controlled virtual machines to fault in the virtual cpu's lowcore pages 2120prior to calling the KVM_RUN ioctl. 2121 2122 21234.68 KVM_SET_ONE_REG 2124-------------------- 2125 2126:Capability: KVM_CAP_ONE_REG 2127:Architectures: all 2128:Type: vcpu ioctl 2129:Parameters: struct kvm_one_reg (in) 2130:Returns: 0 on success, negative value on failure 2131 2132Errors: 2133 2134 ====== ============================================================ 2135 ENOENT no such register 2136 EINVAL invalid register ID, or no such register or used with VMs in 2137 protected virtualization mode on s390 2138 EPERM (arm64) register access not allowed before vcpu finalization 2139 ====== ============================================================ 2140 2141(These error codes are indicative only: do not rely on a specific error 2142code being returned in a specific situation.) 2143 2144:: 2145 2146 struct kvm_one_reg { 2147 __u64 id; 2148 __u64 addr; 2149 }; 2150 2151Using this ioctl, a single vcpu register can be set to a specific value 2152defined by user space with the passed in struct kvm_one_reg, where id 2153refers to the register identifier as described below and addr is a pointer 2154to a variable with the respective size. There can be architecture agnostic 2155and architecture specific registers. Each have their own range of operation 2156and their own constants and width. To keep track of the implemented 2157registers, find a list below: 2158 2159 ======= =============================== ============ 2160 Arch Register Width (bits) 2161 ======= =============================== ============ 2162 PPC KVM_REG_PPC_HIOR 64 2163 PPC KVM_REG_PPC_IAC1 64 2164 PPC KVM_REG_PPC_IAC2 64 2165 PPC KVM_REG_PPC_IAC3 64 2166 PPC KVM_REG_PPC_IAC4 64 2167 PPC KVM_REG_PPC_DAC1 64 2168 PPC KVM_REG_PPC_DAC2 64 2169 PPC KVM_REG_PPC_DABR 64 2170 PPC KVM_REG_PPC_DSCR 64 2171 PPC KVM_REG_PPC_PURR 64 2172 PPC KVM_REG_PPC_SPURR 64 2173 PPC KVM_REG_PPC_DAR 64 2174 PPC KVM_REG_PPC_DSISR 32 2175 PPC KVM_REG_PPC_AMR 64 2176 PPC KVM_REG_PPC_UAMOR 64 2177 PPC KVM_REG_PPC_MMCR0 64 2178 PPC KVM_REG_PPC_MMCR1 64 2179 PPC KVM_REG_PPC_MMCRA 64 2180 PPC KVM_REG_PPC_MMCR2 64 2181 PPC KVM_REG_PPC_MMCRS 64 2182 PPC KVM_REG_PPC_MMCR3 64 2183 PPC KVM_REG_PPC_SIAR 64 2184 PPC KVM_REG_PPC_SDAR 64 2185 PPC KVM_REG_PPC_SIER 64 2186 PPC KVM_REG_PPC_SIER2 64 2187 PPC KVM_REG_PPC_SIER3 64 2188 PPC KVM_REG_PPC_PMC1 32 2189 PPC KVM_REG_PPC_PMC2 32 2190 PPC KVM_REG_PPC_PMC3 32 2191 PPC KVM_REG_PPC_PMC4 32 2192 PPC KVM_REG_PPC_PMC5 32 2193 PPC KVM_REG_PPC_PMC6 32 2194 PPC KVM_REG_PPC_PMC7 32 2195 PPC KVM_REG_PPC_PMC8 32 2196 PPC KVM_REG_PPC_FPR0 64 2197 ... 2198 PPC KVM_REG_PPC_FPR31 64 2199 PPC KVM_REG_PPC_VR0 128 2200 ... 2201 PPC KVM_REG_PPC_VR31 128 2202 PPC KVM_REG_PPC_VSR0 128 2203 ... 2204 PPC KVM_REG_PPC_VSR31 128 2205 PPC KVM_REG_PPC_FPSCR 64 2206 PPC KVM_REG_PPC_VSCR 32 2207 PPC KVM_REG_PPC_VPA_ADDR 64 2208 PPC KVM_REG_PPC_VPA_SLB 128 2209 PPC KVM_REG_PPC_VPA_DTL 128 2210 PPC KVM_REG_PPC_EPCR 32 2211 PPC KVM_REG_PPC_EPR 32 2212 PPC KVM_REG_PPC_TCR 32 2213 PPC KVM_REG_PPC_TSR 32 2214 PPC KVM_REG_PPC_OR_TSR 32 2215 PPC KVM_REG_PPC_CLEAR_TSR 32 2216 PPC KVM_REG_PPC_MAS0 32 2217 PPC KVM_REG_PPC_MAS1 32 2218 PPC KVM_REG_PPC_MAS2 64 2219 PPC KVM_REG_PPC_MAS7_3 64 2220 PPC KVM_REG_PPC_MAS4 32 2221 PPC KVM_REG_PPC_MAS6 32 2222 PPC KVM_REG_PPC_MMUCFG 32 2223 PPC KVM_REG_PPC_TLB0CFG 32 2224 PPC KVM_REG_PPC_TLB1CFG 32 2225 PPC KVM_REG_PPC_TLB2CFG 32 2226 PPC KVM_REG_PPC_TLB3CFG 32 2227 PPC KVM_REG_PPC_TLB0PS 32 2228 PPC KVM_REG_PPC_TLB1PS 32 2229 PPC KVM_REG_PPC_TLB2PS 32 2230 PPC KVM_REG_PPC_TLB3PS 32 2231 PPC KVM_REG_PPC_EPTCFG 32 2232 PPC KVM_REG_PPC_ICP_STATE 64 2233 PPC KVM_REG_PPC_VP_STATE 128 2234 PPC KVM_REG_PPC_TB_OFFSET 64 2235 PPC KVM_REG_PPC_SPMC1 32 2236 PPC KVM_REG_PPC_SPMC2 32 2237 PPC KVM_REG_PPC_IAMR 64 2238 PPC KVM_REG_PPC_TFHAR 64 2239 PPC KVM_REG_PPC_TFIAR 64 2240 PPC KVM_REG_PPC_TEXASR 64 2241 PPC KVM_REG_PPC_FSCR 64 2242 PPC KVM_REG_PPC_PSPB 32 2243 PPC KVM_REG_PPC_EBBHR 64 2244 PPC KVM_REG_PPC_EBBRR 64 2245 PPC KVM_REG_PPC_BESCR 64 2246 PPC KVM_REG_PPC_TAR 64 2247 PPC KVM_REG_PPC_DPDES 64 2248 PPC KVM_REG_PPC_DAWR 64 2249 PPC KVM_REG_PPC_DAWRX 64 2250 PPC KVM_REG_PPC_CIABR 64 2251 PPC KVM_REG_PPC_IC 64 2252 PPC KVM_REG_PPC_VTB 64 2253 PPC KVM_REG_PPC_CSIGR 64 2254 PPC KVM_REG_PPC_TACR 64 2255 PPC KVM_REG_PPC_TCSCR 64 2256 PPC KVM_REG_PPC_PID 64 2257 PPC KVM_REG_PPC_ACOP 64 2258 PPC KVM_REG_PPC_VRSAVE 32 2259 PPC KVM_REG_PPC_LPCR 32 2260 PPC KVM_REG_PPC_LPCR_64 64 2261 PPC KVM_REG_PPC_PPR 64 2262 PPC KVM_REG_PPC_ARCH_COMPAT 32 2263 PPC KVM_REG_PPC_DABRX 32 2264 PPC KVM_REG_PPC_WORT 64 2265 PPC KVM_REG_PPC_SPRG9 64 2266 PPC KVM_REG_PPC_DBSR 32 2267 PPC KVM_REG_PPC_TIDR 64 2268 PPC KVM_REG_PPC_PSSCR 64 2269 PPC KVM_REG_PPC_DEC_EXPIRY 64 2270 PPC KVM_REG_PPC_PTCR 64 2271 PPC KVM_REG_PPC_TM_GPR0 64 2272 ... 2273 PPC KVM_REG_PPC_TM_GPR31 64 2274 PPC KVM_REG_PPC_TM_VSR0 128 2275 ... 2276 PPC KVM_REG_PPC_TM_VSR63 128 2277 PPC KVM_REG_PPC_TM_CR 64 2278 PPC KVM_REG_PPC_TM_LR 64 2279 PPC KVM_REG_PPC_TM_CTR 64 2280 PPC KVM_REG_PPC_TM_FPSCR 64 2281 PPC KVM_REG_PPC_TM_AMR 64 2282 PPC KVM_REG_PPC_TM_PPR 64 2283 PPC KVM_REG_PPC_TM_VRSAVE 64 2284 PPC KVM_REG_PPC_TM_VSCR 32 2285 PPC KVM_REG_PPC_TM_DSCR 64 2286 PPC KVM_REG_PPC_TM_TAR 64 2287 PPC KVM_REG_PPC_TM_XER 64 2288 2289 MIPS KVM_REG_MIPS_R0 64 2290 ... 2291 MIPS KVM_REG_MIPS_R31 64 2292 MIPS KVM_REG_MIPS_HI 64 2293 MIPS KVM_REG_MIPS_LO 64 2294 MIPS KVM_REG_MIPS_PC 64 2295 MIPS KVM_REG_MIPS_CP0_INDEX 32 2296 MIPS KVM_REG_MIPS_CP0_ENTRYLO0 64 2297 MIPS KVM_REG_MIPS_CP0_ENTRYLO1 64 2298 MIPS KVM_REG_MIPS_CP0_CONTEXT 64 2299 MIPS KVM_REG_MIPS_CP0_CONTEXTCONFIG 32 2300 MIPS KVM_REG_MIPS_CP0_USERLOCAL 64 2301 MIPS KVM_REG_MIPS_CP0_XCONTEXTCONFIG 64 2302 MIPS KVM_REG_MIPS_CP0_PAGEMASK 32 2303 MIPS KVM_REG_MIPS_CP0_PAGEGRAIN 32 2304 MIPS KVM_REG_MIPS_CP0_SEGCTL0 64 2305 MIPS KVM_REG_MIPS_CP0_SEGCTL1 64 2306 MIPS KVM_REG_MIPS_CP0_SEGCTL2 64 2307 MIPS KVM_REG_MIPS_CP0_PWBASE 64 2308 MIPS KVM_REG_MIPS_CP0_PWFIELD 64 2309 MIPS KVM_REG_MIPS_CP0_PWSIZE 64 2310 MIPS KVM_REG_MIPS_CP0_WIRED 32 2311 MIPS KVM_REG_MIPS_CP0_PWCTL 32 2312 MIPS KVM_REG_MIPS_CP0_HWRENA 32 2313 MIPS KVM_REG_MIPS_CP0_BADVADDR 64 2314 MIPS KVM_REG_MIPS_CP0_BADINSTR 32 2315 MIPS KVM_REG_MIPS_CP0_BADINSTRP 32 2316 MIPS KVM_REG_MIPS_CP0_COUNT 32 2317 MIPS KVM_REG_MIPS_CP0_ENTRYHI 64 2318 MIPS KVM_REG_MIPS_CP0_COMPARE 32 2319 MIPS KVM_REG_MIPS_CP0_STATUS 32 2320 MIPS KVM_REG_MIPS_CP0_INTCTL 32 2321 MIPS KVM_REG_MIPS_CP0_CAUSE 32 2322 MIPS KVM_REG_MIPS_CP0_EPC 64 2323 MIPS KVM_REG_MIPS_CP0_PRID 32 2324 MIPS KVM_REG_MIPS_CP0_EBASE 64 2325 MIPS KVM_REG_MIPS_CP0_CONFIG 32 2326 MIPS KVM_REG_MIPS_CP0_CONFIG1 32 2327 MIPS KVM_REG_MIPS_CP0_CONFIG2 32 2328 MIPS KVM_REG_MIPS_CP0_CONFIG3 32 2329 MIPS KVM_REG_MIPS_CP0_CONFIG4 32 2330 MIPS KVM_REG_MIPS_CP0_CONFIG5 32 2331 MIPS KVM_REG_MIPS_CP0_CONFIG7 32 2332 MIPS KVM_REG_MIPS_CP0_XCONTEXT 64 2333 MIPS KVM_REG_MIPS_CP0_ERROREPC 64 2334 MIPS KVM_REG_MIPS_CP0_KSCRATCH1 64 2335 MIPS KVM_REG_MIPS_CP0_KSCRATCH2 64 2336 MIPS KVM_REG_MIPS_CP0_KSCRATCH3 64 2337 MIPS KVM_REG_MIPS_CP0_KSCRATCH4 64 2338 MIPS KVM_REG_MIPS_CP0_KSCRATCH5 64 2339 MIPS KVM_REG_MIPS_CP0_KSCRATCH6 64 2340 MIPS KVM_REG_MIPS_CP0_MAAR(0..63) 64 2341 MIPS KVM_REG_MIPS_COUNT_CTL 64 2342 MIPS KVM_REG_MIPS_COUNT_RESUME 64 2343 MIPS KVM_REG_MIPS_COUNT_HZ 64 2344 MIPS KVM_REG_MIPS_FPR_32(0..31) 32 2345 MIPS KVM_REG_MIPS_FPR_64(0..31) 64 2346 MIPS KVM_REG_MIPS_VEC_128(0..31) 128 2347 MIPS KVM_REG_MIPS_FCR_IR 32 2348 MIPS KVM_REG_MIPS_FCR_CSR 32 2349 MIPS KVM_REG_MIPS_MSA_IR 32 2350 MIPS KVM_REG_MIPS_MSA_CSR 32 2351 ======= =============================== ============ 2352 2353ARM registers are mapped using the lower 32 bits. The upper 16 of that 2354is the register group type, or coprocessor number: 2355 2356ARM core registers have the following id bit patterns:: 2357 2358 0x4020 0000 0010 <index into the kvm_regs struct:16> 2359 2360ARM 32-bit CP15 registers have the following id bit patterns:: 2361 2362 0x4020 0000 000F <zero:1> <crn:4> <crm:4> <opc1:4> <opc2:3> 2363 2364ARM 64-bit CP15 registers have the following id bit patterns:: 2365 2366 0x4030 0000 000F <zero:1> <zero:4> <crm:4> <opc1:4> <zero:3> 2367 2368ARM CCSIDR registers are demultiplexed by CSSELR value:: 2369 2370 0x4020 0000 0011 00 <csselr:8> 2371 2372ARM 32-bit VFP control registers have the following id bit patterns:: 2373 2374 0x4020 0000 0012 1 <regno:12> 2375 2376ARM 64-bit FP registers have the following id bit patterns:: 2377 2378 0x4030 0000 0012 0 <regno:12> 2379 2380ARM firmware pseudo-registers have the following bit pattern:: 2381 2382 0x4030 0000 0014 <regno:16> 2383 2384 2385arm64 registers are mapped using the lower 32 bits. The upper 16 of 2386that is the register group type, or coprocessor number: 2387 2388arm64 core/FP-SIMD registers have the following id bit patterns. Note 2389that the size of the access is variable, as the kvm_regs structure 2390contains elements ranging from 32 to 128 bits. The index is a 32bit 2391value in the kvm_regs structure seen as a 32bit array:: 2392 2393 0x60x0 0000 0010 <index into the kvm_regs struct:16> 2394 2395Specifically: 2396 2397======================= ========= ===== ======================================= 2398 Encoding Register Bits kvm_regs member 2399======================= ========= ===== ======================================= 2400 0x6030 0000 0010 0000 X0 64 regs.regs[0] 2401 0x6030 0000 0010 0002 X1 64 regs.regs[1] 2402 ... 2403 0x6030 0000 0010 003c X30 64 regs.regs[30] 2404 0x6030 0000 0010 003e SP 64 regs.sp 2405 0x6030 0000 0010 0040 PC 64 regs.pc 2406 0x6030 0000 0010 0042 PSTATE 64 regs.pstate 2407 0x6030 0000 0010 0044 SP_EL1 64 sp_el1 2408 0x6030 0000 0010 0046 ELR_EL1 64 elr_el1 2409 0x6030 0000 0010 0048 SPSR_EL1 64 spsr[KVM_SPSR_EL1] (alias SPSR_SVC) 2410 0x6030 0000 0010 004a SPSR_ABT 64 spsr[KVM_SPSR_ABT] 2411 0x6030 0000 0010 004c SPSR_UND 64 spsr[KVM_SPSR_UND] 2412 0x6030 0000 0010 004e SPSR_IRQ 64 spsr[KVM_SPSR_IRQ] 2413 0x6060 0000 0010 0050 SPSR_FIQ 64 spsr[KVM_SPSR_FIQ] 2414 0x6040 0000 0010 0054 V0 128 fp_regs.vregs[0] [1]_ 2415 0x6040 0000 0010 0058 V1 128 fp_regs.vregs[1] [1]_ 2416 ... 2417 0x6040 0000 0010 00d0 V31 128 fp_regs.vregs[31] [1]_ 2418 0x6020 0000 0010 00d4 FPSR 32 fp_regs.fpsr 2419 0x6020 0000 0010 00d5 FPCR 32 fp_regs.fpcr 2420======================= ========= ===== ======================================= 2421 2422.. [1] These encodings are not accepted for SVE-enabled vcpus. See 2423 KVM_ARM_VCPU_INIT. 2424 2425 The equivalent register content can be accessed via bits [127:0] of 2426 the corresponding SVE Zn registers instead for vcpus that have SVE 2427 enabled (see below). 2428 2429arm64 CCSIDR registers are demultiplexed by CSSELR value:: 2430 2431 0x6020 0000 0011 00 <csselr:8> 2432 2433arm64 system registers have the following id bit patterns:: 2434 2435 0x6030 0000 0013 <op0:2> <op1:3> <crn:4> <crm:4> <op2:3> 2436 2437.. warning:: 2438 2439 Two system register IDs do not follow the specified pattern. These 2440 are KVM_REG_ARM_TIMER_CVAL and KVM_REG_ARM_TIMER_CNT, which map to 2441 system registers CNTV_CVAL_EL0 and CNTVCT_EL0 respectively. These 2442 two had their values accidentally swapped, which means TIMER_CVAL is 2443 derived from the register encoding for CNTVCT_EL0 and TIMER_CNT is 2444 derived from the register encoding for CNTV_CVAL_EL0. As this is 2445 API, it must remain this way. 2446 2447arm64 firmware pseudo-registers have the following bit pattern:: 2448 2449 0x6030 0000 0014 <regno:16> 2450 2451arm64 SVE registers have the following bit patterns:: 2452 2453 0x6080 0000 0015 00 <n:5> <slice:5> Zn bits[2048*slice + 2047 : 2048*slice] 2454 0x6050 0000 0015 04 <n:4> <slice:5> Pn bits[256*slice + 255 : 256*slice] 2455 0x6050 0000 0015 060 <slice:5> FFR bits[256*slice + 255 : 256*slice] 2456 0x6060 0000 0015 ffff KVM_REG_ARM64_SVE_VLS pseudo-register 2457 2458Access to register IDs where 2048 * slice >= 128 * max_vq will fail with 2459ENOENT. max_vq is the vcpu's maximum supported vector length in 128-bit 2460quadwords: see [2]_ below. 2461 2462These registers are only accessible on vcpus for which SVE is enabled. 2463See KVM_ARM_VCPU_INIT for details. 2464 2465In addition, except for KVM_REG_ARM64_SVE_VLS, these registers are not 2466accessible until the vcpu's SVE configuration has been finalized 2467using KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE). See KVM_ARM_VCPU_INIT 2468and KVM_ARM_VCPU_FINALIZE for more information about this procedure. 2469 2470KVM_REG_ARM64_SVE_VLS is a pseudo-register that allows the set of vector 2471lengths supported by the vcpu to be discovered and configured by 2472userspace. When transferred to or from user memory via KVM_GET_ONE_REG 2473or KVM_SET_ONE_REG, the value of this register is of type 2474__u64[KVM_ARM64_SVE_VLS_WORDS], and encodes the set of vector lengths as 2475follows:: 2476 2477 __u64 vector_lengths[KVM_ARM64_SVE_VLS_WORDS]; 2478 2479 if (vq >= SVE_VQ_MIN && vq <= SVE_VQ_MAX && 2480 ((vector_lengths[(vq - KVM_ARM64_SVE_VQ_MIN) / 64] >> 2481 ((vq - KVM_ARM64_SVE_VQ_MIN) % 64)) & 1)) 2482 /* Vector length vq * 16 bytes supported */ 2483 else 2484 /* Vector length vq * 16 bytes not supported */ 2485 2486.. [2] The maximum value vq for which the above condition is true is 2487 max_vq. This is the maximum vector length available to the guest on 2488 this vcpu, and determines which register slices are visible through 2489 this ioctl interface. 2490 2491(See Documentation/arm64/sve.rst for an explanation of the "vq" 2492nomenclature.) 2493 2494KVM_REG_ARM64_SVE_VLS is only accessible after KVM_ARM_VCPU_INIT. 2495KVM_ARM_VCPU_INIT initialises it to the best set of vector lengths that 2496the host supports. 2497 2498Userspace may subsequently modify it if desired until the vcpu's SVE 2499configuration is finalized using KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE). 2500 2501Apart from simply removing all vector lengths from the host set that 2502exceed some value, support for arbitrarily chosen sets of vector lengths 2503is hardware-dependent and may not be available. Attempting to configure 2504an invalid set of vector lengths via KVM_SET_ONE_REG will fail with 2505EINVAL. 2506 2507After the vcpu's SVE configuration is finalized, further attempts to 2508write this register will fail with EPERM. 2509 2510 2511MIPS registers are mapped using the lower 32 bits. The upper 16 of that is 2512the register group type: 2513 2514MIPS core registers (see above) have the following id bit patterns:: 2515 2516 0x7030 0000 0000 <reg:16> 2517 2518MIPS CP0 registers (see KVM_REG_MIPS_CP0_* above) have the following id bit 2519patterns depending on whether they're 32-bit or 64-bit registers:: 2520 2521 0x7020 0000 0001 00 <reg:5> <sel:3> (32-bit) 2522 0x7030 0000 0001 00 <reg:5> <sel:3> (64-bit) 2523 2524Note: KVM_REG_MIPS_CP0_ENTRYLO0 and KVM_REG_MIPS_CP0_ENTRYLO1 are the MIPS64 2525versions of the EntryLo registers regardless of the word size of the host 2526hardware, host kernel, guest, and whether XPA is present in the guest, i.e. 2527with the RI and XI bits (if they exist) in bits 63 and 62 respectively, and 2528the PFNX field starting at bit 30. 2529 2530MIPS MAARs (see KVM_REG_MIPS_CP0_MAAR(*) above) have the following id bit 2531patterns:: 2532 2533 0x7030 0000 0001 01 <reg:8> 2534 2535MIPS KVM control registers (see above) have the following id bit patterns:: 2536 2537 0x7030 0000 0002 <reg:16> 2538 2539MIPS FPU registers (see KVM_REG_MIPS_FPR_{32,64}() above) have the following 2540id bit patterns depending on the size of the register being accessed. They are 2541always accessed according to the current guest FPU mode (Status.FR and 2542Config5.FRE), i.e. as the guest would see them, and they become unpredictable 2543if the guest FPU mode is changed. MIPS SIMD Architecture (MSA) vector 2544registers (see KVM_REG_MIPS_VEC_128() above) have similar patterns as they 2545overlap the FPU registers:: 2546 2547 0x7020 0000 0003 00 <0:3> <reg:5> (32-bit FPU registers) 2548 0x7030 0000 0003 00 <0:3> <reg:5> (64-bit FPU registers) 2549 0x7040 0000 0003 00 <0:3> <reg:5> (128-bit MSA vector registers) 2550 2551MIPS FPU control registers (see KVM_REG_MIPS_FCR_{IR,CSR} above) have the 2552following id bit patterns:: 2553 2554 0x7020 0000 0003 01 <0:3> <reg:5> 2555 2556MIPS MSA control registers (see KVM_REG_MIPS_MSA_{IR,CSR} above) have the 2557following id bit patterns:: 2558 2559 0x7020 0000 0003 02 <0:3> <reg:5> 2560 2561 25624.69 KVM_GET_ONE_REG 2563-------------------- 2564 2565:Capability: KVM_CAP_ONE_REG 2566:Architectures: all 2567:Type: vcpu ioctl 2568:Parameters: struct kvm_one_reg (in and out) 2569:Returns: 0 on success, negative value on failure 2570 2571Errors include: 2572 2573 ======== ============================================================ 2574 ENOENT no such register 2575 EINVAL invalid register ID, or no such register or used with VMs in 2576 protected virtualization mode on s390 2577 EPERM (arm64) register access not allowed before vcpu finalization 2578 ======== ============================================================ 2579 2580(These error codes are indicative only: do not rely on a specific error 2581code being returned in a specific situation.) 2582 2583This ioctl allows to receive the value of a single register implemented 2584in a vcpu. The register to read is indicated by the "id" field of the 2585kvm_one_reg struct passed in. On success, the register value can be found 2586at the memory location pointed to by "addr". 2587 2588The list of registers accessible using this interface is identical to the 2589list in 4.68. 2590 2591 25924.70 KVM_KVMCLOCK_CTRL 2593---------------------- 2594 2595:Capability: KVM_CAP_KVMCLOCK_CTRL 2596:Architectures: Any that implement pvclocks (currently x86 only) 2597:Type: vcpu ioctl 2598:Parameters: None 2599:Returns: 0 on success, -1 on error 2600 2601This ioctl sets a flag accessible to the guest indicating that the specified 2602vCPU has been paused by the host userspace. 2603 2604The host will set a flag in the pvclock structure that is checked from the 2605soft lockup watchdog. The flag is part of the pvclock structure that is 2606shared between guest and host, specifically the second bit of the flags 2607field of the pvclock_vcpu_time_info structure. It will be set exclusively by 2608the host and read/cleared exclusively by the guest. The guest operation of 2609checking and clearing the flag must be an atomic operation so 2610load-link/store-conditional, or equivalent must be used. There are two cases 2611where the guest will clear the flag: when the soft lockup watchdog timer resets 2612itself or when a soft lockup is detected. This ioctl can be called any time 2613after pausing the vcpu, but before it is resumed. 2614 2615 26164.71 KVM_SIGNAL_MSI 2617------------------- 2618 2619:Capability: KVM_CAP_SIGNAL_MSI 2620:Architectures: x86 arm arm64 2621:Type: vm ioctl 2622:Parameters: struct kvm_msi (in) 2623:Returns: >0 on delivery, 0 if guest blocked the MSI, and -1 on error 2624 2625Directly inject a MSI message. Only valid with in-kernel irqchip that handles 2626MSI messages. 2627 2628:: 2629 2630 struct kvm_msi { 2631 __u32 address_lo; 2632 __u32 address_hi; 2633 __u32 data; 2634 __u32 flags; 2635 __u32 devid; 2636 __u8 pad[12]; 2637 }; 2638 2639flags: 2640 KVM_MSI_VALID_DEVID: devid contains a valid value. The per-VM 2641 KVM_CAP_MSI_DEVID capability advertises the requirement to provide 2642 the device ID. If this capability is not available, userspace 2643 should never set the KVM_MSI_VALID_DEVID flag as the ioctl might fail. 2644 2645If KVM_MSI_VALID_DEVID is set, devid contains a unique device identifier 2646for the device that wrote the MSI message. For PCI, this is usually a 2647BFD identifier in the lower 16 bits. 2648 2649On x86, address_hi is ignored unless the KVM_X2APIC_API_USE_32BIT_IDS 2650feature of KVM_CAP_X2APIC_API capability is enabled. If it is enabled, 2651address_hi bits 31-8 provide bits 31-8 of the destination id. Bits 7-0 of 2652address_hi must be zero. 2653 2654 26554.71 KVM_CREATE_PIT2 2656-------------------- 2657 2658:Capability: KVM_CAP_PIT2 2659:Architectures: x86 2660:Type: vm ioctl 2661:Parameters: struct kvm_pit_config (in) 2662:Returns: 0 on success, -1 on error 2663 2664Creates an in-kernel device model for the i8254 PIT. This call is only valid 2665after enabling in-kernel irqchip support via KVM_CREATE_IRQCHIP. The following 2666parameters have to be passed:: 2667 2668 struct kvm_pit_config { 2669 __u32 flags; 2670 __u32 pad[15]; 2671 }; 2672 2673Valid flags are:: 2674 2675 #define KVM_PIT_SPEAKER_DUMMY 1 /* emulate speaker port stub */ 2676 2677PIT timer interrupts may use a per-VM kernel thread for injection. If it 2678exists, this thread will have a name of the following pattern:: 2679 2680 kvm-pit/<owner-process-pid> 2681 2682When running a guest with elevated priorities, the scheduling parameters of 2683this thread may have to be adjusted accordingly. 2684 2685This IOCTL replaces the obsolete KVM_CREATE_PIT. 2686 2687 26884.72 KVM_GET_PIT2 2689----------------- 2690 2691:Capability: KVM_CAP_PIT_STATE2 2692:Architectures: x86 2693:Type: vm ioctl 2694:Parameters: struct kvm_pit_state2 (out) 2695:Returns: 0 on success, -1 on error 2696 2697Retrieves the state of the in-kernel PIT model. Only valid after 2698KVM_CREATE_PIT2. The state is returned in the following structure:: 2699 2700 struct kvm_pit_state2 { 2701 struct kvm_pit_channel_state channels[3]; 2702 __u32 flags; 2703 __u32 reserved[9]; 2704 }; 2705 2706Valid flags are:: 2707 2708 /* disable PIT in HPET legacy mode */ 2709 #define KVM_PIT_FLAGS_HPET_LEGACY 0x00000001 2710 2711This IOCTL replaces the obsolete KVM_GET_PIT. 2712 2713 27144.73 KVM_SET_PIT2 2715----------------- 2716 2717:Capability: KVM_CAP_PIT_STATE2 2718:Architectures: x86 2719:Type: vm ioctl 2720:Parameters: struct kvm_pit_state2 (in) 2721:Returns: 0 on success, -1 on error 2722 2723Sets the state of the in-kernel PIT model. Only valid after KVM_CREATE_PIT2. 2724See KVM_GET_PIT2 for details on struct kvm_pit_state2. 2725 2726This IOCTL replaces the obsolete KVM_SET_PIT. 2727 2728 27294.74 KVM_PPC_GET_SMMU_INFO 2730-------------------------- 2731 2732:Capability: KVM_CAP_PPC_GET_SMMU_INFO 2733:Architectures: powerpc 2734:Type: vm ioctl 2735:Parameters: None 2736:Returns: 0 on success, -1 on error 2737 2738This populates and returns a structure describing the features of 2739the "Server" class MMU emulation supported by KVM. 2740This can in turn be used by userspace to generate the appropriate 2741device-tree properties for the guest operating system. 2742 2743The structure contains some global information, followed by an 2744array of supported segment page sizes:: 2745 2746 struct kvm_ppc_smmu_info { 2747 __u64 flags; 2748 __u32 slb_size; 2749 __u32 pad; 2750 struct kvm_ppc_one_seg_page_size sps[KVM_PPC_PAGE_SIZES_MAX_SZ]; 2751 }; 2752 2753The supported flags are: 2754 2755 - KVM_PPC_PAGE_SIZES_REAL: 2756 When that flag is set, guest page sizes must "fit" the backing 2757 store page sizes. When not set, any page size in the list can 2758 be used regardless of how they are backed by userspace. 2759 2760 - KVM_PPC_1T_SEGMENTS 2761 The emulated MMU supports 1T segments in addition to the 2762 standard 256M ones. 2763 2764 - KVM_PPC_NO_HASH 2765 This flag indicates that HPT guests are not supported by KVM, 2766 thus all guests must use radix MMU mode. 2767 2768The "slb_size" field indicates how many SLB entries are supported 2769 2770The "sps" array contains 8 entries indicating the supported base 2771page sizes for a segment in increasing order. Each entry is defined 2772as follow:: 2773 2774 struct kvm_ppc_one_seg_page_size { 2775 __u32 page_shift; /* Base page shift of segment (or 0) */ 2776 __u32 slb_enc; /* SLB encoding for BookS */ 2777 struct kvm_ppc_one_page_size enc[KVM_PPC_PAGE_SIZES_MAX_SZ]; 2778 }; 2779 2780An entry with a "page_shift" of 0 is unused. Because the array is 2781organized in increasing order, a lookup can stop when encoutering 2782such an entry. 2783 2784The "slb_enc" field provides the encoding to use in the SLB for the 2785page size. The bits are in positions such as the value can directly 2786be OR'ed into the "vsid" argument of the slbmte instruction. 2787 2788The "enc" array is a list which for each of those segment base page 2789size provides the list of supported actual page sizes (which can be 2790only larger or equal to the base page size), along with the 2791corresponding encoding in the hash PTE. Similarly, the array is 27928 entries sorted by increasing sizes and an entry with a "0" shift 2793is an empty entry and a terminator:: 2794 2795 struct kvm_ppc_one_page_size { 2796 __u32 page_shift; /* Page shift (or 0) */ 2797 __u32 pte_enc; /* Encoding in the HPTE (>>12) */ 2798 }; 2799 2800The "pte_enc" field provides a value that can OR'ed into the hash 2801PTE's RPN field (ie, it needs to be shifted left by 12 to OR it 2802into the hash PTE second double word). 2803 28044.75 KVM_IRQFD 2805-------------- 2806 2807:Capability: KVM_CAP_IRQFD 2808:Architectures: x86 s390 arm arm64 2809:Type: vm ioctl 2810:Parameters: struct kvm_irqfd (in) 2811:Returns: 0 on success, -1 on error 2812 2813Allows setting an eventfd to directly trigger a guest interrupt. 2814kvm_irqfd.fd specifies the file descriptor to use as the eventfd and 2815kvm_irqfd.gsi specifies the irqchip pin toggled by this event. When 2816an event is triggered on the eventfd, an interrupt is injected into 2817the guest using the specified gsi pin. The irqfd is removed using 2818the KVM_IRQFD_FLAG_DEASSIGN flag, specifying both kvm_irqfd.fd 2819and kvm_irqfd.gsi. 2820 2821With KVM_CAP_IRQFD_RESAMPLE, KVM_IRQFD supports a de-assert and notify 2822mechanism allowing emulation of level-triggered, irqfd-based 2823interrupts. When KVM_IRQFD_FLAG_RESAMPLE is set the user must pass an 2824additional eventfd in the kvm_irqfd.resamplefd field. When operating 2825in resample mode, posting of an interrupt through kvm_irq.fd asserts 2826the specified gsi in the irqchip. When the irqchip is resampled, such 2827as from an EOI, the gsi is de-asserted and the user is notified via 2828kvm_irqfd.resamplefd. It is the user's responsibility to re-queue 2829the interrupt if the device making use of it still requires service. 2830Note that closing the resamplefd is not sufficient to disable the 2831irqfd. The KVM_IRQFD_FLAG_RESAMPLE is only necessary on assignment 2832and need not be specified with KVM_IRQFD_FLAG_DEASSIGN. 2833 2834On arm/arm64, gsi routing being supported, the following can happen: 2835 2836- in case no routing entry is associated to this gsi, injection fails 2837- in case the gsi is associated to an irqchip routing entry, 2838 irqchip.pin + 32 corresponds to the injected SPI ID. 2839- in case the gsi is associated to an MSI routing entry, the MSI 2840 message and device ID are translated into an LPI (support restricted 2841 to GICv3 ITS in-kernel emulation). 2842 28434.76 KVM_PPC_ALLOCATE_HTAB 2844-------------------------- 2845 2846:Capability: KVM_CAP_PPC_ALLOC_HTAB 2847:Architectures: powerpc 2848:Type: vm ioctl 2849:Parameters: Pointer to u32 containing hash table order (in/out) 2850:Returns: 0 on success, -1 on error 2851 2852This requests the host kernel to allocate an MMU hash table for a 2853guest using the PAPR paravirtualization interface. This only does 2854anything if the kernel is configured to use the Book 3S HV style of 2855virtualization. Otherwise the capability doesn't exist and the ioctl 2856returns an ENOTTY error. The rest of this description assumes Book 3S 2857HV. 2858 2859There must be no vcpus running when this ioctl is called; if there 2860are, it will do nothing and return an EBUSY error. 2861 2862The parameter is a pointer to a 32-bit unsigned integer variable 2863containing the order (log base 2) of the desired size of the hash 2864table, which must be between 18 and 46. On successful return from the 2865ioctl, the value will not be changed by the kernel. 2866 2867If no hash table has been allocated when any vcpu is asked to run 2868(with the KVM_RUN ioctl), the host kernel will allocate a 2869default-sized hash table (16 MB). 2870 2871If this ioctl is called when a hash table has already been allocated, 2872with a different order from the existing hash table, the existing hash 2873table will be freed and a new one allocated. If this is ioctl is 2874called when a hash table has already been allocated of the same order 2875as specified, the kernel will clear out the existing hash table (zero 2876all HPTEs). In either case, if the guest is using the virtualized 2877real-mode area (VRMA) facility, the kernel will re-create the VMRA 2878HPTEs on the next KVM_RUN of any vcpu. 2879 28804.77 KVM_S390_INTERRUPT 2881----------------------- 2882 2883:Capability: basic 2884:Architectures: s390 2885:Type: vm ioctl, vcpu ioctl 2886:Parameters: struct kvm_s390_interrupt (in) 2887:Returns: 0 on success, -1 on error 2888 2889Allows to inject an interrupt to the guest. Interrupts can be floating 2890(vm ioctl) or per cpu (vcpu ioctl), depending on the interrupt type. 2891 2892Interrupt parameters are passed via kvm_s390_interrupt:: 2893 2894 struct kvm_s390_interrupt { 2895 __u32 type; 2896 __u32 parm; 2897 __u64 parm64; 2898 }; 2899 2900type can be one of the following: 2901 2902KVM_S390_SIGP_STOP (vcpu) 2903 - sigp stop; optional flags in parm 2904KVM_S390_PROGRAM_INT (vcpu) 2905 - program check; code in parm 2906KVM_S390_SIGP_SET_PREFIX (vcpu) 2907 - sigp set prefix; prefix address in parm 2908KVM_S390_RESTART (vcpu) 2909 - restart 2910KVM_S390_INT_CLOCK_COMP (vcpu) 2911 - clock comparator interrupt 2912KVM_S390_INT_CPU_TIMER (vcpu) 2913 - CPU timer interrupt 2914KVM_S390_INT_VIRTIO (vm) 2915 - virtio external interrupt; external interrupt 2916 parameters in parm and parm64 2917KVM_S390_INT_SERVICE (vm) 2918 - sclp external interrupt; sclp parameter in parm 2919KVM_S390_INT_EMERGENCY (vcpu) 2920 - sigp emergency; source cpu in parm 2921KVM_S390_INT_EXTERNAL_CALL (vcpu) 2922 - sigp external call; source cpu in parm 2923KVM_S390_INT_IO(ai,cssid,ssid,schid) (vm) 2924 - compound value to indicate an 2925 I/O interrupt (ai - adapter interrupt; cssid,ssid,schid - subchannel); 2926 I/O interruption parameters in parm (subchannel) and parm64 (intparm, 2927 interruption subclass) 2928KVM_S390_MCHK (vm, vcpu) 2929 - machine check interrupt; cr 14 bits in parm, machine check interrupt 2930 code in parm64 (note that machine checks needing further payload are not 2931 supported by this ioctl) 2932 2933This is an asynchronous vcpu ioctl and can be invoked from any thread. 2934 29354.78 KVM_PPC_GET_HTAB_FD 2936------------------------ 2937 2938:Capability: KVM_CAP_PPC_HTAB_FD 2939:Architectures: powerpc 2940:Type: vm ioctl 2941:Parameters: Pointer to struct kvm_get_htab_fd (in) 2942:Returns: file descriptor number (>= 0) on success, -1 on error 2943 2944This returns a file descriptor that can be used either to read out the 2945entries in the guest's hashed page table (HPT), or to write entries to 2946initialize the HPT. The returned fd can only be written to if the 2947KVM_GET_HTAB_WRITE bit is set in the flags field of the argument, and 2948can only be read if that bit is clear. The argument struct looks like 2949this:: 2950 2951 /* For KVM_PPC_GET_HTAB_FD */ 2952 struct kvm_get_htab_fd { 2953 __u64 flags; 2954 __u64 start_index; 2955 __u64 reserved[2]; 2956 }; 2957 2958 /* Values for kvm_get_htab_fd.flags */ 2959 #define KVM_GET_HTAB_BOLTED_ONLY ((__u64)0x1) 2960 #define KVM_GET_HTAB_WRITE ((__u64)0x2) 2961 2962The 'start_index' field gives the index in the HPT of the entry at 2963which to start reading. It is ignored when writing. 2964 2965Reads on the fd will initially supply information about all 2966"interesting" HPT entries. Interesting entries are those with the 2967bolted bit set, if the KVM_GET_HTAB_BOLTED_ONLY bit is set, otherwise 2968all entries. When the end of the HPT is reached, the read() will 2969return. If read() is called again on the fd, it will start again from 2970the beginning of the HPT, but will only return HPT entries that have 2971changed since they were last read. 2972 2973Data read or written is structured as a header (8 bytes) followed by a 2974series of valid HPT entries (16 bytes) each. The header indicates how 2975many valid HPT entries there are and how many invalid entries follow 2976the valid entries. The invalid entries are not represented explicitly 2977in the stream. The header format is:: 2978 2979 struct kvm_get_htab_header { 2980 __u32 index; 2981 __u16 n_valid; 2982 __u16 n_invalid; 2983 }; 2984 2985Writes to the fd create HPT entries starting at the index given in the 2986header; first 'n_valid' valid entries with contents from the data 2987written, then 'n_invalid' invalid entries, invalidating any previously 2988valid entries found. 2989 29904.79 KVM_CREATE_DEVICE 2991---------------------- 2992 2993:Capability: KVM_CAP_DEVICE_CTRL 2994:Type: vm ioctl 2995:Parameters: struct kvm_create_device (in/out) 2996:Returns: 0 on success, -1 on error 2997 2998Errors: 2999 3000 ====== ======================================================= 3001 ENODEV The device type is unknown or unsupported 3002 EEXIST Device already created, and this type of device may not 3003 be instantiated multiple times 3004 ====== ======================================================= 3005 3006 Other error conditions may be defined by individual device types or 3007 have their standard meanings. 3008 3009Creates an emulated device in the kernel. The file descriptor returned 3010in fd can be used with KVM_SET/GET/HAS_DEVICE_ATTR. 3011 3012If the KVM_CREATE_DEVICE_TEST flag is set, only test whether the 3013device type is supported (not necessarily whether it can be created 3014in the current vm). 3015 3016Individual devices should not define flags. Attributes should be used 3017for specifying any behavior that is not implied by the device type 3018number. 3019 3020:: 3021 3022 struct kvm_create_device { 3023 __u32 type; /* in: KVM_DEV_TYPE_xxx */ 3024 __u32 fd; /* out: device handle */ 3025 __u32 flags; /* in: KVM_CREATE_DEVICE_xxx */ 3026 }; 3027 30284.80 KVM_SET_DEVICE_ATTR/KVM_GET_DEVICE_ATTR 3029-------------------------------------------- 3030 3031:Capability: KVM_CAP_DEVICE_CTRL, KVM_CAP_VM_ATTRIBUTES for vm device, 3032 KVM_CAP_VCPU_ATTRIBUTES for vcpu device 3033:Type: device ioctl, vm ioctl, vcpu ioctl 3034:Parameters: struct kvm_device_attr 3035:Returns: 0 on success, -1 on error 3036 3037Errors: 3038 3039 ===== ============================================================= 3040 ENXIO The group or attribute is unknown/unsupported for this device 3041 or hardware support is missing. 3042 EPERM The attribute cannot (currently) be accessed this way 3043 (e.g. read-only attribute, or attribute that only makes 3044 sense when the device is in a different state) 3045 ===== ============================================================= 3046 3047 Other error conditions may be defined by individual device types. 3048 3049Gets/sets a specified piece of device configuration and/or state. The 3050semantics are device-specific. See individual device documentation in 3051the "devices" directory. As with ONE_REG, the size of the data 3052transferred is defined by the particular attribute. 3053 3054:: 3055 3056 struct kvm_device_attr { 3057 __u32 flags; /* no flags currently defined */ 3058 __u32 group; /* device-defined */ 3059 __u64 attr; /* group-defined */ 3060 __u64 addr; /* userspace address of attr data */ 3061 }; 3062 30634.81 KVM_HAS_DEVICE_ATTR 3064------------------------ 3065 3066:Capability: KVM_CAP_DEVICE_CTRL, KVM_CAP_VM_ATTRIBUTES for vm device, 3067 KVM_CAP_VCPU_ATTRIBUTES for vcpu device 3068:Type: device ioctl, vm ioctl, vcpu ioctl 3069:Parameters: struct kvm_device_attr 3070:Returns: 0 on success, -1 on error 3071 3072Errors: 3073 3074 ===== ============================================================= 3075 ENXIO The group or attribute is unknown/unsupported for this device 3076 or hardware support is missing. 3077 ===== ============================================================= 3078 3079Tests whether a device supports a particular attribute. A successful 3080return indicates the attribute is implemented. It does not necessarily 3081indicate that the attribute can be read or written in the device's 3082current state. "addr" is ignored. 3083 30844.82 KVM_ARM_VCPU_INIT 3085---------------------- 3086 3087:Capability: basic 3088:Architectures: arm, arm64 3089:Type: vcpu ioctl 3090:Parameters: struct kvm_vcpu_init (in) 3091:Returns: 0 on success; -1 on error 3092 3093Errors: 3094 3095 ====== ================================================================= 3096 EINVAL the target is unknown, or the combination of features is invalid. 3097 ENOENT a features bit specified is unknown. 3098 ====== ================================================================= 3099 3100This tells KVM what type of CPU to present to the guest, and what 3101optional features it should have. This will cause a reset of the cpu 3102registers to their initial values. If this is not called, KVM_RUN will 3103return ENOEXEC for that vcpu. 3104 3105Note that because some registers reflect machine topology, all vcpus 3106should be created before this ioctl is invoked. 3107 3108Userspace can call this function multiple times for a given vcpu, including 3109after the vcpu has been run. This will reset the vcpu to its initial 3110state. All calls to this function after the initial call must use the same 3111target and same set of feature flags, otherwise EINVAL will be returned. 3112 3113Possible features: 3114 3115 - KVM_ARM_VCPU_POWER_OFF: Starts the CPU in a power-off state. 3116 Depends on KVM_CAP_ARM_PSCI. If not set, the CPU will be powered on 3117 and execute guest code when KVM_RUN is called. 3118 - KVM_ARM_VCPU_EL1_32BIT: Starts the CPU in a 32bit mode. 3119 Depends on KVM_CAP_ARM_EL1_32BIT (arm64 only). 3120 - KVM_ARM_VCPU_PSCI_0_2: Emulate PSCI v0.2 (or a future revision 3121 backward compatible with v0.2) for the CPU. 3122 Depends on KVM_CAP_ARM_PSCI_0_2. 3123 - KVM_ARM_VCPU_PMU_V3: Emulate PMUv3 for the CPU. 3124 Depends on KVM_CAP_ARM_PMU_V3. 3125 3126 - KVM_ARM_VCPU_PTRAUTH_ADDRESS: Enables Address Pointer authentication 3127 for arm64 only. 3128 Depends on KVM_CAP_ARM_PTRAUTH_ADDRESS. 3129 If KVM_CAP_ARM_PTRAUTH_ADDRESS and KVM_CAP_ARM_PTRAUTH_GENERIC are 3130 both present, then both KVM_ARM_VCPU_PTRAUTH_ADDRESS and 3131 KVM_ARM_VCPU_PTRAUTH_GENERIC must be requested or neither must be 3132 requested. 3133 3134 - KVM_ARM_VCPU_PTRAUTH_GENERIC: Enables Generic Pointer authentication 3135 for arm64 only. 3136 Depends on KVM_CAP_ARM_PTRAUTH_GENERIC. 3137 If KVM_CAP_ARM_PTRAUTH_ADDRESS and KVM_CAP_ARM_PTRAUTH_GENERIC are 3138 both present, then both KVM_ARM_VCPU_PTRAUTH_ADDRESS and 3139 KVM_ARM_VCPU_PTRAUTH_GENERIC must be requested or neither must be 3140 requested. 3141 3142 - KVM_ARM_VCPU_SVE: Enables SVE for the CPU (arm64 only). 3143 Depends on KVM_CAP_ARM_SVE. 3144 Requires KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE): 3145 3146 * After KVM_ARM_VCPU_INIT: 3147 3148 - KVM_REG_ARM64_SVE_VLS may be read using KVM_GET_ONE_REG: the 3149 initial value of this pseudo-register indicates the best set of 3150 vector lengths possible for a vcpu on this host. 3151 3152 * Before KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE): 3153 3154 - KVM_RUN and KVM_GET_REG_LIST are not available; 3155 3156 - KVM_GET_ONE_REG and KVM_SET_ONE_REG cannot be used to access 3157 the scalable archietctural SVE registers 3158 KVM_REG_ARM64_SVE_ZREG(), KVM_REG_ARM64_SVE_PREG() or 3159 KVM_REG_ARM64_SVE_FFR; 3160 3161 - KVM_REG_ARM64_SVE_VLS may optionally be written using 3162 KVM_SET_ONE_REG, to modify the set of vector lengths available 3163 for the vcpu. 3164 3165 * After KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE): 3166 3167 - the KVM_REG_ARM64_SVE_VLS pseudo-register is immutable, and can 3168 no longer be written using KVM_SET_ONE_REG. 3169 31704.83 KVM_ARM_PREFERRED_TARGET 3171----------------------------- 3172 3173:Capability: basic 3174:Architectures: arm, arm64 3175:Type: vm ioctl 3176:Parameters: struct kvm_vcpu_init (out) 3177:Returns: 0 on success; -1 on error 3178 3179Errors: 3180 3181 ====== ========================================== 3182 ENODEV no preferred target available for the host 3183 ====== ========================================== 3184 3185This queries KVM for preferred CPU target type which can be emulated 3186by KVM on underlying host. 3187 3188The ioctl returns struct kvm_vcpu_init instance containing information 3189about preferred CPU target type and recommended features for it. The 3190kvm_vcpu_init->features bitmap returned will have feature bits set if 3191the preferred target recommends setting these features, but this is 3192not mandatory. 3193 3194The information returned by this ioctl can be used to prepare an instance 3195of struct kvm_vcpu_init for KVM_ARM_VCPU_INIT ioctl which will result in 3196VCPU matching underlying host. 3197 3198 31994.84 KVM_GET_REG_LIST 3200--------------------- 3201 3202:Capability: basic 3203:Architectures: arm, arm64, mips 3204:Type: vcpu ioctl 3205:Parameters: struct kvm_reg_list (in/out) 3206:Returns: 0 on success; -1 on error 3207 3208Errors: 3209 3210 ===== ============================================================== 3211 E2BIG the reg index list is too big to fit in the array specified by 3212 the user (the number required will be written into n). 3213 ===== ============================================================== 3214 3215:: 3216 3217 struct kvm_reg_list { 3218 __u64 n; /* number of registers in reg[] */ 3219 __u64 reg[0]; 3220 }; 3221 3222This ioctl returns the guest registers that are supported for the 3223KVM_GET_ONE_REG/KVM_SET_ONE_REG calls. 3224 3225 32264.85 KVM_ARM_SET_DEVICE_ADDR (deprecated) 3227----------------------------------------- 3228 3229:Capability: KVM_CAP_ARM_SET_DEVICE_ADDR 3230:Architectures: arm, arm64 3231:Type: vm ioctl 3232:Parameters: struct kvm_arm_device_address (in) 3233:Returns: 0 on success, -1 on error 3234 3235Errors: 3236 3237 ====== ============================================ 3238 ENODEV The device id is unknown 3239 ENXIO Device not supported on current system 3240 EEXIST Address already set 3241 E2BIG Address outside guest physical address space 3242 EBUSY Address overlaps with other device range 3243 ====== ============================================ 3244 3245:: 3246 3247 struct kvm_arm_device_addr { 3248 __u64 id; 3249 __u64 addr; 3250 }; 3251 3252Specify a device address in the guest's physical address space where guests 3253can access emulated or directly exposed devices, which the host kernel needs 3254to know about. The id field is an architecture specific identifier for a 3255specific device. 3256 3257ARM/arm64 divides the id field into two parts, a device id and an 3258address type id specific to the individual device:: 3259 3260 bits: | 63 ... 32 | 31 ... 16 | 15 ... 0 | 3261 field: | 0x00000000 | device id | addr type id | 3262 3263ARM/arm64 currently only require this when using the in-kernel GIC 3264support for the hardware VGIC features, using KVM_ARM_DEVICE_VGIC_V2 3265as the device id. When setting the base address for the guest's 3266mapping of the VGIC virtual CPU and distributor interface, the ioctl 3267must be called after calling KVM_CREATE_IRQCHIP, but before calling 3268KVM_RUN on any of the VCPUs. Calling this ioctl twice for any of the 3269base addresses will return -EEXIST. 3270 3271Note, this IOCTL is deprecated and the more flexible SET/GET_DEVICE_ATTR API 3272should be used instead. 3273 3274 32754.86 KVM_PPC_RTAS_DEFINE_TOKEN 3276------------------------------ 3277 3278:Capability: KVM_CAP_PPC_RTAS 3279:Architectures: ppc 3280:Type: vm ioctl 3281:Parameters: struct kvm_rtas_token_args 3282:Returns: 0 on success, -1 on error 3283 3284Defines a token value for a RTAS (Run Time Abstraction Services) 3285service in order to allow it to be handled in the kernel. The 3286argument struct gives the name of the service, which must be the name 3287of a service that has a kernel-side implementation. If the token 3288value is non-zero, it will be associated with that service, and 3289subsequent RTAS calls by the guest specifying that token will be 3290handled by the kernel. If the token value is 0, then any token 3291associated with the service will be forgotten, and subsequent RTAS 3292calls by the guest for that service will be passed to userspace to be 3293handled. 3294 32954.87 KVM_SET_GUEST_DEBUG 3296------------------------ 3297 3298:Capability: KVM_CAP_SET_GUEST_DEBUG 3299:Architectures: x86, s390, ppc, arm64 3300:Type: vcpu ioctl 3301:Parameters: struct kvm_guest_debug (in) 3302:Returns: 0 on success; -1 on error 3303 3304:: 3305 3306 struct kvm_guest_debug { 3307 __u32 control; 3308 __u32 pad; 3309 struct kvm_guest_debug_arch arch; 3310 }; 3311 3312Set up the processor specific debug registers and configure vcpu for 3313handling guest debug events. There are two parts to the structure, the 3314first a control bitfield indicates the type of debug events to handle 3315when running. Common control bits are: 3316 3317 - KVM_GUESTDBG_ENABLE: guest debugging is enabled 3318 - KVM_GUESTDBG_SINGLESTEP: the next run should single-step 3319 3320The top 16 bits of the control field are architecture specific control 3321flags which can include the following: 3322 3323 - KVM_GUESTDBG_USE_SW_BP: using software breakpoints [x86, arm64] 3324 - KVM_GUESTDBG_USE_HW_BP: using hardware breakpoints [x86, s390, arm64] 3325 - KVM_GUESTDBG_INJECT_DB: inject DB type exception [x86] 3326 - KVM_GUESTDBG_INJECT_BP: inject BP type exception [x86] 3327 - KVM_GUESTDBG_EXIT_PENDING: trigger an immediate guest exit [s390] 3328 3329For example KVM_GUESTDBG_USE_SW_BP indicates that software breakpoints 3330are enabled in memory so we need to ensure breakpoint exceptions are 3331correctly trapped and the KVM run loop exits at the breakpoint and not 3332running off into the normal guest vector. For KVM_GUESTDBG_USE_HW_BP 3333we need to ensure the guest vCPUs architecture specific registers are 3334updated to the correct (supplied) values. 3335 3336The second part of the structure is architecture specific and 3337typically contains a set of debug registers. 3338 3339For arm64 the number of debug registers is implementation defined and 3340can be determined by querying the KVM_CAP_GUEST_DEBUG_HW_BPS and 3341KVM_CAP_GUEST_DEBUG_HW_WPS capabilities which return a positive number 3342indicating the number of supported registers. 3343 3344For ppc, the KVM_CAP_PPC_GUEST_DEBUG_SSTEP capability indicates whether 3345the single-step debug event (KVM_GUESTDBG_SINGLESTEP) is supported. 3346 3347When debug events exit the main run loop with the reason 3348KVM_EXIT_DEBUG with the kvm_debug_exit_arch part of the kvm_run 3349structure containing architecture specific debug information. 3350 33514.88 KVM_GET_EMULATED_CPUID 3352--------------------------- 3353 3354:Capability: KVM_CAP_EXT_EMUL_CPUID 3355:Architectures: x86 3356:Type: system ioctl 3357:Parameters: struct kvm_cpuid2 (in/out) 3358:Returns: 0 on success, -1 on error 3359 3360:: 3361 3362 struct kvm_cpuid2 { 3363 __u32 nent; 3364 __u32 flags; 3365 struct kvm_cpuid_entry2 entries[0]; 3366 }; 3367 3368The member 'flags' is used for passing flags from userspace. 3369 3370:: 3371 3372 #define KVM_CPUID_FLAG_SIGNIFCANT_INDEX BIT(0) 3373 #define KVM_CPUID_FLAG_STATEFUL_FUNC BIT(1) /* deprecated */ 3374 #define KVM_CPUID_FLAG_STATE_READ_NEXT BIT(2) /* deprecated */ 3375 3376 struct kvm_cpuid_entry2 { 3377 __u32 function; 3378 __u32 index; 3379 __u32 flags; 3380 __u32 eax; 3381 __u32 ebx; 3382 __u32 ecx; 3383 __u32 edx; 3384 __u32 padding[3]; 3385 }; 3386 3387This ioctl returns x86 cpuid features which are emulated by 3388kvm.Userspace can use the information returned by this ioctl to query 3389which features are emulated by kvm instead of being present natively. 3390 3391Userspace invokes KVM_GET_EMULATED_CPUID by passing a kvm_cpuid2 3392structure with the 'nent' field indicating the number of entries in 3393the variable-size array 'entries'. If the number of entries is too low 3394to describe the cpu capabilities, an error (E2BIG) is returned. If the 3395number is too high, the 'nent' field is adjusted and an error (ENOMEM) 3396is returned. If the number is just right, the 'nent' field is adjusted 3397to the number of valid entries in the 'entries' array, which is then 3398filled. 3399 3400The entries returned are the set CPUID bits of the respective features 3401which kvm emulates, as returned by the CPUID instruction, with unknown 3402or unsupported feature bits cleared. 3403 3404Features like x2apic, for example, may not be present in the host cpu 3405but are exposed by kvm in KVM_GET_SUPPORTED_CPUID because they can be 3406emulated efficiently and thus not included here. 3407 3408The fields in each entry are defined as follows: 3409 3410 function: 3411 the eax value used to obtain the entry 3412 index: 3413 the ecx value used to obtain the entry (for entries that are 3414 affected by ecx) 3415 flags: 3416 an OR of zero or more of the following: 3417 3418 KVM_CPUID_FLAG_SIGNIFCANT_INDEX: 3419 if the index field is valid 3420 3421 eax, ebx, ecx, edx: 3422 3423 the values returned by the cpuid instruction for 3424 this function/index combination 3425 34264.89 KVM_S390_MEM_OP 3427-------------------- 3428 3429:Capability: KVM_CAP_S390_MEM_OP 3430:Architectures: s390 3431:Type: vcpu ioctl 3432:Parameters: struct kvm_s390_mem_op (in) 3433:Returns: = 0 on success, 3434 < 0 on generic error (e.g. -EFAULT or -ENOMEM), 3435 > 0 if an exception occurred while walking the page tables 3436 3437Read or write data from/to the logical (virtual) memory of a VCPU. 3438 3439Parameters are specified via the following structure:: 3440 3441 struct kvm_s390_mem_op { 3442 __u64 gaddr; /* the guest address */ 3443 __u64 flags; /* flags */ 3444 __u32 size; /* amount of bytes */ 3445 __u32 op; /* type of operation */ 3446 __u64 buf; /* buffer in userspace */ 3447 __u8 ar; /* the access register number */ 3448 __u8 reserved[31]; /* should be set to 0 */ 3449 }; 3450 3451The type of operation is specified in the "op" field. It is either 3452KVM_S390_MEMOP_LOGICAL_READ for reading from logical memory space or 3453KVM_S390_MEMOP_LOGICAL_WRITE for writing to logical memory space. The 3454KVM_S390_MEMOP_F_CHECK_ONLY flag can be set in the "flags" field to check 3455whether the corresponding memory access would create an access exception 3456(without touching the data in the memory at the destination). In case an 3457access exception occurred while walking the MMU tables of the guest, the 3458ioctl returns a positive error number to indicate the type of exception. 3459This exception is also raised directly at the corresponding VCPU if the 3460flag KVM_S390_MEMOP_F_INJECT_EXCEPTION is set in the "flags" field. 3461 3462The start address of the memory region has to be specified in the "gaddr" 3463field, and the length of the region in the "size" field (which must not 3464be 0). The maximum value for "size" can be obtained by checking the 3465KVM_CAP_S390_MEM_OP capability. "buf" is the buffer supplied by the 3466userspace application where the read data should be written to for 3467KVM_S390_MEMOP_LOGICAL_READ, or where the data that should be written is 3468stored for a KVM_S390_MEMOP_LOGICAL_WRITE. When KVM_S390_MEMOP_F_CHECK_ONLY 3469is specified, "buf" is unused and can be NULL. "ar" designates the access 3470register number to be used; the valid range is 0..15. 3471 3472The "reserved" field is meant for future extensions. It is not used by 3473KVM with the currently defined set of flags. 3474 34754.90 KVM_S390_GET_SKEYS 3476----------------------- 3477 3478:Capability: KVM_CAP_S390_SKEYS 3479:Architectures: s390 3480:Type: vm ioctl 3481:Parameters: struct kvm_s390_skeys 3482:Returns: 0 on success, KVM_S390_GET_KEYS_NONE if guest is not using storage 3483 keys, negative value on error 3484 3485This ioctl is used to get guest storage key values on the s390 3486architecture. The ioctl takes parameters via the kvm_s390_skeys struct:: 3487 3488 struct kvm_s390_skeys { 3489 __u64 start_gfn; 3490 __u64 count; 3491 __u64 skeydata_addr; 3492 __u32 flags; 3493 __u32 reserved[9]; 3494 }; 3495 3496The start_gfn field is the number of the first guest frame whose storage keys 3497you want to get. 3498 3499The count field is the number of consecutive frames (starting from start_gfn) 3500whose storage keys to get. The count field must be at least 1 and the maximum 3501allowed value is defined as KVM_S390_SKEYS_ALLOC_MAX. Values outside this range 3502will cause the ioctl to return -EINVAL. 3503 3504The skeydata_addr field is the address to a buffer large enough to hold count 3505bytes. This buffer will be filled with storage key data by the ioctl. 3506 35074.91 KVM_S390_SET_SKEYS 3508----------------------- 3509 3510:Capability: KVM_CAP_S390_SKEYS 3511:Architectures: s390 3512:Type: vm ioctl 3513:Parameters: struct kvm_s390_skeys 3514:Returns: 0 on success, negative value on error 3515 3516This ioctl is used to set guest storage key values on the s390 3517architecture. The ioctl takes parameters via the kvm_s390_skeys struct. 3518See section on KVM_S390_GET_SKEYS for struct definition. 3519 3520The start_gfn field is the number of the first guest frame whose storage keys 3521you want to set. 3522 3523The count field is the number of consecutive frames (starting from start_gfn) 3524whose storage keys to get. The count field must be at least 1 and the maximum 3525allowed value is defined as KVM_S390_SKEYS_ALLOC_MAX. Values outside this range 3526will cause the ioctl to return -EINVAL. 3527 3528The skeydata_addr field is the address to a buffer containing count bytes of 3529storage keys. Each byte in the buffer will be set as the storage key for a 3530single frame starting at start_gfn for count frames. 3531 3532Note: If any architecturally invalid key value is found in the given data then 3533the ioctl will return -EINVAL. 3534 35354.92 KVM_S390_IRQ 3536----------------- 3537 3538:Capability: KVM_CAP_S390_INJECT_IRQ 3539:Architectures: s390 3540:Type: vcpu ioctl 3541:Parameters: struct kvm_s390_irq (in) 3542:Returns: 0 on success, -1 on error 3543 3544Errors: 3545 3546 3547 ====== ================================================================= 3548 EINVAL interrupt type is invalid 3549 type is KVM_S390_SIGP_STOP and flag parameter is invalid value, 3550 type is KVM_S390_INT_EXTERNAL_CALL and code is bigger 3551 than the maximum of VCPUs 3552 EBUSY type is KVM_S390_SIGP_SET_PREFIX and vcpu is not stopped, 3553 type is KVM_S390_SIGP_STOP and a stop irq is already pending, 3554 type is KVM_S390_INT_EXTERNAL_CALL and an external call interrupt 3555 is already pending 3556 ====== ================================================================= 3557 3558Allows to inject an interrupt to the guest. 3559 3560Using struct kvm_s390_irq as a parameter allows 3561to inject additional payload which is not 3562possible via KVM_S390_INTERRUPT. 3563 3564Interrupt parameters are passed via kvm_s390_irq:: 3565 3566 struct kvm_s390_irq { 3567 __u64 type; 3568 union { 3569 struct kvm_s390_io_info io; 3570 struct kvm_s390_ext_info ext; 3571 struct kvm_s390_pgm_info pgm; 3572 struct kvm_s390_emerg_info emerg; 3573 struct kvm_s390_extcall_info extcall; 3574 struct kvm_s390_prefix_info prefix; 3575 struct kvm_s390_stop_info stop; 3576 struct kvm_s390_mchk_info mchk; 3577 char reserved[64]; 3578 } u; 3579 }; 3580 3581type can be one of the following: 3582 3583- KVM_S390_SIGP_STOP - sigp stop; parameter in .stop 3584- KVM_S390_PROGRAM_INT - program check; parameters in .pgm 3585- KVM_S390_SIGP_SET_PREFIX - sigp set prefix; parameters in .prefix 3586- KVM_S390_RESTART - restart; no parameters 3587- KVM_S390_INT_CLOCK_COMP - clock comparator interrupt; no parameters 3588- KVM_S390_INT_CPU_TIMER - CPU timer interrupt; no parameters 3589- KVM_S390_INT_EMERGENCY - sigp emergency; parameters in .emerg 3590- KVM_S390_INT_EXTERNAL_CALL - sigp external call; parameters in .extcall 3591- KVM_S390_MCHK - machine check interrupt; parameters in .mchk 3592 3593This is an asynchronous vcpu ioctl and can be invoked from any thread. 3594 35954.94 KVM_S390_GET_IRQ_STATE 3596--------------------------- 3597 3598:Capability: KVM_CAP_S390_IRQ_STATE 3599:Architectures: s390 3600:Type: vcpu ioctl 3601:Parameters: struct kvm_s390_irq_state (out) 3602:Returns: >= number of bytes copied into buffer, 3603 -EINVAL if buffer size is 0, 3604 -ENOBUFS if buffer size is too small to fit all pending interrupts, 3605 -EFAULT if the buffer address was invalid 3606 3607This ioctl allows userspace to retrieve the complete state of all currently 3608pending interrupts in a single buffer. Use cases include migration 3609and introspection. The parameter structure contains the address of a 3610userspace buffer and its length:: 3611 3612 struct kvm_s390_irq_state { 3613 __u64 buf; 3614 __u32 flags; /* will stay unused for compatibility reasons */ 3615 __u32 len; 3616 __u32 reserved[4]; /* will stay unused for compatibility reasons */ 3617 }; 3618 3619Userspace passes in the above struct and for each pending interrupt a 3620struct kvm_s390_irq is copied to the provided buffer. 3621 3622The structure contains a flags and a reserved field for future extensions. As 3623the kernel never checked for flags == 0 and QEMU never pre-zeroed flags and 3624reserved, these fields can not be used in the future without breaking 3625compatibility. 3626 3627If -ENOBUFS is returned the buffer provided was too small and userspace 3628may retry with a bigger buffer. 3629 36304.95 KVM_S390_SET_IRQ_STATE 3631--------------------------- 3632 3633:Capability: KVM_CAP_S390_IRQ_STATE 3634:Architectures: s390 3635:Type: vcpu ioctl 3636:Parameters: struct kvm_s390_irq_state (in) 3637:Returns: 0 on success, 3638 -EFAULT if the buffer address was invalid, 3639 -EINVAL for an invalid buffer length (see below), 3640 -EBUSY if there were already interrupts pending, 3641 errors occurring when actually injecting the 3642 interrupt. See KVM_S390_IRQ. 3643 3644This ioctl allows userspace to set the complete state of all cpu-local 3645interrupts currently pending for the vcpu. It is intended for restoring 3646interrupt state after a migration. The input parameter is a userspace buffer 3647containing a struct kvm_s390_irq_state:: 3648 3649 struct kvm_s390_irq_state { 3650 __u64 buf; 3651 __u32 flags; /* will stay unused for compatibility reasons */ 3652 __u32 len; 3653 __u32 reserved[4]; /* will stay unused for compatibility reasons */ 3654 }; 3655 3656The restrictions for flags and reserved apply as well. 3657(see KVM_S390_GET_IRQ_STATE) 3658 3659The userspace memory referenced by buf contains a struct kvm_s390_irq 3660for each interrupt to be injected into the guest. 3661If one of the interrupts could not be injected for some reason the 3662ioctl aborts. 3663 3664len must be a multiple of sizeof(struct kvm_s390_irq). It must be > 0 3665and it must not exceed (max_vcpus + 32) * sizeof(struct kvm_s390_irq), 3666which is the maximum number of possibly pending cpu-local interrupts. 3667 36684.96 KVM_SMI 3669------------ 3670 3671:Capability: KVM_CAP_X86_SMM 3672:Architectures: x86 3673:Type: vcpu ioctl 3674:Parameters: none 3675:Returns: 0 on success, -1 on error 3676 3677Queues an SMI on the thread's vcpu. 3678 36794.97 KVM_CAP_PPC_MULTITCE 3680------------------------- 3681 3682:Capability: KVM_CAP_PPC_MULTITCE 3683:Architectures: ppc 3684:Type: vm 3685 3686This capability means the kernel is capable of handling hypercalls 3687H_PUT_TCE_INDIRECT and H_STUFF_TCE without passing those into the user 3688space. This significantly accelerates DMA operations for PPC KVM guests. 3689User space should expect that its handlers for these hypercalls 3690are not going to be called if user space previously registered LIOBN 3691in KVM (via KVM_CREATE_SPAPR_TCE or similar calls). 3692 3693In order to enable H_PUT_TCE_INDIRECT and H_STUFF_TCE use in the guest, 3694user space might have to advertise it for the guest. For example, 3695IBM pSeries (sPAPR) guest starts using them if "hcall-multi-tce" is 3696present in the "ibm,hypertas-functions" device-tree property. 3697 3698The hypercalls mentioned above may or may not be processed successfully 3699in the kernel based fast path. If they can not be handled by the kernel, 3700they will get passed on to user space. So user space still has to have 3701an implementation for these despite the in kernel acceleration. 3702 3703This capability is always enabled. 3704 37054.98 KVM_CREATE_SPAPR_TCE_64 3706---------------------------- 3707 3708:Capability: KVM_CAP_SPAPR_TCE_64 3709:Architectures: powerpc 3710:Type: vm ioctl 3711:Parameters: struct kvm_create_spapr_tce_64 (in) 3712:Returns: file descriptor for manipulating the created TCE table 3713 3714This is an extension for KVM_CAP_SPAPR_TCE which only supports 32bit 3715windows, described in 4.62 KVM_CREATE_SPAPR_TCE 3716 3717This capability uses extended struct in ioctl interface:: 3718 3719 /* for KVM_CAP_SPAPR_TCE_64 */ 3720 struct kvm_create_spapr_tce_64 { 3721 __u64 liobn; 3722 __u32 page_shift; 3723 __u32 flags; 3724 __u64 offset; /* in pages */ 3725 __u64 size; /* in pages */ 3726 }; 3727 3728The aim of extension is to support an additional bigger DMA window with 3729a variable page size. 3730KVM_CREATE_SPAPR_TCE_64 receives a 64bit window size, an IOMMU page shift and 3731a bus offset of the corresponding DMA window, @size and @offset are numbers 3732of IOMMU pages. 3733 3734@flags are not used at the moment. 3735 3736The rest of functionality is identical to KVM_CREATE_SPAPR_TCE. 3737 37384.99 KVM_REINJECT_CONTROL 3739------------------------- 3740 3741:Capability: KVM_CAP_REINJECT_CONTROL 3742:Architectures: x86 3743:Type: vm ioctl 3744:Parameters: struct kvm_reinject_control (in) 3745:Returns: 0 on success, 3746 -EFAULT if struct kvm_reinject_control cannot be read, 3747 -ENXIO if KVM_CREATE_PIT or KVM_CREATE_PIT2 didn't succeed earlier. 3748 3749i8254 (PIT) has two modes, reinject and !reinject. The default is reinject, 3750where KVM queues elapsed i8254 ticks and monitors completion of interrupt from 3751vector(s) that i8254 injects. Reinject mode dequeues a tick and injects its 3752interrupt whenever there isn't a pending interrupt from i8254. 3753!reinject mode injects an interrupt as soon as a tick arrives. 3754 3755:: 3756 3757 struct kvm_reinject_control { 3758 __u8 pit_reinject; 3759 __u8 reserved[31]; 3760 }; 3761 3762pit_reinject = 0 (!reinject mode) is recommended, unless running an old 3763operating system that uses the PIT for timing (e.g. Linux 2.4.x). 3764 37654.100 KVM_PPC_CONFIGURE_V3_MMU 3766------------------------------ 3767 3768:Capability: KVM_CAP_PPC_RADIX_MMU or KVM_CAP_PPC_HASH_MMU_V3 3769:Architectures: ppc 3770:Type: vm ioctl 3771:Parameters: struct kvm_ppc_mmuv3_cfg (in) 3772:Returns: 0 on success, 3773 -EFAULT if struct kvm_ppc_mmuv3_cfg cannot be read, 3774 -EINVAL if the configuration is invalid 3775 3776This ioctl controls whether the guest will use radix or HPT (hashed 3777page table) translation, and sets the pointer to the process table for 3778the guest. 3779 3780:: 3781 3782 struct kvm_ppc_mmuv3_cfg { 3783 __u64 flags; 3784 __u64 process_table; 3785 }; 3786 3787There are two bits that can be set in flags; KVM_PPC_MMUV3_RADIX and 3788KVM_PPC_MMUV3_GTSE. KVM_PPC_MMUV3_RADIX, if set, configures the guest 3789to use radix tree translation, and if clear, to use HPT translation. 3790KVM_PPC_MMUV3_GTSE, if set and if KVM permits it, configures the guest 3791to be able to use the global TLB and SLB invalidation instructions; 3792if clear, the guest may not use these instructions. 3793 3794The process_table field specifies the address and size of the guest 3795process table, which is in the guest's space. This field is formatted 3796as the second doubleword of the partition table entry, as defined in 3797the Power ISA V3.00, Book III section 5.7.6.1. 3798 37994.101 KVM_PPC_GET_RMMU_INFO 3800--------------------------- 3801 3802:Capability: KVM_CAP_PPC_RADIX_MMU 3803:Architectures: ppc 3804:Type: vm ioctl 3805:Parameters: struct kvm_ppc_rmmu_info (out) 3806:Returns: 0 on success, 3807 -EFAULT if struct kvm_ppc_rmmu_info cannot be written, 3808 -EINVAL if no useful information can be returned 3809 3810This ioctl returns a structure containing two things: (a) a list 3811containing supported radix tree geometries, and (b) a list that maps 3812page sizes to put in the "AP" (actual page size) field for the tlbie 3813(TLB invalidate entry) instruction. 3814 3815:: 3816 3817 struct kvm_ppc_rmmu_info { 3818 struct kvm_ppc_radix_geom { 3819 __u8 page_shift; 3820 __u8 level_bits[4]; 3821 __u8 pad[3]; 3822 } geometries[8]; 3823 __u32 ap_encodings[8]; 3824 }; 3825 3826The geometries[] field gives up to 8 supported geometries for the 3827radix page table, in terms of the log base 2 of the smallest page 3828size, and the number of bits indexed at each level of the tree, from 3829the PTE level up to the PGD level in that order. Any unused entries 3830will have 0 in the page_shift field. 3831 3832The ap_encodings gives the supported page sizes and their AP field 3833encodings, encoded with the AP value in the top 3 bits and the log 3834base 2 of the page size in the bottom 6 bits. 3835 38364.102 KVM_PPC_RESIZE_HPT_PREPARE 3837-------------------------------- 3838 3839:Capability: KVM_CAP_SPAPR_RESIZE_HPT 3840:Architectures: powerpc 3841:Type: vm ioctl 3842:Parameters: struct kvm_ppc_resize_hpt (in) 3843:Returns: 0 on successful completion, 3844 >0 if a new HPT is being prepared, the value is an estimated 3845 number of milliseconds until preparation is complete, 3846 -EFAULT if struct kvm_reinject_control cannot be read, 3847 -EINVAL if the supplied shift or flags are invalid, 3848 -ENOMEM if unable to allocate the new HPT, 3849 -ENOSPC if there was a hash collision 3850 3851:: 3852 3853 struct kvm_ppc_rmmu_info { 3854 struct kvm_ppc_radix_geom { 3855 __u8 page_shift; 3856 __u8 level_bits[4]; 3857 __u8 pad[3]; 3858 } geometries[8]; 3859 __u32 ap_encodings[8]; 3860 }; 3861 3862The geometries[] field gives up to 8 supported geometries for the 3863radix page table, in terms of the log base 2 of the smallest page 3864size, and the number of bits indexed at each level of the tree, from 3865the PTE level up to the PGD level in that order. Any unused entries 3866will have 0 in the page_shift field. 3867 3868The ap_encodings gives the supported page sizes and their AP field 3869encodings, encoded with the AP value in the top 3 bits and the log 3870base 2 of the page size in the bottom 6 bits. 3871 38724.102 KVM_PPC_RESIZE_HPT_PREPARE 3873-------------------------------- 3874 3875:Capability: KVM_CAP_SPAPR_RESIZE_HPT 3876:Architectures: powerpc 3877:Type: vm ioctl 3878:Parameters: struct kvm_ppc_resize_hpt (in) 3879:Returns: 0 on successful completion, 3880 >0 if a new HPT is being prepared, the value is an estimated 3881 number of milliseconds until preparation is complete, 3882 -EFAULT if struct kvm_reinject_control cannot be read, 3883 -EINVAL if the supplied shift or flags are invalid,when moving existing 3884 HPT entries to the new HPT, 3885 -EIO on other error conditions 3886 3887Used to implement the PAPR extension for runtime resizing of a guest's 3888Hashed Page Table (HPT). Specifically this starts, stops or monitors 3889the preparation of a new potential HPT for the guest, essentially 3890implementing the H_RESIZE_HPT_PREPARE hypercall. 3891 3892If called with shift > 0 when there is no pending HPT for the guest, 3893this begins preparation of a new pending HPT of size 2^(shift) bytes. 3894It then returns a positive integer with the estimated number of 3895milliseconds until preparation is complete. 3896 3897If called when there is a pending HPT whose size does not match that 3898requested in the parameters, discards the existing pending HPT and 3899creates a new one as above. 3900 3901If called when there is a pending HPT of the size requested, will: 3902 3903 * If preparation of the pending HPT is already complete, return 0 3904 * If preparation of the pending HPT has failed, return an error 3905 code, then discard the pending HPT. 3906 * If preparation of the pending HPT is still in progress, return an 3907 estimated number of milliseconds until preparation is complete. 3908 3909If called with shift == 0, discards any currently pending HPT and 3910returns 0 (i.e. cancels any in-progress preparation). 3911 3912flags is reserved for future expansion, currently setting any bits in 3913flags will result in an -EINVAL. 3914 3915Normally this will be called repeatedly with the same parameters until 3916it returns <= 0. The first call will initiate preparation, subsequent 3917ones will monitor preparation until it completes or fails. 3918 3919:: 3920 3921 struct kvm_ppc_resize_hpt { 3922 __u64 flags; 3923 __u32 shift; 3924 __u32 pad; 3925 }; 3926 39274.103 KVM_PPC_RESIZE_HPT_COMMIT 3928------------------------------- 3929 3930:Capability: KVM_CAP_SPAPR_RESIZE_HPT 3931:Architectures: powerpc 3932:Type: vm ioctl 3933:Parameters: struct kvm_ppc_resize_hpt (in) 3934:Returns: 0 on successful completion, 3935 -EFAULT if struct kvm_reinject_control cannot be read, 3936 -EINVAL if the supplied shift or flags are invalid, 3937 -ENXIO is there is no pending HPT, or the pending HPT doesn't 3938 have the requested size, 3939 -EBUSY if the pending HPT is not fully prepared, 3940 -ENOSPC if there was a hash collision when moving existing 3941 HPT entries to the new HPT, 3942 -EIO on other error conditions 3943 3944Used to implement the PAPR extension for runtime resizing of a guest's 3945Hashed Page Table (HPT). Specifically this requests that the guest be 3946transferred to working with the new HPT, essentially implementing the 3947H_RESIZE_HPT_COMMIT hypercall. 3948 3949This should only be called after KVM_PPC_RESIZE_HPT_PREPARE has 3950returned 0 with the same parameters. In other cases 3951KVM_PPC_RESIZE_HPT_COMMIT will return an error (usually -ENXIO or 3952-EBUSY, though others may be possible if the preparation was started, 3953but failed). 3954 3955This will have undefined effects on the guest if it has not already 3956placed itself in a quiescent state where no vcpu will make MMU enabled 3957memory accesses. 3958 3959On succsful completion, the pending HPT will become the guest's active 3960HPT and the previous HPT will be discarded. 3961 3962On failure, the guest will still be operating on its previous HPT. 3963 3964:: 3965 3966 struct kvm_ppc_resize_hpt { 3967 __u64 flags; 3968 __u32 shift; 3969 __u32 pad; 3970 }; 3971 39724.104 KVM_X86_GET_MCE_CAP_SUPPORTED 3973----------------------------------- 3974 3975:Capability: KVM_CAP_MCE 3976:Architectures: x86 3977:Type: system ioctl 3978:Parameters: u64 mce_cap (out) 3979:Returns: 0 on success, -1 on error 3980 3981Returns supported MCE capabilities. The u64 mce_cap parameter 3982has the same format as the MSR_IA32_MCG_CAP register. Supported 3983capabilities will have the corresponding bits set. 3984 39854.105 KVM_X86_SETUP_MCE 3986----------------------- 3987 3988:Capability: KVM_CAP_MCE 3989:Architectures: x86 3990:Type: vcpu ioctl 3991:Parameters: u64 mcg_cap (in) 3992:Returns: 0 on success, 3993 -EFAULT if u64 mcg_cap cannot be read, 3994 -EINVAL if the requested number of banks is invalid, 3995 -EINVAL if requested MCE capability is not supported. 3996 3997Initializes MCE support for use. The u64 mcg_cap parameter 3998has the same format as the MSR_IA32_MCG_CAP register and 3999specifies which capabilities should be enabled. The maximum 4000supported number of error-reporting banks can be retrieved when 4001checking for KVM_CAP_MCE. The supported capabilities can be 4002retrieved with KVM_X86_GET_MCE_CAP_SUPPORTED. 4003 40044.106 KVM_X86_SET_MCE 4005--------------------- 4006 4007:Capability: KVM_CAP_MCE 4008:Architectures: x86 4009:Type: vcpu ioctl 4010:Parameters: struct kvm_x86_mce (in) 4011:Returns: 0 on success, 4012 -EFAULT if struct kvm_x86_mce cannot be read, 4013 -EINVAL if the bank number is invalid, 4014 -EINVAL if VAL bit is not set in status field. 4015 4016Inject a machine check error (MCE) into the guest. The input 4017parameter is:: 4018 4019 struct kvm_x86_mce { 4020 __u64 status; 4021 __u64 addr; 4022 __u64 misc; 4023 __u64 mcg_status; 4024 __u8 bank; 4025 __u8 pad1[7]; 4026 __u64 pad2[3]; 4027 }; 4028 4029If the MCE being reported is an uncorrected error, KVM will 4030inject it as an MCE exception into the guest. If the guest 4031MCG_STATUS register reports that an MCE is in progress, KVM 4032causes an KVM_EXIT_SHUTDOWN vmexit. 4033 4034Otherwise, if the MCE is a corrected error, KVM will just 4035store it in the corresponding bank (provided this bank is 4036not holding a previously reported uncorrected error). 4037 40384.107 KVM_S390_GET_CMMA_BITS 4039---------------------------- 4040 4041:Capability: KVM_CAP_S390_CMMA_MIGRATION 4042:Architectures: s390 4043:Type: vm ioctl 4044:Parameters: struct kvm_s390_cmma_log (in, out) 4045:Returns: 0 on success, a negative value on error 4046 4047This ioctl is used to get the values of the CMMA bits on the s390 4048architecture. It is meant to be used in two scenarios: 4049 4050- During live migration to save the CMMA values. Live migration needs 4051 to be enabled via the KVM_REQ_START_MIGRATION VM property. 4052- To non-destructively peek at the CMMA values, with the flag 4053 KVM_S390_CMMA_PEEK set. 4054 4055The ioctl takes parameters via the kvm_s390_cmma_log struct. The desired 4056values are written to a buffer whose location is indicated via the "values" 4057member in the kvm_s390_cmma_log struct. The values in the input struct are 4058also updated as needed. 4059 4060Each CMMA value takes up one byte. 4061 4062:: 4063 4064 struct kvm_s390_cmma_log { 4065 __u64 start_gfn; 4066 __u32 count; 4067 __u32 flags; 4068 union { 4069 __u64 remaining; 4070 __u64 mask; 4071 }; 4072 __u64 values; 4073 }; 4074 4075start_gfn is the number of the first guest frame whose CMMA values are 4076to be retrieved, 4077 4078count is the length of the buffer in bytes, 4079 4080values points to the buffer where the result will be written to. 4081 4082If count is greater than KVM_S390_SKEYS_MAX, then it is considered to be 4083KVM_S390_SKEYS_MAX. KVM_S390_SKEYS_MAX is re-used for consistency with 4084other ioctls. 4085 4086The result is written in the buffer pointed to by the field values, and 4087the values of the input parameter are updated as follows. 4088 4089Depending on the flags, different actions are performed. The only 4090supported flag so far is KVM_S390_CMMA_PEEK. 4091 4092The default behaviour if KVM_S390_CMMA_PEEK is not set is: 4093start_gfn will indicate the first page frame whose CMMA bits were dirty. 4094It is not necessarily the same as the one passed as input, as clean pages 4095are skipped. 4096 4097count will indicate the number of bytes actually written in the buffer. 4098It can (and very often will) be smaller than the input value, since the 4099buffer is only filled until 16 bytes of clean values are found (which 4100are then not copied in the buffer). Since a CMMA migration block needs 4101the base address and the length, for a total of 16 bytes, we will send 4102back some clean data if there is some dirty data afterwards, as long as 4103the size of the clean data does not exceed the size of the header. This 4104allows to minimize the amount of data to be saved or transferred over 4105the network at the expense of more roundtrips to userspace. The next 4106invocation of the ioctl will skip over all the clean values, saving 4107potentially more than just the 16 bytes we found. 4108 4109If KVM_S390_CMMA_PEEK is set: 4110the existing storage attributes are read even when not in migration 4111mode, and no other action is performed; 4112 4113the output start_gfn will be equal to the input start_gfn, 4114 4115the output count will be equal to the input count, except if the end of 4116memory has been reached. 4117 4118In both cases: 4119the field "remaining" will indicate the total number of dirty CMMA values 4120still remaining, or 0 if KVM_S390_CMMA_PEEK is set and migration mode is 4121not enabled. 4122 4123mask is unused. 4124 4125values points to the userspace buffer where the result will be stored. 4126 4127This ioctl can fail with -ENOMEM if not enough memory can be allocated to 4128complete the task, with -ENXIO if CMMA is not enabled, with -EINVAL if 4129KVM_S390_CMMA_PEEK is not set but migration mode was not enabled, with 4130-EFAULT if the userspace address is invalid or if no page table is 4131present for the addresses (e.g. when using hugepages). 4132 41334.108 KVM_S390_SET_CMMA_BITS 4134---------------------------- 4135 4136:Capability: KVM_CAP_S390_CMMA_MIGRATION 4137:Architectures: s390 4138:Type: vm ioctl 4139:Parameters: struct kvm_s390_cmma_log (in) 4140:Returns: 0 on success, a negative value on error 4141 4142This ioctl is used to set the values of the CMMA bits on the s390 4143architecture. It is meant to be used during live migration to restore 4144the CMMA values, but there are no restrictions on its use. 4145The ioctl takes parameters via the kvm_s390_cmma_values struct. 4146Each CMMA value takes up one byte. 4147 4148:: 4149 4150 struct kvm_s390_cmma_log { 4151 __u64 start_gfn; 4152 __u32 count; 4153 __u32 flags; 4154 union { 4155 __u64 remaining; 4156 __u64 mask; 4157 }; 4158 __u64 values; 4159 }; 4160 4161start_gfn indicates the starting guest frame number, 4162 4163count indicates how many values are to be considered in the buffer, 4164 4165flags is not used and must be 0. 4166 4167mask indicates which PGSTE bits are to be considered. 4168 4169remaining is not used. 4170 4171values points to the buffer in userspace where to store the values. 4172 4173This ioctl can fail with -ENOMEM if not enough memory can be allocated to 4174complete the task, with -ENXIO if CMMA is not enabled, with -EINVAL if 4175the count field is too large (e.g. more than KVM_S390_CMMA_SIZE_MAX) or 4176if the flags field was not 0, with -EFAULT if the userspace address is 4177invalid, if invalid pages are written to (e.g. after the end of memory) 4178or if no page table is present for the addresses (e.g. when using 4179hugepages). 4180 41814.109 KVM_PPC_GET_CPU_CHAR 4182-------------------------- 4183 4184:Capability: KVM_CAP_PPC_GET_CPU_CHAR 4185:Architectures: powerpc 4186:Type: vm ioctl 4187:Parameters: struct kvm_ppc_cpu_char (out) 4188:Returns: 0 on successful completion, 4189 -EFAULT if struct kvm_ppc_cpu_char cannot be written 4190 4191This ioctl gives userspace information about certain characteristics 4192of the CPU relating to speculative execution of instructions and 4193possible information leakage resulting from speculative execution (see 4194CVE-2017-5715, CVE-2017-5753 and CVE-2017-5754). The information is 4195returned in struct kvm_ppc_cpu_char, which looks like this:: 4196 4197 struct kvm_ppc_cpu_char { 4198 __u64 character; /* characteristics of the CPU */ 4199 __u64 behaviour; /* recommended software behaviour */ 4200 __u64 character_mask; /* valid bits in character */ 4201 __u64 behaviour_mask; /* valid bits in behaviour */ 4202 }; 4203 4204For extensibility, the character_mask and behaviour_mask fields 4205indicate which bits of character and behaviour have been filled in by 4206the kernel. If the set of defined bits is extended in future then 4207userspace will be able to tell whether it is running on a kernel that 4208knows about the new bits. 4209 4210The character field describes attributes of the CPU which can help 4211with preventing inadvertent information disclosure - specifically, 4212whether there is an instruction to flash-invalidate the L1 data cache 4213(ori 30,30,0 or mtspr SPRN_TRIG2,rN), whether the L1 data cache is set 4214to a mode where entries can only be used by the thread that created 4215them, whether the bcctr[l] instruction prevents speculation, and 4216whether a speculation barrier instruction (ori 31,31,0) is provided. 4217 4218The behaviour field describes actions that software should take to 4219prevent inadvertent information disclosure, and thus describes which 4220vulnerabilities the hardware is subject to; specifically whether the 4221L1 data cache should be flushed when returning to user mode from the 4222kernel, and whether a speculation barrier should be placed between an 4223array bounds check and the array access. 4224 4225These fields use the same bit definitions as the new 4226H_GET_CPU_CHARACTERISTICS hypercall. 4227 42284.110 KVM_MEMORY_ENCRYPT_OP 4229--------------------------- 4230 4231:Capability: basic 4232:Architectures: x86 4233:Type: vm 4234:Parameters: an opaque platform specific structure (in/out) 4235:Returns: 0 on success; -1 on error 4236 4237If the platform supports creating encrypted VMs then this ioctl can be used 4238for issuing platform-specific memory encryption commands to manage those 4239encrypted VMs. 4240 4241Currently, this ioctl is used for issuing Secure Encrypted Virtualization 4242(SEV) commands on AMD Processors. The SEV commands are defined in 4243Documentation/virt/kvm/amd-memory-encryption.rst. 4244 42454.111 KVM_MEMORY_ENCRYPT_REG_REGION 4246----------------------------------- 4247 4248:Capability: basic 4249:Architectures: x86 4250:Type: system 4251:Parameters: struct kvm_enc_region (in) 4252:Returns: 0 on success; -1 on error 4253 4254This ioctl can be used to register a guest memory region which may 4255contain encrypted data (e.g. guest RAM, SMRAM etc). 4256 4257It is used in the SEV-enabled guest. When encryption is enabled, a guest 4258memory region may contain encrypted data. The SEV memory encryption 4259engine uses a tweak such that two identical plaintext pages, each at 4260different locations will have differing ciphertexts. So swapping or 4261moving ciphertext of those pages will not result in plaintext being 4262swapped. So relocating (or migrating) physical backing pages for the SEV 4263guest will require some additional steps. 4264 4265Note: The current SEV key management spec does not provide commands to 4266swap or migrate (move) ciphertext pages. Hence, for now we pin the guest 4267memory region registered with the ioctl. 4268 42694.112 KVM_MEMORY_ENCRYPT_UNREG_REGION 4270------------------------------------- 4271 4272:Capability: basic 4273:Architectures: x86 4274:Type: system 4275:Parameters: struct kvm_enc_region (in) 4276:Returns: 0 on success; -1 on error 4277 4278This ioctl can be used to unregister the guest memory region registered 4279with KVM_MEMORY_ENCRYPT_REG_REGION ioctl above. 4280 42814.113 KVM_HYPERV_EVENTFD 4282------------------------ 4283 4284:Capability: KVM_CAP_HYPERV_EVENTFD 4285:Architectures: x86 4286:Type: vm ioctl 4287:Parameters: struct kvm_hyperv_eventfd (in) 4288 4289This ioctl (un)registers an eventfd to receive notifications from the guest on 4290the specified Hyper-V connection id through the SIGNAL_EVENT hypercall, without 4291causing a user exit. SIGNAL_EVENT hypercall with non-zero event flag number 4292(bits 24-31) still triggers a KVM_EXIT_HYPERV_HCALL user exit. 4293 4294:: 4295 4296 struct kvm_hyperv_eventfd { 4297 __u32 conn_id; 4298 __s32 fd; 4299 __u32 flags; 4300 __u32 padding[3]; 4301 }; 4302 4303The conn_id field should fit within 24 bits:: 4304 4305 #define KVM_HYPERV_CONN_ID_MASK 0x00ffffff 4306 4307The acceptable values for the flags field are:: 4308 4309 #define KVM_HYPERV_EVENTFD_DEASSIGN (1 << 0) 4310 4311:Returns: 0 on success, 4312 -EINVAL if conn_id or flags is outside the allowed range, 4313 -ENOENT on deassign if the conn_id isn't registered, 4314 -EEXIST on assign if the conn_id is already registered 4315 43164.114 KVM_GET_NESTED_STATE 4317-------------------------- 4318 4319:Capability: KVM_CAP_NESTED_STATE 4320:Architectures: x86 4321:Type: vcpu ioctl 4322:Parameters: struct kvm_nested_state (in/out) 4323:Returns: 0 on success, -1 on error 4324 4325Errors: 4326 4327 ===== ============================================================= 4328 E2BIG the total state size exceeds the value of 'size' specified by 4329 the user; the size required will be written into size. 4330 ===== ============================================================= 4331 4332:: 4333 4334 struct kvm_nested_state { 4335 __u16 flags; 4336 __u16 format; 4337 __u32 size; 4338 4339 union { 4340 struct kvm_vmx_nested_state_hdr vmx; 4341 struct kvm_svm_nested_state_hdr svm; 4342 4343 /* Pad the header to 128 bytes. */ 4344 __u8 pad[120]; 4345 } hdr; 4346 4347 union { 4348 struct kvm_vmx_nested_state_data vmx[0]; 4349 struct kvm_svm_nested_state_data svm[0]; 4350 } data; 4351 }; 4352 4353 #define KVM_STATE_NESTED_GUEST_MODE 0x00000001 4354 #define KVM_STATE_NESTED_RUN_PENDING 0x00000002 4355 #define KVM_STATE_NESTED_EVMCS 0x00000004 4356 4357 #define KVM_STATE_NESTED_FORMAT_VMX 0 4358 #define KVM_STATE_NESTED_FORMAT_SVM 1 4359 4360 #define KVM_STATE_NESTED_VMX_VMCS_SIZE 0x1000 4361 4362 #define KVM_STATE_NESTED_VMX_SMM_GUEST_MODE 0x00000001 4363 #define KVM_STATE_NESTED_VMX_SMM_VMXON 0x00000002 4364 4365 #define KVM_STATE_VMX_PREEMPTION_TIMER_DEADLINE 0x00000001 4366 4367 struct kvm_vmx_nested_state_hdr { 4368 __u64 vmxon_pa; 4369 __u64 vmcs12_pa; 4370 4371 struct { 4372 __u16 flags; 4373 } smm; 4374 4375 __u32 flags; 4376 __u64 preemption_timer_deadline; 4377 }; 4378 4379 struct kvm_vmx_nested_state_data { 4380 __u8 vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE]; 4381 __u8 shadow_vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE]; 4382 }; 4383 4384This ioctl copies the vcpu's nested virtualization state from the kernel to 4385userspace. 4386 4387The maximum size of the state can be retrieved by passing KVM_CAP_NESTED_STATE 4388to the KVM_CHECK_EXTENSION ioctl(). 4389 43904.115 KVM_SET_NESTED_STATE 4391-------------------------- 4392 4393:Capability: KVM_CAP_NESTED_STATE 4394:Architectures: x86 4395:Type: vcpu ioctl 4396:Parameters: struct kvm_nested_state (in) 4397:Returns: 0 on success, -1 on error 4398 4399This copies the vcpu's kvm_nested_state struct from userspace to the kernel. 4400For the definition of struct kvm_nested_state, see KVM_GET_NESTED_STATE. 4401 44024.116 KVM_(UN)REGISTER_COALESCED_MMIO 4403------------------------------------- 4404 4405:Capability: KVM_CAP_COALESCED_MMIO (for coalesced mmio) 4406 KVM_CAP_COALESCED_PIO (for coalesced pio) 4407:Architectures: all 4408:Type: vm ioctl 4409:Parameters: struct kvm_coalesced_mmio_zone 4410:Returns: 0 on success, < 0 on error 4411 4412Coalesced I/O is a performance optimization that defers hardware 4413register write emulation so that userspace exits are avoided. It is 4414typically used to reduce the overhead of emulating frequently accessed 4415hardware registers. 4416 4417When a hardware register is configured for coalesced I/O, write accesses 4418do not exit to userspace and their value is recorded in a ring buffer 4419that is shared between kernel and userspace. 4420 4421Coalesced I/O is used if one or more write accesses to a hardware 4422register can be deferred until a read or a write to another hardware 4423register on the same device. This last access will cause a vmexit and 4424userspace will process accesses from the ring buffer before emulating 4425it. That will avoid exiting to userspace on repeated writes. 4426 4427Coalesced pio is based on coalesced mmio. There is little difference 4428between coalesced mmio and pio except that coalesced pio records accesses 4429to I/O ports. 4430 44314.117 KVM_CLEAR_DIRTY_LOG (vm ioctl) 4432------------------------------------ 4433 4434:Capability: KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 4435:Architectures: x86, arm, arm64, mips 4436:Type: vm ioctl 4437:Parameters: struct kvm_clear_dirty_log (in) 4438:Returns: 0 on success, -1 on error 4439 4440:: 4441 4442 /* for KVM_CLEAR_DIRTY_LOG */ 4443 struct kvm_clear_dirty_log { 4444 __u32 slot; 4445 __u32 num_pages; 4446 __u64 first_page; 4447 union { 4448 void __user *dirty_bitmap; /* one bit per page */ 4449 __u64 padding; 4450 }; 4451 }; 4452 4453The ioctl clears the dirty status of pages in a memory slot, according to 4454the bitmap that is passed in struct kvm_clear_dirty_log's dirty_bitmap 4455field. Bit 0 of the bitmap corresponds to page "first_page" in the 4456memory slot, and num_pages is the size in bits of the input bitmap. 4457first_page must be a multiple of 64; num_pages must also be a multiple of 445864 unless first_page + num_pages is the size of the memory slot. For each 4459bit that is set in the input bitmap, the corresponding page is marked "clean" 4460in KVM's dirty bitmap, and dirty tracking is re-enabled for that page 4461(for example via write-protection, or by clearing the dirty bit in 4462a page table entry). 4463 4464If KVM_CAP_MULTI_ADDRESS_SPACE is available, bits 16-31 of slot field specifies 4465the address space for which you want to clear the dirty status. See 4466KVM_SET_USER_MEMORY_REGION for details on the usage of slot field. 4467 4468This ioctl is mostly useful when KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 4469is enabled; for more information, see the description of the capability. 4470However, it can always be used as long as KVM_CHECK_EXTENSION confirms 4471that KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 is present. 4472 44734.118 KVM_GET_SUPPORTED_HV_CPUID 4474-------------------------------- 4475 4476:Capability: KVM_CAP_HYPERV_CPUID (vcpu), KVM_CAP_SYS_HYPERV_CPUID (system) 4477:Architectures: x86 4478:Type: system ioctl, vcpu ioctl 4479:Parameters: struct kvm_cpuid2 (in/out) 4480:Returns: 0 on success, -1 on error 4481 4482:: 4483 4484 struct kvm_cpuid2 { 4485 __u32 nent; 4486 __u32 padding; 4487 struct kvm_cpuid_entry2 entries[0]; 4488 }; 4489 4490 struct kvm_cpuid_entry2 { 4491 __u32 function; 4492 __u32 index; 4493 __u32 flags; 4494 __u32 eax; 4495 __u32 ebx; 4496 __u32 ecx; 4497 __u32 edx; 4498 __u32 padding[3]; 4499 }; 4500 4501This ioctl returns x86 cpuid features leaves related to Hyper-V emulation in 4502KVM. Userspace can use the information returned by this ioctl to construct 4503cpuid information presented to guests consuming Hyper-V enlightenments (e.g. 4504Windows or Hyper-V guests). 4505 4506CPUID feature leaves returned by this ioctl are defined by Hyper-V Top Level 4507Functional Specification (TLFS). These leaves can't be obtained with 4508KVM_GET_SUPPORTED_CPUID ioctl because some of them intersect with KVM feature 4509leaves (0x40000000, 0x40000001). 4510 4511Currently, the following list of CPUID leaves are returned: 4512 - HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS 4513 - HYPERV_CPUID_INTERFACE 4514 - HYPERV_CPUID_VERSION 4515 - HYPERV_CPUID_FEATURES 4516 - HYPERV_CPUID_ENLIGHTMENT_INFO 4517 - HYPERV_CPUID_IMPLEMENT_LIMITS 4518 - HYPERV_CPUID_NESTED_FEATURES 4519 - HYPERV_CPUID_SYNDBG_VENDOR_AND_MAX_FUNCTIONS 4520 - HYPERV_CPUID_SYNDBG_INTERFACE 4521 - HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES 4522 4523Userspace invokes KVM_GET_SUPPORTED_HV_CPUID by passing a kvm_cpuid2 structure 4524with the 'nent' field indicating the number of entries in the variable-size 4525array 'entries'. If the number of entries is too low to describe all Hyper-V 4526feature leaves, an error (E2BIG) is returned. If the number is more or equal 4527to the number of Hyper-V feature leaves, the 'nent' field is adjusted to the 4528number of valid entries in the 'entries' array, which is then filled. 4529 4530'index' and 'flags' fields in 'struct kvm_cpuid_entry2' are currently reserved, 4531userspace should not expect to get any particular value there. 4532 4533Note, vcpu version of KVM_GET_SUPPORTED_HV_CPUID is currently deprecated. Unlike 4534system ioctl which exposes all supported feature bits unconditionally, vcpu 4535version has the following quirks: 4536- HYPERV_CPUID_NESTED_FEATURES leaf and HV_X64_ENLIGHTENED_VMCS_RECOMMENDED 4537 feature bit are only exposed when Enlightened VMCS was previously enabled 4538 on the corresponding vCPU (KVM_CAP_HYPERV_ENLIGHTENED_VMCS). 4539- HV_STIMER_DIRECT_MODE_AVAILABLE bit is only exposed with in-kernel LAPIC. 4540 (presumes KVM_CREATE_IRQCHIP has already been called). 4541 45424.119 KVM_ARM_VCPU_FINALIZE 4543--------------------------- 4544 4545:Architectures: arm, arm64 4546:Type: vcpu ioctl 4547:Parameters: int feature (in) 4548:Returns: 0 on success, -1 on error 4549 4550Errors: 4551 4552 ====== ============================================================== 4553 EPERM feature not enabled, needs configuration, or already finalized 4554 EINVAL feature unknown or not present 4555 ====== ============================================================== 4556 4557Recognised values for feature: 4558 4559 ===== =========================================== 4560 arm64 KVM_ARM_VCPU_SVE (requires KVM_CAP_ARM_SVE) 4561 ===== =========================================== 4562 4563Finalizes the configuration of the specified vcpu feature. 4564 4565The vcpu must already have been initialised, enabling the affected feature, by 4566means of a successful KVM_ARM_VCPU_INIT call with the appropriate flag set in 4567features[]. 4568 4569For affected vcpu features, this is a mandatory step that must be performed 4570before the vcpu is fully usable. 4571 4572Between KVM_ARM_VCPU_INIT and KVM_ARM_VCPU_FINALIZE, the feature may be 4573configured by use of ioctls such as KVM_SET_ONE_REG. The exact configuration 4574that should be performaned and how to do it are feature-dependent. 4575 4576Other calls that depend on a particular feature being finalized, such as 4577KVM_RUN, KVM_GET_REG_LIST, KVM_GET_ONE_REG and KVM_SET_ONE_REG, will fail with 4578-EPERM unless the feature has already been finalized by means of a 4579KVM_ARM_VCPU_FINALIZE call. 4580 4581See KVM_ARM_VCPU_INIT for details of vcpu features that require finalization 4582using this ioctl. 4583 45844.120 KVM_SET_PMU_EVENT_FILTER 4585------------------------------ 4586 4587:Capability: KVM_CAP_PMU_EVENT_FILTER 4588:Architectures: x86 4589:Type: vm ioctl 4590:Parameters: struct kvm_pmu_event_filter (in) 4591:Returns: 0 on success, -1 on error 4592 4593:: 4594 4595 struct kvm_pmu_event_filter { 4596 __u32 action; 4597 __u32 nevents; 4598 __u32 fixed_counter_bitmap; 4599 __u32 flags; 4600 __u32 pad[4]; 4601 __u64 events[0]; 4602 }; 4603 4604This ioctl restricts the set of PMU events that the guest can program. 4605The argument holds a list of events which will be allowed or denied. 4606The eventsel+umask of each event the guest attempts to program is compared 4607against the events field to determine whether the guest should have access. 4608The events field only controls general purpose counters; fixed purpose 4609counters are controlled by the fixed_counter_bitmap. 4610 4611No flags are defined yet, the field must be zero. 4612 4613Valid values for 'action':: 4614 4615 #define KVM_PMU_EVENT_ALLOW 0 4616 #define KVM_PMU_EVENT_DENY 1 4617 46184.121 KVM_PPC_SVM_OFF 4619--------------------- 4620 4621:Capability: basic 4622:Architectures: powerpc 4623:Type: vm ioctl 4624:Parameters: none 4625:Returns: 0 on successful completion, 4626 4627Errors: 4628 4629 ====== ================================================================ 4630 EINVAL if ultravisor failed to terminate the secure guest 4631 ENOMEM if hypervisor failed to allocate new radix page tables for guest 4632 ====== ================================================================ 4633 4634This ioctl is used to turn off the secure mode of the guest or transition 4635the guest from secure mode to normal mode. This is invoked when the guest 4636is reset. This has no effect if called for a normal guest. 4637 4638This ioctl issues an ultravisor call to terminate the secure guest, 4639unpins the VPA pages and releases all the device pages that are used to 4640track the secure pages by hypervisor. 4641 46424.122 KVM_S390_NORMAL_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 cpu reset definition in the POP (Principles Of Operation). 4653 46544.123 KVM_S390_INITIAL_RESET 4655---------------------------- 4656 4657:Capability: none 4658:Architectures: s390 4659:Type: vcpu ioctl 4660:Parameters: none 4661:Returns: 0 4662 4663This ioctl resets VCPU registers and control structures according to 4664the initial cpu reset definition in the POP. However, the cpu is not 4665put into ESA mode. This reset is a superset of the normal reset. 4666 46674.124 KVM_S390_CLEAR_RESET 4668-------------------------- 4669 4670:Capability: KVM_CAP_S390_VCPU_RESETS 4671:Architectures: s390 4672:Type: vcpu ioctl 4673:Parameters: none 4674:Returns: 0 4675 4676This ioctl resets VCPU registers and control structures according to 4677the clear cpu reset definition in the POP. However, the cpu is not put 4678into ESA mode. This reset is a superset of the initial reset. 4679 4680 46814.125 KVM_S390_PV_COMMAND 4682------------------------- 4683 4684:Capability: KVM_CAP_S390_PROTECTED 4685:Architectures: s390 4686:Type: vm ioctl 4687:Parameters: struct kvm_pv_cmd 4688:Returns: 0 on success, < 0 on error 4689 4690:: 4691 4692 struct kvm_pv_cmd { 4693 __u32 cmd; /* Command to be executed */ 4694 __u16 rc; /* Ultravisor return code */ 4695 __u16 rrc; /* Ultravisor return reason code */ 4696 __u64 data; /* Data or address */ 4697 __u32 flags; /* flags for future extensions. Must be 0 for now */ 4698 __u32 reserved[3]; 4699 }; 4700 4701cmd values: 4702 4703KVM_PV_ENABLE 4704 Allocate memory and register the VM with the Ultravisor, thereby 4705 donating memory to the Ultravisor that will become inaccessible to 4706 KVM. All existing CPUs are converted to protected ones. After this 4707 command has succeeded, any CPU added via hotplug will become 4708 protected during its creation as well. 4709 4710 Errors: 4711 4712 ===== ============================= 4713 EINTR an unmasked signal is pending 4714 ===== ============================= 4715 4716KVM_PV_DISABLE 4717 4718 Deregister the VM from the Ultravisor and reclaim the memory that 4719 had been donated to the Ultravisor, making it usable by the kernel 4720 again. All registered VCPUs are converted back to non-protected 4721 ones. 4722 4723KVM_PV_VM_SET_SEC_PARMS 4724 Pass the image header from VM memory to the Ultravisor in 4725 preparation of image unpacking and verification. 4726 4727KVM_PV_VM_UNPACK 4728 Unpack (protect and decrypt) a page of the encrypted boot image. 4729 4730KVM_PV_VM_VERIFY 4731 Verify the integrity of the unpacked image. Only if this succeeds, 4732 KVM is allowed to start protected VCPUs. 4733 47344.126 KVM_X86_SET_MSR_FILTER 4735---------------------------- 4736 4737:Capability: KVM_X86_SET_MSR_FILTER 4738:Architectures: x86 4739:Type: vm ioctl 4740:Parameters: struct kvm_msr_filter 4741:Returns: 0 on success, < 0 on error 4742 4743:: 4744 4745 struct kvm_msr_filter_range { 4746 #define KVM_MSR_FILTER_READ (1 << 0) 4747 #define KVM_MSR_FILTER_WRITE (1 << 1) 4748 __u32 flags; 4749 __u32 nmsrs; /* number of msrs in bitmap */ 4750 __u32 base; /* MSR index the bitmap starts at */ 4751 __u8 *bitmap; /* a 1 bit allows the operations in flags, 0 denies */ 4752 }; 4753 4754 #define KVM_MSR_FILTER_MAX_RANGES 16 4755 struct kvm_msr_filter { 4756 #define KVM_MSR_FILTER_DEFAULT_ALLOW (0 << 0) 4757 #define KVM_MSR_FILTER_DEFAULT_DENY (1 << 0) 4758 __u32 flags; 4759 struct kvm_msr_filter_range ranges[KVM_MSR_FILTER_MAX_RANGES]; 4760 }; 4761 4762flags values for ``struct kvm_msr_filter_range``: 4763 4764``KVM_MSR_FILTER_READ`` 4765 4766 Filter read accesses to MSRs using the given bitmap. A 0 in the bitmap 4767 indicates that a read should immediately fail, while a 1 indicates that 4768 a read for a particular MSR should be handled regardless of the default 4769 filter action. 4770 4771``KVM_MSR_FILTER_WRITE`` 4772 4773 Filter write accesses to MSRs using the given bitmap. A 0 in the bitmap 4774 indicates that a write should immediately fail, while a 1 indicates that 4775 a write for a particular MSR should be handled regardless of the default 4776 filter action. 4777 4778``KVM_MSR_FILTER_READ | KVM_MSR_FILTER_WRITE`` 4779 4780 Filter both read and write accesses to MSRs using the given bitmap. A 0 4781 in the bitmap indicates that both reads and writes should immediately fail, 4782 while a 1 indicates that reads and writes for a particular MSR are not 4783 filtered by this range. 4784 4785flags values for ``struct kvm_msr_filter``: 4786 4787``KVM_MSR_FILTER_DEFAULT_ALLOW`` 4788 4789 If no filter range matches an MSR index that is getting accessed, KVM will 4790 fall back to allowing access to the MSR. 4791 4792``KVM_MSR_FILTER_DEFAULT_DENY`` 4793 4794 If no filter range matches an MSR index that is getting accessed, KVM will 4795 fall back to rejecting access to the MSR. In this mode, all MSRs that should 4796 be processed by KVM need to explicitly be marked as allowed in the bitmaps. 4797 4798This ioctl allows user space to define up to 16 bitmaps of MSR ranges to 4799specify whether a certain MSR access should be explicitly filtered for or not. 4800 4801If this ioctl has never been invoked, MSR accesses are not guarded and the 4802default KVM in-kernel emulation behavior is fully preserved. 4803 4804Calling this ioctl with an empty set of ranges (all nmsrs == 0) disables MSR 4805filtering. In that mode, ``KVM_MSR_FILTER_DEFAULT_DENY`` is invalid and causes 4806an error. 4807 4808As soon as the filtering is in place, every MSR access is processed through 4809the filtering except for accesses to the x2APIC MSRs (from 0x800 to 0x8ff); 4810x2APIC MSRs are always allowed, independent of the ``default_allow`` setting, 4811and their behavior depends on the ``X2APIC_ENABLE`` bit of the APIC base 4812register. 4813 4814If a bit is within one of the defined ranges, read and write accesses are 4815guarded by the bitmap's value for the MSR index if the kind of access 4816is included in the ``struct kvm_msr_filter_range`` flags. If no range 4817cover this particular access, the behavior is determined by the flags 4818field in the kvm_msr_filter struct: ``KVM_MSR_FILTER_DEFAULT_ALLOW`` 4819and ``KVM_MSR_FILTER_DEFAULT_DENY``. 4820 4821Each bitmap range specifies a range of MSRs to potentially allow access on. 4822The range goes from MSR index [base .. base+nmsrs]. The flags field 4823indicates whether reads, writes or both reads and writes are filtered 4824by setting a 1 bit in the bitmap for the corresponding MSR index. 4825 4826If an MSR access is not permitted through the filtering, it generates a 4827#GP inside the guest. When combined with KVM_CAP_X86_USER_SPACE_MSR, that 4828allows user space to deflect and potentially handle various MSR accesses 4829into user space. 4830 4831If a vCPU is in running state while this ioctl is invoked, the vCPU may 4832experience inconsistent filtering behavior on MSR accesses. 4833 4834 48355. The kvm_run structure 4836======================== 4837 4838Application code obtains a pointer to the kvm_run structure by 4839mmap()ing a vcpu fd. From that point, application code can control 4840execution by changing fields in kvm_run prior to calling the KVM_RUN 4841ioctl, and obtain information about the reason KVM_RUN returned by 4842looking up structure members. 4843 4844:: 4845 4846 struct kvm_run { 4847 /* in */ 4848 __u8 request_interrupt_window; 4849 4850Request that KVM_RUN return when it becomes possible to inject external 4851interrupts into the guest. Useful in conjunction with KVM_INTERRUPT. 4852 4853:: 4854 4855 __u8 immediate_exit; 4856 4857This field is polled once when KVM_RUN starts; if non-zero, KVM_RUN 4858exits immediately, returning -EINTR. In the common scenario where a 4859signal is used to "kick" a VCPU out of KVM_RUN, this field can be used 4860to avoid usage of KVM_SET_SIGNAL_MASK, which has worse scalability. 4861Rather than blocking the signal outside KVM_RUN, userspace can set up 4862a signal handler that sets run->immediate_exit to a non-zero value. 4863 4864This field is ignored if KVM_CAP_IMMEDIATE_EXIT is not available. 4865 4866:: 4867 4868 __u8 padding1[6]; 4869 4870 /* out */ 4871 __u32 exit_reason; 4872 4873When KVM_RUN has returned successfully (return value 0), this informs 4874application code why KVM_RUN has returned. Allowable values for this 4875field are detailed below. 4876 4877:: 4878 4879 __u8 ready_for_interrupt_injection; 4880 4881If request_interrupt_window has been specified, this field indicates 4882an interrupt can be injected now with KVM_INTERRUPT. 4883 4884:: 4885 4886 __u8 if_flag; 4887 4888The value of the current interrupt flag. Only valid if in-kernel 4889local APIC is not used. 4890 4891:: 4892 4893 __u16 flags; 4894 4895More architecture-specific flags detailing state of the VCPU that may 4896affect the device's behavior. The only currently defined flag is 4897KVM_RUN_X86_SMM, which is valid on x86 machines and is set if the 4898VCPU is in system management mode. 4899 4900:: 4901 4902 /* in (pre_kvm_run), out (post_kvm_run) */ 4903 __u64 cr8; 4904 4905The value of the cr8 register. Only valid if in-kernel local APIC is 4906not used. Both input and output. 4907 4908:: 4909 4910 __u64 apic_base; 4911 4912The value of the APIC BASE msr. Only valid if in-kernel local 4913APIC is not used. Both input and output. 4914 4915:: 4916 4917 union { 4918 /* KVM_EXIT_UNKNOWN */ 4919 struct { 4920 __u64 hardware_exit_reason; 4921 } hw; 4922 4923If exit_reason is KVM_EXIT_UNKNOWN, the vcpu has exited due to unknown 4924reasons. Further architecture-specific information is available in 4925hardware_exit_reason. 4926 4927:: 4928 4929 /* KVM_EXIT_FAIL_ENTRY */ 4930 struct { 4931 __u64 hardware_entry_failure_reason; 4932 __u32 cpu; /* if KVM_LAST_CPU */ 4933 } fail_entry; 4934 4935If exit_reason is KVM_EXIT_FAIL_ENTRY, the vcpu could not be run due 4936to unknown reasons. Further architecture-specific information is 4937available in hardware_entry_failure_reason. 4938 4939:: 4940 4941 /* KVM_EXIT_EXCEPTION */ 4942 struct { 4943 __u32 exception; 4944 __u32 error_code; 4945 } ex; 4946 4947Unused. 4948 4949:: 4950 4951 /* KVM_EXIT_IO */ 4952 struct { 4953 #define KVM_EXIT_IO_IN 0 4954 #define KVM_EXIT_IO_OUT 1 4955 __u8 direction; 4956 __u8 size; /* bytes */ 4957 __u16 port; 4958 __u32 count; 4959 __u64 data_offset; /* relative to kvm_run start */ 4960 } io; 4961 4962If exit_reason is KVM_EXIT_IO, then the vcpu has 4963executed a port I/O instruction which could not be satisfied by kvm. 4964data_offset describes where the data is located (KVM_EXIT_IO_OUT) or 4965where kvm expects application code to place the data for the next 4966KVM_RUN invocation (KVM_EXIT_IO_IN). Data format is a packed array. 4967 4968:: 4969 4970 /* KVM_EXIT_DEBUG */ 4971 struct { 4972 struct kvm_debug_exit_arch arch; 4973 } debug; 4974 4975If the exit_reason is KVM_EXIT_DEBUG, then a vcpu is processing a debug event 4976for which architecture specific information is returned. 4977 4978:: 4979 4980 /* KVM_EXIT_MMIO */ 4981 struct { 4982 __u64 phys_addr; 4983 __u8 data[8]; 4984 __u32 len; 4985 __u8 is_write; 4986 } mmio; 4987 4988If exit_reason is KVM_EXIT_MMIO, then the vcpu has 4989executed a memory-mapped I/O instruction which could not be satisfied 4990by kvm. The 'data' member contains the written data if 'is_write' is 4991true, and should be filled by application code otherwise. 4992 4993The 'data' member contains, in its first 'len' bytes, the value as it would 4994appear if the VCPU performed a load or store of the appropriate width directly 4995to the byte array. 4996 4997.. note:: 4998 4999 For KVM_EXIT_IO, KVM_EXIT_MMIO, KVM_EXIT_OSI, KVM_EXIT_PAPR, 5000 KVM_EXIT_EPR, KVM_EXIT_X86_RDMSR and KVM_EXIT_X86_WRMSR the corresponding 5001 operations are complete (and guest state is consistent) only after userspace 5002 has re-entered the kernel with KVM_RUN. The kernel side will first finish 5003 incomplete operations and then check for pending signals. Userspace 5004 can re-enter the guest with an unmasked signal pending to complete 5005 pending operations. 5006 5007:: 5008 5009 /* KVM_EXIT_HYPERCALL */ 5010 struct { 5011 __u64 nr; 5012 __u64 args[6]; 5013 __u64 ret; 5014 __u32 longmode; 5015 __u32 pad; 5016 } hypercall; 5017 5018Unused. This was once used for 'hypercall to userspace'. To implement 5019such functionality, use KVM_EXIT_IO (x86) or KVM_EXIT_MMIO (all except s390). 5020 5021.. note:: KVM_EXIT_IO is significantly faster than KVM_EXIT_MMIO. 5022 5023:: 5024 5025 /* KVM_EXIT_TPR_ACCESS */ 5026 struct { 5027 __u64 rip; 5028 __u32 is_write; 5029 __u32 pad; 5030 } tpr_access; 5031 5032To be documented (KVM_TPR_ACCESS_REPORTING). 5033 5034:: 5035 5036 /* KVM_EXIT_S390_SIEIC */ 5037 struct { 5038 __u8 icptcode; 5039 __u64 mask; /* psw upper half */ 5040 __u64 addr; /* psw lower half */ 5041 __u16 ipa; 5042 __u32 ipb; 5043 } s390_sieic; 5044 5045s390 specific. 5046 5047:: 5048 5049 /* KVM_EXIT_S390_RESET */ 5050 #define KVM_S390_RESET_POR 1 5051 #define KVM_S390_RESET_CLEAR 2 5052 #define KVM_S390_RESET_SUBSYSTEM 4 5053 #define KVM_S390_RESET_CPU_INIT 8 5054 #define KVM_S390_RESET_IPL 16 5055 __u64 s390_reset_flags; 5056 5057s390 specific. 5058 5059:: 5060 5061 /* KVM_EXIT_S390_UCONTROL */ 5062 struct { 5063 __u64 trans_exc_code; 5064 __u32 pgm_code; 5065 } s390_ucontrol; 5066 5067s390 specific. A page fault has occurred for a user controlled virtual 5068machine (KVM_VM_S390_UNCONTROL) on it's host page table that cannot be 5069resolved by the kernel. 5070The program code and the translation exception code that were placed 5071in the cpu's lowcore are presented here as defined by the z Architecture 5072Principles of Operation Book in the Chapter for Dynamic Address Translation 5073(DAT) 5074 5075:: 5076 5077 /* KVM_EXIT_DCR */ 5078 struct { 5079 __u32 dcrn; 5080 __u32 data; 5081 __u8 is_write; 5082 } dcr; 5083 5084Deprecated - was used for 440 KVM. 5085 5086:: 5087 5088 /* KVM_EXIT_OSI */ 5089 struct { 5090 __u64 gprs[32]; 5091 } osi; 5092 5093MOL uses a special hypercall interface it calls 'OSI'. To enable it, we catch 5094hypercalls and exit with this exit struct that contains all the guest gprs. 5095 5096If exit_reason is KVM_EXIT_OSI, then the vcpu has triggered such a hypercall. 5097Userspace can now handle the hypercall and when it's done modify the gprs as 5098necessary. Upon guest entry all guest GPRs will then be replaced by the values 5099in this struct. 5100 5101:: 5102 5103 /* KVM_EXIT_PAPR_HCALL */ 5104 struct { 5105 __u64 nr; 5106 __u64 ret; 5107 __u64 args[9]; 5108 } papr_hcall; 5109 5110This is used on 64-bit PowerPC when emulating a pSeries partition, 5111e.g. with the 'pseries' machine type in qemu. It occurs when the 5112guest does a hypercall using the 'sc 1' instruction. The 'nr' field 5113contains the hypercall number (from the guest R3), and 'args' contains 5114the arguments (from the guest R4 - R12). Userspace should put the 5115return code in 'ret' and any extra returned values in args[]. 5116The possible hypercalls are defined in the Power Architecture Platform 5117Requirements (PAPR) document available from www.power.org (free 5118developer registration required to access it). 5119 5120:: 5121 5122 /* KVM_EXIT_S390_TSCH */ 5123 struct { 5124 __u16 subchannel_id; 5125 __u16 subchannel_nr; 5126 __u32 io_int_parm; 5127 __u32 io_int_word; 5128 __u32 ipb; 5129 __u8 dequeued; 5130 } s390_tsch; 5131 5132s390 specific. This exit occurs when KVM_CAP_S390_CSS_SUPPORT has been enabled 5133and TEST SUBCHANNEL was intercepted. If dequeued is set, a pending I/O 5134interrupt for the target subchannel has been dequeued and subchannel_id, 5135subchannel_nr, io_int_parm and io_int_word contain the parameters for that 5136interrupt. ipb is needed for instruction parameter decoding. 5137 5138:: 5139 5140 /* KVM_EXIT_EPR */ 5141 struct { 5142 __u32 epr; 5143 } epr; 5144 5145On FSL BookE PowerPC chips, the interrupt controller has a fast patch 5146interrupt acknowledge path to the core. When the core successfully 5147delivers an interrupt, it automatically populates the EPR register with 5148the interrupt vector number and acknowledges the interrupt inside 5149the interrupt controller. 5150 5151In case the interrupt controller lives in user space, we need to do 5152the interrupt acknowledge cycle through it to fetch the next to be 5153delivered interrupt vector using this exit. 5154 5155It gets triggered whenever both KVM_CAP_PPC_EPR are enabled and an 5156external interrupt has just been delivered into the guest. User space 5157should put the acknowledged interrupt vector into the 'epr' field. 5158 5159:: 5160 5161 /* KVM_EXIT_SYSTEM_EVENT */ 5162 struct { 5163 #define KVM_SYSTEM_EVENT_SHUTDOWN 1 5164 #define KVM_SYSTEM_EVENT_RESET 2 5165 #define KVM_SYSTEM_EVENT_CRASH 3 5166 __u32 type; 5167 __u64 flags; 5168 } system_event; 5169 5170If exit_reason is KVM_EXIT_SYSTEM_EVENT then the vcpu has triggered 5171a system-level event using some architecture specific mechanism (hypercall 5172or some special instruction). In case of ARM/ARM64, this is triggered using 5173HVC instruction based PSCI call from the vcpu. The 'type' field describes 5174the system-level event type. The 'flags' field describes architecture 5175specific flags for the system-level event. 5176 5177Valid values for 'type' are: 5178 5179 - KVM_SYSTEM_EVENT_SHUTDOWN -- the guest has requested a shutdown of the 5180 VM. Userspace is not obliged to honour this, and if it does honour 5181 this does not need to destroy the VM synchronously (ie it may call 5182 KVM_RUN again before shutdown finally occurs). 5183 - KVM_SYSTEM_EVENT_RESET -- the guest has requested a reset of the VM. 5184 As with SHUTDOWN, userspace can choose to ignore the request, or 5185 to schedule the reset to occur in the future and may call KVM_RUN again. 5186 - KVM_SYSTEM_EVENT_CRASH -- the guest crash occurred and the guest 5187 has requested a crash condition maintenance. Userspace can choose 5188 to ignore the request, or to gather VM memory core dump and/or 5189 reset/shutdown of the VM. 5190 5191:: 5192 5193 /* KVM_EXIT_IOAPIC_EOI */ 5194 struct { 5195 __u8 vector; 5196 } eoi; 5197 5198Indicates that the VCPU's in-kernel local APIC received an EOI for a 5199level-triggered IOAPIC interrupt. This exit only triggers when the 5200IOAPIC is implemented in userspace (i.e. KVM_CAP_SPLIT_IRQCHIP is enabled); 5201the userspace IOAPIC should process the EOI and retrigger the interrupt if 5202it is still asserted. Vector is the LAPIC interrupt vector for which the 5203EOI was received. 5204 5205:: 5206 5207 struct kvm_hyperv_exit { 5208 #define KVM_EXIT_HYPERV_SYNIC 1 5209 #define KVM_EXIT_HYPERV_HCALL 2 5210 #define KVM_EXIT_HYPERV_SYNDBG 3 5211 __u32 type; 5212 __u32 pad1; 5213 union { 5214 struct { 5215 __u32 msr; 5216 __u32 pad2; 5217 __u64 control; 5218 __u64 evt_page; 5219 __u64 msg_page; 5220 } synic; 5221 struct { 5222 __u64 input; 5223 __u64 result; 5224 __u64 params[2]; 5225 } hcall; 5226 struct { 5227 __u32 msr; 5228 __u32 pad2; 5229 __u64 control; 5230 __u64 status; 5231 __u64 send_page; 5232 __u64 recv_page; 5233 __u64 pending_page; 5234 } syndbg; 5235 } u; 5236 }; 5237 /* KVM_EXIT_HYPERV */ 5238 struct kvm_hyperv_exit hyperv; 5239 5240Indicates that the VCPU exits into userspace to process some tasks 5241related to Hyper-V emulation. 5242 5243Valid values for 'type' are: 5244 5245 - KVM_EXIT_HYPERV_SYNIC -- synchronously notify user-space about 5246 5247Hyper-V SynIC state change. Notification is used to remap SynIC 5248event/message pages and to enable/disable SynIC messages/events processing 5249in userspace. 5250 5251 - KVM_EXIT_HYPERV_SYNDBG -- synchronously notify user-space about 5252 5253Hyper-V Synthetic debugger state change. Notification is used to either update 5254the pending_page location or to send a control command (send the buffer located 5255in send_page or recv a buffer to recv_page). 5256 5257:: 5258 5259 /* KVM_EXIT_ARM_NISV */ 5260 struct { 5261 __u64 esr_iss; 5262 __u64 fault_ipa; 5263 } arm_nisv; 5264 5265Used on arm and arm64 systems. If a guest accesses memory not in a memslot, 5266KVM will typically return to userspace and ask it to do MMIO emulation on its 5267behalf. However, for certain classes of instructions, no instruction decode 5268(direction, length of memory access) is provided, and fetching and decoding 5269the instruction from the VM is overly complicated to live in the kernel. 5270 5271Historically, when this situation occurred, KVM would print a warning and kill 5272the VM. KVM assumed that if the guest accessed non-memslot memory, it was 5273trying to do I/O, which just couldn't be emulated, and the warning message was 5274phrased accordingly. However, what happened more often was that a guest bug 5275caused access outside the guest memory areas which should lead to a more 5276meaningful warning message and an external abort in the guest, if the access 5277did not fall within an I/O window. 5278 5279Userspace implementations can query for KVM_CAP_ARM_NISV_TO_USER, and enable 5280this capability at VM creation. Once this is done, these types of errors will 5281instead return to userspace with KVM_EXIT_ARM_NISV, with the valid bits from 5282the HSR (arm) and ESR_EL2 (arm64) in the esr_iss field, and the faulting IPA 5283in the fault_ipa field. Userspace can either fix up the access if it's 5284actually an I/O access by decoding the instruction from guest memory (if it's 5285very brave) and continue executing the guest, or it can decide to suspend, 5286dump, or restart the guest. 5287 5288Note that KVM does not skip the faulting instruction as it does for 5289KVM_EXIT_MMIO, but userspace has to emulate any change to the processing state 5290if it decides to decode and emulate the instruction. 5291 5292:: 5293 5294 /* KVM_EXIT_X86_RDMSR / KVM_EXIT_X86_WRMSR */ 5295 struct { 5296 __u8 error; /* user -> kernel */ 5297 __u8 pad[7]; 5298 __u32 reason; /* kernel -> user */ 5299 __u32 index; /* kernel -> user */ 5300 __u64 data; /* kernel <-> user */ 5301 } msr; 5302 5303Used on x86 systems. When the VM capability KVM_CAP_X86_USER_SPACE_MSR is 5304enabled, MSR accesses to registers that would invoke a #GP by KVM kernel code 5305will instead trigger a KVM_EXIT_X86_RDMSR exit for reads and KVM_EXIT_X86_WRMSR 5306exit for writes. 5307 5308The "reason" field specifies why the MSR trap occurred. User space will only 5309receive MSR exit traps when a particular reason was requested during through 5310ENABLE_CAP. Currently valid exit reasons are: 5311 5312 KVM_MSR_EXIT_REASON_UNKNOWN - access to MSR that is unknown to KVM 5313 KVM_MSR_EXIT_REASON_INVAL - access to invalid MSRs or reserved bits 5314 KVM_MSR_EXIT_REASON_FILTER - access blocked by KVM_X86_SET_MSR_FILTER 5315 5316For KVM_EXIT_X86_RDMSR, the "index" field tells user space which MSR the guest 5317wants to read. To respond to this request with a successful read, user space 5318writes the respective data into the "data" field and must continue guest 5319execution to ensure the read data is transferred into guest register state. 5320 5321If the RDMSR request was unsuccessful, user space indicates that with a "1" in 5322the "error" field. This will inject a #GP into the guest when the VCPU is 5323executed again. 5324 5325For KVM_EXIT_X86_WRMSR, the "index" field tells user space which MSR the guest 5326wants to write. Once finished processing the event, user space must continue 5327vCPU execution. If the MSR write was unsuccessful, user space also sets the 5328"error" field to "1". 5329 5330:: 5331 5332 /* Fix the size of the union. */ 5333 char padding[256]; 5334 }; 5335 5336 /* 5337 * shared registers between kvm and userspace. 5338 * kvm_valid_regs specifies the register classes set by the host 5339 * kvm_dirty_regs specified the register classes dirtied by userspace 5340 * struct kvm_sync_regs is architecture specific, as well as the 5341 * bits for kvm_valid_regs and kvm_dirty_regs 5342 */ 5343 __u64 kvm_valid_regs; 5344 __u64 kvm_dirty_regs; 5345 union { 5346 struct kvm_sync_regs regs; 5347 char padding[SYNC_REGS_SIZE_BYTES]; 5348 } s; 5349 5350If KVM_CAP_SYNC_REGS is defined, these fields allow userspace to access 5351certain guest registers without having to call SET/GET_*REGS. Thus we can 5352avoid some system call overhead if userspace has to handle the exit. 5353Userspace can query the validity of the structure by checking 5354kvm_valid_regs for specific bits. These bits are architecture specific 5355and usually define the validity of a groups of registers. (e.g. one bit 5356for general purpose registers) 5357 5358Please note that the kernel is allowed to use the kvm_run structure as the 5359primary storage for certain register types. Therefore, the kernel may use the 5360values in kvm_run even if the corresponding bit in kvm_dirty_regs is not set. 5361 5362:: 5363 5364 }; 5365 5366 5367 53686. Capabilities that can be enabled on vCPUs 5369============================================ 5370 5371There are certain capabilities that change the behavior of the virtual CPU or 5372the virtual machine when enabled. To enable them, please see section 4.37. 5373Below you can find a list of capabilities and what their effect on the vCPU or 5374the virtual machine is when enabling them. 5375 5376The following information is provided along with the description: 5377 5378 Architectures: 5379 which instruction set architectures provide this ioctl. 5380 x86 includes both i386 and x86_64. 5381 5382 Target: 5383 whether this is a per-vcpu or per-vm capability. 5384 5385 Parameters: 5386 what parameters are accepted by the capability. 5387 5388 Returns: 5389 the return value. General error numbers (EBADF, ENOMEM, EINVAL) 5390 are not detailed, but errors with specific meanings are. 5391 5392 53936.1 KVM_CAP_PPC_OSI 5394------------------- 5395 5396:Architectures: ppc 5397:Target: vcpu 5398:Parameters: none 5399:Returns: 0 on success; -1 on error 5400 5401This capability enables interception of OSI hypercalls that otherwise would 5402be treated as normal system calls to be injected into the guest. OSI hypercalls 5403were invented by Mac-on-Linux to have a standardized communication mechanism 5404between the guest and the host. 5405 5406When this capability is enabled, KVM_EXIT_OSI can occur. 5407 5408 54096.2 KVM_CAP_PPC_PAPR 5410-------------------- 5411 5412:Architectures: ppc 5413:Target: vcpu 5414:Parameters: none 5415:Returns: 0 on success; -1 on error 5416 5417This capability enables interception of PAPR hypercalls. PAPR hypercalls are 5418done using the hypercall instruction "sc 1". 5419 5420It also sets the guest privilege level to "supervisor" mode. Usually the guest 5421runs in "hypervisor" privilege mode with a few missing features. 5422 5423In addition to the above, it changes the semantics of SDR1. In this mode, the 5424HTAB address part of SDR1 contains an HVA instead of a GPA, as PAPR keeps the 5425HTAB invisible to the guest. 5426 5427When this capability is enabled, KVM_EXIT_PAPR_HCALL can occur. 5428 5429 54306.3 KVM_CAP_SW_TLB 5431------------------ 5432 5433:Architectures: ppc 5434:Target: vcpu 5435:Parameters: args[0] is the address of a struct kvm_config_tlb 5436:Returns: 0 on success; -1 on error 5437 5438:: 5439 5440 struct kvm_config_tlb { 5441 __u64 params; 5442 __u64 array; 5443 __u32 mmu_type; 5444 __u32 array_len; 5445 }; 5446 5447Configures the virtual CPU's TLB array, establishing a shared memory area 5448between userspace and KVM. The "params" and "array" fields are userspace 5449addresses of mmu-type-specific data structures. The "array_len" field is an 5450safety mechanism, and should be set to the size in bytes of the memory that 5451userspace has reserved for the array. It must be at least the size dictated 5452by "mmu_type" and "params". 5453 5454While KVM_RUN is active, the shared region is under control of KVM. Its 5455contents are undefined, and any modification by userspace results in 5456boundedly undefined behavior. 5457 5458On return from KVM_RUN, the shared region will reflect the current state of 5459the guest's TLB. If userspace makes any changes, it must call KVM_DIRTY_TLB 5460to tell KVM which entries have been changed, prior to calling KVM_RUN again 5461on this vcpu. 5462 5463For mmu types KVM_MMU_FSL_BOOKE_NOHV and KVM_MMU_FSL_BOOKE_HV: 5464 5465 - The "params" field is of type "struct kvm_book3e_206_tlb_params". 5466 - The "array" field points to an array of type "struct 5467 kvm_book3e_206_tlb_entry". 5468 - The array consists of all entries in the first TLB, followed by all 5469 entries in the second TLB. 5470 - Within a TLB, entries are ordered first by increasing set number. Within a 5471 set, entries are ordered by way (increasing ESEL). 5472 - The hash for determining set number in TLB0 is: (MAS2 >> 12) & (num_sets - 1) 5473 where "num_sets" is the tlb_sizes[] value divided by the tlb_ways[] value. 5474 - The tsize field of mas1 shall be set to 4K on TLB0, even though the 5475 hardware ignores this value for TLB0. 5476 54776.4 KVM_CAP_S390_CSS_SUPPORT 5478---------------------------- 5479 5480:Architectures: s390 5481:Target: vcpu 5482:Parameters: none 5483:Returns: 0 on success; -1 on error 5484 5485This capability enables support for handling of channel I/O instructions. 5486 5487TEST PENDING INTERRUPTION and the interrupt portion of TEST SUBCHANNEL are 5488handled in-kernel, while the other I/O instructions are passed to userspace. 5489 5490When this capability is enabled, KVM_EXIT_S390_TSCH will occur on TEST 5491SUBCHANNEL intercepts. 5492 5493Note that even though this capability is enabled per-vcpu, the complete 5494virtual machine is affected. 5495 54966.5 KVM_CAP_PPC_EPR 5497------------------- 5498 5499:Architectures: ppc 5500:Target: vcpu 5501:Parameters: args[0] defines whether the proxy facility is active 5502:Returns: 0 on success; -1 on error 5503 5504This capability enables or disables the delivery of interrupts through the 5505external proxy facility. 5506 5507When enabled (args[0] != 0), every time the guest gets an external interrupt 5508delivered, it automatically exits into user space with a KVM_EXIT_EPR exit 5509to receive the topmost interrupt vector. 5510 5511When disabled (args[0] == 0), behavior is as if this facility is unsupported. 5512 5513When this capability is enabled, KVM_EXIT_EPR can occur. 5514 55156.6 KVM_CAP_IRQ_MPIC 5516-------------------- 5517 5518:Architectures: ppc 5519:Parameters: args[0] is the MPIC device fd; 5520 args[1] is the MPIC CPU number for this vcpu 5521 5522This capability connects the vcpu to an in-kernel MPIC device. 5523 55246.7 KVM_CAP_IRQ_XICS 5525-------------------- 5526 5527:Architectures: ppc 5528:Target: vcpu 5529:Parameters: args[0] is the XICS device fd; 5530 args[1] is the XICS CPU number (server ID) for this vcpu 5531 5532This capability connects the vcpu to an in-kernel XICS device. 5533 55346.8 KVM_CAP_S390_IRQCHIP 5535------------------------ 5536 5537:Architectures: s390 5538:Target: vm 5539:Parameters: none 5540 5541This capability enables the in-kernel irqchip for s390. Please refer to 5542"4.24 KVM_CREATE_IRQCHIP" for details. 5543 55446.9 KVM_CAP_MIPS_FPU 5545-------------------- 5546 5547:Architectures: mips 5548:Target: vcpu 5549:Parameters: args[0] is reserved for future use (should be 0). 5550 5551This capability allows the use of the host Floating Point Unit by the guest. It 5552allows the Config1.FP bit to be set to enable the FPU in the guest. Once this is 5553done the ``KVM_REG_MIPS_FPR_*`` and ``KVM_REG_MIPS_FCR_*`` registers can be 5554accessed (depending on the current guest FPU register mode), and the Status.FR, 5555Config5.FRE bits are accessible via the KVM API and also from the guest, 5556depending on them being supported by the FPU. 5557 55586.10 KVM_CAP_MIPS_MSA 5559--------------------- 5560 5561:Architectures: mips 5562:Target: vcpu 5563:Parameters: args[0] is reserved for future use (should be 0). 5564 5565This capability allows the use of the MIPS SIMD Architecture (MSA) by the guest. 5566It allows the Config3.MSAP bit to be set to enable the use of MSA by the guest. 5567Once this is done the ``KVM_REG_MIPS_VEC_*`` and ``KVM_REG_MIPS_MSA_*`` 5568registers can be accessed, and the Config5.MSAEn bit is accessible via the 5569KVM API and also from the guest. 5570 55716.74 KVM_CAP_SYNC_REGS 5572---------------------- 5573 5574:Architectures: s390, x86 5575:Target: s390: always enabled, x86: vcpu 5576:Parameters: none 5577:Returns: x86: KVM_CHECK_EXTENSION returns a bit-array indicating which register 5578 sets are supported 5579 (bitfields defined in arch/x86/include/uapi/asm/kvm.h). 5580 5581As described above in the kvm_sync_regs struct info in section 5 (kvm_run): 5582KVM_CAP_SYNC_REGS "allow[s] userspace to access certain guest registers 5583without having to call SET/GET_*REGS". This reduces overhead by eliminating 5584repeated ioctl calls for setting and/or getting register values. This is 5585particularly important when userspace is making synchronous guest state 5586modifications, e.g. when emulating and/or intercepting instructions in 5587userspace. 5588 5589For s390 specifics, please refer to the source code. 5590 5591For x86: 5592 5593- the register sets to be copied out to kvm_run are selectable 5594 by userspace (rather that all sets being copied out for every exit). 5595- vcpu_events are available in addition to regs and sregs. 5596 5597For x86, the 'kvm_valid_regs' field of struct kvm_run is overloaded to 5598function as an input bit-array field set by userspace to indicate the 5599specific register sets to be copied out on the next exit. 5600 5601To indicate when userspace has modified values that should be copied into 5602the vCPU, the all architecture bitarray field, 'kvm_dirty_regs' must be set. 5603This is done using the same bitflags as for the 'kvm_valid_regs' field. 5604If the dirty bit is not set, then the register set values will not be copied 5605into the vCPU even if they've been modified. 5606 5607Unused bitfields in the bitarrays must be set to zero. 5608 5609:: 5610 5611 struct kvm_sync_regs { 5612 struct kvm_regs regs; 5613 struct kvm_sregs sregs; 5614 struct kvm_vcpu_events events; 5615 }; 5616 56176.75 KVM_CAP_PPC_IRQ_XIVE 5618------------------------- 5619 5620:Architectures: ppc 5621:Target: vcpu 5622:Parameters: args[0] is the XIVE device fd; 5623 args[1] is the XIVE CPU number (server ID) for this vcpu 5624 5625This capability connects the vcpu to an in-kernel XIVE device. 5626 56277. Capabilities that can be enabled on VMs 5628========================================== 5629 5630There are certain capabilities that change the behavior of the virtual 5631machine when enabled. To enable them, please see section 4.37. Below 5632you can find a list of capabilities and what their effect on the VM 5633is when enabling them. 5634 5635The following information is provided along with the description: 5636 5637 Architectures: 5638 which instruction set architectures provide this ioctl. 5639 x86 includes both i386 and x86_64. 5640 5641 Parameters: 5642 what parameters are accepted by the capability. 5643 5644 Returns: 5645 the return value. General error numbers (EBADF, ENOMEM, EINVAL) 5646 are not detailed, but errors with specific meanings are. 5647 5648 56497.1 KVM_CAP_PPC_ENABLE_HCALL 5650---------------------------- 5651 5652:Architectures: ppc 5653:Parameters: args[0] is the sPAPR hcall number; 5654 args[1] is 0 to disable, 1 to enable in-kernel handling 5655 5656This capability controls whether individual sPAPR hypercalls (hcalls) 5657get handled by the kernel or not. Enabling or disabling in-kernel 5658handling of an hcall is effective across the VM. On creation, an 5659initial set of hcalls are enabled for in-kernel handling, which 5660consists of those hcalls for which in-kernel handlers were implemented 5661before this capability was implemented. If disabled, the kernel will 5662not to attempt to handle the hcall, but will always exit to userspace 5663to handle it. Note that it may not make sense to enable some and 5664disable others of a group of related hcalls, but KVM does not prevent 5665userspace from doing that. 5666 5667If the hcall number specified is not one that has an in-kernel 5668implementation, the KVM_ENABLE_CAP ioctl will fail with an EINVAL 5669error. 5670 56717.2 KVM_CAP_S390_USER_SIGP 5672-------------------------- 5673 5674:Architectures: s390 5675:Parameters: none 5676 5677This capability controls which SIGP orders will be handled completely in user 5678space. With this capability enabled, all fast orders will be handled completely 5679in the kernel: 5680 5681- SENSE 5682- SENSE RUNNING 5683- EXTERNAL CALL 5684- EMERGENCY SIGNAL 5685- CONDITIONAL EMERGENCY SIGNAL 5686 5687All other orders will be handled completely in user space. 5688 5689Only privileged operation exceptions will be checked for in the kernel (or even 5690in the hardware prior to interception). If this capability is not enabled, the 5691old way of handling SIGP orders is used (partially in kernel and user space). 5692 56937.3 KVM_CAP_S390_VECTOR_REGISTERS 5694--------------------------------- 5695 5696:Architectures: s390 5697:Parameters: none 5698:Returns: 0 on success, negative value on error 5699 5700Allows use of the vector registers introduced with z13 processor, and 5701provides for the synchronization between host and user space. Will 5702return -EINVAL if the machine does not support vectors. 5703 57047.4 KVM_CAP_S390_USER_STSI 5705-------------------------- 5706 5707:Architectures: s390 5708:Parameters: none 5709 5710This capability allows post-handlers for the STSI instruction. After 5711initial handling in the kernel, KVM exits to user space with 5712KVM_EXIT_S390_STSI to allow user space to insert further data. 5713 5714Before exiting to userspace, kvm handlers should fill in s390_stsi field of 5715vcpu->run:: 5716 5717 struct { 5718 __u64 addr; 5719 __u8 ar; 5720 __u8 reserved; 5721 __u8 fc; 5722 __u8 sel1; 5723 __u16 sel2; 5724 } s390_stsi; 5725 5726 @addr - guest address of STSI SYSIB 5727 @fc - function code 5728 @sel1 - selector 1 5729 @sel2 - selector 2 5730 @ar - access register number 5731 5732KVM handlers should exit to userspace with rc = -EREMOTE. 5733 57347.5 KVM_CAP_SPLIT_IRQCHIP 5735------------------------- 5736 5737:Architectures: x86 5738:Parameters: args[0] - number of routes reserved for userspace IOAPICs 5739:Returns: 0 on success, -1 on error 5740 5741Create a local apic for each processor in the kernel. This can be used 5742instead of KVM_CREATE_IRQCHIP if the userspace VMM wishes to emulate the 5743IOAPIC and PIC (and also the PIT, even though this has to be enabled 5744separately). 5745 5746This capability also enables in kernel routing of interrupt requests; 5747when KVM_CAP_SPLIT_IRQCHIP only routes of KVM_IRQ_ROUTING_MSI type are 5748used in the IRQ routing table. The first args[0] MSI routes are reserved 5749for the IOAPIC pins. Whenever the LAPIC receives an EOI for these routes, 5750a KVM_EXIT_IOAPIC_EOI vmexit will be reported to userspace. 5751 5752Fails if VCPU has already been created, or if the irqchip is already in the 5753kernel (i.e. KVM_CREATE_IRQCHIP has already been called). 5754 57557.6 KVM_CAP_S390_RI 5756------------------- 5757 5758:Architectures: s390 5759:Parameters: none 5760 5761Allows use of runtime-instrumentation introduced with zEC12 processor. 5762Will return -EINVAL if the machine does not support runtime-instrumentation. 5763Will return -EBUSY if a VCPU has already been created. 5764 57657.7 KVM_CAP_X2APIC_API 5766---------------------- 5767 5768:Architectures: x86 5769:Parameters: args[0] - features that should be enabled 5770:Returns: 0 on success, -EINVAL when args[0] contains invalid features 5771 5772Valid feature flags in args[0] are:: 5773 5774 #define KVM_X2APIC_API_USE_32BIT_IDS (1ULL << 0) 5775 #define KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK (1ULL << 1) 5776 5777Enabling KVM_X2APIC_API_USE_32BIT_IDS changes the behavior of 5778KVM_SET_GSI_ROUTING, KVM_SIGNAL_MSI, KVM_SET_LAPIC, and KVM_GET_LAPIC, 5779allowing the use of 32-bit APIC IDs. See KVM_CAP_X2APIC_API in their 5780respective sections. 5781 5782KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK must be enabled for x2APIC to work 5783in logical mode or with more than 255 VCPUs. Otherwise, KVM treats 0xff 5784as a broadcast even in x2APIC mode in order to support physical x2APIC 5785without interrupt remapping. This is undesirable in logical mode, 5786where 0xff represents CPUs 0-7 in cluster 0. 5787 57887.8 KVM_CAP_S390_USER_INSTR0 5789---------------------------- 5790 5791:Architectures: s390 5792:Parameters: none 5793 5794With this capability enabled, all illegal instructions 0x0000 (2 bytes) will 5795be intercepted and forwarded to user space. User space can use this 5796mechanism e.g. to realize 2-byte software breakpoints. The kernel will 5797not inject an operating exception for these instructions, user space has 5798to take care of that. 5799 5800This capability can be enabled dynamically even if VCPUs were already 5801created and are running. 5802 58037.9 KVM_CAP_S390_GS 5804------------------- 5805 5806:Architectures: s390 5807:Parameters: none 5808:Returns: 0 on success; -EINVAL if the machine does not support 5809 guarded storage; -EBUSY if a VCPU has already been created. 5810 5811Allows use of guarded storage for the KVM guest. 5812 58137.10 KVM_CAP_S390_AIS 5814--------------------- 5815 5816:Architectures: s390 5817:Parameters: none 5818 5819Allow use of adapter-interruption suppression. 5820:Returns: 0 on success; -EBUSY if a VCPU has already been created. 5821 58227.11 KVM_CAP_PPC_SMT 5823-------------------- 5824 5825:Architectures: ppc 5826:Parameters: vsmt_mode, flags 5827 5828Enabling this capability on a VM provides userspace with a way to set 5829the desired virtual SMT mode (i.e. the number of virtual CPUs per 5830virtual core). The virtual SMT mode, vsmt_mode, must be a power of 2 5831between 1 and 8. On POWER8, vsmt_mode must also be no greater than 5832the number of threads per subcore for the host. Currently flags must 5833be 0. A successful call to enable this capability will result in 5834vsmt_mode being returned when the KVM_CAP_PPC_SMT capability is 5835subsequently queried for the VM. This capability is only supported by 5836HV KVM, and can only be set before any VCPUs have been created. 5837The KVM_CAP_PPC_SMT_POSSIBLE capability indicates which virtual SMT 5838modes are available. 5839 58407.12 KVM_CAP_PPC_FWNMI 5841---------------------- 5842 5843:Architectures: ppc 5844:Parameters: none 5845 5846With this capability a machine check exception in the guest address 5847space will cause KVM to exit the guest with NMI exit reason. This 5848enables QEMU to build error log and branch to guest kernel registered 5849machine check handling routine. Without this capability KVM will 5850branch to guests' 0x200 interrupt vector. 5851 58527.13 KVM_CAP_X86_DISABLE_EXITS 5853------------------------------ 5854 5855:Architectures: x86 5856:Parameters: args[0] defines which exits are disabled 5857:Returns: 0 on success, -EINVAL when args[0] contains invalid exits 5858 5859Valid bits in args[0] are:: 5860 5861 #define KVM_X86_DISABLE_EXITS_MWAIT (1 << 0) 5862 #define KVM_X86_DISABLE_EXITS_HLT (1 << 1) 5863 #define KVM_X86_DISABLE_EXITS_PAUSE (1 << 2) 5864 #define KVM_X86_DISABLE_EXITS_CSTATE (1 << 3) 5865 5866Enabling this capability on a VM provides userspace with a way to no 5867longer intercept some instructions for improved latency in some 5868workloads, and is suggested when vCPUs are associated to dedicated 5869physical CPUs. More bits can be added in the future; userspace can 5870just pass the KVM_CHECK_EXTENSION result to KVM_ENABLE_CAP to disable 5871all such vmexits. 5872 5873Do not enable KVM_FEATURE_PV_UNHALT if you disable HLT exits. 5874 58757.14 KVM_CAP_S390_HPAGE_1M 5876-------------------------- 5877 5878:Architectures: s390 5879:Parameters: none 5880:Returns: 0 on success, -EINVAL if hpage module parameter was not set 5881 or cmma is enabled, or the VM has the KVM_VM_S390_UCONTROL 5882 flag set 5883 5884With this capability the KVM support for memory backing with 1m pages 5885through hugetlbfs can be enabled for a VM. After the capability is 5886enabled, cmma can't be enabled anymore and pfmfi and the storage key 5887interpretation are disabled. If cmma has already been enabled or the 5888hpage module parameter is not set to 1, -EINVAL is returned. 5889 5890While it is generally possible to create a huge page backed VM without 5891this capability, the VM will not be able to run. 5892 58937.15 KVM_CAP_MSR_PLATFORM_INFO 5894------------------------------ 5895 5896:Architectures: x86 5897:Parameters: args[0] whether feature should be enabled or not 5898 5899With this capability, a guest may read the MSR_PLATFORM_INFO MSR. Otherwise, 5900a #GP would be raised when the guest tries to access. Currently, this 5901capability does not enable write permissions of this MSR for the guest. 5902 59037.16 KVM_CAP_PPC_NESTED_HV 5904-------------------------- 5905 5906:Architectures: ppc 5907:Parameters: none 5908:Returns: 0 on success, -EINVAL when the implementation doesn't support 5909 nested-HV virtualization. 5910 5911HV-KVM on POWER9 and later systems allows for "nested-HV" 5912virtualization, which provides a way for a guest VM to run guests that 5913can run using the CPU's supervisor mode (privileged non-hypervisor 5914state). Enabling this capability on a VM depends on the CPU having 5915the necessary functionality and on the facility being enabled with a 5916kvm-hv module parameter. 5917 59187.17 KVM_CAP_EXCEPTION_PAYLOAD 5919------------------------------ 5920 5921:Architectures: x86 5922:Parameters: args[0] whether feature should be enabled or not 5923 5924With this capability enabled, CR2 will not be modified prior to the 5925emulated VM-exit when L1 intercepts a #PF exception that occurs in 5926L2. Similarly, for kvm-intel only, DR6 will not be modified prior to 5927the emulated VM-exit when L1 intercepts a #DB exception that occurs in 5928L2. As a result, when KVM_GET_VCPU_EVENTS reports a pending #PF (or 5929#DB) exception for L2, exception.has_payload will be set and the 5930faulting address (or the new DR6 bits*) will be reported in the 5931exception_payload field. Similarly, when userspace injects a #PF (or 5932#DB) into L2 using KVM_SET_VCPU_EVENTS, it is expected to set 5933exception.has_payload and to put the faulting address - or the new DR6 5934bits\ [#]_ - in the exception_payload field. 5935 5936This capability also enables exception.pending in struct 5937kvm_vcpu_events, which allows userspace to distinguish between pending 5938and injected exceptions. 5939 5940 5941.. [#] For the new DR6 bits, note that bit 16 is set iff the #DB exception 5942 will clear DR6.RTM. 5943 59447.18 KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 5945 5946:Architectures: x86, arm, arm64, mips 5947:Parameters: args[0] whether feature should be enabled or not 5948 5949Valid flags are:: 5950 5951 #define KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE (1 << 0) 5952 #define KVM_DIRTY_LOG_INITIALLY_SET (1 << 1) 5953 5954With KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE is set, KVM_GET_DIRTY_LOG will not 5955automatically clear and write-protect all pages that are returned as dirty. 5956Rather, userspace will have to do this operation separately using 5957KVM_CLEAR_DIRTY_LOG. 5958 5959At the cost of a slightly more complicated operation, this provides better 5960scalability and responsiveness for two reasons. First, 5961KVM_CLEAR_DIRTY_LOG ioctl can operate on a 64-page granularity rather 5962than requiring to sync a full memslot; this ensures that KVM does not 5963take spinlocks for an extended period of time. Second, in some cases a 5964large amount of time can pass between a call to KVM_GET_DIRTY_LOG and 5965userspace actually using the data in the page. Pages can be modified 5966during this time, which is inefficient for both the guest and userspace: 5967the guest will incur a higher penalty due to write protection faults, 5968while userspace can see false reports of dirty pages. Manual reprotection 5969helps reducing this time, improving guest performance and reducing the 5970number of dirty log false positives. 5971 5972With KVM_DIRTY_LOG_INITIALLY_SET set, all the bits of the dirty bitmap 5973will be initialized to 1 when created. This also improves performance because 5974dirty logging can be enabled gradually in small chunks on the first call 5975to KVM_CLEAR_DIRTY_LOG. KVM_DIRTY_LOG_INITIALLY_SET depends on 5976KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE (it is also only available on 5977x86 and arm64 for now). 5978 5979KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 was previously available under the name 5980KVM_CAP_MANUAL_DIRTY_LOG_PROTECT, but the implementation had bugs that make 5981it hard or impossible to use it correctly. The availability of 5982KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 signals that those bugs are fixed. 5983Userspace should not try to use KVM_CAP_MANUAL_DIRTY_LOG_PROTECT. 5984 59857.19 KVM_CAP_PPC_SECURE_GUEST 5986------------------------------ 5987 5988:Architectures: ppc 5989 5990This capability indicates that KVM is running on a host that has 5991ultravisor firmware and thus can support a secure guest. On such a 5992system, a guest can ask the ultravisor to make it a secure guest, 5993one whose memory is inaccessible to the host except for pages which 5994are explicitly requested to be shared with the host. The ultravisor 5995notifies KVM when a guest requests to become a secure guest, and KVM 5996has the opportunity to veto the transition. 5997 5998If present, this capability can be enabled for a VM, meaning that KVM 5999will allow the transition to secure guest mode. Otherwise KVM will 6000veto the transition. 6001 60027.20 KVM_CAP_HALT_POLL 6003---------------------- 6004 6005:Architectures: all 6006:Target: VM 6007:Parameters: args[0] is the maximum poll time in nanoseconds 6008:Returns: 0 on success; -1 on error 6009 6010This capability overrides the kvm module parameter halt_poll_ns for the 6011target VM. 6012 6013VCPU polling allows a VCPU to poll for wakeup events instead of immediately 6014scheduling during guest halts. The maximum time a VCPU can spend polling is 6015controlled by the kvm module parameter halt_poll_ns. This capability allows 6016the maximum halt time to specified on a per-VM basis, effectively overriding 6017the module parameter for the target VM. 6018 60197.21 KVM_CAP_X86_USER_SPACE_MSR 6020------------------------------- 6021 6022:Architectures: x86 6023:Target: VM 6024:Parameters: args[0] contains the mask of KVM_MSR_EXIT_REASON_* events to report 6025:Returns: 0 on success; -1 on error 6026 6027This capability enables trapping of #GP invoking RDMSR and WRMSR instructions 6028into user space. 6029 6030When a guest requests to read or write an MSR, KVM may not implement all MSRs 6031that are relevant to a respective system. It also does not differentiate by 6032CPU type. 6033 6034To allow more fine grained control over MSR handling, user space may enable 6035this capability. With it enabled, MSR accesses that match the mask specified in 6036args[0] and trigger a #GP event inside the guest by KVM will instead trigger 6037KVM_EXIT_X86_RDMSR and KVM_EXIT_X86_WRMSR exit notifications which user space 6038can then handle to implement model specific MSR handling and/or user notifications 6039to inform a user that an MSR was not handled. 6040 60418. Other capabilities. 6042====================== 6043 6044This section lists capabilities that give information about other 6045features of the KVM implementation. 6046 60478.1 KVM_CAP_PPC_HWRNG 6048--------------------- 6049 6050:Architectures: ppc 6051 6052This capability, if KVM_CHECK_EXTENSION indicates that it is 6053available, means that the kernel has an implementation of the 6054H_RANDOM hypercall backed by a hardware random-number generator. 6055If present, the kernel H_RANDOM handler can be enabled for guest use 6056with the KVM_CAP_PPC_ENABLE_HCALL capability. 6057 60588.2 KVM_CAP_HYPERV_SYNIC 6059------------------------ 6060 6061:Architectures: x86 6062 6063This capability, if KVM_CHECK_EXTENSION indicates that it is 6064available, means that the kernel has an implementation of the 6065Hyper-V Synthetic interrupt controller(SynIC). Hyper-V SynIC is 6066used to support Windows Hyper-V based guest paravirt drivers(VMBus). 6067 6068In order to use SynIC, it has to be activated by setting this 6069capability via KVM_ENABLE_CAP ioctl on the vcpu fd. Note that this 6070will disable the use of APIC hardware virtualization even if supported 6071by the CPU, as it's incompatible with SynIC auto-EOI behavior. 6072 60738.3 KVM_CAP_PPC_RADIX_MMU 6074------------------------- 6075 6076:Architectures: ppc 6077 6078This capability, if KVM_CHECK_EXTENSION indicates that it is 6079available, means that the kernel can support guests using the 6080radix MMU defined in Power ISA V3.00 (as implemented in the POWER9 6081processor). 6082 60838.4 KVM_CAP_PPC_HASH_MMU_V3 6084--------------------------- 6085 6086:Architectures: ppc 6087 6088This capability, if KVM_CHECK_EXTENSION indicates that it is 6089available, means that the kernel can support guests using the 6090hashed page table MMU defined in Power ISA V3.00 (as implemented in 6091the POWER9 processor), including in-memory segment tables. 6092 60938.5 KVM_CAP_MIPS_VZ 6094------------------- 6095 6096:Architectures: mips 6097 6098This capability, if KVM_CHECK_EXTENSION on the main kvm handle indicates that 6099it is available, means that full hardware assisted virtualization capabilities 6100of the hardware are available for use through KVM. An appropriate 6101KVM_VM_MIPS_* type must be passed to KVM_CREATE_VM to create a VM which 6102utilises it. 6103 6104If KVM_CHECK_EXTENSION on a kvm VM handle indicates that this capability is 6105available, it means that the VM is using full hardware assisted virtualization 6106capabilities of the hardware. This is useful to check after creating a VM with 6107KVM_VM_MIPS_DEFAULT. 6108 6109The value returned by KVM_CHECK_EXTENSION should be compared against known 6110values (see below). All other values are reserved. This is to allow for the 6111possibility of other hardware assisted virtualization implementations which 6112may be incompatible with the MIPS VZ ASE. 6113 6114== ========================================================================== 6115 0 The trap & emulate implementation is in use to run guest code in user 6116 mode. Guest virtual memory segments are rearranged to fit the guest in the 6117 user mode address space. 6118 6119 1 The MIPS VZ ASE is in use, providing full hardware assisted 6120 virtualization, including standard guest virtual memory segments. 6121== ========================================================================== 6122 61238.6 KVM_CAP_MIPS_TE 6124------------------- 6125 6126:Architectures: mips 6127 6128This capability, if KVM_CHECK_EXTENSION on the main kvm handle indicates that 6129it is available, means that the trap & emulate implementation is available to 6130run guest code in user mode, even if KVM_CAP_MIPS_VZ indicates that hardware 6131assisted virtualisation is also available. KVM_VM_MIPS_TE (0) must be passed 6132to KVM_CREATE_VM to create a VM which utilises it. 6133 6134If KVM_CHECK_EXTENSION on a kvm VM handle indicates that this capability is 6135available, it means that the VM is using trap & emulate. 6136 61378.7 KVM_CAP_MIPS_64BIT 6138---------------------- 6139 6140:Architectures: mips 6141 6142This capability indicates the supported architecture type of the guest, i.e. the 6143supported register and address width. 6144 6145The values returned when this capability is checked by KVM_CHECK_EXTENSION on a 6146kvm VM handle correspond roughly to the CP0_Config.AT register field, and should 6147be checked specifically against known values (see below). All other values are 6148reserved. 6149 6150== ======================================================================== 6151 0 MIPS32 or microMIPS32. 6152 Both registers and addresses are 32-bits wide. 6153 It will only be possible to run 32-bit guest code. 6154 6155 1 MIPS64 or microMIPS64 with access only to 32-bit compatibility segments. 6156 Registers are 64-bits wide, but addresses are 32-bits wide. 6157 64-bit guest code may run but cannot access MIPS64 memory segments. 6158 It will also be possible to run 32-bit guest code. 6159 6160 2 MIPS64 or microMIPS64 with access to all address segments. 6161 Both registers and addresses are 64-bits wide. 6162 It will be possible to run 64-bit or 32-bit guest code. 6163== ======================================================================== 6164 61658.9 KVM_CAP_ARM_USER_IRQ 6166------------------------ 6167 6168:Architectures: arm, arm64 6169 6170This capability, if KVM_CHECK_EXTENSION indicates that it is available, means 6171that if userspace creates a VM without an in-kernel interrupt controller, it 6172will be notified of changes to the output level of in-kernel emulated devices, 6173which can generate virtual interrupts, presented to the VM. 6174For such VMs, on every return to userspace, the kernel 6175updates the vcpu's run->s.regs.device_irq_level field to represent the actual 6176output level of the device. 6177 6178Whenever kvm detects a change in the device output level, kvm guarantees at 6179least one return to userspace before running the VM. This exit could either 6180be a KVM_EXIT_INTR or any other exit event, like KVM_EXIT_MMIO. This way, 6181userspace can always sample the device output level and re-compute the state of 6182the userspace interrupt controller. Userspace should always check the state 6183of run->s.regs.device_irq_level on every kvm exit. 6184The value in run->s.regs.device_irq_level can represent both level and edge 6185triggered interrupt signals, depending on the device. Edge triggered interrupt 6186signals will exit to userspace with the bit in run->s.regs.device_irq_level 6187set exactly once per edge signal. 6188 6189The field run->s.regs.device_irq_level is available independent of 6190run->kvm_valid_regs or run->kvm_dirty_regs bits. 6191 6192If KVM_CAP_ARM_USER_IRQ is supported, the KVM_CHECK_EXTENSION ioctl returns a 6193number larger than 0 indicating the version of this capability is implemented 6194and thereby which bits in run->s.regs.device_irq_level can signal values. 6195 6196Currently the following bits are defined for the device_irq_level bitmap:: 6197 6198 KVM_CAP_ARM_USER_IRQ >= 1: 6199 6200 KVM_ARM_DEV_EL1_VTIMER - EL1 virtual timer 6201 KVM_ARM_DEV_EL1_PTIMER - EL1 physical timer 6202 KVM_ARM_DEV_PMU - ARM PMU overflow interrupt signal 6203 6204Future versions of kvm may implement additional events. These will get 6205indicated by returning a higher number from KVM_CHECK_EXTENSION and will be 6206listed above. 6207 62088.10 KVM_CAP_PPC_SMT_POSSIBLE 6209----------------------------- 6210 6211:Architectures: ppc 6212 6213Querying this capability returns a bitmap indicating the possible 6214virtual SMT modes that can be set using KVM_CAP_PPC_SMT. If bit N 6215(counting from the right) is set, then a virtual SMT mode of 2^N is 6216available. 6217 62188.11 KVM_CAP_HYPERV_SYNIC2 6219-------------------------- 6220 6221:Architectures: x86 6222 6223This capability enables a newer version of Hyper-V Synthetic interrupt 6224controller (SynIC). The only difference with KVM_CAP_HYPERV_SYNIC is that KVM 6225doesn't clear SynIC message and event flags pages when they are enabled by 6226writing to the respective MSRs. 6227 62288.12 KVM_CAP_HYPERV_VP_INDEX 6229---------------------------- 6230 6231:Architectures: x86 6232 6233This capability indicates that userspace can load HV_X64_MSR_VP_INDEX msr. Its 6234value is used to denote the target vcpu for a SynIC interrupt. For 6235compatibilty, KVM initializes this msr to KVM's internal vcpu index. When this 6236capability is absent, userspace can still query this msr's value. 6237 62388.13 KVM_CAP_S390_AIS_MIGRATION 6239------------------------------- 6240 6241:Architectures: s390 6242:Parameters: none 6243 6244This capability indicates if the flic device will be able to get/set the 6245AIS states for migration via the KVM_DEV_FLIC_AISM_ALL attribute and allows 6246to discover this without having to create a flic device. 6247 62488.14 KVM_CAP_S390_PSW 6249--------------------- 6250 6251:Architectures: s390 6252 6253This capability indicates that the PSW is exposed via the kvm_run structure. 6254 62558.15 KVM_CAP_S390_GMAP 6256---------------------- 6257 6258:Architectures: s390 6259 6260This capability indicates that the user space memory used as guest mapping can 6261be anywhere in the user memory address space, as long as the memory slots are 6262aligned and sized to a segment (1MB) boundary. 6263 62648.16 KVM_CAP_S390_COW 6265--------------------- 6266 6267:Architectures: s390 6268 6269This capability indicates that the user space memory used as guest mapping can 6270use copy-on-write semantics as well as dirty pages tracking via read-only page 6271tables. 6272 62738.17 KVM_CAP_S390_BPB 6274--------------------- 6275 6276:Architectures: s390 6277 6278This capability indicates that kvm will implement the interfaces to handle 6279reset, migration and nested KVM for branch prediction blocking. The stfle 6280facility 82 should not be provided to the guest without this capability. 6281 62828.18 KVM_CAP_HYPERV_TLBFLUSH 6283---------------------------- 6284 6285:Architectures: x86 6286 6287This capability indicates that KVM supports paravirtualized Hyper-V TLB Flush 6288hypercalls: 6289HvFlushVirtualAddressSpace, HvFlushVirtualAddressSpaceEx, 6290HvFlushVirtualAddressList, HvFlushVirtualAddressListEx. 6291 62928.19 KVM_CAP_ARM_INJECT_SERROR_ESR 6293---------------------------------- 6294 6295:Architectures: arm, arm64 6296 6297This capability indicates that userspace can specify (via the 6298KVM_SET_VCPU_EVENTS ioctl) the syndrome value reported to the guest when it 6299takes a virtual SError interrupt exception. 6300If KVM advertises this capability, userspace can only specify the ISS field for 6301the ESR syndrome. Other parts of the ESR, such as the EC are generated by the 6302CPU when the exception is taken. If this virtual SError is taken to EL1 using 6303AArch64, this value will be reported in the ISS field of ESR_ELx. 6304 6305See KVM_CAP_VCPU_EVENTS for more details. 6306 63078.20 KVM_CAP_HYPERV_SEND_IPI 6308---------------------------- 6309 6310:Architectures: x86 6311 6312This capability indicates that KVM supports paravirtualized Hyper-V IPI send 6313hypercalls: 6314HvCallSendSyntheticClusterIpi, HvCallSendSyntheticClusterIpiEx. 6315 63168.21 KVM_CAP_HYPERV_DIRECT_TLBFLUSH 6317----------------------------------- 6318 6319:Architectures: x86 6320 6321This capability indicates that KVM running on top of Hyper-V hypervisor 6322enables Direct TLB flush for its guests meaning that TLB flush 6323hypercalls are handled by Level 0 hypervisor (Hyper-V) bypassing KVM. 6324Due to the different ABI for hypercall parameters between Hyper-V and 6325KVM, enabling this capability effectively disables all hypercall 6326handling by KVM (as some KVM hypercall may be mistakenly treated as TLB 6327flush hypercalls by Hyper-V) so userspace should disable KVM identification 6328in CPUID and only exposes Hyper-V identification. In this case, guest 6329thinks it's running on Hyper-V and only use Hyper-V hypercalls. 6330 63318.22 KVM_CAP_S390_VCPU_RESETS 6332----------------------------- 6333 6334:Architectures: s390 6335 6336This capability indicates that the KVM_S390_NORMAL_RESET and 6337KVM_S390_CLEAR_RESET ioctls are available. 6338 63398.23 KVM_CAP_S390_PROTECTED 6340--------------------------- 6341 6342:Architectures: s390 6343 6344This capability indicates that the Ultravisor has been initialized and 6345KVM can therefore start protected VMs. 6346This capability governs the KVM_S390_PV_COMMAND ioctl and the 6347KVM_MP_STATE_LOAD MP_STATE. KVM_SET_MP_STATE can fail for protected 6348guests when the state change is invalid. 6349 63508.24 KVM_CAP_STEAL_TIME 6351----------------------- 6352 6353:Architectures: arm64, x86 6354 6355This capability indicates that KVM supports steal time accounting. 6356When steal time accounting is supported it may be enabled with 6357architecture-specific interfaces. This capability and the architecture- 6358specific interfaces must be consistent, i.e. if one says the feature 6359is supported, than the other should as well and vice versa. For arm64 6360see Documentation/virt/kvm/devices/vcpu.rst "KVM_ARM_VCPU_PVTIME_CTRL". 6361For x86 see Documentation/virt/kvm/msr.rst "MSR_KVM_STEAL_TIME". 6362 63638.25 KVM_CAP_S390_DIAG318 6364------------------------- 6365 6366:Architectures: s390 6367 6368This capability enables a guest to set information about its control program 6369(i.e. guest kernel type and version). The information is helpful during 6370system/firmware service events, providing additional data about the guest 6371environments running on the machine. 6372 6373The information is associated with the DIAGNOSE 0x318 instruction, which sets 6374an 8-byte value consisting of a one-byte Control Program Name Code (CPNC) and 6375a 7-byte Control Program Version Code (CPVC). The CPNC determines what 6376environment the control program is running in (e.g. Linux, z/VM...), and the 6377CPVC is used for information specific to OS (e.g. Linux version, Linux 6378distribution...) 6379 6380If this capability is available, then the CPNC and CPVC can be synchronized 6381between KVM and userspace via the sync regs mechanism (KVM_SYNC_DIAG318). 6382 63838.26 KVM_CAP_X86_USER_SPACE_MSR 6384------------------------------- 6385 6386:Architectures: x86 6387 6388This capability indicates that KVM supports deflection of MSR reads and 6389writes to user space. It can be enabled on a VM level. If enabled, MSR 6390accesses that would usually trigger a #GP by KVM into the guest will 6391instead get bounced to user space through the KVM_EXIT_X86_RDMSR and 6392KVM_EXIT_X86_WRMSR exit notifications. 6393 63948.27 KVM_X86_SET_MSR_FILTER 6395--------------------------- 6396 6397:Architectures: x86 6398 6399This capability indicates that KVM supports that accesses to user defined MSRs 6400may be rejected. With this capability exposed, KVM exports new VM ioctl 6401KVM_X86_SET_MSR_FILTER which user space can call to specify bitmaps of MSR 6402ranges that KVM should reject access to. 6403 6404In combination with KVM_CAP_X86_USER_SPACE_MSR, this allows user space to 6405trap and emulate MSRs that are outside of the scope of KVM as well as 6406limit the attack surface on KVM's MSR emulation code. 6407 64088.28 KVM_CAP_ENFORCE_PV_CPUID 6409----------------------------- 6410 6411Architectures: x86 6412 6413When enabled, KVM will disable paravirtual features provided to the 6414guest according to the bits in the KVM_CPUID_FEATURES CPUID leaf 6415(0x40000001). Otherwise, a guest may use the paravirtual features 6416regardless of what has actually been exposed through the CPUID leaf. 6417 6418 64198.29 KVM_CAP_DIRTY_LOG_RING 6420--------------------------- 6421 6422:Architectures: x86 6423:Parameters: args[0] - size of the dirty log ring 6424 6425KVM is capable of tracking dirty memory using ring buffers that are 6426mmaped into userspace; there is one dirty ring per vcpu. 6427 6428The dirty ring is available to userspace as an array of 6429``struct kvm_dirty_gfn``. Each dirty entry it's defined as:: 6430 6431 struct kvm_dirty_gfn { 6432 __u32 flags; 6433 __u32 slot; /* as_id | slot_id */ 6434 __u64 offset; 6435 }; 6436 6437The following values are defined for the flags field to define the 6438current state of the entry:: 6439 6440 #define KVM_DIRTY_GFN_F_DIRTY BIT(0) 6441 #define KVM_DIRTY_GFN_F_RESET BIT(1) 6442 #define KVM_DIRTY_GFN_F_MASK 0x3 6443 6444Userspace should call KVM_ENABLE_CAP ioctl right after KVM_CREATE_VM 6445ioctl to enable this capability for the new guest and set the size of 6446the rings. Enabling the capability is only allowed before creating any 6447vCPU, and the size of the ring must be a power of two. The larger the 6448ring buffer, the less likely the ring is full and the VM is forced to 6449exit to userspace. The optimal size depends on the workload, but it is 6450recommended that it be at least 64 KiB (4096 entries). 6451 6452Just like for dirty page bitmaps, the buffer tracks writes to 6453all user memory regions for which the KVM_MEM_LOG_DIRTY_PAGES flag was 6454set in KVM_SET_USER_MEMORY_REGION. Once a memory region is registered 6455with the flag set, userspace can start harvesting dirty pages from the 6456ring buffer. 6457 6458An entry in the ring buffer can be unused (flag bits ``00``), 6459dirty (flag bits ``01``) or harvested (flag bits ``1X``). The 6460state machine for the entry is as follows:: 6461 6462 dirtied harvested reset 6463 00 -----------> 01 -------------> 1X -------+ 6464 ^ | 6465 | | 6466 +------------------------------------------+ 6467 6468To harvest the dirty pages, userspace accesses the mmaped ring buffer 6469to read the dirty GFNs. If the flags has the DIRTY bit set (at this stage 6470the RESET bit must be cleared), then it means this GFN is a dirty GFN. 6471The userspace should harvest this GFN and mark the flags from state 6472``01b`` to ``1Xb`` (bit 0 will be ignored by KVM, but bit 1 must be set 6473to show that this GFN is harvested and waiting for a reset), and move 6474on to the next GFN. The userspace should continue to do this until the 6475flags of a GFN have the DIRTY bit cleared, meaning that it has harvested 6476all the dirty GFNs that were available. 6477 6478It's not necessary for userspace to harvest the all dirty GFNs at once. 6479However it must collect the dirty GFNs in sequence, i.e., the userspace 6480program cannot skip one dirty GFN to collect the one next to it. 6481 6482After processing one or more entries in the ring buffer, userspace 6483calls the VM ioctl KVM_RESET_DIRTY_RINGS to notify the kernel about 6484it, so that the kernel will reprotect those collected GFNs. 6485Therefore, the ioctl must be called *before* reading the content of 6486the dirty pages. 6487 6488The dirty ring can get full. When it happens, the KVM_RUN of the 6489vcpu will return with exit reason KVM_EXIT_DIRTY_LOG_FULL. 6490 6491The dirty ring interface has a major difference comparing to the 6492KVM_GET_DIRTY_LOG interface in that, when reading the dirty ring from 6493userspace, it's still possible that the kernel has not yet flushed the 6494processor's dirty page buffers into the kernel buffer (with dirty bitmaps, the 6495flushing is done by the KVM_GET_DIRTY_LOG ioctl). To achieve that, one 6496needs to kick the vcpu out of KVM_RUN using a signal. The resulting 6497vmexit ensures that all dirty GFNs are flushed to the dirty rings. 6498 6499NOTE: the capability KVM_CAP_DIRTY_LOG_RING and the corresponding 6500ioctl KVM_RESET_DIRTY_RINGS are mutual exclusive to the existing ioctls 6501KVM_GET_DIRTY_LOG and KVM_CLEAR_DIRTY_LOG. After enabling 6502KVM_CAP_DIRTY_LOG_RING with an acceptable dirty ring size, the virtual 6503machine will switch to ring-buffer dirty page tracking and further 6504KVM_GET_DIRTY_LOG or KVM_CLEAR_DIRTY_LOG ioctls will fail. 6505