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 specifies 364the address space for which you want to return the dirty bitmap. 365They must be less than the value that KVM_CHECK_EXTENSION returns for 366the KVM_CAP_MULTI_ADDRESS_SPACE capability. 367 368The bits in the dirty bitmap are cleared before the ioctl returns, unless 369KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 is enabled. For more information, 370see the description of the capability. 371 3724.9 KVM_SET_MEMORY_ALIAS 373------------------------ 374 375:Capability: basic 376:Architectures: x86 377:Type: vm ioctl 378:Parameters: struct kvm_memory_alias (in) 379:Returns: 0 (success), -1 (error) 380 381This ioctl is obsolete and has been removed. 382 383 3844.10 KVM_RUN 385------------ 386 387:Capability: basic 388:Architectures: all 389:Type: vcpu ioctl 390:Parameters: none 391:Returns: 0 on success, -1 on error 392 393Errors: 394 395 ======= ============================================================== 396 EINTR an unmasked signal is pending 397 ENOEXEC the vcpu hasn't been initialized or the guest tried to execute 398 instructions from device memory (arm64) 399 ENOSYS data abort outside memslots with no syndrome info and 400 KVM_CAP_ARM_NISV_TO_USER not enabled (arm64) 401 EPERM SVE feature set but not finalized (arm64) 402 ======= ============================================================== 403 404This ioctl is used to run a guest virtual cpu. While there are no 405explicit parameters, there is an implicit parameter block that can be 406obtained by mmap()ing the vcpu fd at offset 0, with the size given by 407KVM_GET_VCPU_MMAP_SIZE. The parameter block is formatted as a 'struct 408kvm_run' (see below). 409 410 4114.11 KVM_GET_REGS 412----------------- 413 414:Capability: basic 415:Architectures: all except ARM, arm64 416:Type: vcpu ioctl 417:Parameters: struct kvm_regs (out) 418:Returns: 0 on success, -1 on error 419 420Reads the general purpose registers from the vcpu. 421 422:: 423 424 /* x86 */ 425 struct kvm_regs { 426 /* out (KVM_GET_REGS) / in (KVM_SET_REGS) */ 427 __u64 rax, rbx, rcx, rdx; 428 __u64 rsi, rdi, rsp, rbp; 429 __u64 r8, r9, r10, r11; 430 __u64 r12, r13, r14, r15; 431 __u64 rip, rflags; 432 }; 433 434 /* mips */ 435 struct kvm_regs { 436 /* out (KVM_GET_REGS) / in (KVM_SET_REGS) */ 437 __u64 gpr[32]; 438 __u64 hi; 439 __u64 lo; 440 __u64 pc; 441 }; 442 443 4444.12 KVM_SET_REGS 445----------------- 446 447:Capability: basic 448:Architectures: all except ARM, arm64 449:Type: vcpu ioctl 450:Parameters: struct kvm_regs (in) 451:Returns: 0 on success, -1 on error 452 453Writes the general purpose registers into the vcpu. 454 455See KVM_GET_REGS for the data structure. 456 457 4584.13 KVM_GET_SREGS 459------------------ 460 461:Capability: basic 462:Architectures: x86, ppc 463:Type: vcpu ioctl 464:Parameters: struct kvm_sregs (out) 465:Returns: 0 on success, -1 on error 466 467Reads special registers from the vcpu. 468 469:: 470 471 /* x86 */ 472 struct kvm_sregs { 473 struct kvm_segment cs, ds, es, fs, gs, ss; 474 struct kvm_segment tr, ldt; 475 struct kvm_dtable gdt, idt; 476 __u64 cr0, cr2, cr3, cr4, cr8; 477 __u64 efer; 478 __u64 apic_base; 479 __u64 interrupt_bitmap[(KVM_NR_INTERRUPTS + 63) / 64]; 480 }; 481 482 /* ppc -- see arch/powerpc/include/uapi/asm/kvm.h */ 483 484interrupt_bitmap is a bitmap of pending external interrupts. At most 485one bit may be set. This interrupt has been acknowledged by the APIC 486but not yet injected into the cpu core. 487 488 4894.14 KVM_SET_SREGS 490------------------ 491 492:Capability: basic 493:Architectures: x86, ppc 494:Type: vcpu ioctl 495:Parameters: struct kvm_sregs (in) 496:Returns: 0 on success, -1 on error 497 498Writes special registers into the vcpu. See KVM_GET_SREGS for the 499data structures. 500 501 5024.15 KVM_TRANSLATE 503------------------ 504 505:Capability: basic 506:Architectures: x86 507:Type: vcpu ioctl 508:Parameters: struct kvm_translation (in/out) 509:Returns: 0 on success, -1 on error 510 511Translates a virtual address according to the vcpu's current address 512translation mode. 513 514:: 515 516 struct kvm_translation { 517 /* in */ 518 __u64 linear_address; 519 520 /* out */ 521 __u64 physical_address; 522 __u8 valid; 523 __u8 writeable; 524 __u8 usermode; 525 __u8 pad[5]; 526 }; 527 528 5294.16 KVM_INTERRUPT 530------------------ 531 532:Capability: basic 533:Architectures: x86, ppc, mips 534:Type: vcpu ioctl 535:Parameters: struct kvm_interrupt (in) 536:Returns: 0 on success, negative on failure. 537 538Queues a hardware interrupt vector to be injected. 539 540:: 541 542 /* for KVM_INTERRUPT */ 543 struct kvm_interrupt { 544 /* in */ 545 __u32 irq; 546 }; 547 548X86: 549^^^^ 550 551:Returns: 552 553 ========= =================================== 554 0 on success, 555 -EEXIST if an interrupt is already enqueued 556 -EINVAL the irq number is invalid 557 -ENXIO if the PIC is in the kernel 558 -EFAULT if the pointer is invalid 559 ========= =================================== 560 561Note 'irq' is an interrupt vector, not an interrupt pin or line. This 562ioctl is useful if the in-kernel PIC is not used. 563 564PPC: 565^^^^ 566 567Queues an external interrupt to be injected. This ioctl is overleaded 568with 3 different irq values: 569 570a) KVM_INTERRUPT_SET 571 572 This injects an edge type external interrupt into the guest once it's ready 573 to receive interrupts. When injected, the interrupt is done. 574 575b) KVM_INTERRUPT_UNSET 576 577 This unsets any pending interrupt. 578 579 Only available with KVM_CAP_PPC_UNSET_IRQ. 580 581c) KVM_INTERRUPT_SET_LEVEL 582 583 This injects a level type external interrupt into the guest context. The 584 interrupt stays pending until a specific ioctl with KVM_INTERRUPT_UNSET 585 is triggered. 586 587 Only available with KVM_CAP_PPC_IRQ_LEVEL. 588 589Note that any value for 'irq' other than the ones stated above is invalid 590and incurs unexpected behavior. 591 592This is an asynchronous vcpu ioctl and can be invoked from any thread. 593 594MIPS: 595^^^^^ 596 597Queues an external interrupt to be injected into the virtual CPU. A negative 598interrupt number dequeues the interrupt. 599 600This is an asynchronous vcpu ioctl and can be invoked from any thread. 601 602 6034.17 KVM_DEBUG_GUEST 604-------------------- 605 606:Capability: basic 607:Architectures: none 608:Type: vcpu ioctl 609:Parameters: none) 610:Returns: -1 on error 611 612Support for this has been removed. Use KVM_SET_GUEST_DEBUG instead. 613 614 6154.18 KVM_GET_MSRS 616----------------- 617 618:Capability: basic (vcpu), KVM_CAP_GET_MSR_FEATURES (system) 619:Architectures: x86 620:Type: system ioctl, vcpu ioctl 621:Parameters: struct kvm_msrs (in/out) 622:Returns: number of msrs successfully returned; 623 -1 on error 624 625When used as a system ioctl: 626Reads the values of MSR-based features that are available for the VM. This 627is similar to KVM_GET_SUPPORTED_CPUID, but it returns MSR indices and values. 628The list of msr-based features can be obtained using KVM_GET_MSR_FEATURE_INDEX_LIST 629in a system ioctl. 630 631When used as a vcpu ioctl: 632Reads model-specific registers from the vcpu. Supported msr indices can 633be obtained using KVM_GET_MSR_INDEX_LIST in a system ioctl. 634 635:: 636 637 struct kvm_msrs { 638 __u32 nmsrs; /* number of msrs in entries */ 639 __u32 pad; 640 641 struct kvm_msr_entry entries[0]; 642 }; 643 644 struct kvm_msr_entry { 645 __u32 index; 646 __u32 reserved; 647 __u64 data; 648 }; 649 650Application code should set the 'nmsrs' member (which indicates the 651size of the entries array) and the 'index' member of each array entry. 652kvm will fill in the 'data' member. 653 654 6554.19 KVM_SET_MSRS 656----------------- 657 658:Capability: basic 659:Architectures: x86 660:Type: vcpu ioctl 661:Parameters: struct kvm_msrs (in) 662:Returns: number of msrs successfully set (see below), -1 on error 663 664Writes model-specific registers to the vcpu. See KVM_GET_MSRS for the 665data structures. 666 667Application code should set the 'nmsrs' member (which indicates the 668size of the entries array), and the 'index' and 'data' members of each 669array entry. 670 671It tries to set the MSRs in array entries[] one by one. If setting an MSR 672fails, e.g., due to setting reserved bits, the MSR isn't supported/emulated 673by KVM, etc..., it stops processing the MSR list and returns the number of 674MSRs that have been set successfully. 675 676 6774.20 KVM_SET_CPUID 678------------------ 679 680:Capability: basic 681:Architectures: x86 682:Type: vcpu ioctl 683:Parameters: struct kvm_cpuid (in) 684:Returns: 0 on success, -1 on error 685 686Defines the vcpu responses to the cpuid instruction. Applications 687should use the KVM_SET_CPUID2 ioctl if available. 688 689Note, when this IOCTL fails, KVM gives no guarantees that previous valid CPUID 690configuration (if there is) is not corrupted. Userspace can get a copy of the 691resulting CPUID configuration through KVM_GET_CPUID2 in case. 692 693:: 694 695 struct kvm_cpuid_entry { 696 __u32 function; 697 __u32 eax; 698 __u32 ebx; 699 __u32 ecx; 700 __u32 edx; 701 __u32 padding; 702 }; 703 704 /* for KVM_SET_CPUID */ 705 struct kvm_cpuid { 706 __u32 nent; 707 __u32 padding; 708 struct kvm_cpuid_entry entries[0]; 709 }; 710 711 7124.21 KVM_SET_SIGNAL_MASK 713------------------------ 714 715:Capability: basic 716:Architectures: all 717:Type: vcpu ioctl 718:Parameters: struct kvm_signal_mask (in) 719:Returns: 0 on success, -1 on error 720 721Defines which signals are blocked during execution of KVM_RUN. This 722signal mask temporarily overrides the threads signal mask. Any 723unblocked signal received (except SIGKILL and SIGSTOP, which retain 724their traditional behaviour) will cause KVM_RUN to return with -EINTR. 725 726Note the signal will only be delivered if not blocked by the original 727signal mask. 728 729:: 730 731 /* for KVM_SET_SIGNAL_MASK */ 732 struct kvm_signal_mask { 733 __u32 len; 734 __u8 sigset[0]; 735 }; 736 737 7384.22 KVM_GET_FPU 739---------------- 740 741:Capability: basic 742:Architectures: x86 743:Type: vcpu ioctl 744:Parameters: struct kvm_fpu (out) 745:Returns: 0 on success, -1 on error 746 747Reads the floating point state from the vcpu. 748 749:: 750 751 /* for KVM_GET_FPU and KVM_SET_FPU */ 752 struct kvm_fpu { 753 __u8 fpr[8][16]; 754 __u16 fcw; 755 __u16 fsw; 756 __u8 ftwx; /* in fxsave format */ 757 __u8 pad1; 758 __u16 last_opcode; 759 __u64 last_ip; 760 __u64 last_dp; 761 __u8 xmm[16][16]; 762 __u32 mxcsr; 763 __u32 pad2; 764 }; 765 766 7674.23 KVM_SET_FPU 768---------------- 769 770:Capability: basic 771:Architectures: x86 772:Type: vcpu ioctl 773:Parameters: struct kvm_fpu (in) 774:Returns: 0 on success, -1 on error 775 776Writes the floating point state to the vcpu. 777 778:: 779 780 /* for KVM_GET_FPU and KVM_SET_FPU */ 781 struct kvm_fpu { 782 __u8 fpr[8][16]; 783 __u16 fcw; 784 __u16 fsw; 785 __u8 ftwx; /* in fxsave format */ 786 __u8 pad1; 787 __u16 last_opcode; 788 __u64 last_ip; 789 __u64 last_dp; 790 __u8 xmm[16][16]; 791 __u32 mxcsr; 792 __u32 pad2; 793 }; 794 795 7964.24 KVM_CREATE_IRQCHIP 797----------------------- 798 799:Capability: KVM_CAP_IRQCHIP, KVM_CAP_S390_IRQCHIP (s390) 800:Architectures: x86, ARM, arm64, s390 801:Type: vm ioctl 802:Parameters: none 803:Returns: 0 on success, -1 on error 804 805Creates an interrupt controller model in the kernel. 806On x86, creates a virtual ioapic, a virtual PIC (two PICs, nested), and sets up 807future vcpus to have a local APIC. IRQ routing for GSIs 0-15 is set to both 808PIC and IOAPIC; GSI 16-23 only go to the IOAPIC. 809On ARM/arm64, a GICv2 is created. Any other GIC versions require the usage of 810KVM_CREATE_DEVICE, which also supports creating a GICv2. Using 811KVM_CREATE_DEVICE is preferred over KVM_CREATE_IRQCHIP for GICv2. 812On s390, a dummy irq routing table is created. 813 814Note that on s390 the KVM_CAP_S390_IRQCHIP vm capability needs to be enabled 815before KVM_CREATE_IRQCHIP can be used. 816 817 8184.25 KVM_IRQ_LINE 819----------------- 820 821:Capability: KVM_CAP_IRQCHIP 822:Architectures: x86, arm, arm64 823:Type: vm ioctl 824:Parameters: struct kvm_irq_level 825:Returns: 0 on success, -1 on error 826 827Sets the level of a GSI input to the interrupt controller model in the kernel. 828On some architectures it is required that an interrupt controller model has 829been previously created with KVM_CREATE_IRQCHIP. Note that edge-triggered 830interrupts require the level to be set to 1 and then back to 0. 831 832On real hardware, interrupt pins can be active-low or active-high. This 833does not matter for the level field of struct kvm_irq_level: 1 always 834means active (asserted), 0 means inactive (deasserted). 835 836x86 allows the operating system to program the interrupt polarity 837(active-low/active-high) for level-triggered interrupts, and KVM used 838to consider the polarity. However, due to bitrot in the handling of 839active-low interrupts, the above convention is now valid on x86 too. 840This is signaled by KVM_CAP_X86_IOAPIC_POLARITY_IGNORED. Userspace 841should not present interrupts to the guest as active-low unless this 842capability is present (or unless it is not using the in-kernel irqchip, 843of course). 844 845 846ARM/arm64 can signal an interrupt either at the CPU level, or at the 847in-kernel irqchip (GIC), and for in-kernel irqchip can tell the GIC to 848use PPIs designated for specific cpus. The irq field is interpreted 849like this:: 850 851 bits: | 31 ... 28 | 27 ... 24 | 23 ... 16 | 15 ... 0 | 852 field: | vcpu2_index | irq_type | vcpu_index | irq_id | 853 854The irq_type field has the following values: 855 856- irq_type[0]: 857 out-of-kernel GIC: irq_id 0 is IRQ, irq_id 1 is FIQ 858- irq_type[1]: 859 in-kernel GIC: SPI, irq_id between 32 and 1019 (incl.) 860 (the vcpu_index field is ignored) 861- irq_type[2]: 862 in-kernel GIC: PPI, irq_id between 16 and 31 (incl.) 863 864(The irq_id field thus corresponds nicely to the IRQ ID in the ARM GIC specs) 865 866In both cases, level is used to assert/deassert the line. 867 868When KVM_CAP_ARM_IRQ_LINE_LAYOUT_2 is supported, the target vcpu is 869identified as (256 * vcpu2_index + vcpu_index). Otherwise, vcpu2_index 870must be zero. 871 872Note that on arm/arm64, the KVM_CAP_IRQCHIP capability only conditions 873injection of interrupts for the in-kernel irqchip. KVM_IRQ_LINE can always 874be used for a userspace interrupt controller. 875 876:: 877 878 struct kvm_irq_level { 879 union { 880 __u32 irq; /* GSI */ 881 __s32 status; /* not used for KVM_IRQ_LEVEL */ 882 }; 883 __u32 level; /* 0 or 1 */ 884 }; 885 886 8874.26 KVM_GET_IRQCHIP 888-------------------- 889 890:Capability: KVM_CAP_IRQCHIP 891:Architectures: x86 892:Type: vm ioctl 893:Parameters: struct kvm_irqchip (in/out) 894:Returns: 0 on success, -1 on error 895 896Reads the state of a kernel interrupt controller created with 897KVM_CREATE_IRQCHIP into a buffer provided by the caller. 898 899:: 900 901 struct kvm_irqchip { 902 __u32 chip_id; /* 0 = PIC1, 1 = PIC2, 2 = IOAPIC */ 903 __u32 pad; 904 union { 905 char dummy[512]; /* reserving space */ 906 struct kvm_pic_state pic; 907 struct kvm_ioapic_state ioapic; 908 } chip; 909 }; 910 911 9124.27 KVM_SET_IRQCHIP 913-------------------- 914 915:Capability: KVM_CAP_IRQCHIP 916:Architectures: x86 917:Type: vm ioctl 918:Parameters: struct kvm_irqchip (in) 919:Returns: 0 on success, -1 on error 920 921Sets the state of a kernel interrupt controller created with 922KVM_CREATE_IRQCHIP from a buffer provided by the caller. 923 924:: 925 926 struct kvm_irqchip { 927 __u32 chip_id; /* 0 = PIC1, 1 = PIC2, 2 = IOAPIC */ 928 __u32 pad; 929 union { 930 char dummy[512]; /* reserving space */ 931 struct kvm_pic_state pic; 932 struct kvm_ioapic_state ioapic; 933 } chip; 934 }; 935 936 9374.28 KVM_XEN_HVM_CONFIG 938----------------------- 939 940:Capability: KVM_CAP_XEN_HVM 941:Architectures: x86 942:Type: vm ioctl 943:Parameters: struct kvm_xen_hvm_config (in) 944:Returns: 0 on success, -1 on error 945 946Sets the MSR that the Xen HVM guest uses to initialize its hypercall 947page, and provides the starting address and size of the hypercall 948blobs in userspace. When the guest writes the MSR, kvm copies one 949page of a blob (32- or 64-bit, depending on the vcpu mode) to guest 950memory. 951 952:: 953 954 struct kvm_xen_hvm_config { 955 __u32 flags; 956 __u32 msr; 957 __u64 blob_addr_32; 958 __u64 blob_addr_64; 959 __u8 blob_size_32; 960 __u8 blob_size_64; 961 __u8 pad2[30]; 962 }; 963 964 9654.29 KVM_GET_CLOCK 966------------------ 967 968:Capability: KVM_CAP_ADJUST_CLOCK 969:Architectures: x86 970:Type: vm ioctl 971:Parameters: struct kvm_clock_data (out) 972:Returns: 0 on success, -1 on error 973 974Gets the current timestamp of kvmclock as seen by the current guest. In 975conjunction with KVM_SET_CLOCK, it is used to ensure monotonicity on scenarios 976such as migration. 977 978When KVM_CAP_ADJUST_CLOCK is passed to KVM_CHECK_EXTENSION, it returns the 979set of bits that KVM can return in struct kvm_clock_data's flag member. 980 981The only flag defined now is KVM_CLOCK_TSC_STABLE. If set, the returned 982value is the exact kvmclock value seen by all VCPUs at the instant 983when KVM_GET_CLOCK was called. If clear, the returned value is simply 984CLOCK_MONOTONIC plus a constant offset; the offset can be modified 985with KVM_SET_CLOCK. KVM will try to make all VCPUs follow this clock, 986but the exact value read by each VCPU could differ, because the host 987TSC is not stable. 988 989:: 990 991 struct kvm_clock_data { 992 __u64 clock; /* kvmclock current value */ 993 __u32 flags; 994 __u32 pad[9]; 995 }; 996 997 9984.30 KVM_SET_CLOCK 999------------------ 1000 1001:Capability: KVM_CAP_ADJUST_CLOCK 1002:Architectures: x86 1003:Type: vm ioctl 1004:Parameters: struct kvm_clock_data (in) 1005:Returns: 0 on success, -1 on error 1006 1007Sets the current timestamp of kvmclock to the value specified in its parameter. 1008In conjunction with KVM_GET_CLOCK, it is used to ensure monotonicity on scenarios 1009such as migration. 1010 1011:: 1012 1013 struct kvm_clock_data { 1014 __u64 clock; /* kvmclock current value */ 1015 __u32 flags; 1016 __u32 pad[9]; 1017 }; 1018 1019 10204.31 KVM_GET_VCPU_EVENTS 1021------------------------ 1022 1023:Capability: KVM_CAP_VCPU_EVENTS 1024:Extended by: KVM_CAP_INTR_SHADOW 1025:Architectures: x86, arm, arm64 1026:Type: vcpu ioctl 1027:Parameters: struct kvm_vcpu_event (out) 1028:Returns: 0 on success, -1 on error 1029 1030X86: 1031^^^^ 1032 1033Gets currently pending exceptions, interrupts, and NMIs as well as related 1034states of the vcpu. 1035 1036:: 1037 1038 struct kvm_vcpu_events { 1039 struct { 1040 __u8 injected; 1041 __u8 nr; 1042 __u8 has_error_code; 1043 __u8 pending; 1044 __u32 error_code; 1045 } exception; 1046 struct { 1047 __u8 injected; 1048 __u8 nr; 1049 __u8 soft; 1050 __u8 shadow; 1051 } interrupt; 1052 struct { 1053 __u8 injected; 1054 __u8 pending; 1055 __u8 masked; 1056 __u8 pad; 1057 } nmi; 1058 __u32 sipi_vector; 1059 __u32 flags; 1060 struct { 1061 __u8 smm; 1062 __u8 pending; 1063 __u8 smm_inside_nmi; 1064 __u8 latched_init; 1065 } smi; 1066 __u8 reserved[27]; 1067 __u8 exception_has_payload; 1068 __u64 exception_payload; 1069 }; 1070 1071The following bits are defined in the flags field: 1072 1073- KVM_VCPUEVENT_VALID_SHADOW may be set to signal that 1074 interrupt.shadow contains a valid state. 1075 1076- KVM_VCPUEVENT_VALID_SMM may be set to signal that smi contains a 1077 valid state. 1078 1079- KVM_VCPUEVENT_VALID_PAYLOAD may be set to signal that the 1080 exception_has_payload, exception_payload, and exception.pending 1081 fields contain a valid state. This bit will be set whenever 1082 KVM_CAP_EXCEPTION_PAYLOAD is enabled. 1083 1084ARM/ARM64: 1085^^^^^^^^^^ 1086 1087If the guest accesses a device that is being emulated by the host kernel in 1088such a way that a real device would generate a physical SError, KVM may make 1089a virtual SError pending for that VCPU. This system error interrupt remains 1090pending until the guest takes the exception by unmasking PSTATE.A. 1091 1092Running the VCPU may cause it to take a pending SError, or make an access that 1093causes an SError to become pending. The event's description is only valid while 1094the VPCU is not running. 1095 1096This API provides a way to read and write the pending 'event' state that is not 1097visible to the guest. To save, restore or migrate a VCPU the struct representing 1098the state can be read then written using this GET/SET API, along with the other 1099guest-visible registers. It is not possible to 'cancel' an SError that has been 1100made pending. 1101 1102A device being emulated in user-space may also wish to generate an SError. To do 1103this the events structure can be populated by user-space. The current state 1104should be read first, to ensure no existing SError is pending. If an existing 1105SError is pending, the architecture's 'Multiple SError interrupts' rules should 1106be followed. (2.5.3 of DDI0587.a "ARM Reliability, Availability, and 1107Serviceability (RAS) Specification"). 1108 1109SError exceptions always have an ESR value. Some CPUs have the ability to 1110specify what the virtual SError's ESR value should be. These systems will 1111advertise KVM_CAP_ARM_INJECT_SERROR_ESR. In this case exception.has_esr will 1112always have a non-zero value when read, and the agent making an SError pending 1113should specify the ISS field in the lower 24 bits of exception.serror_esr. If 1114the system supports KVM_CAP_ARM_INJECT_SERROR_ESR, but user-space sets the events 1115with exception.has_esr as zero, KVM will choose an ESR. 1116 1117Specifying exception.has_esr on a system that does not support it will return 1118-EINVAL. Setting anything other than the lower 24bits of exception.serror_esr 1119will return -EINVAL. 1120 1121It is not possible to read back a pending external abort (injected via 1122KVM_SET_VCPU_EVENTS or otherwise) because such an exception is always delivered 1123directly to the virtual CPU). 1124 1125:: 1126 1127 struct kvm_vcpu_events { 1128 struct { 1129 __u8 serror_pending; 1130 __u8 serror_has_esr; 1131 __u8 ext_dabt_pending; 1132 /* Align it to 8 bytes */ 1133 __u8 pad[5]; 1134 __u64 serror_esr; 1135 } exception; 1136 __u32 reserved[12]; 1137 }; 1138 11394.32 KVM_SET_VCPU_EVENTS 1140------------------------ 1141 1142:Capability: KVM_CAP_VCPU_EVENTS 1143:Extended by: KVM_CAP_INTR_SHADOW 1144:Architectures: x86, arm, arm64 1145:Type: vcpu ioctl 1146:Parameters: struct kvm_vcpu_event (in) 1147:Returns: 0 on success, -1 on error 1148 1149X86: 1150^^^^ 1151 1152Set pending exceptions, interrupts, and NMIs as well as related states of the 1153vcpu. 1154 1155See KVM_GET_VCPU_EVENTS for the data structure. 1156 1157Fields that may be modified asynchronously by running VCPUs can be excluded 1158from the update. These fields are nmi.pending, sipi_vector, smi.smm, 1159smi.pending. Keep the corresponding bits in the flags field cleared to 1160suppress overwriting the current in-kernel state. The bits are: 1161 1162=============================== ================================== 1163KVM_VCPUEVENT_VALID_NMI_PENDING transfer nmi.pending to the kernel 1164KVM_VCPUEVENT_VALID_SIPI_VECTOR transfer sipi_vector 1165KVM_VCPUEVENT_VALID_SMM transfer the smi sub-struct. 1166=============================== ================================== 1167 1168If KVM_CAP_INTR_SHADOW is available, KVM_VCPUEVENT_VALID_SHADOW can be set in 1169the flags field to signal that interrupt.shadow contains a valid state and 1170shall be written into the VCPU. 1171 1172KVM_VCPUEVENT_VALID_SMM can only be set if KVM_CAP_X86_SMM is available. 1173 1174If KVM_CAP_EXCEPTION_PAYLOAD is enabled, KVM_VCPUEVENT_VALID_PAYLOAD 1175can be set in the flags field to signal that the 1176exception_has_payload, exception_payload, and exception.pending fields 1177contain a valid state and shall be written into the VCPU. 1178 1179ARM/ARM64: 1180^^^^^^^^^^ 1181 1182User space may need to inject several types of events to the guest. 1183 1184Set the pending SError exception state for this VCPU. It is not possible to 1185'cancel' an Serror that has been made pending. 1186 1187If the guest performed an access to I/O memory which could not be handled by 1188userspace, for example because of missing instruction syndrome decode 1189information or because there is no device mapped at the accessed IPA, then 1190userspace can ask the kernel to inject an external abort using the address 1191from the exiting fault on the VCPU. It is a programming error to set 1192ext_dabt_pending after an exit which was not either KVM_EXIT_MMIO or 1193KVM_EXIT_ARM_NISV. This feature is only available if the system supports 1194KVM_CAP_ARM_INJECT_EXT_DABT. This is a helper which provides commonality in 1195how userspace reports accesses for the above cases to guests, across different 1196userspace implementations. Nevertheless, userspace can still emulate all Arm 1197exceptions by manipulating individual registers using the KVM_SET_ONE_REG API. 1198 1199See KVM_GET_VCPU_EVENTS for the data structure. 1200 1201 12024.33 KVM_GET_DEBUGREGS 1203---------------------- 1204 1205:Capability: KVM_CAP_DEBUGREGS 1206:Architectures: x86 1207:Type: vm ioctl 1208:Parameters: struct kvm_debugregs (out) 1209:Returns: 0 on success, -1 on error 1210 1211Reads debug registers from the vcpu. 1212 1213:: 1214 1215 struct kvm_debugregs { 1216 __u64 db[4]; 1217 __u64 dr6; 1218 __u64 dr7; 1219 __u64 flags; 1220 __u64 reserved[9]; 1221 }; 1222 1223 12244.34 KVM_SET_DEBUGREGS 1225---------------------- 1226 1227:Capability: KVM_CAP_DEBUGREGS 1228:Architectures: x86 1229:Type: vm ioctl 1230:Parameters: struct kvm_debugregs (in) 1231:Returns: 0 on success, -1 on error 1232 1233Writes debug registers into the vcpu. 1234 1235See KVM_GET_DEBUGREGS for the data structure. The flags field is unused 1236yet and must be cleared on entry. 1237 1238 12394.35 KVM_SET_USER_MEMORY_REGION 1240------------------------------- 1241 1242:Capability: KVM_CAP_USER_MEMORY 1243:Architectures: all 1244:Type: vm ioctl 1245:Parameters: struct kvm_userspace_memory_region (in) 1246:Returns: 0 on success, -1 on error 1247 1248:: 1249 1250 struct kvm_userspace_memory_region { 1251 __u32 slot; 1252 __u32 flags; 1253 __u64 guest_phys_addr; 1254 __u64 memory_size; /* bytes */ 1255 __u64 userspace_addr; /* start of the userspace allocated memory */ 1256 }; 1257 1258 /* for kvm_memory_region::flags */ 1259 #define KVM_MEM_LOG_DIRTY_PAGES (1UL << 0) 1260 #define KVM_MEM_READONLY (1UL << 1) 1261 1262This ioctl allows the user to create, modify or delete a guest physical 1263memory slot. Bits 0-15 of "slot" specify the slot id and this value 1264should be less than the maximum number of user memory slots supported per 1265VM. The maximum allowed slots can be queried using KVM_CAP_NR_MEMSLOTS. 1266Slots may not overlap in guest physical address space. 1267 1268If KVM_CAP_MULTI_ADDRESS_SPACE is available, bits 16-31 of "slot" 1269specifies the address space which is being modified. They must be 1270less than the value that KVM_CHECK_EXTENSION returns for the 1271KVM_CAP_MULTI_ADDRESS_SPACE capability. Slots in separate address spaces 1272are unrelated; the restriction on overlapping slots only applies within 1273each address space. 1274 1275Deleting a slot is done by passing zero for memory_size. When changing 1276an existing slot, it may be moved in the guest physical memory space, 1277or its flags may be modified, but it may not be resized. 1278 1279Memory for the region is taken starting at the address denoted by the 1280field userspace_addr, which must point at user addressable memory for 1281the entire memory slot size. Any object may back this memory, including 1282anonymous memory, ordinary files, and hugetlbfs. 1283 1284It is recommended that the lower 21 bits of guest_phys_addr and userspace_addr 1285be identical. This allows large pages in the guest to be backed by large 1286pages in the host. 1287 1288The flags field supports two flags: KVM_MEM_LOG_DIRTY_PAGES and 1289KVM_MEM_READONLY. The former can be set to instruct KVM to keep track of 1290writes to memory within the slot. See KVM_GET_DIRTY_LOG ioctl to know how to 1291use it. The latter can be set, if KVM_CAP_READONLY_MEM capability allows it, 1292to make a new slot read-only. In this case, writes to this memory will be 1293posted to userspace as KVM_EXIT_MMIO exits. 1294 1295When the KVM_CAP_SYNC_MMU capability is available, changes in the backing of 1296the memory region are automatically reflected into the guest. For example, an 1297mmap() that affects the region will be made visible immediately. Another 1298example is madvise(MADV_DROP). 1299 1300It is recommended to use this API instead of the KVM_SET_MEMORY_REGION ioctl. 1301The KVM_SET_MEMORY_REGION does not allow fine grained control over memory 1302allocation and is deprecated. 1303 1304 13054.36 KVM_SET_TSS_ADDR 1306--------------------- 1307 1308:Capability: KVM_CAP_SET_TSS_ADDR 1309:Architectures: x86 1310:Type: vm ioctl 1311:Parameters: unsigned long tss_address (in) 1312:Returns: 0 on success, -1 on error 1313 1314This ioctl defines the physical address of a three-page region in the guest 1315physical address space. The region must be within the first 4GB of the 1316guest physical address space and must not conflict with any memory slot 1317or any mmio address. The guest may malfunction if it accesses this memory 1318region. 1319 1320This ioctl is required on Intel-based hosts. This is needed on Intel hardware 1321because of a quirk in the virtualization implementation (see the internals 1322documentation when it pops into existence). 1323 1324 13254.37 KVM_ENABLE_CAP 1326------------------- 1327 1328:Capability: KVM_CAP_ENABLE_CAP 1329:Architectures: mips, ppc, s390 1330:Type: vcpu ioctl 1331:Parameters: struct kvm_enable_cap (in) 1332:Returns: 0 on success; -1 on error 1333 1334:Capability: KVM_CAP_ENABLE_CAP_VM 1335:Architectures: all 1336:Type: vcpu ioctl 1337:Parameters: struct kvm_enable_cap (in) 1338:Returns: 0 on success; -1 on error 1339 1340.. note:: 1341 1342 Not all extensions are enabled by default. Using this ioctl the application 1343 can enable an extension, making it available to the guest. 1344 1345On systems that do not support this ioctl, it always fails. On systems that 1346do support it, it only works for extensions that are supported for enablement. 1347 1348To check if a capability can be enabled, the KVM_CHECK_EXTENSION ioctl should 1349be used. 1350 1351:: 1352 1353 struct kvm_enable_cap { 1354 /* in */ 1355 __u32 cap; 1356 1357The capability that is supposed to get enabled. 1358 1359:: 1360 1361 __u32 flags; 1362 1363A bitfield indicating future enhancements. Has to be 0 for now. 1364 1365:: 1366 1367 __u64 args[4]; 1368 1369Arguments for enabling a feature. If a feature needs initial values to 1370function properly, this is the place to put them. 1371 1372:: 1373 1374 __u8 pad[64]; 1375 }; 1376 1377The vcpu ioctl should be used for vcpu-specific capabilities, the vm ioctl 1378for vm-wide capabilities. 1379 13804.38 KVM_GET_MP_STATE 1381--------------------- 1382 1383:Capability: KVM_CAP_MP_STATE 1384:Architectures: x86, s390, arm, arm64 1385:Type: vcpu ioctl 1386:Parameters: struct kvm_mp_state (out) 1387:Returns: 0 on success; -1 on error 1388 1389:: 1390 1391 struct kvm_mp_state { 1392 __u32 mp_state; 1393 }; 1394 1395Returns the vcpu's current "multiprocessing state" (though also valid on 1396uniprocessor guests). 1397 1398Possible values are: 1399 1400 ========================== =============================================== 1401 KVM_MP_STATE_RUNNABLE the vcpu is currently running [x86,arm/arm64] 1402 KVM_MP_STATE_UNINITIALIZED the vcpu is an application processor (AP) 1403 which has not yet received an INIT signal [x86] 1404 KVM_MP_STATE_INIT_RECEIVED the vcpu has received an INIT signal, and is 1405 now ready for a SIPI [x86] 1406 KVM_MP_STATE_HALTED the vcpu has executed a HLT instruction and 1407 is waiting for an interrupt [x86] 1408 KVM_MP_STATE_SIPI_RECEIVED the vcpu has just received a SIPI (vector 1409 accessible via KVM_GET_VCPU_EVENTS) [x86] 1410 KVM_MP_STATE_STOPPED the vcpu is stopped [s390,arm/arm64] 1411 KVM_MP_STATE_CHECK_STOP the vcpu is in a special error state [s390] 1412 KVM_MP_STATE_OPERATING the vcpu is operating (running or halted) 1413 [s390] 1414 KVM_MP_STATE_LOAD the vcpu is in a special load/startup state 1415 [s390] 1416 ========================== =============================================== 1417 1418On x86, this ioctl is only useful after KVM_CREATE_IRQCHIP. Without an 1419in-kernel irqchip, the multiprocessing state must be maintained by userspace on 1420these architectures. 1421 1422For arm/arm64: 1423^^^^^^^^^^^^^^ 1424 1425The only states that are valid are KVM_MP_STATE_STOPPED and 1426KVM_MP_STATE_RUNNABLE which reflect if the vcpu is paused or not. 1427 14284.39 KVM_SET_MP_STATE 1429--------------------- 1430 1431:Capability: KVM_CAP_MP_STATE 1432:Architectures: x86, s390, arm, arm64 1433:Type: vcpu ioctl 1434:Parameters: struct kvm_mp_state (in) 1435:Returns: 0 on success; -1 on error 1436 1437Sets the vcpu's current "multiprocessing state"; see KVM_GET_MP_STATE for 1438arguments. 1439 1440On x86, this ioctl is only useful after KVM_CREATE_IRQCHIP. Without an 1441in-kernel irqchip, the multiprocessing state must be maintained by userspace on 1442these architectures. 1443 1444For arm/arm64: 1445^^^^^^^^^^^^^^ 1446 1447The only states that are valid are KVM_MP_STATE_STOPPED and 1448KVM_MP_STATE_RUNNABLE which reflect if the vcpu should be paused or not. 1449 14504.40 KVM_SET_IDENTITY_MAP_ADDR 1451------------------------------ 1452 1453:Capability: KVM_CAP_SET_IDENTITY_MAP_ADDR 1454:Architectures: x86 1455:Type: vm ioctl 1456:Parameters: unsigned long identity (in) 1457:Returns: 0 on success, -1 on error 1458 1459This ioctl defines the physical address of a one-page region in the guest 1460physical address space. The region must be within the first 4GB of the 1461guest physical address space and must not conflict with any memory slot 1462or any mmio address. The guest may malfunction if it accesses this memory 1463region. 1464 1465Setting the address to 0 will result in resetting the address to its default 1466(0xfffbc000). 1467 1468This ioctl is required on Intel-based hosts. This is needed on Intel hardware 1469because of a quirk in the virtualization implementation (see the internals 1470documentation when it pops into existence). 1471 1472Fails if any VCPU has already been created. 1473 14744.41 KVM_SET_BOOT_CPU_ID 1475------------------------ 1476 1477:Capability: KVM_CAP_SET_BOOT_CPU_ID 1478:Architectures: x86 1479:Type: vm ioctl 1480:Parameters: unsigned long vcpu_id 1481:Returns: 0 on success, -1 on error 1482 1483Define which vcpu is the Bootstrap Processor (BSP). Values are the same 1484as the vcpu id in KVM_CREATE_VCPU. If this ioctl is not called, the default 1485is vcpu 0. 1486 1487 14884.42 KVM_GET_XSAVE 1489------------------ 1490 1491:Capability: KVM_CAP_XSAVE 1492:Architectures: x86 1493:Type: vcpu ioctl 1494:Parameters: struct kvm_xsave (out) 1495:Returns: 0 on success, -1 on error 1496 1497 1498:: 1499 1500 struct kvm_xsave { 1501 __u32 region[1024]; 1502 }; 1503 1504This ioctl would copy current vcpu's xsave struct to the userspace. 1505 1506 15074.43 KVM_SET_XSAVE 1508------------------ 1509 1510:Capability: KVM_CAP_XSAVE 1511:Architectures: x86 1512:Type: vcpu ioctl 1513:Parameters: struct kvm_xsave (in) 1514:Returns: 0 on success, -1 on error 1515 1516:: 1517 1518 1519 struct kvm_xsave { 1520 __u32 region[1024]; 1521 }; 1522 1523This ioctl would copy userspace's xsave struct to the kernel. 1524 1525 15264.44 KVM_GET_XCRS 1527----------------- 1528 1529:Capability: KVM_CAP_XCRS 1530:Architectures: x86 1531:Type: vcpu ioctl 1532:Parameters: struct kvm_xcrs (out) 1533:Returns: 0 on success, -1 on error 1534 1535:: 1536 1537 struct kvm_xcr { 1538 __u32 xcr; 1539 __u32 reserved; 1540 __u64 value; 1541 }; 1542 1543 struct kvm_xcrs { 1544 __u32 nr_xcrs; 1545 __u32 flags; 1546 struct kvm_xcr xcrs[KVM_MAX_XCRS]; 1547 __u64 padding[16]; 1548 }; 1549 1550This ioctl would copy current vcpu's xcrs to the userspace. 1551 1552 15534.45 KVM_SET_XCRS 1554----------------- 1555 1556:Capability: KVM_CAP_XCRS 1557:Architectures: x86 1558:Type: vcpu ioctl 1559:Parameters: struct kvm_xcrs (in) 1560:Returns: 0 on success, -1 on error 1561 1562:: 1563 1564 struct kvm_xcr { 1565 __u32 xcr; 1566 __u32 reserved; 1567 __u64 value; 1568 }; 1569 1570 struct kvm_xcrs { 1571 __u32 nr_xcrs; 1572 __u32 flags; 1573 struct kvm_xcr xcrs[KVM_MAX_XCRS]; 1574 __u64 padding[16]; 1575 }; 1576 1577This ioctl would set vcpu's xcr to the value userspace specified. 1578 1579 15804.46 KVM_GET_SUPPORTED_CPUID 1581---------------------------- 1582 1583:Capability: KVM_CAP_EXT_CPUID 1584:Architectures: x86 1585:Type: system ioctl 1586:Parameters: struct kvm_cpuid2 (in/out) 1587:Returns: 0 on success, -1 on error 1588 1589:: 1590 1591 struct kvm_cpuid2 { 1592 __u32 nent; 1593 __u32 padding; 1594 struct kvm_cpuid_entry2 entries[0]; 1595 }; 1596 1597 #define KVM_CPUID_FLAG_SIGNIFCANT_INDEX BIT(0) 1598 #define KVM_CPUID_FLAG_STATEFUL_FUNC BIT(1) /* deprecated */ 1599 #define KVM_CPUID_FLAG_STATE_READ_NEXT BIT(2) /* deprecated */ 1600 1601 struct kvm_cpuid_entry2 { 1602 __u32 function; 1603 __u32 index; 1604 __u32 flags; 1605 __u32 eax; 1606 __u32 ebx; 1607 __u32 ecx; 1608 __u32 edx; 1609 __u32 padding[3]; 1610 }; 1611 1612This ioctl returns x86 cpuid features which are supported by both the 1613hardware and kvm in its default configuration. Userspace can use the 1614information returned by this ioctl to construct cpuid information (for 1615KVM_SET_CPUID2) that is consistent with hardware, kernel, and 1616userspace capabilities, and with user requirements (for example, the 1617user may wish to constrain cpuid to emulate older hardware, or for 1618feature consistency across a cluster). 1619 1620Note that certain capabilities, such as KVM_CAP_X86_DISABLE_EXITS, may 1621expose cpuid features (e.g. MONITOR) which are not supported by kvm in 1622its default configuration. If userspace enables such capabilities, it 1623is responsible for modifying the results of this ioctl appropriately. 1624 1625Userspace invokes KVM_GET_SUPPORTED_CPUID by passing a kvm_cpuid2 structure 1626with the 'nent' field indicating the number of entries in the variable-size 1627array 'entries'. If the number of entries is too low to describe the cpu 1628capabilities, an error (E2BIG) is returned. If the number is too high, 1629the 'nent' field is adjusted and an error (ENOMEM) is returned. If the 1630number is just right, the 'nent' field is adjusted to the number of valid 1631entries in the 'entries' array, which is then filled. 1632 1633The entries returned are the host cpuid as returned by the cpuid instruction, 1634with unknown or unsupported features masked out. Some features (for example, 1635x2apic), may not be present in the host cpu, but are exposed by kvm if it can 1636emulate them efficiently. The fields in each entry are defined as follows: 1637 1638 function: 1639 the eax value used to obtain the entry 1640 1641 index: 1642 the ecx value used to obtain the entry (for entries that are 1643 affected by ecx) 1644 1645 flags: 1646 an OR of zero or more of the following: 1647 1648 KVM_CPUID_FLAG_SIGNIFCANT_INDEX: 1649 if the index field is valid 1650 1651 eax, ebx, ecx, edx: 1652 the values returned by the cpuid instruction for 1653 this function/index combination 1654 1655The TSC deadline timer feature (CPUID leaf 1, ecx[24]) is always returned 1656as false, since the feature depends on KVM_CREATE_IRQCHIP for local APIC 1657support. Instead it is reported via:: 1658 1659 ioctl(KVM_CHECK_EXTENSION, KVM_CAP_TSC_DEADLINE_TIMER) 1660 1661if that returns true and you use KVM_CREATE_IRQCHIP, or if you emulate the 1662feature in userspace, then you can enable the feature for KVM_SET_CPUID2. 1663 1664 16654.47 KVM_PPC_GET_PVINFO 1666----------------------- 1667 1668:Capability: KVM_CAP_PPC_GET_PVINFO 1669:Architectures: ppc 1670:Type: vm ioctl 1671:Parameters: struct kvm_ppc_pvinfo (out) 1672:Returns: 0 on success, !0 on error 1673 1674:: 1675 1676 struct kvm_ppc_pvinfo { 1677 __u32 flags; 1678 __u32 hcall[4]; 1679 __u8 pad[108]; 1680 }; 1681 1682This ioctl fetches PV specific information that need to be passed to the guest 1683using the device tree or other means from vm context. 1684 1685The hcall array defines 4 instructions that make up a hypercall. 1686 1687If any additional field gets added to this structure later on, a bit for that 1688additional piece of information will be set in the flags bitmap. 1689 1690The flags bitmap is defined as:: 1691 1692 /* the host supports the ePAPR idle hcall 1693 #define KVM_PPC_PVINFO_FLAGS_EV_IDLE (1<<0) 1694 16954.52 KVM_SET_GSI_ROUTING 1696------------------------ 1697 1698:Capability: KVM_CAP_IRQ_ROUTING 1699:Architectures: x86 s390 arm arm64 1700:Type: vm ioctl 1701:Parameters: struct kvm_irq_routing (in) 1702:Returns: 0 on success, -1 on error 1703 1704Sets the GSI routing table entries, overwriting any previously set entries. 1705 1706On arm/arm64, GSI routing has the following limitation: 1707 1708- GSI routing does not apply to KVM_IRQ_LINE but only to KVM_IRQFD. 1709 1710:: 1711 1712 struct kvm_irq_routing { 1713 __u32 nr; 1714 __u32 flags; 1715 struct kvm_irq_routing_entry entries[0]; 1716 }; 1717 1718No flags are specified so far, the corresponding field must be set to zero. 1719 1720:: 1721 1722 struct kvm_irq_routing_entry { 1723 __u32 gsi; 1724 __u32 type; 1725 __u32 flags; 1726 __u32 pad; 1727 union { 1728 struct kvm_irq_routing_irqchip irqchip; 1729 struct kvm_irq_routing_msi msi; 1730 struct kvm_irq_routing_s390_adapter adapter; 1731 struct kvm_irq_routing_hv_sint hv_sint; 1732 __u32 pad[8]; 1733 } u; 1734 }; 1735 1736 /* gsi routing entry types */ 1737 #define KVM_IRQ_ROUTING_IRQCHIP 1 1738 #define KVM_IRQ_ROUTING_MSI 2 1739 #define KVM_IRQ_ROUTING_S390_ADAPTER 3 1740 #define KVM_IRQ_ROUTING_HV_SINT 4 1741 1742flags: 1743 1744- KVM_MSI_VALID_DEVID: used along with KVM_IRQ_ROUTING_MSI routing entry 1745 type, specifies that the devid field contains a valid value. The per-VM 1746 KVM_CAP_MSI_DEVID capability advertises the requirement to provide 1747 the device ID. If this capability is not available, userspace should 1748 never set the KVM_MSI_VALID_DEVID flag as the ioctl might fail. 1749- zero otherwise 1750 1751:: 1752 1753 struct kvm_irq_routing_irqchip { 1754 __u32 irqchip; 1755 __u32 pin; 1756 }; 1757 1758 struct kvm_irq_routing_msi { 1759 __u32 address_lo; 1760 __u32 address_hi; 1761 __u32 data; 1762 union { 1763 __u32 pad; 1764 __u32 devid; 1765 }; 1766 }; 1767 1768If KVM_MSI_VALID_DEVID is set, devid contains a unique device identifier 1769for the device that wrote the MSI message. For PCI, this is usually a 1770BFD identifier in the lower 16 bits. 1771 1772On x86, address_hi is ignored unless the KVM_X2APIC_API_USE_32BIT_IDS 1773feature of KVM_CAP_X2APIC_API capability is enabled. If it is enabled, 1774address_hi bits 31-8 provide bits 31-8 of the destination id. Bits 7-0 of 1775address_hi must be zero. 1776 1777:: 1778 1779 struct kvm_irq_routing_s390_adapter { 1780 __u64 ind_addr; 1781 __u64 summary_addr; 1782 __u64 ind_offset; 1783 __u32 summary_offset; 1784 __u32 adapter_id; 1785 }; 1786 1787 struct kvm_irq_routing_hv_sint { 1788 __u32 vcpu; 1789 __u32 sint; 1790 }; 1791 1792 17934.55 KVM_SET_TSC_KHZ 1794-------------------- 1795 1796:Capability: KVM_CAP_TSC_CONTROL 1797:Architectures: x86 1798:Type: vcpu ioctl 1799:Parameters: virtual tsc_khz 1800:Returns: 0 on success, -1 on error 1801 1802Specifies the tsc frequency for the virtual machine. The unit of the 1803frequency is KHz. 1804 1805 18064.56 KVM_GET_TSC_KHZ 1807-------------------- 1808 1809:Capability: KVM_CAP_GET_TSC_KHZ 1810:Architectures: x86 1811:Type: vcpu ioctl 1812:Parameters: none 1813:Returns: virtual tsc-khz on success, negative value on error 1814 1815Returns the tsc frequency of the guest. The unit of the return value is 1816KHz. If the host has unstable tsc this ioctl returns -EIO instead as an 1817error. 1818 1819 18204.57 KVM_GET_LAPIC 1821------------------ 1822 1823:Capability: KVM_CAP_IRQCHIP 1824:Architectures: x86 1825:Type: vcpu ioctl 1826:Parameters: struct kvm_lapic_state (out) 1827:Returns: 0 on success, -1 on error 1828 1829:: 1830 1831 #define KVM_APIC_REG_SIZE 0x400 1832 struct kvm_lapic_state { 1833 char regs[KVM_APIC_REG_SIZE]; 1834 }; 1835 1836Reads the Local APIC registers and copies them into the input argument. The 1837data format and layout are the same as documented in the architecture manual. 1838 1839If KVM_X2APIC_API_USE_32BIT_IDS feature of KVM_CAP_X2APIC_API is 1840enabled, then the format of APIC_ID register depends on the APIC mode 1841(reported by MSR_IA32_APICBASE) of its VCPU. x2APIC stores APIC ID in 1842the APIC_ID register (bytes 32-35). xAPIC only allows an 8-bit APIC ID 1843which is stored in bits 31-24 of the APIC register, or equivalently in 1844byte 35 of struct kvm_lapic_state's regs field. KVM_GET_LAPIC must then 1845be called after MSR_IA32_APICBASE has been set with KVM_SET_MSR. 1846 1847If KVM_X2APIC_API_USE_32BIT_IDS feature is disabled, struct kvm_lapic_state 1848always uses xAPIC format. 1849 1850 18514.58 KVM_SET_LAPIC 1852------------------ 1853 1854:Capability: KVM_CAP_IRQCHIP 1855:Architectures: x86 1856:Type: vcpu ioctl 1857:Parameters: struct kvm_lapic_state (in) 1858:Returns: 0 on success, -1 on error 1859 1860:: 1861 1862 #define KVM_APIC_REG_SIZE 0x400 1863 struct kvm_lapic_state { 1864 char regs[KVM_APIC_REG_SIZE]; 1865 }; 1866 1867Copies the input argument into the Local APIC registers. The data format 1868and layout are the same as documented in the architecture manual. 1869 1870The format of the APIC ID register (bytes 32-35 of struct kvm_lapic_state's 1871regs field) depends on the state of the KVM_CAP_X2APIC_API capability. 1872See the note in KVM_GET_LAPIC. 1873 1874 18754.59 KVM_IOEVENTFD 1876------------------ 1877 1878:Capability: KVM_CAP_IOEVENTFD 1879:Architectures: all 1880:Type: vm ioctl 1881:Parameters: struct kvm_ioeventfd (in) 1882:Returns: 0 on success, !0 on error 1883 1884This ioctl attaches or detaches an ioeventfd to a legal pio/mmio address 1885within the guest. A guest write in the registered address will signal the 1886provided event instead of triggering an exit. 1887 1888:: 1889 1890 struct kvm_ioeventfd { 1891 __u64 datamatch; 1892 __u64 addr; /* legal pio/mmio address */ 1893 __u32 len; /* 0, 1, 2, 4, or 8 bytes */ 1894 __s32 fd; 1895 __u32 flags; 1896 __u8 pad[36]; 1897 }; 1898 1899For the special case of virtio-ccw devices on s390, the ioevent is matched 1900to a subchannel/virtqueue tuple instead. 1901 1902The following flags are defined:: 1903 1904 #define KVM_IOEVENTFD_FLAG_DATAMATCH (1 << kvm_ioeventfd_flag_nr_datamatch) 1905 #define KVM_IOEVENTFD_FLAG_PIO (1 << kvm_ioeventfd_flag_nr_pio) 1906 #define KVM_IOEVENTFD_FLAG_DEASSIGN (1 << kvm_ioeventfd_flag_nr_deassign) 1907 #define KVM_IOEVENTFD_FLAG_VIRTIO_CCW_NOTIFY \ 1908 (1 << kvm_ioeventfd_flag_nr_virtio_ccw_notify) 1909 1910If datamatch flag is set, the event will be signaled only if the written value 1911to the registered address is equal to datamatch in struct kvm_ioeventfd. 1912 1913For virtio-ccw devices, addr contains the subchannel id and datamatch the 1914virtqueue index. 1915 1916With KVM_CAP_IOEVENTFD_ANY_LENGTH, a zero length ioeventfd is allowed, and 1917the kernel will ignore the length of guest write and may get a faster vmexit. 1918The speedup may only apply to specific architectures, but the ioeventfd will 1919work anyway. 1920 19214.60 KVM_DIRTY_TLB 1922------------------ 1923 1924:Capability: KVM_CAP_SW_TLB 1925:Architectures: ppc 1926:Type: vcpu ioctl 1927:Parameters: struct kvm_dirty_tlb (in) 1928:Returns: 0 on success, -1 on error 1929 1930:: 1931 1932 struct kvm_dirty_tlb { 1933 __u64 bitmap; 1934 __u32 num_dirty; 1935 }; 1936 1937This must be called whenever userspace has changed an entry in the shared 1938TLB, prior to calling KVM_RUN on the associated vcpu. 1939 1940The "bitmap" field is the userspace address of an array. This array 1941consists of a number of bits, equal to the total number of TLB entries as 1942determined by the last successful call to KVM_CONFIG_TLB, rounded up to the 1943nearest multiple of 64. 1944 1945Each bit corresponds to one TLB entry, ordered the same as in the shared TLB 1946array. 1947 1948The array is little-endian: the bit 0 is the least significant bit of the 1949first byte, bit 8 is the least significant bit of the second byte, etc. 1950This avoids any complications with differing word sizes. 1951 1952The "num_dirty" field is a performance hint for KVM to determine whether it 1953should skip processing the bitmap and just invalidate everything. It must 1954be set to the number of set bits in the bitmap. 1955 1956 19574.62 KVM_CREATE_SPAPR_TCE 1958------------------------- 1959 1960:Capability: KVM_CAP_SPAPR_TCE 1961:Architectures: powerpc 1962:Type: vm ioctl 1963:Parameters: struct kvm_create_spapr_tce (in) 1964:Returns: file descriptor for manipulating the created TCE table 1965 1966This creates a virtual TCE (translation control entry) table, which 1967is an IOMMU for PAPR-style virtual I/O. It is used to translate 1968logical addresses used in virtual I/O into guest physical addresses, 1969and provides a scatter/gather capability for PAPR virtual I/O. 1970 1971:: 1972 1973 /* for KVM_CAP_SPAPR_TCE */ 1974 struct kvm_create_spapr_tce { 1975 __u64 liobn; 1976 __u32 window_size; 1977 }; 1978 1979The liobn field gives the logical IO bus number for which to create a 1980TCE table. The window_size field specifies the size of the DMA window 1981which this TCE table will translate - the table will contain one 64 1982bit TCE entry for every 4kiB of the DMA window. 1983 1984When the guest issues an H_PUT_TCE hcall on a liobn for which a TCE 1985table has been created using this ioctl(), the kernel will handle it 1986in real mode, updating the TCE table. H_PUT_TCE calls for other 1987liobns will cause a vm exit and must be handled by userspace. 1988 1989The return value is a file descriptor which can be passed to mmap(2) 1990to map the created TCE table into userspace. This lets userspace read 1991the entries written by kernel-handled H_PUT_TCE calls, and also lets 1992userspace update the TCE table directly which is useful in some 1993circumstances. 1994 1995 19964.63 KVM_ALLOCATE_RMA 1997--------------------- 1998 1999:Capability: KVM_CAP_PPC_RMA 2000:Architectures: powerpc 2001:Type: vm ioctl 2002:Parameters: struct kvm_allocate_rma (out) 2003:Returns: file descriptor for mapping the allocated RMA 2004 2005This allocates a Real Mode Area (RMA) from the pool allocated at boot 2006time by the kernel. An RMA is a physically-contiguous, aligned region 2007of memory used on older POWER processors to provide the memory which 2008will be accessed by real-mode (MMU off) accesses in a KVM guest. 2009POWER processors support a set of sizes for the RMA that usually 2010includes 64MB, 128MB, 256MB and some larger powers of two. 2011 2012:: 2013 2014 /* for KVM_ALLOCATE_RMA */ 2015 struct kvm_allocate_rma { 2016 __u64 rma_size; 2017 }; 2018 2019The return value is a file descriptor which can be passed to mmap(2) 2020to map the allocated RMA into userspace. The mapped area can then be 2021passed to the KVM_SET_USER_MEMORY_REGION ioctl to establish it as the 2022RMA for a virtual machine. The size of the RMA in bytes (which is 2023fixed at host kernel boot time) is returned in the rma_size field of 2024the argument structure. 2025 2026The KVM_CAP_PPC_RMA capability is 1 or 2 if the KVM_ALLOCATE_RMA ioctl 2027is supported; 2 if the processor requires all virtual machines to have 2028an RMA, or 1 if the processor can use an RMA but doesn't require it, 2029because it supports the Virtual RMA (VRMA) facility. 2030 2031 20324.64 KVM_NMI 2033------------ 2034 2035:Capability: KVM_CAP_USER_NMI 2036:Architectures: x86 2037:Type: vcpu ioctl 2038:Parameters: none 2039:Returns: 0 on success, -1 on error 2040 2041Queues an NMI on the thread's vcpu. Note this is well defined only 2042when KVM_CREATE_IRQCHIP has not been called, since this is an interface 2043between the virtual cpu core and virtual local APIC. After KVM_CREATE_IRQCHIP 2044has been called, this interface is completely emulated within the kernel. 2045 2046To use this to emulate the LINT1 input with KVM_CREATE_IRQCHIP, use the 2047following algorithm: 2048 2049 - pause the vcpu 2050 - read the local APIC's state (KVM_GET_LAPIC) 2051 - check whether changing LINT1 will queue an NMI (see the LVT entry for LINT1) 2052 - if so, issue KVM_NMI 2053 - resume the vcpu 2054 2055Some guests configure the LINT1 NMI input to cause a panic, aiding in 2056debugging. 2057 2058 20594.65 KVM_S390_UCAS_MAP 2060---------------------- 2061 2062:Capability: KVM_CAP_S390_UCONTROL 2063:Architectures: s390 2064:Type: vcpu ioctl 2065:Parameters: struct kvm_s390_ucas_mapping (in) 2066:Returns: 0 in case of success 2067 2068The parameter is defined like this:: 2069 2070 struct kvm_s390_ucas_mapping { 2071 __u64 user_addr; 2072 __u64 vcpu_addr; 2073 __u64 length; 2074 }; 2075 2076This ioctl maps the memory at "user_addr" with the length "length" to 2077the vcpu's address space starting at "vcpu_addr". All parameters need to 2078be aligned by 1 megabyte. 2079 2080 20814.66 KVM_S390_UCAS_UNMAP 2082------------------------ 2083 2084:Capability: KVM_CAP_S390_UCONTROL 2085:Architectures: s390 2086:Type: vcpu ioctl 2087:Parameters: struct kvm_s390_ucas_mapping (in) 2088:Returns: 0 in case of success 2089 2090The parameter is defined like this:: 2091 2092 struct kvm_s390_ucas_mapping { 2093 __u64 user_addr; 2094 __u64 vcpu_addr; 2095 __u64 length; 2096 }; 2097 2098This ioctl unmaps the memory in the vcpu's address space starting at 2099"vcpu_addr" with the length "length". The field "user_addr" is ignored. 2100All parameters need to be aligned by 1 megabyte. 2101 2102 21034.67 KVM_S390_VCPU_FAULT 2104------------------------ 2105 2106:Capability: KVM_CAP_S390_UCONTROL 2107:Architectures: s390 2108:Type: vcpu ioctl 2109:Parameters: vcpu absolute address (in) 2110:Returns: 0 in case of success 2111 2112This call creates a page table entry on the virtual cpu's address space 2113(for user controlled virtual machines) or the virtual machine's address 2114space (for regular virtual machines). This only works for minor faults, 2115thus it's recommended to access subject memory page via the user page 2116table upfront. This is useful to handle validity intercepts for user 2117controlled virtual machines to fault in the virtual cpu's lowcore pages 2118prior to calling the KVM_RUN ioctl. 2119 2120 21214.68 KVM_SET_ONE_REG 2122-------------------- 2123 2124:Capability: KVM_CAP_ONE_REG 2125:Architectures: all 2126:Type: vcpu ioctl 2127:Parameters: struct kvm_one_reg (in) 2128:Returns: 0 on success, negative value on failure 2129 2130Errors: 2131 2132 ====== ============================================================ 2133 ENOENT no such register 2134 EINVAL invalid register ID, or no such register or used with VMs in 2135 protected virtualization mode on s390 2136 EPERM (arm64) register access not allowed before vcpu finalization 2137 ====== ============================================================ 2138 2139(These error codes are indicative only: do not rely on a specific error 2140code being returned in a specific situation.) 2141 2142:: 2143 2144 struct kvm_one_reg { 2145 __u64 id; 2146 __u64 addr; 2147 }; 2148 2149Using this ioctl, a single vcpu register can be set to a specific value 2150defined by user space with the passed in struct kvm_one_reg, where id 2151refers to the register identifier as described below and addr is a pointer 2152to a variable with the respective size. There can be architecture agnostic 2153and architecture specific registers. Each have their own range of operation 2154and their own constants and width. To keep track of the implemented 2155registers, find a list below: 2156 2157 ======= =============================== ============ 2158 Arch Register Width (bits) 2159 ======= =============================== ============ 2160 PPC KVM_REG_PPC_HIOR 64 2161 PPC KVM_REG_PPC_IAC1 64 2162 PPC KVM_REG_PPC_IAC2 64 2163 PPC KVM_REG_PPC_IAC3 64 2164 PPC KVM_REG_PPC_IAC4 64 2165 PPC KVM_REG_PPC_DAC1 64 2166 PPC KVM_REG_PPC_DAC2 64 2167 PPC KVM_REG_PPC_DABR 64 2168 PPC KVM_REG_PPC_DSCR 64 2169 PPC KVM_REG_PPC_PURR 64 2170 PPC KVM_REG_PPC_SPURR 64 2171 PPC KVM_REG_PPC_DAR 64 2172 PPC KVM_REG_PPC_DSISR 32 2173 PPC KVM_REG_PPC_AMR 64 2174 PPC KVM_REG_PPC_UAMOR 64 2175 PPC KVM_REG_PPC_MMCR0 64 2176 PPC KVM_REG_PPC_MMCR1 64 2177 PPC KVM_REG_PPC_MMCRA 64 2178 PPC KVM_REG_PPC_MMCR2 64 2179 PPC KVM_REG_PPC_MMCRS 64 2180 PPC KVM_REG_PPC_MMCR3 64 2181 PPC KVM_REG_PPC_SIAR 64 2182 PPC KVM_REG_PPC_SDAR 64 2183 PPC KVM_REG_PPC_SIER 64 2184 PPC KVM_REG_PPC_SIER2 64 2185 PPC KVM_REG_PPC_SIER3 64 2186 PPC KVM_REG_PPC_PMC1 32 2187 PPC KVM_REG_PPC_PMC2 32 2188 PPC KVM_REG_PPC_PMC3 32 2189 PPC KVM_REG_PPC_PMC4 32 2190 PPC KVM_REG_PPC_PMC5 32 2191 PPC KVM_REG_PPC_PMC6 32 2192 PPC KVM_REG_PPC_PMC7 32 2193 PPC KVM_REG_PPC_PMC8 32 2194 PPC KVM_REG_PPC_FPR0 64 2195 ... 2196 PPC KVM_REG_PPC_FPR31 64 2197 PPC KVM_REG_PPC_VR0 128 2198 ... 2199 PPC KVM_REG_PPC_VR31 128 2200 PPC KVM_REG_PPC_VSR0 128 2201 ... 2202 PPC KVM_REG_PPC_VSR31 128 2203 PPC KVM_REG_PPC_FPSCR 64 2204 PPC KVM_REG_PPC_VSCR 32 2205 PPC KVM_REG_PPC_VPA_ADDR 64 2206 PPC KVM_REG_PPC_VPA_SLB 128 2207 PPC KVM_REG_PPC_VPA_DTL 128 2208 PPC KVM_REG_PPC_EPCR 32 2209 PPC KVM_REG_PPC_EPR 32 2210 PPC KVM_REG_PPC_TCR 32 2211 PPC KVM_REG_PPC_TSR 32 2212 PPC KVM_REG_PPC_OR_TSR 32 2213 PPC KVM_REG_PPC_CLEAR_TSR 32 2214 PPC KVM_REG_PPC_MAS0 32 2215 PPC KVM_REG_PPC_MAS1 32 2216 PPC KVM_REG_PPC_MAS2 64 2217 PPC KVM_REG_PPC_MAS7_3 64 2218 PPC KVM_REG_PPC_MAS4 32 2219 PPC KVM_REG_PPC_MAS6 32 2220 PPC KVM_REG_PPC_MMUCFG 32 2221 PPC KVM_REG_PPC_TLB0CFG 32 2222 PPC KVM_REG_PPC_TLB1CFG 32 2223 PPC KVM_REG_PPC_TLB2CFG 32 2224 PPC KVM_REG_PPC_TLB3CFG 32 2225 PPC KVM_REG_PPC_TLB0PS 32 2226 PPC KVM_REG_PPC_TLB1PS 32 2227 PPC KVM_REG_PPC_TLB2PS 32 2228 PPC KVM_REG_PPC_TLB3PS 32 2229 PPC KVM_REG_PPC_EPTCFG 32 2230 PPC KVM_REG_PPC_ICP_STATE 64 2231 PPC KVM_REG_PPC_VP_STATE 128 2232 PPC KVM_REG_PPC_TB_OFFSET 64 2233 PPC KVM_REG_PPC_SPMC1 32 2234 PPC KVM_REG_PPC_SPMC2 32 2235 PPC KVM_REG_PPC_IAMR 64 2236 PPC KVM_REG_PPC_TFHAR 64 2237 PPC KVM_REG_PPC_TFIAR 64 2238 PPC KVM_REG_PPC_TEXASR 64 2239 PPC KVM_REG_PPC_FSCR 64 2240 PPC KVM_REG_PPC_PSPB 32 2241 PPC KVM_REG_PPC_EBBHR 64 2242 PPC KVM_REG_PPC_EBBRR 64 2243 PPC KVM_REG_PPC_BESCR 64 2244 PPC KVM_REG_PPC_TAR 64 2245 PPC KVM_REG_PPC_DPDES 64 2246 PPC KVM_REG_PPC_DAWR 64 2247 PPC KVM_REG_PPC_DAWRX 64 2248 PPC KVM_REG_PPC_CIABR 64 2249 PPC KVM_REG_PPC_IC 64 2250 PPC KVM_REG_PPC_VTB 64 2251 PPC KVM_REG_PPC_CSIGR 64 2252 PPC KVM_REG_PPC_TACR 64 2253 PPC KVM_REG_PPC_TCSCR 64 2254 PPC KVM_REG_PPC_PID 64 2255 PPC KVM_REG_PPC_ACOP 64 2256 PPC KVM_REG_PPC_VRSAVE 32 2257 PPC KVM_REG_PPC_LPCR 32 2258 PPC KVM_REG_PPC_LPCR_64 64 2259 PPC KVM_REG_PPC_PPR 64 2260 PPC KVM_REG_PPC_ARCH_COMPAT 32 2261 PPC KVM_REG_PPC_DABRX 32 2262 PPC KVM_REG_PPC_WORT 64 2263 PPC KVM_REG_PPC_SPRG9 64 2264 PPC KVM_REG_PPC_DBSR 32 2265 PPC KVM_REG_PPC_TIDR 64 2266 PPC KVM_REG_PPC_PSSCR 64 2267 PPC KVM_REG_PPC_DEC_EXPIRY 64 2268 PPC KVM_REG_PPC_PTCR 64 2269 PPC KVM_REG_PPC_TM_GPR0 64 2270 ... 2271 PPC KVM_REG_PPC_TM_GPR31 64 2272 PPC KVM_REG_PPC_TM_VSR0 128 2273 ... 2274 PPC KVM_REG_PPC_TM_VSR63 128 2275 PPC KVM_REG_PPC_TM_CR 64 2276 PPC KVM_REG_PPC_TM_LR 64 2277 PPC KVM_REG_PPC_TM_CTR 64 2278 PPC KVM_REG_PPC_TM_FPSCR 64 2279 PPC KVM_REG_PPC_TM_AMR 64 2280 PPC KVM_REG_PPC_TM_PPR 64 2281 PPC KVM_REG_PPC_TM_VRSAVE 64 2282 PPC KVM_REG_PPC_TM_VSCR 32 2283 PPC KVM_REG_PPC_TM_DSCR 64 2284 PPC KVM_REG_PPC_TM_TAR 64 2285 PPC KVM_REG_PPC_TM_XER 64 2286 2287 MIPS KVM_REG_MIPS_R0 64 2288 ... 2289 MIPS KVM_REG_MIPS_R31 64 2290 MIPS KVM_REG_MIPS_HI 64 2291 MIPS KVM_REG_MIPS_LO 64 2292 MIPS KVM_REG_MIPS_PC 64 2293 MIPS KVM_REG_MIPS_CP0_INDEX 32 2294 MIPS KVM_REG_MIPS_CP0_ENTRYLO0 64 2295 MIPS KVM_REG_MIPS_CP0_ENTRYLO1 64 2296 MIPS KVM_REG_MIPS_CP0_CONTEXT 64 2297 MIPS KVM_REG_MIPS_CP0_CONTEXTCONFIG 32 2298 MIPS KVM_REG_MIPS_CP0_USERLOCAL 64 2299 MIPS KVM_REG_MIPS_CP0_XCONTEXTCONFIG 64 2300 MIPS KVM_REG_MIPS_CP0_PAGEMASK 32 2301 MIPS KVM_REG_MIPS_CP0_PAGEGRAIN 32 2302 MIPS KVM_REG_MIPS_CP0_SEGCTL0 64 2303 MIPS KVM_REG_MIPS_CP0_SEGCTL1 64 2304 MIPS KVM_REG_MIPS_CP0_SEGCTL2 64 2305 MIPS KVM_REG_MIPS_CP0_PWBASE 64 2306 MIPS KVM_REG_MIPS_CP0_PWFIELD 64 2307 MIPS KVM_REG_MIPS_CP0_PWSIZE 64 2308 MIPS KVM_REG_MIPS_CP0_WIRED 32 2309 MIPS KVM_REG_MIPS_CP0_PWCTL 32 2310 MIPS KVM_REG_MIPS_CP0_HWRENA 32 2311 MIPS KVM_REG_MIPS_CP0_BADVADDR 64 2312 MIPS KVM_REG_MIPS_CP0_BADINSTR 32 2313 MIPS KVM_REG_MIPS_CP0_BADINSTRP 32 2314 MIPS KVM_REG_MIPS_CP0_COUNT 32 2315 MIPS KVM_REG_MIPS_CP0_ENTRYHI 64 2316 MIPS KVM_REG_MIPS_CP0_COMPARE 32 2317 MIPS KVM_REG_MIPS_CP0_STATUS 32 2318 MIPS KVM_REG_MIPS_CP0_INTCTL 32 2319 MIPS KVM_REG_MIPS_CP0_CAUSE 32 2320 MIPS KVM_REG_MIPS_CP0_EPC 64 2321 MIPS KVM_REG_MIPS_CP0_PRID 32 2322 MIPS KVM_REG_MIPS_CP0_EBASE 64 2323 MIPS KVM_REG_MIPS_CP0_CONFIG 32 2324 MIPS KVM_REG_MIPS_CP0_CONFIG1 32 2325 MIPS KVM_REG_MIPS_CP0_CONFIG2 32 2326 MIPS KVM_REG_MIPS_CP0_CONFIG3 32 2327 MIPS KVM_REG_MIPS_CP0_CONFIG4 32 2328 MIPS KVM_REG_MIPS_CP0_CONFIG5 32 2329 MIPS KVM_REG_MIPS_CP0_CONFIG7 32 2330 MIPS KVM_REG_MIPS_CP0_XCONTEXT 64 2331 MIPS KVM_REG_MIPS_CP0_ERROREPC 64 2332 MIPS KVM_REG_MIPS_CP0_KSCRATCH1 64 2333 MIPS KVM_REG_MIPS_CP0_KSCRATCH2 64 2334 MIPS KVM_REG_MIPS_CP0_KSCRATCH3 64 2335 MIPS KVM_REG_MIPS_CP0_KSCRATCH4 64 2336 MIPS KVM_REG_MIPS_CP0_KSCRATCH5 64 2337 MIPS KVM_REG_MIPS_CP0_KSCRATCH6 64 2338 MIPS KVM_REG_MIPS_CP0_MAAR(0..63) 64 2339 MIPS KVM_REG_MIPS_COUNT_CTL 64 2340 MIPS KVM_REG_MIPS_COUNT_RESUME 64 2341 MIPS KVM_REG_MIPS_COUNT_HZ 64 2342 MIPS KVM_REG_MIPS_FPR_32(0..31) 32 2343 MIPS KVM_REG_MIPS_FPR_64(0..31) 64 2344 MIPS KVM_REG_MIPS_VEC_128(0..31) 128 2345 MIPS KVM_REG_MIPS_FCR_IR 32 2346 MIPS KVM_REG_MIPS_FCR_CSR 32 2347 MIPS KVM_REG_MIPS_MSA_IR 32 2348 MIPS KVM_REG_MIPS_MSA_CSR 32 2349 ======= =============================== ============ 2350 2351ARM registers are mapped using the lower 32 bits. The upper 16 of that 2352is the register group type, or coprocessor number: 2353 2354ARM core registers have the following id bit patterns:: 2355 2356 0x4020 0000 0010 <index into the kvm_regs struct:16> 2357 2358ARM 32-bit CP15 registers have the following id bit patterns:: 2359 2360 0x4020 0000 000F <zero:1> <crn:4> <crm:4> <opc1:4> <opc2:3> 2361 2362ARM 64-bit CP15 registers have the following id bit patterns:: 2363 2364 0x4030 0000 000F <zero:1> <zero:4> <crm:4> <opc1:4> <zero:3> 2365 2366ARM CCSIDR registers are demultiplexed by CSSELR value:: 2367 2368 0x4020 0000 0011 00 <csselr:8> 2369 2370ARM 32-bit VFP control registers have the following id bit patterns:: 2371 2372 0x4020 0000 0012 1 <regno:12> 2373 2374ARM 64-bit FP registers have the following id bit patterns:: 2375 2376 0x4030 0000 0012 0 <regno:12> 2377 2378ARM firmware pseudo-registers have the following bit pattern:: 2379 2380 0x4030 0000 0014 <regno:16> 2381 2382 2383arm64 registers are mapped using the lower 32 bits. The upper 16 of 2384that is the register group type, or coprocessor number: 2385 2386arm64 core/FP-SIMD registers have the following id bit patterns. Note 2387that the size of the access is variable, as the kvm_regs structure 2388contains elements ranging from 32 to 128 bits. The index is a 32bit 2389value in the kvm_regs structure seen as a 32bit array:: 2390 2391 0x60x0 0000 0010 <index into the kvm_regs struct:16> 2392 2393Specifically: 2394 2395======================= ========= ===== ======================================= 2396 Encoding Register Bits kvm_regs member 2397======================= ========= ===== ======================================= 2398 0x6030 0000 0010 0000 X0 64 regs.regs[0] 2399 0x6030 0000 0010 0002 X1 64 regs.regs[1] 2400 ... 2401 0x6030 0000 0010 003c X30 64 regs.regs[30] 2402 0x6030 0000 0010 003e SP 64 regs.sp 2403 0x6030 0000 0010 0040 PC 64 regs.pc 2404 0x6030 0000 0010 0042 PSTATE 64 regs.pstate 2405 0x6030 0000 0010 0044 SP_EL1 64 sp_el1 2406 0x6030 0000 0010 0046 ELR_EL1 64 elr_el1 2407 0x6030 0000 0010 0048 SPSR_EL1 64 spsr[KVM_SPSR_EL1] (alias SPSR_SVC) 2408 0x6030 0000 0010 004a SPSR_ABT 64 spsr[KVM_SPSR_ABT] 2409 0x6030 0000 0010 004c SPSR_UND 64 spsr[KVM_SPSR_UND] 2410 0x6030 0000 0010 004e SPSR_IRQ 64 spsr[KVM_SPSR_IRQ] 2411 0x6060 0000 0010 0050 SPSR_FIQ 64 spsr[KVM_SPSR_FIQ] 2412 0x6040 0000 0010 0054 V0 128 fp_regs.vregs[0] [1]_ 2413 0x6040 0000 0010 0058 V1 128 fp_regs.vregs[1] [1]_ 2414 ... 2415 0x6040 0000 0010 00d0 V31 128 fp_regs.vregs[31] [1]_ 2416 0x6020 0000 0010 00d4 FPSR 32 fp_regs.fpsr 2417 0x6020 0000 0010 00d5 FPCR 32 fp_regs.fpcr 2418======================= ========= ===== ======================================= 2419 2420.. [1] These encodings are not accepted for SVE-enabled vcpus. See 2421 KVM_ARM_VCPU_INIT. 2422 2423 The equivalent register content can be accessed via bits [127:0] of 2424 the corresponding SVE Zn registers instead for vcpus that have SVE 2425 enabled (see below). 2426 2427arm64 CCSIDR registers are demultiplexed by CSSELR value:: 2428 2429 0x6020 0000 0011 00 <csselr:8> 2430 2431arm64 system registers have the following id bit patterns:: 2432 2433 0x6030 0000 0013 <op0:2> <op1:3> <crn:4> <crm:4> <op2:3> 2434 2435.. warning:: 2436 2437 Two system register IDs do not follow the specified pattern. These 2438 are KVM_REG_ARM_TIMER_CVAL and KVM_REG_ARM_TIMER_CNT, which map to 2439 system registers CNTV_CVAL_EL0 and CNTVCT_EL0 respectively. These 2440 two had their values accidentally swapped, which means TIMER_CVAL is 2441 derived from the register encoding for CNTVCT_EL0 and TIMER_CNT is 2442 derived from the register encoding for CNTV_CVAL_EL0. As this is 2443 API, it must remain this way. 2444 2445arm64 firmware pseudo-registers have the following bit pattern:: 2446 2447 0x6030 0000 0014 <regno:16> 2448 2449arm64 SVE registers have the following bit patterns:: 2450 2451 0x6080 0000 0015 00 <n:5> <slice:5> Zn bits[2048*slice + 2047 : 2048*slice] 2452 0x6050 0000 0015 04 <n:4> <slice:5> Pn bits[256*slice + 255 : 256*slice] 2453 0x6050 0000 0015 060 <slice:5> FFR bits[256*slice + 255 : 256*slice] 2454 0x6060 0000 0015 ffff KVM_REG_ARM64_SVE_VLS pseudo-register 2455 2456Access to register IDs where 2048 * slice >= 128 * max_vq will fail with 2457ENOENT. max_vq is the vcpu's maximum supported vector length in 128-bit 2458quadwords: see [2]_ below. 2459 2460These registers are only accessible on vcpus for which SVE is enabled. 2461See KVM_ARM_VCPU_INIT for details. 2462 2463In addition, except for KVM_REG_ARM64_SVE_VLS, these registers are not 2464accessible until the vcpu's SVE configuration has been finalized 2465using KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE). See KVM_ARM_VCPU_INIT 2466and KVM_ARM_VCPU_FINALIZE for more information about this procedure. 2467 2468KVM_REG_ARM64_SVE_VLS is a pseudo-register that allows the set of vector 2469lengths supported by the vcpu to be discovered and configured by 2470userspace. When transferred to or from user memory via KVM_GET_ONE_REG 2471or KVM_SET_ONE_REG, the value of this register is of type 2472__u64[KVM_ARM64_SVE_VLS_WORDS], and encodes the set of vector lengths as 2473follows:: 2474 2475 __u64 vector_lengths[KVM_ARM64_SVE_VLS_WORDS]; 2476 2477 if (vq >= SVE_VQ_MIN && vq <= SVE_VQ_MAX && 2478 ((vector_lengths[(vq - KVM_ARM64_SVE_VQ_MIN) / 64] >> 2479 ((vq - KVM_ARM64_SVE_VQ_MIN) % 64)) & 1)) 2480 /* Vector length vq * 16 bytes supported */ 2481 else 2482 /* Vector length vq * 16 bytes not supported */ 2483 2484.. [2] The maximum value vq for which the above condition is true is 2485 max_vq. This is the maximum vector length available to the guest on 2486 this vcpu, and determines which register slices are visible through 2487 this ioctl interface. 2488 2489(See Documentation/arm64/sve.rst for an explanation of the "vq" 2490nomenclature.) 2491 2492KVM_REG_ARM64_SVE_VLS is only accessible after KVM_ARM_VCPU_INIT. 2493KVM_ARM_VCPU_INIT initialises it to the best set of vector lengths that 2494the host supports. 2495 2496Userspace may subsequently modify it if desired until the vcpu's SVE 2497configuration is finalized using KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE). 2498 2499Apart from simply removing all vector lengths from the host set that 2500exceed some value, support for arbitrarily chosen sets of vector lengths 2501is hardware-dependent and may not be available. Attempting to configure 2502an invalid set of vector lengths via KVM_SET_ONE_REG will fail with 2503EINVAL. 2504 2505After the vcpu's SVE configuration is finalized, further attempts to 2506write this register will fail with EPERM. 2507 2508 2509MIPS registers are mapped using the lower 32 bits. The upper 16 of that is 2510the register group type: 2511 2512MIPS core registers (see above) have the following id bit patterns:: 2513 2514 0x7030 0000 0000 <reg:16> 2515 2516MIPS CP0 registers (see KVM_REG_MIPS_CP0_* above) have the following id bit 2517patterns depending on whether they're 32-bit or 64-bit registers:: 2518 2519 0x7020 0000 0001 00 <reg:5> <sel:3> (32-bit) 2520 0x7030 0000 0001 00 <reg:5> <sel:3> (64-bit) 2521 2522Note: KVM_REG_MIPS_CP0_ENTRYLO0 and KVM_REG_MIPS_CP0_ENTRYLO1 are the MIPS64 2523versions of the EntryLo registers regardless of the word size of the host 2524hardware, host kernel, guest, and whether XPA is present in the guest, i.e. 2525with the RI and XI bits (if they exist) in bits 63 and 62 respectively, and 2526the PFNX field starting at bit 30. 2527 2528MIPS MAARs (see KVM_REG_MIPS_CP0_MAAR(*) above) have the following id bit 2529patterns:: 2530 2531 0x7030 0000 0001 01 <reg:8> 2532 2533MIPS KVM control registers (see above) have the following id bit patterns:: 2534 2535 0x7030 0000 0002 <reg:16> 2536 2537MIPS FPU registers (see KVM_REG_MIPS_FPR_{32,64}() above) have the following 2538id bit patterns depending on the size of the register being accessed. They are 2539always accessed according to the current guest FPU mode (Status.FR and 2540Config5.FRE), i.e. as the guest would see them, and they become unpredictable 2541if the guest FPU mode is changed. MIPS SIMD Architecture (MSA) vector 2542registers (see KVM_REG_MIPS_VEC_128() above) have similar patterns as they 2543overlap the FPU registers:: 2544 2545 0x7020 0000 0003 00 <0:3> <reg:5> (32-bit FPU registers) 2546 0x7030 0000 0003 00 <0:3> <reg:5> (64-bit FPU registers) 2547 0x7040 0000 0003 00 <0:3> <reg:5> (128-bit MSA vector registers) 2548 2549MIPS FPU control registers (see KVM_REG_MIPS_FCR_{IR,CSR} above) have the 2550following id bit patterns:: 2551 2552 0x7020 0000 0003 01 <0:3> <reg:5> 2553 2554MIPS MSA control registers (see KVM_REG_MIPS_MSA_{IR,CSR} above) have the 2555following id bit patterns:: 2556 2557 0x7020 0000 0003 02 <0:3> <reg:5> 2558 2559 25604.69 KVM_GET_ONE_REG 2561-------------------- 2562 2563:Capability: KVM_CAP_ONE_REG 2564:Architectures: all 2565:Type: vcpu ioctl 2566:Parameters: struct kvm_one_reg (in and out) 2567:Returns: 0 on success, negative value on failure 2568 2569Errors include: 2570 2571 ======== ============================================================ 2572 ENOENT no such register 2573 EINVAL invalid register ID, or no such register or used with VMs in 2574 protected virtualization mode on s390 2575 EPERM (arm64) register access not allowed before vcpu finalization 2576 ======== ============================================================ 2577 2578(These error codes are indicative only: do not rely on a specific error 2579code being returned in a specific situation.) 2580 2581This ioctl allows to receive the value of a single register implemented 2582in a vcpu. The register to read is indicated by the "id" field of the 2583kvm_one_reg struct passed in. On success, the register value can be found 2584at the memory location pointed to by "addr". 2585 2586The list of registers accessible using this interface is identical to the 2587list in 4.68. 2588 2589 25904.70 KVM_KVMCLOCK_CTRL 2591---------------------- 2592 2593:Capability: KVM_CAP_KVMCLOCK_CTRL 2594:Architectures: Any that implement pvclocks (currently x86 only) 2595:Type: vcpu ioctl 2596:Parameters: None 2597:Returns: 0 on success, -1 on error 2598 2599This ioctl sets a flag accessible to the guest indicating that the specified 2600vCPU has been paused by the host userspace. 2601 2602The host will set a flag in the pvclock structure that is checked from the 2603soft lockup watchdog. The flag is part of the pvclock structure that is 2604shared between guest and host, specifically the second bit of the flags 2605field of the pvclock_vcpu_time_info structure. It will be set exclusively by 2606the host and read/cleared exclusively by the guest. The guest operation of 2607checking and clearing the flag must be an atomic operation so 2608load-link/store-conditional, or equivalent must be used. There are two cases 2609where the guest will clear the flag: when the soft lockup watchdog timer resets 2610itself or when a soft lockup is detected. This ioctl can be called any time 2611after pausing the vcpu, but before it is resumed. 2612 2613 26144.71 KVM_SIGNAL_MSI 2615------------------- 2616 2617:Capability: KVM_CAP_SIGNAL_MSI 2618:Architectures: x86 arm arm64 2619:Type: vm ioctl 2620:Parameters: struct kvm_msi (in) 2621:Returns: >0 on delivery, 0 if guest blocked the MSI, and -1 on error 2622 2623Directly inject a MSI message. Only valid with in-kernel irqchip that handles 2624MSI messages. 2625 2626:: 2627 2628 struct kvm_msi { 2629 __u32 address_lo; 2630 __u32 address_hi; 2631 __u32 data; 2632 __u32 flags; 2633 __u32 devid; 2634 __u8 pad[12]; 2635 }; 2636 2637flags: 2638 KVM_MSI_VALID_DEVID: devid contains a valid value. The per-VM 2639 KVM_CAP_MSI_DEVID capability advertises the requirement to provide 2640 the device ID. If this capability is not available, userspace 2641 should never set the KVM_MSI_VALID_DEVID flag as the ioctl might fail. 2642 2643If KVM_MSI_VALID_DEVID is set, devid contains a unique device identifier 2644for the device that wrote the MSI message. For PCI, this is usually a 2645BFD identifier in the lower 16 bits. 2646 2647On x86, address_hi is ignored unless the KVM_X2APIC_API_USE_32BIT_IDS 2648feature of KVM_CAP_X2APIC_API capability is enabled. If it is enabled, 2649address_hi bits 31-8 provide bits 31-8 of the destination id. Bits 7-0 of 2650address_hi must be zero. 2651 2652 26534.71 KVM_CREATE_PIT2 2654-------------------- 2655 2656:Capability: KVM_CAP_PIT2 2657:Architectures: x86 2658:Type: vm ioctl 2659:Parameters: struct kvm_pit_config (in) 2660:Returns: 0 on success, -1 on error 2661 2662Creates an in-kernel device model for the i8254 PIT. This call is only valid 2663after enabling in-kernel irqchip support via KVM_CREATE_IRQCHIP. The following 2664parameters have to be passed:: 2665 2666 struct kvm_pit_config { 2667 __u32 flags; 2668 __u32 pad[15]; 2669 }; 2670 2671Valid flags are:: 2672 2673 #define KVM_PIT_SPEAKER_DUMMY 1 /* emulate speaker port stub */ 2674 2675PIT timer interrupts may use a per-VM kernel thread for injection. If it 2676exists, this thread will have a name of the following pattern:: 2677 2678 kvm-pit/<owner-process-pid> 2679 2680When running a guest with elevated priorities, the scheduling parameters of 2681this thread may have to be adjusted accordingly. 2682 2683This IOCTL replaces the obsolete KVM_CREATE_PIT. 2684 2685 26864.72 KVM_GET_PIT2 2687----------------- 2688 2689:Capability: KVM_CAP_PIT_STATE2 2690:Architectures: x86 2691:Type: vm ioctl 2692:Parameters: struct kvm_pit_state2 (out) 2693:Returns: 0 on success, -1 on error 2694 2695Retrieves the state of the in-kernel PIT model. Only valid after 2696KVM_CREATE_PIT2. The state is returned in the following structure:: 2697 2698 struct kvm_pit_state2 { 2699 struct kvm_pit_channel_state channels[3]; 2700 __u32 flags; 2701 __u32 reserved[9]; 2702 }; 2703 2704Valid flags are:: 2705 2706 /* disable PIT in HPET legacy mode */ 2707 #define KVM_PIT_FLAGS_HPET_LEGACY 0x00000001 2708 2709This IOCTL replaces the obsolete KVM_GET_PIT. 2710 2711 27124.73 KVM_SET_PIT2 2713----------------- 2714 2715:Capability: KVM_CAP_PIT_STATE2 2716:Architectures: x86 2717:Type: vm ioctl 2718:Parameters: struct kvm_pit_state2 (in) 2719:Returns: 0 on success, -1 on error 2720 2721Sets the state of the in-kernel PIT model. Only valid after KVM_CREATE_PIT2. 2722See KVM_GET_PIT2 for details on struct kvm_pit_state2. 2723 2724This IOCTL replaces the obsolete KVM_SET_PIT. 2725 2726 27274.74 KVM_PPC_GET_SMMU_INFO 2728-------------------------- 2729 2730:Capability: KVM_CAP_PPC_GET_SMMU_INFO 2731:Architectures: powerpc 2732:Type: vm ioctl 2733:Parameters: None 2734:Returns: 0 on success, -1 on error 2735 2736This populates and returns a structure describing the features of 2737the "Server" class MMU emulation supported by KVM. 2738This can in turn be used by userspace to generate the appropriate 2739device-tree properties for the guest operating system. 2740 2741The structure contains some global information, followed by an 2742array of supported segment page sizes:: 2743 2744 struct kvm_ppc_smmu_info { 2745 __u64 flags; 2746 __u32 slb_size; 2747 __u32 pad; 2748 struct kvm_ppc_one_seg_page_size sps[KVM_PPC_PAGE_SIZES_MAX_SZ]; 2749 }; 2750 2751The supported flags are: 2752 2753 - KVM_PPC_PAGE_SIZES_REAL: 2754 When that flag is set, guest page sizes must "fit" the backing 2755 store page sizes. When not set, any page size in the list can 2756 be used regardless of how they are backed by userspace. 2757 2758 - KVM_PPC_1T_SEGMENTS 2759 The emulated MMU supports 1T segments in addition to the 2760 standard 256M ones. 2761 2762 - KVM_PPC_NO_HASH 2763 This flag indicates that HPT guests are not supported by KVM, 2764 thus all guests must use radix MMU mode. 2765 2766The "slb_size" field indicates how many SLB entries are supported 2767 2768The "sps" array contains 8 entries indicating the supported base 2769page sizes for a segment in increasing order. Each entry is defined 2770as follow:: 2771 2772 struct kvm_ppc_one_seg_page_size { 2773 __u32 page_shift; /* Base page shift of segment (or 0) */ 2774 __u32 slb_enc; /* SLB encoding for BookS */ 2775 struct kvm_ppc_one_page_size enc[KVM_PPC_PAGE_SIZES_MAX_SZ]; 2776 }; 2777 2778An entry with a "page_shift" of 0 is unused. Because the array is 2779organized in increasing order, a lookup can stop when encoutering 2780such an entry. 2781 2782The "slb_enc" field provides the encoding to use in the SLB for the 2783page size. The bits are in positions such as the value can directly 2784be OR'ed into the "vsid" argument of the slbmte instruction. 2785 2786The "enc" array is a list which for each of those segment base page 2787size provides the list of supported actual page sizes (which can be 2788only larger or equal to the base page size), along with the 2789corresponding encoding in the hash PTE. Similarly, the array is 27908 entries sorted by increasing sizes and an entry with a "0" shift 2791is an empty entry and a terminator:: 2792 2793 struct kvm_ppc_one_page_size { 2794 __u32 page_shift; /* Page shift (or 0) */ 2795 __u32 pte_enc; /* Encoding in the HPTE (>>12) */ 2796 }; 2797 2798The "pte_enc" field provides a value that can OR'ed into the hash 2799PTE's RPN field (ie, it needs to be shifted left by 12 to OR it 2800into the hash PTE second double word). 2801 28024.75 KVM_IRQFD 2803-------------- 2804 2805:Capability: KVM_CAP_IRQFD 2806:Architectures: x86 s390 arm arm64 2807:Type: vm ioctl 2808:Parameters: struct kvm_irqfd (in) 2809:Returns: 0 on success, -1 on error 2810 2811Allows setting an eventfd to directly trigger a guest interrupt. 2812kvm_irqfd.fd specifies the file descriptor to use as the eventfd and 2813kvm_irqfd.gsi specifies the irqchip pin toggled by this event. When 2814an event is triggered on the eventfd, an interrupt is injected into 2815the guest using the specified gsi pin. The irqfd is removed using 2816the KVM_IRQFD_FLAG_DEASSIGN flag, specifying both kvm_irqfd.fd 2817and kvm_irqfd.gsi. 2818 2819With KVM_CAP_IRQFD_RESAMPLE, KVM_IRQFD supports a de-assert and notify 2820mechanism allowing emulation of level-triggered, irqfd-based 2821interrupts. When KVM_IRQFD_FLAG_RESAMPLE is set the user must pass an 2822additional eventfd in the kvm_irqfd.resamplefd field. When operating 2823in resample mode, posting of an interrupt through kvm_irq.fd asserts 2824the specified gsi in the irqchip. When the irqchip is resampled, such 2825as from an EOI, the gsi is de-asserted and the user is notified via 2826kvm_irqfd.resamplefd. It is the user's responsibility to re-queue 2827the interrupt if the device making use of it still requires service. 2828Note that closing the resamplefd is not sufficient to disable the 2829irqfd. The KVM_IRQFD_FLAG_RESAMPLE is only necessary on assignment 2830and need not be specified with KVM_IRQFD_FLAG_DEASSIGN. 2831 2832On arm/arm64, gsi routing being supported, the following can happen: 2833 2834- in case no routing entry is associated to this gsi, injection fails 2835- in case the gsi is associated to an irqchip routing entry, 2836 irqchip.pin + 32 corresponds to the injected SPI ID. 2837- in case the gsi is associated to an MSI routing entry, the MSI 2838 message and device ID are translated into an LPI (support restricted 2839 to GICv3 ITS in-kernel emulation). 2840 28414.76 KVM_PPC_ALLOCATE_HTAB 2842-------------------------- 2843 2844:Capability: KVM_CAP_PPC_ALLOC_HTAB 2845:Architectures: powerpc 2846:Type: vm ioctl 2847:Parameters: Pointer to u32 containing hash table order (in/out) 2848:Returns: 0 on success, -1 on error 2849 2850This requests the host kernel to allocate an MMU hash table for a 2851guest using the PAPR paravirtualization interface. This only does 2852anything if the kernel is configured to use the Book 3S HV style of 2853virtualization. Otherwise the capability doesn't exist and the ioctl 2854returns an ENOTTY error. The rest of this description assumes Book 3S 2855HV. 2856 2857There must be no vcpus running when this ioctl is called; if there 2858are, it will do nothing and return an EBUSY error. 2859 2860The parameter is a pointer to a 32-bit unsigned integer variable 2861containing the order (log base 2) of the desired size of the hash 2862table, which must be between 18 and 46. On successful return from the 2863ioctl, the value will not be changed by the kernel. 2864 2865If no hash table has been allocated when any vcpu is asked to run 2866(with the KVM_RUN ioctl), the host kernel will allocate a 2867default-sized hash table (16 MB). 2868 2869If this ioctl is called when a hash table has already been allocated, 2870with a different order from the existing hash table, the existing hash 2871table will be freed and a new one allocated. If this is ioctl is 2872called when a hash table has already been allocated of the same order 2873as specified, the kernel will clear out the existing hash table (zero 2874all HPTEs). In either case, if the guest is using the virtualized 2875real-mode area (VRMA) facility, the kernel will re-create the VMRA 2876HPTEs on the next KVM_RUN of any vcpu. 2877 28784.77 KVM_S390_INTERRUPT 2879----------------------- 2880 2881:Capability: basic 2882:Architectures: s390 2883:Type: vm ioctl, vcpu ioctl 2884:Parameters: struct kvm_s390_interrupt (in) 2885:Returns: 0 on success, -1 on error 2886 2887Allows to inject an interrupt to the guest. Interrupts can be floating 2888(vm ioctl) or per cpu (vcpu ioctl), depending on the interrupt type. 2889 2890Interrupt parameters are passed via kvm_s390_interrupt:: 2891 2892 struct kvm_s390_interrupt { 2893 __u32 type; 2894 __u32 parm; 2895 __u64 parm64; 2896 }; 2897 2898type can be one of the following: 2899 2900KVM_S390_SIGP_STOP (vcpu) 2901 - sigp stop; optional flags in parm 2902KVM_S390_PROGRAM_INT (vcpu) 2903 - program check; code in parm 2904KVM_S390_SIGP_SET_PREFIX (vcpu) 2905 - sigp set prefix; prefix address in parm 2906KVM_S390_RESTART (vcpu) 2907 - restart 2908KVM_S390_INT_CLOCK_COMP (vcpu) 2909 - clock comparator interrupt 2910KVM_S390_INT_CPU_TIMER (vcpu) 2911 - CPU timer interrupt 2912KVM_S390_INT_VIRTIO (vm) 2913 - virtio external interrupt; external interrupt 2914 parameters in parm and parm64 2915KVM_S390_INT_SERVICE (vm) 2916 - sclp external interrupt; sclp parameter in parm 2917KVM_S390_INT_EMERGENCY (vcpu) 2918 - sigp emergency; source cpu in parm 2919KVM_S390_INT_EXTERNAL_CALL (vcpu) 2920 - sigp external call; source cpu in parm 2921KVM_S390_INT_IO(ai,cssid,ssid,schid) (vm) 2922 - compound value to indicate an 2923 I/O interrupt (ai - adapter interrupt; cssid,ssid,schid - subchannel); 2924 I/O interruption parameters in parm (subchannel) and parm64 (intparm, 2925 interruption subclass) 2926KVM_S390_MCHK (vm, vcpu) 2927 - machine check interrupt; cr 14 bits in parm, machine check interrupt 2928 code in parm64 (note that machine checks needing further payload are not 2929 supported by this ioctl) 2930 2931This is an asynchronous vcpu ioctl and can be invoked from any thread. 2932 29334.78 KVM_PPC_GET_HTAB_FD 2934------------------------ 2935 2936:Capability: KVM_CAP_PPC_HTAB_FD 2937:Architectures: powerpc 2938:Type: vm ioctl 2939:Parameters: Pointer to struct kvm_get_htab_fd (in) 2940:Returns: file descriptor number (>= 0) on success, -1 on error 2941 2942This returns a file descriptor that can be used either to read out the 2943entries in the guest's hashed page table (HPT), or to write entries to 2944initialize the HPT. The returned fd can only be written to if the 2945KVM_GET_HTAB_WRITE bit is set in the flags field of the argument, and 2946can only be read if that bit is clear. The argument struct looks like 2947this:: 2948 2949 /* For KVM_PPC_GET_HTAB_FD */ 2950 struct kvm_get_htab_fd { 2951 __u64 flags; 2952 __u64 start_index; 2953 __u64 reserved[2]; 2954 }; 2955 2956 /* Values for kvm_get_htab_fd.flags */ 2957 #define KVM_GET_HTAB_BOLTED_ONLY ((__u64)0x1) 2958 #define KVM_GET_HTAB_WRITE ((__u64)0x2) 2959 2960The 'start_index' field gives the index in the HPT of the entry at 2961which to start reading. It is ignored when writing. 2962 2963Reads on the fd will initially supply information about all 2964"interesting" HPT entries. Interesting entries are those with the 2965bolted bit set, if the KVM_GET_HTAB_BOLTED_ONLY bit is set, otherwise 2966all entries. When the end of the HPT is reached, the read() will 2967return. If read() is called again on the fd, it will start again from 2968the beginning of the HPT, but will only return HPT entries that have 2969changed since they were last read. 2970 2971Data read or written is structured as a header (8 bytes) followed by a 2972series of valid HPT entries (16 bytes) each. The header indicates how 2973many valid HPT entries there are and how many invalid entries follow 2974the valid entries. The invalid entries are not represented explicitly 2975in the stream. The header format is:: 2976 2977 struct kvm_get_htab_header { 2978 __u32 index; 2979 __u16 n_valid; 2980 __u16 n_invalid; 2981 }; 2982 2983Writes to the fd create HPT entries starting at the index given in the 2984header; first 'n_valid' valid entries with contents from the data 2985written, then 'n_invalid' invalid entries, invalidating any previously 2986valid entries found. 2987 29884.79 KVM_CREATE_DEVICE 2989---------------------- 2990 2991:Capability: KVM_CAP_DEVICE_CTRL 2992:Type: vm ioctl 2993:Parameters: struct kvm_create_device (in/out) 2994:Returns: 0 on success, -1 on error 2995 2996Errors: 2997 2998 ====== ======================================================= 2999 ENODEV The device type is unknown or unsupported 3000 EEXIST Device already created, and this type of device may not 3001 be instantiated multiple times 3002 ====== ======================================================= 3003 3004 Other error conditions may be defined by individual device types or 3005 have their standard meanings. 3006 3007Creates an emulated device in the kernel. The file descriptor returned 3008in fd can be used with KVM_SET/GET/HAS_DEVICE_ATTR. 3009 3010If the KVM_CREATE_DEVICE_TEST flag is set, only test whether the 3011device type is supported (not necessarily whether it can be created 3012in the current vm). 3013 3014Individual devices should not define flags. Attributes should be used 3015for specifying any behavior that is not implied by the device type 3016number. 3017 3018:: 3019 3020 struct kvm_create_device { 3021 __u32 type; /* in: KVM_DEV_TYPE_xxx */ 3022 __u32 fd; /* out: device handle */ 3023 __u32 flags; /* in: KVM_CREATE_DEVICE_xxx */ 3024 }; 3025 30264.80 KVM_SET_DEVICE_ATTR/KVM_GET_DEVICE_ATTR 3027-------------------------------------------- 3028 3029:Capability: KVM_CAP_DEVICE_CTRL, KVM_CAP_VM_ATTRIBUTES for vm device, 3030 KVM_CAP_VCPU_ATTRIBUTES for vcpu device 3031:Type: device ioctl, vm ioctl, vcpu ioctl 3032:Parameters: struct kvm_device_attr 3033:Returns: 0 on success, -1 on error 3034 3035Errors: 3036 3037 ===== ============================================================= 3038 ENXIO The group or attribute is unknown/unsupported for this device 3039 or hardware support is missing. 3040 EPERM The attribute cannot (currently) be accessed this way 3041 (e.g. read-only attribute, or attribute that only makes 3042 sense when the device is in a different state) 3043 ===== ============================================================= 3044 3045 Other error conditions may be defined by individual device types. 3046 3047Gets/sets a specified piece of device configuration and/or state. The 3048semantics are device-specific. See individual device documentation in 3049the "devices" directory. As with ONE_REG, the size of the data 3050transferred is defined by the particular attribute. 3051 3052:: 3053 3054 struct kvm_device_attr { 3055 __u32 flags; /* no flags currently defined */ 3056 __u32 group; /* device-defined */ 3057 __u64 attr; /* group-defined */ 3058 __u64 addr; /* userspace address of attr data */ 3059 }; 3060 30614.81 KVM_HAS_DEVICE_ATTR 3062------------------------ 3063 3064:Capability: KVM_CAP_DEVICE_CTRL, KVM_CAP_VM_ATTRIBUTES for vm device, 3065 KVM_CAP_VCPU_ATTRIBUTES for vcpu device 3066:Type: device ioctl, vm ioctl, vcpu ioctl 3067:Parameters: struct kvm_device_attr 3068:Returns: 0 on success, -1 on error 3069 3070Errors: 3071 3072 ===== ============================================================= 3073 ENXIO The group or attribute is unknown/unsupported for this device 3074 or hardware support is missing. 3075 ===== ============================================================= 3076 3077Tests whether a device supports a particular attribute. A successful 3078return indicates the attribute is implemented. It does not necessarily 3079indicate that the attribute can be read or written in the device's 3080current state. "addr" is ignored. 3081 30824.82 KVM_ARM_VCPU_INIT 3083---------------------- 3084 3085:Capability: basic 3086:Architectures: arm, arm64 3087:Type: vcpu ioctl 3088:Parameters: struct kvm_vcpu_init (in) 3089:Returns: 0 on success; -1 on error 3090 3091Errors: 3092 3093 ====== ================================================================= 3094 EINVAL the target is unknown, or the combination of features is invalid. 3095 ENOENT a features bit specified is unknown. 3096 ====== ================================================================= 3097 3098This tells KVM what type of CPU to present to the guest, and what 3099optional features it should have. This will cause a reset of the cpu 3100registers to their initial values. If this is not called, KVM_RUN will 3101return ENOEXEC for that vcpu. 3102 3103Note that because some registers reflect machine topology, all vcpus 3104should be created before this ioctl is invoked. 3105 3106Userspace can call this function multiple times for a given vcpu, including 3107after the vcpu has been run. This will reset the vcpu to its initial 3108state. All calls to this function after the initial call must use the same 3109target and same set of feature flags, otherwise EINVAL will be returned. 3110 3111Possible features: 3112 3113 - KVM_ARM_VCPU_POWER_OFF: Starts the CPU in a power-off state. 3114 Depends on KVM_CAP_ARM_PSCI. If not set, the CPU will be powered on 3115 and execute guest code when KVM_RUN is called. 3116 - KVM_ARM_VCPU_EL1_32BIT: Starts the CPU in a 32bit mode. 3117 Depends on KVM_CAP_ARM_EL1_32BIT (arm64 only). 3118 - KVM_ARM_VCPU_PSCI_0_2: Emulate PSCI v0.2 (or a future revision 3119 backward compatible with v0.2) for the CPU. 3120 Depends on KVM_CAP_ARM_PSCI_0_2. 3121 - KVM_ARM_VCPU_PMU_V3: Emulate PMUv3 for the CPU. 3122 Depends on KVM_CAP_ARM_PMU_V3. 3123 3124 - KVM_ARM_VCPU_PTRAUTH_ADDRESS: Enables Address Pointer authentication 3125 for arm64 only. 3126 Depends on KVM_CAP_ARM_PTRAUTH_ADDRESS. 3127 If KVM_CAP_ARM_PTRAUTH_ADDRESS and KVM_CAP_ARM_PTRAUTH_GENERIC are 3128 both present, then both KVM_ARM_VCPU_PTRAUTH_ADDRESS and 3129 KVM_ARM_VCPU_PTRAUTH_GENERIC must be requested or neither must be 3130 requested. 3131 3132 - KVM_ARM_VCPU_PTRAUTH_GENERIC: Enables Generic Pointer authentication 3133 for arm64 only. 3134 Depends on KVM_CAP_ARM_PTRAUTH_GENERIC. 3135 If KVM_CAP_ARM_PTRAUTH_ADDRESS and KVM_CAP_ARM_PTRAUTH_GENERIC are 3136 both present, then both KVM_ARM_VCPU_PTRAUTH_ADDRESS and 3137 KVM_ARM_VCPU_PTRAUTH_GENERIC must be requested or neither must be 3138 requested. 3139 3140 - KVM_ARM_VCPU_SVE: Enables SVE for the CPU (arm64 only). 3141 Depends on KVM_CAP_ARM_SVE. 3142 Requires KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE): 3143 3144 * After KVM_ARM_VCPU_INIT: 3145 3146 - KVM_REG_ARM64_SVE_VLS may be read using KVM_GET_ONE_REG: the 3147 initial value of this pseudo-register indicates the best set of 3148 vector lengths possible for a vcpu on this host. 3149 3150 * Before KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE): 3151 3152 - KVM_RUN and KVM_GET_REG_LIST are not available; 3153 3154 - KVM_GET_ONE_REG and KVM_SET_ONE_REG cannot be used to access 3155 the scalable archietctural SVE registers 3156 KVM_REG_ARM64_SVE_ZREG(), KVM_REG_ARM64_SVE_PREG() or 3157 KVM_REG_ARM64_SVE_FFR; 3158 3159 - KVM_REG_ARM64_SVE_VLS may optionally be written using 3160 KVM_SET_ONE_REG, to modify the set of vector lengths available 3161 for the vcpu. 3162 3163 * After KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE): 3164 3165 - the KVM_REG_ARM64_SVE_VLS pseudo-register is immutable, and can 3166 no longer be written using KVM_SET_ONE_REG. 3167 31684.83 KVM_ARM_PREFERRED_TARGET 3169----------------------------- 3170 3171:Capability: basic 3172:Architectures: arm, arm64 3173:Type: vm ioctl 3174:Parameters: struct kvm_vcpu_init (out) 3175:Returns: 0 on success; -1 on error 3176 3177Errors: 3178 3179 ====== ========================================== 3180 ENODEV no preferred target available for the host 3181 ====== ========================================== 3182 3183This queries KVM for preferred CPU target type which can be emulated 3184by KVM on underlying host. 3185 3186The ioctl returns struct kvm_vcpu_init instance containing information 3187about preferred CPU target type and recommended features for it. The 3188kvm_vcpu_init->features bitmap returned will have feature bits set if 3189the preferred target recommends setting these features, but this is 3190not mandatory. 3191 3192The information returned by this ioctl can be used to prepare an instance 3193of struct kvm_vcpu_init for KVM_ARM_VCPU_INIT ioctl which will result in 3194VCPU matching underlying host. 3195 3196 31974.84 KVM_GET_REG_LIST 3198--------------------- 3199 3200:Capability: basic 3201:Architectures: arm, arm64, mips 3202:Type: vcpu ioctl 3203:Parameters: struct kvm_reg_list (in/out) 3204:Returns: 0 on success; -1 on error 3205 3206Errors: 3207 3208 ===== ============================================================== 3209 E2BIG the reg index list is too big to fit in the array specified by 3210 the user (the number required will be written into n). 3211 ===== ============================================================== 3212 3213:: 3214 3215 struct kvm_reg_list { 3216 __u64 n; /* number of registers in reg[] */ 3217 __u64 reg[0]; 3218 }; 3219 3220This ioctl returns the guest registers that are supported for the 3221KVM_GET_ONE_REG/KVM_SET_ONE_REG calls. 3222 3223 32244.85 KVM_ARM_SET_DEVICE_ADDR (deprecated) 3225----------------------------------------- 3226 3227:Capability: KVM_CAP_ARM_SET_DEVICE_ADDR 3228:Architectures: arm, arm64 3229:Type: vm ioctl 3230:Parameters: struct kvm_arm_device_address (in) 3231:Returns: 0 on success, -1 on error 3232 3233Errors: 3234 3235 ====== ============================================ 3236 ENODEV The device id is unknown 3237 ENXIO Device not supported on current system 3238 EEXIST Address already set 3239 E2BIG Address outside guest physical address space 3240 EBUSY Address overlaps with other device range 3241 ====== ============================================ 3242 3243:: 3244 3245 struct kvm_arm_device_addr { 3246 __u64 id; 3247 __u64 addr; 3248 }; 3249 3250Specify a device address in the guest's physical address space where guests 3251can access emulated or directly exposed devices, which the host kernel needs 3252to know about. The id field is an architecture specific identifier for a 3253specific device. 3254 3255ARM/arm64 divides the id field into two parts, a device id and an 3256address type id specific to the individual device:: 3257 3258 bits: | 63 ... 32 | 31 ... 16 | 15 ... 0 | 3259 field: | 0x00000000 | device id | addr type id | 3260 3261ARM/arm64 currently only require this when using the in-kernel GIC 3262support for the hardware VGIC features, using KVM_ARM_DEVICE_VGIC_V2 3263as the device id. When setting the base address for the guest's 3264mapping of the VGIC virtual CPU and distributor interface, the ioctl 3265must be called after calling KVM_CREATE_IRQCHIP, but before calling 3266KVM_RUN on any of the VCPUs. Calling this ioctl twice for any of the 3267base addresses will return -EEXIST. 3268 3269Note, this IOCTL is deprecated and the more flexible SET/GET_DEVICE_ATTR API 3270should be used instead. 3271 3272 32734.86 KVM_PPC_RTAS_DEFINE_TOKEN 3274------------------------------ 3275 3276:Capability: KVM_CAP_PPC_RTAS 3277:Architectures: ppc 3278:Type: vm ioctl 3279:Parameters: struct kvm_rtas_token_args 3280:Returns: 0 on success, -1 on error 3281 3282Defines a token value for a RTAS (Run Time Abstraction Services) 3283service in order to allow it to be handled in the kernel. The 3284argument struct gives the name of the service, which must be the name 3285of a service that has a kernel-side implementation. If the token 3286value is non-zero, it will be associated with that service, and 3287subsequent RTAS calls by the guest specifying that token will be 3288handled by the kernel. If the token value is 0, then any token 3289associated with the service will be forgotten, and subsequent RTAS 3290calls by the guest for that service will be passed to userspace to be 3291handled. 3292 32934.87 KVM_SET_GUEST_DEBUG 3294------------------------ 3295 3296:Capability: KVM_CAP_SET_GUEST_DEBUG 3297:Architectures: x86, s390, ppc, arm64 3298:Type: vcpu ioctl 3299:Parameters: struct kvm_guest_debug (in) 3300:Returns: 0 on success; -1 on error 3301 3302:: 3303 3304 struct kvm_guest_debug { 3305 __u32 control; 3306 __u32 pad; 3307 struct kvm_guest_debug_arch arch; 3308 }; 3309 3310Set up the processor specific debug registers and configure vcpu for 3311handling guest debug events. There are two parts to the structure, the 3312first a control bitfield indicates the type of debug events to handle 3313when running. Common control bits are: 3314 3315 - KVM_GUESTDBG_ENABLE: guest debugging is enabled 3316 - KVM_GUESTDBG_SINGLESTEP: the next run should single-step 3317 3318The top 16 bits of the control field are architecture specific control 3319flags which can include the following: 3320 3321 - KVM_GUESTDBG_USE_SW_BP: using software breakpoints [x86, arm64] 3322 - KVM_GUESTDBG_USE_HW_BP: using hardware breakpoints [x86, s390, arm64] 3323 - KVM_GUESTDBG_INJECT_DB: inject DB type exception [x86] 3324 - KVM_GUESTDBG_INJECT_BP: inject BP type exception [x86] 3325 - KVM_GUESTDBG_EXIT_PENDING: trigger an immediate guest exit [s390] 3326 3327For example KVM_GUESTDBG_USE_SW_BP indicates that software breakpoints 3328are enabled in memory so we need to ensure breakpoint exceptions are 3329correctly trapped and the KVM run loop exits at the breakpoint and not 3330running off into the normal guest vector. For KVM_GUESTDBG_USE_HW_BP 3331we need to ensure the guest vCPUs architecture specific registers are 3332updated to the correct (supplied) values. 3333 3334The second part of the structure is architecture specific and 3335typically contains a set of debug registers. 3336 3337For arm64 the number of debug registers is implementation defined and 3338can be determined by querying the KVM_CAP_GUEST_DEBUG_HW_BPS and 3339KVM_CAP_GUEST_DEBUG_HW_WPS capabilities which return a positive number 3340indicating the number of supported registers. 3341 3342For ppc, the KVM_CAP_PPC_GUEST_DEBUG_SSTEP capability indicates whether 3343the single-step debug event (KVM_GUESTDBG_SINGLESTEP) is supported. 3344 3345When debug events exit the main run loop with the reason 3346KVM_EXIT_DEBUG with the kvm_debug_exit_arch part of the kvm_run 3347structure containing architecture specific debug information. 3348 33494.88 KVM_GET_EMULATED_CPUID 3350--------------------------- 3351 3352:Capability: KVM_CAP_EXT_EMUL_CPUID 3353:Architectures: x86 3354:Type: system ioctl 3355:Parameters: struct kvm_cpuid2 (in/out) 3356:Returns: 0 on success, -1 on error 3357 3358:: 3359 3360 struct kvm_cpuid2 { 3361 __u32 nent; 3362 __u32 flags; 3363 struct kvm_cpuid_entry2 entries[0]; 3364 }; 3365 3366The member 'flags' is used for passing flags from userspace. 3367 3368:: 3369 3370 #define KVM_CPUID_FLAG_SIGNIFCANT_INDEX BIT(0) 3371 #define KVM_CPUID_FLAG_STATEFUL_FUNC BIT(1) /* deprecated */ 3372 #define KVM_CPUID_FLAG_STATE_READ_NEXT BIT(2) /* deprecated */ 3373 3374 struct kvm_cpuid_entry2 { 3375 __u32 function; 3376 __u32 index; 3377 __u32 flags; 3378 __u32 eax; 3379 __u32 ebx; 3380 __u32 ecx; 3381 __u32 edx; 3382 __u32 padding[3]; 3383 }; 3384 3385This ioctl returns x86 cpuid features which are emulated by 3386kvm.Userspace can use the information returned by this ioctl to query 3387which features are emulated by kvm instead of being present natively. 3388 3389Userspace invokes KVM_GET_EMULATED_CPUID by passing a kvm_cpuid2 3390structure with the 'nent' field indicating the number of entries in 3391the variable-size array 'entries'. If the number of entries is too low 3392to describe the cpu capabilities, an error (E2BIG) is returned. If the 3393number is too high, the 'nent' field is adjusted and an error (ENOMEM) 3394is returned. If the number is just right, the 'nent' field is adjusted 3395to the number of valid entries in the 'entries' array, which is then 3396filled. 3397 3398The entries returned are the set CPUID bits of the respective features 3399which kvm emulates, as returned by the CPUID instruction, with unknown 3400or unsupported feature bits cleared. 3401 3402Features like x2apic, for example, may not be present in the host cpu 3403but are exposed by kvm in KVM_GET_SUPPORTED_CPUID because they can be 3404emulated efficiently and thus not included here. 3405 3406The fields in each entry are defined as follows: 3407 3408 function: 3409 the eax value used to obtain the entry 3410 index: 3411 the ecx value used to obtain the entry (for entries that are 3412 affected by ecx) 3413 flags: 3414 an OR of zero or more of the following: 3415 3416 KVM_CPUID_FLAG_SIGNIFCANT_INDEX: 3417 if the index field is valid 3418 3419 eax, ebx, ecx, edx: 3420 3421 the values returned by the cpuid instruction for 3422 this function/index combination 3423 34244.89 KVM_S390_MEM_OP 3425-------------------- 3426 3427:Capability: KVM_CAP_S390_MEM_OP 3428:Architectures: s390 3429:Type: vcpu ioctl 3430:Parameters: struct kvm_s390_mem_op (in) 3431:Returns: = 0 on success, 3432 < 0 on generic error (e.g. -EFAULT or -ENOMEM), 3433 > 0 if an exception occurred while walking the page tables 3434 3435Read or write data from/to the logical (virtual) memory of a VCPU. 3436 3437Parameters are specified via the following structure:: 3438 3439 struct kvm_s390_mem_op { 3440 __u64 gaddr; /* the guest address */ 3441 __u64 flags; /* flags */ 3442 __u32 size; /* amount of bytes */ 3443 __u32 op; /* type of operation */ 3444 __u64 buf; /* buffer in userspace */ 3445 __u8 ar; /* the access register number */ 3446 __u8 reserved[31]; /* should be set to 0 */ 3447 }; 3448 3449The type of operation is specified in the "op" field. It is either 3450KVM_S390_MEMOP_LOGICAL_READ for reading from logical memory space or 3451KVM_S390_MEMOP_LOGICAL_WRITE for writing to logical memory space. The 3452KVM_S390_MEMOP_F_CHECK_ONLY flag can be set in the "flags" field to check 3453whether the corresponding memory access would create an access exception 3454(without touching the data in the memory at the destination). In case an 3455access exception occurred while walking the MMU tables of the guest, the 3456ioctl returns a positive error number to indicate the type of exception. 3457This exception is also raised directly at the corresponding VCPU if the 3458flag KVM_S390_MEMOP_F_INJECT_EXCEPTION is set in the "flags" field. 3459 3460The start address of the memory region has to be specified in the "gaddr" 3461field, and the length of the region in the "size" field (which must not 3462be 0). The maximum value for "size" can be obtained by checking the 3463KVM_CAP_S390_MEM_OP capability. "buf" is the buffer supplied by the 3464userspace application where the read data should be written to for 3465KVM_S390_MEMOP_LOGICAL_READ, or where the data that should be written is 3466stored for a KVM_S390_MEMOP_LOGICAL_WRITE. When KVM_S390_MEMOP_F_CHECK_ONLY 3467is specified, "buf" is unused and can be NULL. "ar" designates the access 3468register number to be used; the valid range is 0..15. 3469 3470The "reserved" field is meant for future extensions. It is not used by 3471KVM with the currently defined set of flags. 3472 34734.90 KVM_S390_GET_SKEYS 3474----------------------- 3475 3476:Capability: KVM_CAP_S390_SKEYS 3477:Architectures: s390 3478:Type: vm ioctl 3479:Parameters: struct kvm_s390_skeys 3480:Returns: 0 on success, KVM_S390_GET_KEYS_NONE if guest is not using storage 3481 keys, negative value on error 3482 3483This ioctl is used to get guest storage key values on the s390 3484architecture. The ioctl takes parameters via the kvm_s390_skeys struct:: 3485 3486 struct kvm_s390_skeys { 3487 __u64 start_gfn; 3488 __u64 count; 3489 __u64 skeydata_addr; 3490 __u32 flags; 3491 __u32 reserved[9]; 3492 }; 3493 3494The start_gfn field is the number of the first guest frame whose storage keys 3495you want to get. 3496 3497The count field is the number of consecutive frames (starting from start_gfn) 3498whose storage keys to get. The count field must be at least 1 and the maximum 3499allowed value is defined as KVM_S390_SKEYS_ALLOC_MAX. Values outside this range 3500will cause the ioctl to return -EINVAL. 3501 3502The skeydata_addr field is the address to a buffer large enough to hold count 3503bytes. This buffer will be filled with storage key data by the ioctl. 3504 35054.91 KVM_S390_SET_SKEYS 3506----------------------- 3507 3508:Capability: KVM_CAP_S390_SKEYS 3509:Architectures: s390 3510:Type: vm ioctl 3511:Parameters: struct kvm_s390_skeys 3512:Returns: 0 on success, negative value on error 3513 3514This ioctl is used to set guest storage key values on the s390 3515architecture. The ioctl takes parameters via the kvm_s390_skeys struct. 3516See section on KVM_S390_GET_SKEYS for struct definition. 3517 3518The start_gfn field is the number of the first guest frame whose storage keys 3519you want to set. 3520 3521The count field is the number of consecutive frames (starting from start_gfn) 3522whose storage keys to get. The count field must be at least 1 and the maximum 3523allowed value is defined as KVM_S390_SKEYS_ALLOC_MAX. Values outside this range 3524will cause the ioctl to return -EINVAL. 3525 3526The skeydata_addr field is the address to a buffer containing count bytes of 3527storage keys. Each byte in the buffer will be set as the storage key for a 3528single frame starting at start_gfn for count frames. 3529 3530Note: If any architecturally invalid key value is found in the given data then 3531the ioctl will return -EINVAL. 3532 35334.92 KVM_S390_IRQ 3534----------------- 3535 3536:Capability: KVM_CAP_S390_INJECT_IRQ 3537:Architectures: s390 3538:Type: vcpu ioctl 3539:Parameters: struct kvm_s390_irq (in) 3540:Returns: 0 on success, -1 on error 3541 3542Errors: 3543 3544 3545 ====== ================================================================= 3546 EINVAL interrupt type is invalid 3547 type is KVM_S390_SIGP_STOP and flag parameter is invalid value, 3548 type is KVM_S390_INT_EXTERNAL_CALL and code is bigger 3549 than the maximum of VCPUs 3550 EBUSY type is KVM_S390_SIGP_SET_PREFIX and vcpu is not stopped, 3551 type is KVM_S390_SIGP_STOP and a stop irq is already pending, 3552 type is KVM_S390_INT_EXTERNAL_CALL and an external call interrupt 3553 is already pending 3554 ====== ================================================================= 3555 3556Allows to inject an interrupt to the guest. 3557 3558Using struct kvm_s390_irq as a parameter allows 3559to inject additional payload which is not 3560possible via KVM_S390_INTERRUPT. 3561 3562Interrupt parameters are passed via kvm_s390_irq:: 3563 3564 struct kvm_s390_irq { 3565 __u64 type; 3566 union { 3567 struct kvm_s390_io_info io; 3568 struct kvm_s390_ext_info ext; 3569 struct kvm_s390_pgm_info pgm; 3570 struct kvm_s390_emerg_info emerg; 3571 struct kvm_s390_extcall_info extcall; 3572 struct kvm_s390_prefix_info prefix; 3573 struct kvm_s390_stop_info stop; 3574 struct kvm_s390_mchk_info mchk; 3575 char reserved[64]; 3576 } u; 3577 }; 3578 3579type can be one of the following: 3580 3581- KVM_S390_SIGP_STOP - sigp stop; parameter in .stop 3582- KVM_S390_PROGRAM_INT - program check; parameters in .pgm 3583- KVM_S390_SIGP_SET_PREFIX - sigp set prefix; parameters in .prefix 3584- KVM_S390_RESTART - restart; no parameters 3585- KVM_S390_INT_CLOCK_COMP - clock comparator interrupt; no parameters 3586- KVM_S390_INT_CPU_TIMER - CPU timer interrupt; no parameters 3587- KVM_S390_INT_EMERGENCY - sigp emergency; parameters in .emerg 3588- KVM_S390_INT_EXTERNAL_CALL - sigp external call; parameters in .extcall 3589- KVM_S390_MCHK - machine check interrupt; parameters in .mchk 3590 3591This is an asynchronous vcpu ioctl and can be invoked from any thread. 3592 35934.94 KVM_S390_GET_IRQ_STATE 3594--------------------------- 3595 3596:Capability: KVM_CAP_S390_IRQ_STATE 3597:Architectures: s390 3598:Type: vcpu ioctl 3599:Parameters: struct kvm_s390_irq_state (out) 3600:Returns: >= number of bytes copied into buffer, 3601 -EINVAL if buffer size is 0, 3602 -ENOBUFS if buffer size is too small to fit all pending interrupts, 3603 -EFAULT if the buffer address was invalid 3604 3605This ioctl allows userspace to retrieve the complete state of all currently 3606pending interrupts in a single buffer. Use cases include migration 3607and introspection. The parameter structure contains the address of a 3608userspace buffer and its length:: 3609 3610 struct kvm_s390_irq_state { 3611 __u64 buf; 3612 __u32 flags; /* will stay unused for compatibility reasons */ 3613 __u32 len; 3614 __u32 reserved[4]; /* will stay unused for compatibility reasons */ 3615 }; 3616 3617Userspace passes in the above struct and for each pending interrupt a 3618struct kvm_s390_irq is copied to the provided buffer. 3619 3620The structure contains a flags and a reserved field for future extensions. As 3621the kernel never checked for flags == 0 and QEMU never pre-zeroed flags and 3622reserved, these fields can not be used in the future without breaking 3623compatibility. 3624 3625If -ENOBUFS is returned the buffer provided was too small and userspace 3626may retry with a bigger buffer. 3627 36284.95 KVM_S390_SET_IRQ_STATE 3629--------------------------- 3630 3631:Capability: KVM_CAP_S390_IRQ_STATE 3632:Architectures: s390 3633:Type: vcpu ioctl 3634:Parameters: struct kvm_s390_irq_state (in) 3635:Returns: 0 on success, 3636 -EFAULT if the buffer address was invalid, 3637 -EINVAL for an invalid buffer length (see below), 3638 -EBUSY if there were already interrupts pending, 3639 errors occurring when actually injecting the 3640 interrupt. See KVM_S390_IRQ. 3641 3642This ioctl allows userspace to set the complete state of all cpu-local 3643interrupts currently pending for the vcpu. It is intended for restoring 3644interrupt state after a migration. The input parameter is a userspace buffer 3645containing a struct kvm_s390_irq_state:: 3646 3647 struct kvm_s390_irq_state { 3648 __u64 buf; 3649 __u32 flags; /* will stay unused for compatibility reasons */ 3650 __u32 len; 3651 __u32 reserved[4]; /* will stay unused for compatibility reasons */ 3652 }; 3653 3654The restrictions for flags and reserved apply as well. 3655(see KVM_S390_GET_IRQ_STATE) 3656 3657The userspace memory referenced by buf contains a struct kvm_s390_irq 3658for each interrupt to be injected into the guest. 3659If one of the interrupts could not be injected for some reason the 3660ioctl aborts. 3661 3662len must be a multiple of sizeof(struct kvm_s390_irq). It must be > 0 3663and it must not exceed (max_vcpus + 32) * sizeof(struct kvm_s390_irq), 3664which is the maximum number of possibly pending cpu-local interrupts. 3665 36664.96 KVM_SMI 3667------------ 3668 3669:Capability: KVM_CAP_X86_SMM 3670:Architectures: x86 3671:Type: vcpu ioctl 3672:Parameters: none 3673:Returns: 0 on success, -1 on error 3674 3675Queues an SMI on the thread's vcpu. 3676 36774.97 KVM_CAP_PPC_MULTITCE 3678------------------------- 3679 3680:Capability: KVM_CAP_PPC_MULTITCE 3681:Architectures: ppc 3682:Type: vm 3683 3684This capability means the kernel is capable of handling hypercalls 3685H_PUT_TCE_INDIRECT and H_STUFF_TCE without passing those into the user 3686space. This significantly accelerates DMA operations for PPC KVM guests. 3687User space should expect that its handlers for these hypercalls 3688are not going to be called if user space previously registered LIOBN 3689in KVM (via KVM_CREATE_SPAPR_TCE or similar calls). 3690 3691In order to enable H_PUT_TCE_INDIRECT and H_STUFF_TCE use in the guest, 3692user space might have to advertise it for the guest. For example, 3693IBM pSeries (sPAPR) guest starts using them if "hcall-multi-tce" is 3694present in the "ibm,hypertas-functions" device-tree property. 3695 3696The hypercalls mentioned above may or may not be processed successfully 3697in the kernel based fast path. If they can not be handled by the kernel, 3698they will get passed on to user space. So user space still has to have 3699an implementation for these despite the in kernel acceleration. 3700 3701This capability is always enabled. 3702 37034.98 KVM_CREATE_SPAPR_TCE_64 3704---------------------------- 3705 3706:Capability: KVM_CAP_SPAPR_TCE_64 3707:Architectures: powerpc 3708:Type: vm ioctl 3709:Parameters: struct kvm_create_spapr_tce_64 (in) 3710:Returns: file descriptor for manipulating the created TCE table 3711 3712This is an extension for KVM_CAP_SPAPR_TCE which only supports 32bit 3713windows, described in 4.62 KVM_CREATE_SPAPR_TCE 3714 3715This capability uses extended struct in ioctl interface:: 3716 3717 /* for KVM_CAP_SPAPR_TCE_64 */ 3718 struct kvm_create_spapr_tce_64 { 3719 __u64 liobn; 3720 __u32 page_shift; 3721 __u32 flags; 3722 __u64 offset; /* in pages */ 3723 __u64 size; /* in pages */ 3724 }; 3725 3726The aim of extension is to support an additional bigger DMA window with 3727a variable page size. 3728KVM_CREATE_SPAPR_TCE_64 receives a 64bit window size, an IOMMU page shift and 3729a bus offset of the corresponding DMA window, @size and @offset are numbers 3730of IOMMU pages. 3731 3732@flags are not used at the moment. 3733 3734The rest of functionality is identical to KVM_CREATE_SPAPR_TCE. 3735 37364.99 KVM_REINJECT_CONTROL 3737------------------------- 3738 3739:Capability: KVM_CAP_REINJECT_CONTROL 3740:Architectures: x86 3741:Type: vm ioctl 3742:Parameters: struct kvm_reinject_control (in) 3743:Returns: 0 on success, 3744 -EFAULT if struct kvm_reinject_control cannot be read, 3745 -ENXIO if KVM_CREATE_PIT or KVM_CREATE_PIT2 didn't succeed earlier. 3746 3747i8254 (PIT) has two modes, reinject and !reinject. The default is reinject, 3748where KVM queues elapsed i8254 ticks and monitors completion of interrupt from 3749vector(s) that i8254 injects. Reinject mode dequeues a tick and injects its 3750interrupt whenever there isn't a pending interrupt from i8254. 3751!reinject mode injects an interrupt as soon as a tick arrives. 3752 3753:: 3754 3755 struct kvm_reinject_control { 3756 __u8 pit_reinject; 3757 __u8 reserved[31]; 3758 }; 3759 3760pit_reinject = 0 (!reinject mode) is recommended, unless running an old 3761operating system that uses the PIT for timing (e.g. Linux 2.4.x). 3762 37634.100 KVM_PPC_CONFIGURE_V3_MMU 3764------------------------------ 3765 3766:Capability: KVM_CAP_PPC_RADIX_MMU or KVM_CAP_PPC_HASH_MMU_V3 3767:Architectures: ppc 3768:Type: vm ioctl 3769:Parameters: struct kvm_ppc_mmuv3_cfg (in) 3770:Returns: 0 on success, 3771 -EFAULT if struct kvm_ppc_mmuv3_cfg cannot be read, 3772 -EINVAL if the configuration is invalid 3773 3774This ioctl controls whether the guest will use radix or HPT (hashed 3775page table) translation, and sets the pointer to the process table for 3776the guest. 3777 3778:: 3779 3780 struct kvm_ppc_mmuv3_cfg { 3781 __u64 flags; 3782 __u64 process_table; 3783 }; 3784 3785There are two bits that can be set in flags; KVM_PPC_MMUV3_RADIX and 3786KVM_PPC_MMUV3_GTSE. KVM_PPC_MMUV3_RADIX, if set, configures the guest 3787to use radix tree translation, and if clear, to use HPT translation. 3788KVM_PPC_MMUV3_GTSE, if set and if KVM permits it, configures the guest 3789to be able to use the global TLB and SLB invalidation instructions; 3790if clear, the guest may not use these instructions. 3791 3792The process_table field specifies the address and size of the guest 3793process table, which is in the guest's space. This field is formatted 3794as the second doubleword of the partition table entry, as defined in 3795the Power ISA V3.00, Book III section 5.7.6.1. 3796 37974.101 KVM_PPC_GET_RMMU_INFO 3798--------------------------- 3799 3800:Capability: KVM_CAP_PPC_RADIX_MMU 3801:Architectures: ppc 3802:Type: vm ioctl 3803:Parameters: struct kvm_ppc_rmmu_info (out) 3804:Returns: 0 on success, 3805 -EFAULT if struct kvm_ppc_rmmu_info cannot be written, 3806 -EINVAL if no useful information can be returned 3807 3808This ioctl returns a structure containing two things: (a) a list 3809containing supported radix tree geometries, and (b) a list that maps 3810page sizes to put in the "AP" (actual page size) field for the tlbie 3811(TLB invalidate entry) instruction. 3812 3813:: 3814 3815 struct kvm_ppc_rmmu_info { 3816 struct kvm_ppc_radix_geom { 3817 __u8 page_shift; 3818 __u8 level_bits[4]; 3819 __u8 pad[3]; 3820 } geometries[8]; 3821 __u32 ap_encodings[8]; 3822 }; 3823 3824The geometries[] field gives up to 8 supported geometries for the 3825radix page table, in terms of the log base 2 of the smallest page 3826size, and the number of bits indexed at each level of the tree, from 3827the PTE level up to the PGD level in that order. Any unused entries 3828will have 0 in the page_shift field. 3829 3830The ap_encodings gives the supported page sizes and their AP field 3831encodings, encoded with the AP value in the top 3 bits and the log 3832base 2 of the page size in the bottom 6 bits. 3833 38344.102 KVM_PPC_RESIZE_HPT_PREPARE 3835-------------------------------- 3836 3837:Capability: KVM_CAP_SPAPR_RESIZE_HPT 3838:Architectures: powerpc 3839:Type: vm ioctl 3840:Parameters: struct kvm_ppc_resize_hpt (in) 3841:Returns: 0 on successful completion, 3842 >0 if a new HPT is being prepared, the value is an estimated 3843 number of milliseconds until preparation is complete, 3844 -EFAULT if struct kvm_reinject_control cannot be read, 3845 -EINVAL if the supplied shift or flags are invalid, 3846 -ENOMEM if unable to allocate the new HPT, 3847 -ENOSPC if there was a hash collision 3848 3849:: 3850 3851 struct kvm_ppc_rmmu_info { 3852 struct kvm_ppc_radix_geom { 3853 __u8 page_shift; 3854 __u8 level_bits[4]; 3855 __u8 pad[3]; 3856 } geometries[8]; 3857 __u32 ap_encodings[8]; 3858 }; 3859 3860The geometries[] field gives up to 8 supported geometries for the 3861radix page table, in terms of the log base 2 of the smallest page 3862size, and the number of bits indexed at each level of the tree, from 3863the PTE level up to the PGD level in that order. Any unused entries 3864will have 0 in the page_shift field. 3865 3866The ap_encodings gives the supported page sizes and their AP field 3867encodings, encoded with the AP value in the top 3 bits and the log 3868base 2 of the page size in the bottom 6 bits. 3869 38704.102 KVM_PPC_RESIZE_HPT_PREPARE 3871-------------------------------- 3872 3873:Capability: KVM_CAP_SPAPR_RESIZE_HPT 3874:Architectures: powerpc 3875:Type: vm ioctl 3876:Parameters: struct kvm_ppc_resize_hpt (in) 3877:Returns: 0 on successful completion, 3878 >0 if a new HPT is being prepared, the value is an estimated 3879 number of milliseconds until preparation is complete, 3880 -EFAULT if struct kvm_reinject_control cannot be read, 3881 -EINVAL if the supplied shift or flags are invalid,when moving existing 3882 HPT entries to the new HPT, 3883 -EIO on other error conditions 3884 3885Used to implement the PAPR extension for runtime resizing of a guest's 3886Hashed Page Table (HPT). Specifically this starts, stops or monitors 3887the preparation of a new potential HPT for the guest, essentially 3888implementing the H_RESIZE_HPT_PREPARE hypercall. 3889 3890If called with shift > 0 when there is no pending HPT for the guest, 3891this begins preparation of a new pending HPT of size 2^(shift) bytes. 3892It then returns a positive integer with the estimated number of 3893milliseconds until preparation is complete. 3894 3895If called when there is a pending HPT whose size does not match that 3896requested in the parameters, discards the existing pending HPT and 3897creates a new one as above. 3898 3899If called when there is a pending HPT of the size requested, will: 3900 3901 * If preparation of the pending HPT is already complete, return 0 3902 * If preparation of the pending HPT has failed, return an error 3903 code, then discard the pending HPT. 3904 * If preparation of the pending HPT is still in progress, return an 3905 estimated number of milliseconds until preparation is complete. 3906 3907If called with shift == 0, discards any currently pending HPT and 3908returns 0 (i.e. cancels any in-progress preparation). 3909 3910flags is reserved for future expansion, currently setting any bits in 3911flags will result in an -EINVAL. 3912 3913Normally this will be called repeatedly with the same parameters until 3914it returns <= 0. The first call will initiate preparation, subsequent 3915ones will monitor preparation until it completes or fails. 3916 3917:: 3918 3919 struct kvm_ppc_resize_hpt { 3920 __u64 flags; 3921 __u32 shift; 3922 __u32 pad; 3923 }; 3924 39254.103 KVM_PPC_RESIZE_HPT_COMMIT 3926------------------------------- 3927 3928:Capability: KVM_CAP_SPAPR_RESIZE_HPT 3929:Architectures: powerpc 3930:Type: vm ioctl 3931:Parameters: struct kvm_ppc_resize_hpt (in) 3932:Returns: 0 on successful completion, 3933 -EFAULT if struct kvm_reinject_control cannot be read, 3934 -EINVAL if the supplied shift or flags are invalid, 3935 -ENXIO is there is no pending HPT, or the pending HPT doesn't 3936 have the requested size, 3937 -EBUSY if the pending HPT is not fully prepared, 3938 -ENOSPC if there was a hash collision when moving existing 3939 HPT entries to the new HPT, 3940 -EIO on other error conditions 3941 3942Used to implement the PAPR extension for runtime resizing of a guest's 3943Hashed Page Table (HPT). Specifically this requests that the guest be 3944transferred to working with the new HPT, essentially implementing the 3945H_RESIZE_HPT_COMMIT hypercall. 3946 3947This should only be called after KVM_PPC_RESIZE_HPT_PREPARE has 3948returned 0 with the same parameters. In other cases 3949KVM_PPC_RESIZE_HPT_COMMIT will return an error (usually -ENXIO or 3950-EBUSY, though others may be possible if the preparation was started, 3951but failed). 3952 3953This will have undefined effects on the guest if it has not already 3954placed itself in a quiescent state where no vcpu will make MMU enabled 3955memory accesses. 3956 3957On succsful completion, the pending HPT will become the guest's active 3958HPT and the previous HPT will be discarded. 3959 3960On failure, the guest will still be operating on its previous HPT. 3961 3962:: 3963 3964 struct kvm_ppc_resize_hpt { 3965 __u64 flags; 3966 __u32 shift; 3967 __u32 pad; 3968 }; 3969 39704.104 KVM_X86_GET_MCE_CAP_SUPPORTED 3971----------------------------------- 3972 3973:Capability: KVM_CAP_MCE 3974:Architectures: x86 3975:Type: system ioctl 3976:Parameters: u64 mce_cap (out) 3977:Returns: 0 on success, -1 on error 3978 3979Returns supported MCE capabilities. The u64 mce_cap parameter 3980has the same format as the MSR_IA32_MCG_CAP register. Supported 3981capabilities will have the corresponding bits set. 3982 39834.105 KVM_X86_SETUP_MCE 3984----------------------- 3985 3986:Capability: KVM_CAP_MCE 3987:Architectures: x86 3988:Type: vcpu ioctl 3989:Parameters: u64 mcg_cap (in) 3990:Returns: 0 on success, 3991 -EFAULT if u64 mcg_cap cannot be read, 3992 -EINVAL if the requested number of banks is invalid, 3993 -EINVAL if requested MCE capability is not supported. 3994 3995Initializes MCE support for use. The u64 mcg_cap parameter 3996has the same format as the MSR_IA32_MCG_CAP register and 3997specifies which capabilities should be enabled. The maximum 3998supported number of error-reporting banks can be retrieved when 3999checking for KVM_CAP_MCE. The supported capabilities can be 4000retrieved with KVM_X86_GET_MCE_CAP_SUPPORTED. 4001 40024.106 KVM_X86_SET_MCE 4003--------------------- 4004 4005:Capability: KVM_CAP_MCE 4006:Architectures: x86 4007:Type: vcpu ioctl 4008:Parameters: struct kvm_x86_mce (in) 4009:Returns: 0 on success, 4010 -EFAULT if struct kvm_x86_mce cannot be read, 4011 -EINVAL if the bank number is invalid, 4012 -EINVAL if VAL bit is not set in status field. 4013 4014Inject a machine check error (MCE) into the guest. The input 4015parameter is:: 4016 4017 struct kvm_x86_mce { 4018 __u64 status; 4019 __u64 addr; 4020 __u64 misc; 4021 __u64 mcg_status; 4022 __u8 bank; 4023 __u8 pad1[7]; 4024 __u64 pad2[3]; 4025 }; 4026 4027If the MCE being reported is an uncorrected error, KVM will 4028inject it as an MCE exception into the guest. If the guest 4029MCG_STATUS register reports that an MCE is in progress, KVM 4030causes an KVM_EXIT_SHUTDOWN vmexit. 4031 4032Otherwise, if the MCE is a corrected error, KVM will just 4033store it in the corresponding bank (provided this bank is 4034not holding a previously reported uncorrected error). 4035 40364.107 KVM_S390_GET_CMMA_BITS 4037---------------------------- 4038 4039:Capability: KVM_CAP_S390_CMMA_MIGRATION 4040:Architectures: s390 4041:Type: vm ioctl 4042:Parameters: struct kvm_s390_cmma_log (in, out) 4043:Returns: 0 on success, a negative value on error 4044 4045This ioctl is used to get the values of the CMMA bits on the s390 4046architecture. It is meant to be used in two scenarios: 4047 4048- During live migration to save the CMMA values. Live migration needs 4049 to be enabled via the KVM_REQ_START_MIGRATION VM property. 4050- To non-destructively peek at the CMMA values, with the flag 4051 KVM_S390_CMMA_PEEK set. 4052 4053The ioctl takes parameters via the kvm_s390_cmma_log struct. The desired 4054values are written to a buffer whose location is indicated via the "values" 4055member in the kvm_s390_cmma_log struct. The values in the input struct are 4056also updated as needed. 4057 4058Each CMMA value takes up one byte. 4059 4060:: 4061 4062 struct kvm_s390_cmma_log { 4063 __u64 start_gfn; 4064 __u32 count; 4065 __u32 flags; 4066 union { 4067 __u64 remaining; 4068 __u64 mask; 4069 }; 4070 __u64 values; 4071 }; 4072 4073start_gfn is the number of the first guest frame whose CMMA values are 4074to be retrieved, 4075 4076count is the length of the buffer in bytes, 4077 4078values points to the buffer where the result will be written to. 4079 4080If count is greater than KVM_S390_SKEYS_MAX, then it is considered to be 4081KVM_S390_SKEYS_MAX. KVM_S390_SKEYS_MAX is re-used for consistency with 4082other ioctls. 4083 4084The result is written in the buffer pointed to by the field values, and 4085the values of the input parameter are updated as follows. 4086 4087Depending on the flags, different actions are performed. The only 4088supported flag so far is KVM_S390_CMMA_PEEK. 4089 4090The default behaviour if KVM_S390_CMMA_PEEK is not set is: 4091start_gfn will indicate the first page frame whose CMMA bits were dirty. 4092It is not necessarily the same as the one passed as input, as clean pages 4093are skipped. 4094 4095count will indicate the number of bytes actually written in the buffer. 4096It can (and very often will) be smaller than the input value, since the 4097buffer is only filled until 16 bytes of clean values are found (which 4098are then not copied in the buffer). Since a CMMA migration block needs 4099the base address and the length, for a total of 16 bytes, we will send 4100back some clean data if there is some dirty data afterwards, as long as 4101the size of the clean data does not exceed the size of the header. This 4102allows to minimize the amount of data to be saved or transferred over 4103the network at the expense of more roundtrips to userspace. The next 4104invocation of the ioctl will skip over all the clean values, saving 4105potentially more than just the 16 bytes we found. 4106 4107If KVM_S390_CMMA_PEEK is set: 4108the existing storage attributes are read even when not in migration 4109mode, and no other action is performed; 4110 4111the output start_gfn will be equal to the input start_gfn, 4112 4113the output count will be equal to the input count, except if the end of 4114memory has been reached. 4115 4116In both cases: 4117the field "remaining" will indicate the total number of dirty CMMA values 4118still remaining, or 0 if KVM_S390_CMMA_PEEK is set and migration mode is 4119not enabled. 4120 4121mask is unused. 4122 4123values points to the userspace buffer where the result will be stored. 4124 4125This ioctl can fail with -ENOMEM if not enough memory can be allocated to 4126complete the task, with -ENXIO if CMMA is not enabled, with -EINVAL if 4127KVM_S390_CMMA_PEEK is not set but migration mode was not enabled, with 4128-EFAULT if the userspace address is invalid or if no page table is 4129present for the addresses (e.g. when using hugepages). 4130 41314.108 KVM_S390_SET_CMMA_BITS 4132---------------------------- 4133 4134:Capability: KVM_CAP_S390_CMMA_MIGRATION 4135:Architectures: s390 4136:Type: vm ioctl 4137:Parameters: struct kvm_s390_cmma_log (in) 4138:Returns: 0 on success, a negative value on error 4139 4140This ioctl is used to set the values of the CMMA bits on the s390 4141architecture. It is meant to be used during live migration to restore 4142the CMMA values, but there are no restrictions on its use. 4143The ioctl takes parameters via the kvm_s390_cmma_values struct. 4144Each CMMA value takes up one byte. 4145 4146:: 4147 4148 struct kvm_s390_cmma_log { 4149 __u64 start_gfn; 4150 __u32 count; 4151 __u32 flags; 4152 union { 4153 __u64 remaining; 4154 __u64 mask; 4155 }; 4156 __u64 values; 4157 }; 4158 4159start_gfn indicates the starting guest frame number, 4160 4161count indicates how many values are to be considered in the buffer, 4162 4163flags is not used and must be 0. 4164 4165mask indicates which PGSTE bits are to be considered. 4166 4167remaining is not used. 4168 4169values points to the buffer in userspace where to store the values. 4170 4171This ioctl can fail with -ENOMEM if not enough memory can be allocated to 4172complete the task, with -ENXIO if CMMA is not enabled, with -EINVAL if 4173the count field is too large (e.g. more than KVM_S390_CMMA_SIZE_MAX) or 4174if the flags field was not 0, with -EFAULT if the userspace address is 4175invalid, if invalid pages are written to (e.g. after the end of memory) 4176or if no page table is present for the addresses (e.g. when using 4177hugepages). 4178 41794.109 KVM_PPC_GET_CPU_CHAR 4180-------------------------- 4181 4182:Capability: KVM_CAP_PPC_GET_CPU_CHAR 4183:Architectures: powerpc 4184:Type: vm ioctl 4185:Parameters: struct kvm_ppc_cpu_char (out) 4186:Returns: 0 on successful completion, 4187 -EFAULT if struct kvm_ppc_cpu_char cannot be written 4188 4189This ioctl gives userspace information about certain characteristics 4190of the CPU relating to speculative execution of instructions and 4191possible information leakage resulting from speculative execution (see 4192CVE-2017-5715, CVE-2017-5753 and CVE-2017-5754). The information is 4193returned in struct kvm_ppc_cpu_char, which looks like this:: 4194 4195 struct kvm_ppc_cpu_char { 4196 __u64 character; /* characteristics of the CPU */ 4197 __u64 behaviour; /* recommended software behaviour */ 4198 __u64 character_mask; /* valid bits in character */ 4199 __u64 behaviour_mask; /* valid bits in behaviour */ 4200 }; 4201 4202For extensibility, the character_mask and behaviour_mask fields 4203indicate which bits of character and behaviour have been filled in by 4204the kernel. If the set of defined bits is extended in future then 4205userspace will be able to tell whether it is running on a kernel that 4206knows about the new bits. 4207 4208The character field describes attributes of the CPU which can help 4209with preventing inadvertent information disclosure - specifically, 4210whether there is an instruction to flash-invalidate the L1 data cache 4211(ori 30,30,0 or mtspr SPRN_TRIG2,rN), whether the L1 data cache is set 4212to a mode where entries can only be used by the thread that created 4213them, whether the bcctr[l] instruction prevents speculation, and 4214whether a speculation barrier instruction (ori 31,31,0) is provided. 4215 4216The behaviour field describes actions that software should take to 4217prevent inadvertent information disclosure, and thus describes which 4218vulnerabilities the hardware is subject to; specifically whether the 4219L1 data cache should be flushed when returning to user mode from the 4220kernel, and whether a speculation barrier should be placed between an 4221array bounds check and the array access. 4222 4223These fields use the same bit definitions as the new 4224H_GET_CPU_CHARACTERISTICS hypercall. 4225 42264.110 KVM_MEMORY_ENCRYPT_OP 4227--------------------------- 4228 4229:Capability: basic 4230:Architectures: x86 4231:Type: vm 4232:Parameters: an opaque platform specific structure (in/out) 4233:Returns: 0 on success; -1 on error 4234 4235If the platform supports creating encrypted VMs then this ioctl can be used 4236for issuing platform-specific memory encryption commands to manage those 4237encrypted VMs. 4238 4239Currently, this ioctl is used for issuing Secure Encrypted Virtualization 4240(SEV) commands on AMD Processors. The SEV commands are defined in 4241Documentation/virt/kvm/amd-memory-encryption.rst. 4242 42434.111 KVM_MEMORY_ENCRYPT_REG_REGION 4244----------------------------------- 4245 4246:Capability: basic 4247:Architectures: x86 4248:Type: system 4249:Parameters: struct kvm_enc_region (in) 4250:Returns: 0 on success; -1 on error 4251 4252This ioctl can be used to register a guest memory region which may 4253contain encrypted data (e.g. guest RAM, SMRAM etc). 4254 4255It is used in the SEV-enabled guest. When encryption is enabled, a guest 4256memory region may contain encrypted data. The SEV memory encryption 4257engine uses a tweak such that two identical plaintext pages, each at 4258different locations will have differing ciphertexts. So swapping or 4259moving ciphertext of those pages will not result in plaintext being 4260swapped. So relocating (or migrating) physical backing pages for the SEV 4261guest will require some additional steps. 4262 4263Note: The current SEV key management spec does not provide commands to 4264swap or migrate (move) ciphertext pages. Hence, for now we pin the guest 4265memory region registered with the ioctl. 4266 42674.112 KVM_MEMORY_ENCRYPT_UNREG_REGION 4268------------------------------------- 4269 4270:Capability: basic 4271:Architectures: x86 4272:Type: system 4273:Parameters: struct kvm_enc_region (in) 4274:Returns: 0 on success; -1 on error 4275 4276This ioctl can be used to unregister the guest memory region registered 4277with KVM_MEMORY_ENCRYPT_REG_REGION ioctl above. 4278 42794.113 KVM_HYPERV_EVENTFD 4280------------------------ 4281 4282:Capability: KVM_CAP_HYPERV_EVENTFD 4283:Architectures: x86 4284:Type: vm ioctl 4285:Parameters: struct kvm_hyperv_eventfd (in) 4286 4287This ioctl (un)registers an eventfd to receive notifications from the guest on 4288the specified Hyper-V connection id through the SIGNAL_EVENT hypercall, without 4289causing a user exit. SIGNAL_EVENT hypercall with non-zero event flag number 4290(bits 24-31) still triggers a KVM_EXIT_HYPERV_HCALL user exit. 4291 4292:: 4293 4294 struct kvm_hyperv_eventfd { 4295 __u32 conn_id; 4296 __s32 fd; 4297 __u32 flags; 4298 __u32 padding[3]; 4299 }; 4300 4301The conn_id field should fit within 24 bits:: 4302 4303 #define KVM_HYPERV_CONN_ID_MASK 0x00ffffff 4304 4305The acceptable values for the flags field are:: 4306 4307 #define KVM_HYPERV_EVENTFD_DEASSIGN (1 << 0) 4308 4309:Returns: 0 on success, 4310 -EINVAL if conn_id or flags is outside the allowed range, 4311 -ENOENT on deassign if the conn_id isn't registered, 4312 -EEXIST on assign if the conn_id is already registered 4313 43144.114 KVM_GET_NESTED_STATE 4315-------------------------- 4316 4317:Capability: KVM_CAP_NESTED_STATE 4318:Architectures: x86 4319:Type: vcpu ioctl 4320:Parameters: struct kvm_nested_state (in/out) 4321:Returns: 0 on success, -1 on error 4322 4323Errors: 4324 4325 ===== ============================================================= 4326 E2BIG the total state size exceeds the value of 'size' specified by 4327 the user; the size required will be written into size. 4328 ===== ============================================================= 4329 4330:: 4331 4332 struct kvm_nested_state { 4333 __u16 flags; 4334 __u16 format; 4335 __u32 size; 4336 4337 union { 4338 struct kvm_vmx_nested_state_hdr vmx; 4339 struct kvm_svm_nested_state_hdr svm; 4340 4341 /* Pad the header to 128 bytes. */ 4342 __u8 pad[120]; 4343 } hdr; 4344 4345 union { 4346 struct kvm_vmx_nested_state_data vmx[0]; 4347 struct kvm_svm_nested_state_data svm[0]; 4348 } data; 4349 }; 4350 4351 #define KVM_STATE_NESTED_GUEST_MODE 0x00000001 4352 #define KVM_STATE_NESTED_RUN_PENDING 0x00000002 4353 #define KVM_STATE_NESTED_EVMCS 0x00000004 4354 4355 #define KVM_STATE_NESTED_FORMAT_VMX 0 4356 #define KVM_STATE_NESTED_FORMAT_SVM 1 4357 4358 #define KVM_STATE_NESTED_VMX_VMCS_SIZE 0x1000 4359 4360 #define KVM_STATE_NESTED_VMX_SMM_GUEST_MODE 0x00000001 4361 #define KVM_STATE_NESTED_VMX_SMM_VMXON 0x00000002 4362 4363 #define KVM_STATE_VMX_PREEMPTION_TIMER_DEADLINE 0x00000001 4364 4365 struct kvm_vmx_nested_state_hdr { 4366 __u64 vmxon_pa; 4367 __u64 vmcs12_pa; 4368 4369 struct { 4370 __u16 flags; 4371 } smm; 4372 4373 __u32 flags; 4374 __u64 preemption_timer_deadline; 4375 }; 4376 4377 struct kvm_vmx_nested_state_data { 4378 __u8 vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE]; 4379 __u8 shadow_vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE]; 4380 }; 4381 4382This ioctl copies the vcpu's nested virtualization state from the kernel to 4383userspace. 4384 4385The maximum size of the state can be retrieved by passing KVM_CAP_NESTED_STATE 4386to the KVM_CHECK_EXTENSION ioctl(). 4387 43884.115 KVM_SET_NESTED_STATE 4389-------------------------- 4390 4391:Capability: KVM_CAP_NESTED_STATE 4392:Architectures: x86 4393:Type: vcpu ioctl 4394:Parameters: struct kvm_nested_state (in) 4395:Returns: 0 on success, -1 on error 4396 4397This copies the vcpu's kvm_nested_state struct from userspace to the kernel. 4398For the definition of struct kvm_nested_state, see KVM_GET_NESTED_STATE. 4399 44004.116 KVM_(UN)REGISTER_COALESCED_MMIO 4401------------------------------------- 4402 4403:Capability: KVM_CAP_COALESCED_MMIO (for coalesced mmio) 4404 KVM_CAP_COALESCED_PIO (for coalesced pio) 4405:Architectures: all 4406:Type: vm ioctl 4407:Parameters: struct kvm_coalesced_mmio_zone 4408:Returns: 0 on success, < 0 on error 4409 4410Coalesced I/O is a performance optimization that defers hardware 4411register write emulation so that userspace exits are avoided. It is 4412typically used to reduce the overhead of emulating frequently accessed 4413hardware registers. 4414 4415When a hardware register is configured for coalesced I/O, write accesses 4416do not exit to userspace and their value is recorded in a ring buffer 4417that is shared between kernel and userspace. 4418 4419Coalesced I/O is used if one or more write accesses to a hardware 4420register can be deferred until a read or a write to another hardware 4421register on the same device. This last access will cause a vmexit and 4422userspace will process accesses from the ring buffer before emulating 4423it. That will avoid exiting to userspace on repeated writes. 4424 4425Coalesced pio is based on coalesced mmio. There is little difference 4426between coalesced mmio and pio except that coalesced pio records accesses 4427to I/O ports. 4428 44294.117 KVM_CLEAR_DIRTY_LOG (vm ioctl) 4430------------------------------------ 4431 4432:Capability: KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 4433:Architectures: x86, arm, arm64, mips 4434:Type: vm ioctl 4435:Parameters: struct kvm_dirty_log (in) 4436:Returns: 0 on success, -1 on error 4437 4438:: 4439 4440 /* for KVM_CLEAR_DIRTY_LOG */ 4441 struct kvm_clear_dirty_log { 4442 __u32 slot; 4443 __u32 num_pages; 4444 __u64 first_page; 4445 union { 4446 void __user *dirty_bitmap; /* one bit per page */ 4447 __u64 padding; 4448 }; 4449 }; 4450 4451The ioctl clears the dirty status of pages in a memory slot, according to 4452the bitmap that is passed in struct kvm_clear_dirty_log's dirty_bitmap 4453field. Bit 0 of the bitmap corresponds to page "first_page" in the 4454memory slot, and num_pages is the size in bits of the input bitmap. 4455first_page must be a multiple of 64; num_pages must also be a multiple of 445664 unless first_page + num_pages is the size of the memory slot. For each 4457bit that is set in the input bitmap, the corresponding page is marked "clean" 4458in KVM's dirty bitmap, and dirty tracking is re-enabled for that page 4459(for example via write-protection, or by clearing the dirty bit in 4460a page table entry). 4461 4462If KVM_CAP_MULTI_ADDRESS_SPACE is available, bits 16-31 specifies 4463the address space for which you want to return the dirty bitmap. 4464They must be less than the value that KVM_CHECK_EXTENSION returns for 4465the KVM_CAP_MULTI_ADDRESS_SPACE capability. 4466 4467This ioctl is mostly useful when KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 4468is enabled; for more information, see the description of the capability. 4469However, it can always be used as long as KVM_CHECK_EXTENSION confirms 4470that KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 is present. 4471 44724.118 KVM_GET_SUPPORTED_HV_CPUID 4473-------------------------------- 4474 4475:Capability: KVM_CAP_HYPERV_CPUID (vcpu), KVM_CAP_SYS_HYPERV_CPUID (system) 4476:Architectures: x86 4477:Type: system ioctl, vcpu ioctl 4478:Parameters: struct kvm_cpuid2 (in/out) 4479:Returns: 0 on success, -1 on error 4480 4481:: 4482 4483 struct kvm_cpuid2 { 4484 __u32 nent; 4485 __u32 padding; 4486 struct kvm_cpuid_entry2 entries[0]; 4487 }; 4488 4489 struct kvm_cpuid_entry2 { 4490 __u32 function; 4491 __u32 index; 4492 __u32 flags; 4493 __u32 eax; 4494 __u32 ebx; 4495 __u32 ecx; 4496 __u32 edx; 4497 __u32 padding[3]; 4498 }; 4499 4500This ioctl returns x86 cpuid features leaves related to Hyper-V emulation in 4501KVM. Userspace can use the information returned by this ioctl to construct 4502cpuid information presented to guests consuming Hyper-V enlightenments (e.g. 4503Windows or Hyper-V guests). 4504 4505CPUID feature leaves returned by this ioctl are defined by Hyper-V Top Level 4506Functional Specification (TLFS). These leaves can't be obtained with 4507KVM_GET_SUPPORTED_CPUID ioctl because some of them intersect with KVM feature 4508leaves (0x40000000, 0x40000001). 4509 4510Currently, the following list of CPUID leaves are returned: 4511 - HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS 4512 - HYPERV_CPUID_INTERFACE 4513 - HYPERV_CPUID_VERSION 4514 - HYPERV_CPUID_FEATURES 4515 - HYPERV_CPUID_ENLIGHTMENT_INFO 4516 - HYPERV_CPUID_IMPLEMENT_LIMITS 4517 - HYPERV_CPUID_NESTED_FEATURES 4518 - HYPERV_CPUID_SYNDBG_VENDOR_AND_MAX_FUNCTIONS 4519 - HYPERV_CPUID_SYNDBG_INTERFACE 4520 - HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES 4521 4522Userspace invokes KVM_GET_SUPPORTED_HV_CPUID by passing a kvm_cpuid2 structure 4523with the 'nent' field indicating the number of entries in the variable-size 4524array 'entries'. If the number of entries is too low to describe all Hyper-V 4525feature leaves, an error (E2BIG) is returned. If the number is more or equal 4526to the number of Hyper-V feature leaves, the 'nent' field is adjusted to the 4527number of valid entries in the 'entries' array, which is then filled. 4528 4529'index' and 'flags' fields in 'struct kvm_cpuid_entry2' are currently reserved, 4530userspace should not expect to get any particular value there. 4531 4532Note, vcpu version of KVM_GET_SUPPORTED_HV_CPUID is currently deprecated. Unlike 4533system ioctl which exposes all supported feature bits unconditionally, vcpu 4534version has the following quirks: 4535- HYPERV_CPUID_NESTED_FEATURES leaf and HV_X64_ENLIGHTENED_VMCS_RECOMMENDED 4536 feature bit are only exposed when Enlightened VMCS was previously enabled 4537 on the corresponding vCPU (KVM_CAP_HYPERV_ENLIGHTENED_VMCS). 4538- HV_STIMER_DIRECT_MODE_AVAILABLE bit is only exposed with in-kernel LAPIC. 4539 (presumes KVM_CREATE_IRQCHIP has already been called). 4540 45414.119 KVM_ARM_VCPU_FINALIZE 4542--------------------------- 4543 4544:Architectures: arm, arm64 4545:Type: vcpu ioctl 4546:Parameters: int feature (in) 4547:Returns: 0 on success, -1 on error 4548 4549Errors: 4550 4551 ====== ============================================================== 4552 EPERM feature not enabled, needs configuration, or already finalized 4553 EINVAL feature unknown or not present 4554 ====== ============================================================== 4555 4556Recognised values for feature: 4557 4558 ===== =========================================== 4559 arm64 KVM_ARM_VCPU_SVE (requires KVM_CAP_ARM_SVE) 4560 ===== =========================================== 4561 4562Finalizes the configuration of the specified vcpu feature. 4563 4564The vcpu must already have been initialised, enabling the affected feature, by 4565means of a successful KVM_ARM_VCPU_INIT call with the appropriate flag set in 4566features[]. 4567 4568For affected vcpu features, this is a mandatory step that must be performed 4569before the vcpu is fully usable. 4570 4571Between KVM_ARM_VCPU_INIT and KVM_ARM_VCPU_FINALIZE, the feature may be 4572configured by use of ioctls such as KVM_SET_ONE_REG. The exact configuration 4573that should be performaned and how to do it are feature-dependent. 4574 4575Other calls that depend on a particular feature being finalized, such as 4576KVM_RUN, KVM_GET_REG_LIST, KVM_GET_ONE_REG and KVM_SET_ONE_REG, will fail with 4577-EPERM unless the feature has already been finalized by means of a 4578KVM_ARM_VCPU_FINALIZE call. 4579 4580See KVM_ARM_VCPU_INIT for details of vcpu features that require finalization 4581using this ioctl. 4582 45834.120 KVM_SET_PMU_EVENT_FILTER 4584------------------------------ 4585 4586:Capability: KVM_CAP_PMU_EVENT_FILTER 4587:Architectures: x86 4588:Type: vm ioctl 4589:Parameters: struct kvm_pmu_event_filter (in) 4590:Returns: 0 on success, -1 on error 4591 4592:: 4593 4594 struct kvm_pmu_event_filter { 4595 __u32 action; 4596 __u32 nevents; 4597 __u32 fixed_counter_bitmap; 4598 __u32 flags; 4599 __u32 pad[4]; 4600 __u64 events[0]; 4601 }; 4602 4603This ioctl restricts the set of PMU events that the guest can program. 4604The argument holds a list of events which will be allowed or denied. 4605The eventsel+umask of each event the guest attempts to program is compared 4606against the events field to determine whether the guest should have access. 4607The events field only controls general purpose counters; fixed purpose 4608counters are controlled by the fixed_counter_bitmap. 4609 4610No flags are defined yet, the field must be zero. 4611 4612Valid values for 'action':: 4613 4614 #define KVM_PMU_EVENT_ALLOW 0 4615 #define KVM_PMU_EVENT_DENY 1 4616 46174.121 KVM_PPC_SVM_OFF 4618--------------------- 4619 4620:Capability: basic 4621:Architectures: powerpc 4622:Type: vm ioctl 4623:Parameters: none 4624:Returns: 0 on successful completion, 4625 4626Errors: 4627 4628 ====== ================================================================ 4629 EINVAL if ultravisor failed to terminate the secure guest 4630 ENOMEM if hypervisor failed to allocate new radix page tables for guest 4631 ====== ================================================================ 4632 4633This ioctl is used to turn off the secure mode of the guest or transition 4634the guest from secure mode to normal mode. This is invoked when the guest 4635is reset. This has no effect if called for a normal guest. 4636 4637This ioctl issues an ultravisor call to terminate the secure guest, 4638unpins the VPA pages and releases all the device pages that are used to 4639track the secure pages by hypervisor. 4640 46414.122 KVM_S390_NORMAL_RESET 4642--------------------------- 4643 4644:Capability: KVM_CAP_S390_VCPU_RESETS 4645:Architectures: s390 4646:Type: vcpu ioctl 4647:Parameters: none 4648:Returns: 0 4649 4650This ioctl resets VCPU registers and control structures according to 4651the cpu reset definition in the POP (Principles Of Operation). 4652 46534.123 KVM_S390_INITIAL_RESET 4654---------------------------- 4655 4656:Capability: none 4657:Architectures: s390 4658:Type: vcpu ioctl 4659:Parameters: none 4660:Returns: 0 4661 4662This ioctl resets VCPU registers and control structures according to 4663the initial cpu reset definition in the POP. However, the cpu is not 4664put into ESA mode. This reset is a superset of the normal reset. 4665 46664.124 KVM_S390_CLEAR_RESET 4667-------------------------- 4668 4669:Capability: KVM_CAP_S390_VCPU_RESETS 4670:Architectures: s390 4671:Type: vcpu ioctl 4672:Parameters: none 4673:Returns: 0 4674 4675This ioctl resets VCPU registers and control structures according to 4676the clear cpu reset definition in the POP. However, the cpu is not put 4677into ESA mode. This reset is a superset of the initial reset. 4678 4679 46804.125 KVM_S390_PV_COMMAND 4681------------------------- 4682 4683:Capability: KVM_CAP_S390_PROTECTED 4684:Architectures: s390 4685:Type: vm ioctl 4686:Parameters: struct kvm_pv_cmd 4687:Returns: 0 on success, < 0 on error 4688 4689:: 4690 4691 struct kvm_pv_cmd { 4692 __u32 cmd; /* Command to be executed */ 4693 __u16 rc; /* Ultravisor return code */ 4694 __u16 rrc; /* Ultravisor return reason code */ 4695 __u64 data; /* Data or address */ 4696 __u32 flags; /* flags for future extensions. Must be 0 for now */ 4697 __u32 reserved[3]; 4698 }; 4699 4700cmd values: 4701 4702KVM_PV_ENABLE 4703 Allocate memory and register the VM with the Ultravisor, thereby 4704 donating memory to the Ultravisor that will become inaccessible to 4705 KVM. All existing CPUs are converted to protected ones. After this 4706 command has succeeded, any CPU added via hotplug will become 4707 protected during its creation as well. 4708 4709 Errors: 4710 4711 ===== ============================= 4712 EINTR an unmasked signal is pending 4713 ===== ============================= 4714 4715KVM_PV_DISABLE 4716 4717 Deregister the VM from the Ultravisor and reclaim the memory that 4718 had been donated to the Ultravisor, making it usable by the kernel 4719 again. All registered VCPUs are converted back to non-protected 4720 ones. 4721 4722KVM_PV_VM_SET_SEC_PARMS 4723 Pass the image header from VM memory to the Ultravisor in 4724 preparation of image unpacking and verification. 4725 4726KVM_PV_VM_UNPACK 4727 Unpack (protect and decrypt) a page of the encrypted boot image. 4728 4729KVM_PV_VM_VERIFY 4730 Verify the integrity of the unpacked image. Only if this succeeds, 4731 KVM is allowed to start protected VCPUs. 4732 47334.126 KVM_X86_SET_MSR_FILTER 4734---------------------------- 4735 4736:Capability: KVM_X86_SET_MSR_FILTER 4737:Architectures: x86 4738:Type: vm ioctl 4739:Parameters: struct kvm_msr_filter 4740:Returns: 0 on success, < 0 on error 4741 4742:: 4743 4744 struct kvm_msr_filter_range { 4745 #define KVM_MSR_FILTER_READ (1 << 0) 4746 #define KVM_MSR_FILTER_WRITE (1 << 1) 4747 __u32 flags; 4748 __u32 nmsrs; /* number of msrs in bitmap */ 4749 __u32 base; /* MSR index the bitmap starts at */ 4750 __u8 *bitmap; /* a 1 bit allows the operations in flags, 0 denies */ 4751 }; 4752 4753 #define KVM_MSR_FILTER_MAX_RANGES 16 4754 struct kvm_msr_filter { 4755 #define KVM_MSR_FILTER_DEFAULT_ALLOW (0 << 0) 4756 #define KVM_MSR_FILTER_DEFAULT_DENY (1 << 0) 4757 __u32 flags; 4758 struct kvm_msr_filter_range ranges[KVM_MSR_FILTER_MAX_RANGES]; 4759 }; 4760 4761flags values for ``struct kvm_msr_filter_range``: 4762 4763``KVM_MSR_FILTER_READ`` 4764 4765 Filter read accesses to MSRs using the given bitmap. A 0 in the bitmap 4766 indicates that a read should immediately fail, while a 1 indicates that 4767 a read for a particular MSR should be handled regardless of the default 4768 filter action. 4769 4770``KVM_MSR_FILTER_WRITE`` 4771 4772 Filter write accesses to MSRs using the given bitmap. A 0 in the bitmap 4773 indicates that a write should immediately fail, while a 1 indicates that 4774 a write for a particular MSR should be handled regardless of the default 4775 filter action. 4776 4777``KVM_MSR_FILTER_READ | KVM_MSR_FILTER_WRITE`` 4778 4779 Filter both read and write accesses to MSRs using the given bitmap. A 0 4780 in the bitmap indicates that both reads and writes should immediately fail, 4781 while a 1 indicates that reads and writes for a particular MSR are not 4782 filtered by this range. 4783 4784flags values for ``struct kvm_msr_filter``: 4785 4786``KVM_MSR_FILTER_DEFAULT_ALLOW`` 4787 4788 If no filter range matches an MSR index that is getting accessed, KVM will 4789 fall back to allowing access to the MSR. 4790 4791``KVM_MSR_FILTER_DEFAULT_DENY`` 4792 4793 If no filter range matches an MSR index that is getting accessed, KVM will 4794 fall back to rejecting access to the MSR. In this mode, all MSRs that should 4795 be processed by KVM need to explicitly be marked as allowed in the bitmaps. 4796 4797This ioctl allows user space to define up to 16 bitmaps of MSR ranges to 4798specify whether a certain MSR access should be explicitly filtered for or not. 4799 4800If this ioctl has never been invoked, MSR accesses are not guarded and the 4801default KVM in-kernel emulation behavior is fully preserved. 4802 4803Calling this ioctl with an empty set of ranges (all nmsrs == 0) disables MSR 4804filtering. In that mode, ``KVM_MSR_FILTER_DEFAULT_DENY`` is invalid and causes 4805an error. 4806 4807As soon as the filtering is in place, every MSR access is processed through 4808the filtering except for accesses to the x2APIC MSRs (from 0x800 to 0x8ff); 4809x2APIC MSRs are always allowed, independent of the ``default_allow`` setting, 4810and their behavior depends on the ``X2APIC_ENABLE`` bit of the APIC base 4811register. 4812 4813If a bit is within one of the defined ranges, read and write accesses are 4814guarded by the bitmap's value for the MSR index if the kind of access 4815is included in the ``struct kvm_msr_filter_range`` flags. If no range 4816cover this particular access, the behavior is determined by the flags 4817field in the kvm_msr_filter struct: ``KVM_MSR_FILTER_DEFAULT_ALLOW`` 4818and ``KVM_MSR_FILTER_DEFAULT_DENY``. 4819 4820Each bitmap range specifies a range of MSRs to potentially allow access on. 4821The range goes from MSR index [base .. base+nmsrs]. The flags field 4822indicates whether reads, writes or both reads and writes are filtered 4823by setting a 1 bit in the bitmap for the corresponding MSR index. 4824 4825If an MSR access is not permitted through the filtering, it generates a 4826#GP inside the guest. When combined with KVM_CAP_X86_USER_SPACE_MSR, that 4827allows user space to deflect and potentially handle various MSR accesses 4828into user space. 4829 4830If a vCPU is in running state while this ioctl is invoked, the vCPU may 4831experience inconsistent filtering behavior on MSR accesses. 4832 4833 48345. The kvm_run structure 4835======================== 4836 4837Application code obtains a pointer to the kvm_run structure by 4838mmap()ing a vcpu fd. From that point, application code can control 4839execution by changing fields in kvm_run prior to calling the KVM_RUN 4840ioctl, and obtain information about the reason KVM_RUN returned by 4841looking up structure members. 4842 4843:: 4844 4845 struct kvm_run { 4846 /* in */ 4847 __u8 request_interrupt_window; 4848 4849Request that KVM_RUN return when it becomes possible to inject external 4850interrupts into the guest. Useful in conjunction with KVM_INTERRUPT. 4851 4852:: 4853 4854 __u8 immediate_exit; 4855 4856This field is polled once when KVM_RUN starts; if non-zero, KVM_RUN 4857exits immediately, returning -EINTR. In the common scenario where a 4858signal is used to "kick" a VCPU out of KVM_RUN, this field can be used 4859to avoid usage of KVM_SET_SIGNAL_MASK, which has worse scalability. 4860Rather than blocking the signal outside KVM_RUN, userspace can set up 4861a signal handler that sets run->immediate_exit to a non-zero value. 4862 4863This field is ignored if KVM_CAP_IMMEDIATE_EXIT is not available. 4864 4865:: 4866 4867 __u8 padding1[6]; 4868 4869 /* out */ 4870 __u32 exit_reason; 4871 4872When KVM_RUN has returned successfully (return value 0), this informs 4873application code why KVM_RUN has returned. Allowable values for this 4874field are detailed below. 4875 4876:: 4877 4878 __u8 ready_for_interrupt_injection; 4879 4880If request_interrupt_window has been specified, this field indicates 4881an interrupt can be injected now with KVM_INTERRUPT. 4882 4883:: 4884 4885 __u8 if_flag; 4886 4887The value of the current interrupt flag. Only valid if in-kernel 4888local APIC is not used. 4889 4890:: 4891 4892 __u16 flags; 4893 4894More architecture-specific flags detailing state of the VCPU that may 4895affect the device's behavior. The only currently defined flag is 4896KVM_RUN_X86_SMM, which is valid on x86 machines and is set if the 4897VCPU is in system management mode. 4898 4899:: 4900 4901 /* in (pre_kvm_run), out (post_kvm_run) */ 4902 __u64 cr8; 4903 4904The value of the cr8 register. Only valid if in-kernel local APIC is 4905not used. Both input and output. 4906 4907:: 4908 4909 __u64 apic_base; 4910 4911The value of the APIC BASE msr. Only valid if in-kernel local 4912APIC is not used. Both input and output. 4913 4914:: 4915 4916 union { 4917 /* KVM_EXIT_UNKNOWN */ 4918 struct { 4919 __u64 hardware_exit_reason; 4920 } hw; 4921 4922If exit_reason is KVM_EXIT_UNKNOWN, the vcpu has exited due to unknown 4923reasons. Further architecture-specific information is available in 4924hardware_exit_reason. 4925 4926:: 4927 4928 /* KVM_EXIT_FAIL_ENTRY */ 4929 struct { 4930 __u64 hardware_entry_failure_reason; 4931 __u32 cpu; /* if KVM_LAST_CPU */ 4932 } fail_entry; 4933 4934If exit_reason is KVM_EXIT_FAIL_ENTRY, the vcpu could not be run due 4935to unknown reasons. Further architecture-specific information is 4936available in hardware_entry_failure_reason. 4937 4938:: 4939 4940 /* KVM_EXIT_EXCEPTION */ 4941 struct { 4942 __u32 exception; 4943 __u32 error_code; 4944 } ex; 4945 4946Unused. 4947 4948:: 4949 4950 /* KVM_EXIT_IO */ 4951 struct { 4952 #define KVM_EXIT_IO_IN 0 4953 #define KVM_EXIT_IO_OUT 1 4954 __u8 direction; 4955 __u8 size; /* bytes */ 4956 __u16 port; 4957 __u32 count; 4958 __u64 data_offset; /* relative to kvm_run start */ 4959 } io; 4960 4961If exit_reason is KVM_EXIT_IO, then the vcpu has 4962executed a port I/O instruction which could not be satisfied by kvm. 4963data_offset describes where the data is located (KVM_EXIT_IO_OUT) or 4964where kvm expects application code to place the data for the next 4965KVM_RUN invocation (KVM_EXIT_IO_IN). Data format is a packed array. 4966 4967:: 4968 4969 /* KVM_EXIT_DEBUG */ 4970 struct { 4971 struct kvm_debug_exit_arch arch; 4972 } debug; 4973 4974If the exit_reason is KVM_EXIT_DEBUG, then a vcpu is processing a debug event 4975for which architecture specific information is returned. 4976 4977:: 4978 4979 /* KVM_EXIT_MMIO */ 4980 struct { 4981 __u64 phys_addr; 4982 __u8 data[8]; 4983 __u32 len; 4984 __u8 is_write; 4985 } mmio; 4986 4987If exit_reason is KVM_EXIT_MMIO, then the vcpu has 4988executed a memory-mapped I/O instruction which could not be satisfied 4989by kvm. The 'data' member contains the written data if 'is_write' is 4990true, and should be filled by application code otherwise. 4991 4992The 'data' member contains, in its first 'len' bytes, the value as it would 4993appear if the VCPU performed a load or store of the appropriate width directly 4994to the byte array. 4995 4996.. note:: 4997 4998 For KVM_EXIT_IO, KVM_EXIT_MMIO, KVM_EXIT_OSI, KVM_EXIT_PAPR, 4999 KVM_EXIT_EPR, KVM_EXIT_X86_RDMSR and KVM_EXIT_X86_WRMSR the corresponding 5000 operations are complete (and guest state is consistent) only after userspace 5001 has re-entered the kernel with KVM_RUN. The kernel side will first finish 5002 incomplete operations and then check for pending signals. Userspace 5003 can re-enter the guest with an unmasked signal pending to complete 5004 pending operations. 5005 5006:: 5007 5008 /* KVM_EXIT_HYPERCALL */ 5009 struct { 5010 __u64 nr; 5011 __u64 args[6]; 5012 __u64 ret; 5013 __u32 longmode; 5014 __u32 pad; 5015 } hypercall; 5016 5017Unused. This was once used for 'hypercall to userspace'. To implement 5018such functionality, use KVM_EXIT_IO (x86) or KVM_EXIT_MMIO (all except s390). 5019 5020.. note:: KVM_EXIT_IO is significantly faster than KVM_EXIT_MMIO. 5021 5022:: 5023 5024 /* KVM_EXIT_TPR_ACCESS */ 5025 struct { 5026 __u64 rip; 5027 __u32 is_write; 5028 __u32 pad; 5029 } tpr_access; 5030 5031To be documented (KVM_TPR_ACCESS_REPORTING). 5032 5033:: 5034 5035 /* KVM_EXIT_S390_SIEIC */ 5036 struct { 5037 __u8 icptcode; 5038 __u64 mask; /* psw upper half */ 5039 __u64 addr; /* psw lower half */ 5040 __u16 ipa; 5041 __u32 ipb; 5042 } s390_sieic; 5043 5044s390 specific. 5045 5046:: 5047 5048 /* KVM_EXIT_S390_RESET */ 5049 #define KVM_S390_RESET_POR 1 5050 #define KVM_S390_RESET_CLEAR 2 5051 #define KVM_S390_RESET_SUBSYSTEM 4 5052 #define KVM_S390_RESET_CPU_INIT 8 5053 #define KVM_S390_RESET_IPL 16 5054 __u64 s390_reset_flags; 5055 5056s390 specific. 5057 5058:: 5059 5060 /* KVM_EXIT_S390_UCONTROL */ 5061 struct { 5062 __u64 trans_exc_code; 5063 __u32 pgm_code; 5064 } s390_ucontrol; 5065 5066s390 specific. A page fault has occurred for a user controlled virtual 5067machine (KVM_VM_S390_UNCONTROL) on it's host page table that cannot be 5068resolved by the kernel. 5069The program code and the translation exception code that were placed 5070in the cpu's lowcore are presented here as defined by the z Architecture 5071Principles of Operation Book in the Chapter for Dynamic Address Translation 5072(DAT) 5073 5074:: 5075 5076 /* KVM_EXIT_DCR */ 5077 struct { 5078 __u32 dcrn; 5079 __u32 data; 5080 __u8 is_write; 5081 } dcr; 5082 5083Deprecated - was used for 440 KVM. 5084 5085:: 5086 5087 /* KVM_EXIT_OSI */ 5088 struct { 5089 __u64 gprs[32]; 5090 } osi; 5091 5092MOL uses a special hypercall interface it calls 'OSI'. To enable it, we catch 5093hypercalls and exit with this exit struct that contains all the guest gprs. 5094 5095If exit_reason is KVM_EXIT_OSI, then the vcpu has triggered such a hypercall. 5096Userspace can now handle the hypercall and when it's done modify the gprs as 5097necessary. Upon guest entry all guest GPRs will then be replaced by the values 5098in this struct. 5099 5100:: 5101 5102 /* KVM_EXIT_PAPR_HCALL */ 5103 struct { 5104 __u64 nr; 5105 __u64 ret; 5106 __u64 args[9]; 5107 } papr_hcall; 5108 5109This is used on 64-bit PowerPC when emulating a pSeries partition, 5110e.g. with the 'pseries' machine type in qemu. It occurs when the 5111guest does a hypercall using the 'sc 1' instruction. The 'nr' field 5112contains the hypercall number (from the guest R3), and 'args' contains 5113the arguments (from the guest R4 - R12). Userspace should put the 5114return code in 'ret' and any extra returned values in args[]. 5115The possible hypercalls are defined in the Power Architecture Platform 5116Requirements (PAPR) document available from www.power.org (free 5117developer registration required to access it). 5118 5119:: 5120 5121 /* KVM_EXIT_S390_TSCH */ 5122 struct { 5123 __u16 subchannel_id; 5124 __u16 subchannel_nr; 5125 __u32 io_int_parm; 5126 __u32 io_int_word; 5127 __u32 ipb; 5128 __u8 dequeued; 5129 } s390_tsch; 5130 5131s390 specific. This exit occurs when KVM_CAP_S390_CSS_SUPPORT has been enabled 5132and TEST SUBCHANNEL was intercepted. If dequeued is set, a pending I/O 5133interrupt for the target subchannel has been dequeued and subchannel_id, 5134subchannel_nr, io_int_parm and io_int_word contain the parameters for that 5135interrupt. ipb is needed for instruction parameter decoding. 5136 5137:: 5138 5139 /* KVM_EXIT_EPR */ 5140 struct { 5141 __u32 epr; 5142 } epr; 5143 5144On FSL BookE PowerPC chips, the interrupt controller has a fast patch 5145interrupt acknowledge path to the core. When the core successfully 5146delivers an interrupt, it automatically populates the EPR register with 5147the interrupt vector number and acknowledges the interrupt inside 5148the interrupt controller. 5149 5150In case the interrupt controller lives in user space, we need to do 5151the interrupt acknowledge cycle through it to fetch the next to be 5152delivered interrupt vector using this exit. 5153 5154It gets triggered whenever both KVM_CAP_PPC_EPR are enabled and an 5155external interrupt has just been delivered into the guest. User space 5156should put the acknowledged interrupt vector into the 'epr' field. 5157 5158:: 5159 5160 /* KVM_EXIT_SYSTEM_EVENT */ 5161 struct { 5162 #define KVM_SYSTEM_EVENT_SHUTDOWN 1 5163 #define KVM_SYSTEM_EVENT_RESET 2 5164 #define KVM_SYSTEM_EVENT_CRASH 3 5165 __u32 type; 5166 __u64 flags; 5167 } system_event; 5168 5169If exit_reason is KVM_EXIT_SYSTEM_EVENT then the vcpu has triggered 5170a system-level event using some architecture specific mechanism (hypercall 5171or some special instruction). In case of ARM/ARM64, this is triggered using 5172HVC instruction based PSCI call from the vcpu. The 'type' field describes 5173the system-level event type. The 'flags' field describes architecture 5174specific flags for the system-level event. 5175 5176Valid values for 'type' are: 5177 5178 - KVM_SYSTEM_EVENT_SHUTDOWN -- the guest has requested a shutdown of the 5179 VM. Userspace is not obliged to honour this, and if it does honour 5180 this does not need to destroy the VM synchronously (ie it may call 5181 KVM_RUN again before shutdown finally occurs). 5182 - KVM_SYSTEM_EVENT_RESET -- the guest has requested a reset of the VM. 5183 As with SHUTDOWN, userspace can choose to ignore the request, or 5184 to schedule the reset to occur in the future and may call KVM_RUN again. 5185 - KVM_SYSTEM_EVENT_CRASH -- the guest crash occurred and the guest 5186 has requested a crash condition maintenance. Userspace can choose 5187 to ignore the request, or to gather VM memory core dump and/or 5188 reset/shutdown of the VM. 5189 5190:: 5191 5192 /* KVM_EXIT_IOAPIC_EOI */ 5193 struct { 5194 __u8 vector; 5195 } eoi; 5196 5197Indicates that the VCPU's in-kernel local APIC received an EOI for a 5198level-triggered IOAPIC interrupt. This exit only triggers when the 5199IOAPIC is implemented in userspace (i.e. KVM_CAP_SPLIT_IRQCHIP is enabled); 5200the userspace IOAPIC should process the EOI and retrigger the interrupt if 5201it is still asserted. Vector is the LAPIC interrupt vector for which the 5202EOI was received. 5203 5204:: 5205 5206 struct kvm_hyperv_exit { 5207 #define KVM_EXIT_HYPERV_SYNIC 1 5208 #define KVM_EXIT_HYPERV_HCALL 2 5209 #define KVM_EXIT_HYPERV_SYNDBG 3 5210 __u32 type; 5211 __u32 pad1; 5212 union { 5213 struct { 5214 __u32 msr; 5215 __u32 pad2; 5216 __u64 control; 5217 __u64 evt_page; 5218 __u64 msg_page; 5219 } synic; 5220 struct { 5221 __u64 input; 5222 __u64 result; 5223 __u64 params[2]; 5224 } hcall; 5225 struct { 5226 __u32 msr; 5227 __u32 pad2; 5228 __u64 control; 5229 __u64 status; 5230 __u64 send_page; 5231 __u64 recv_page; 5232 __u64 pending_page; 5233 } syndbg; 5234 } u; 5235 }; 5236 /* KVM_EXIT_HYPERV */ 5237 struct kvm_hyperv_exit hyperv; 5238 5239Indicates that the VCPU exits into userspace to process some tasks 5240related to Hyper-V emulation. 5241 5242Valid values for 'type' are: 5243 5244 - KVM_EXIT_HYPERV_SYNIC -- synchronously notify user-space about 5245 5246Hyper-V SynIC state change. Notification is used to remap SynIC 5247event/message pages and to enable/disable SynIC messages/events processing 5248in userspace. 5249 5250 - KVM_EXIT_HYPERV_SYNDBG -- synchronously notify user-space about 5251 5252Hyper-V Synthetic debugger state change. Notification is used to either update 5253the pending_page location or to send a control command (send the buffer located 5254in send_page or recv a buffer to recv_page). 5255 5256:: 5257 5258 /* KVM_EXIT_ARM_NISV */ 5259 struct { 5260 __u64 esr_iss; 5261 __u64 fault_ipa; 5262 } arm_nisv; 5263 5264Used on arm and arm64 systems. If a guest accesses memory not in a memslot, 5265KVM will typically return to userspace and ask it to do MMIO emulation on its 5266behalf. However, for certain classes of instructions, no instruction decode 5267(direction, length of memory access) is provided, and fetching and decoding 5268the instruction from the VM is overly complicated to live in the kernel. 5269 5270Historically, when this situation occurred, KVM would print a warning and kill 5271the VM. KVM assumed that if the guest accessed non-memslot memory, it was 5272trying to do I/O, which just couldn't be emulated, and the warning message was 5273phrased accordingly. However, what happened more often was that a guest bug 5274caused access outside the guest memory areas which should lead to a more 5275meaningful warning message and an external abort in the guest, if the access 5276did not fall within an I/O window. 5277 5278Userspace implementations can query for KVM_CAP_ARM_NISV_TO_USER, and enable 5279this capability at VM creation. Once this is done, these types of errors will 5280instead return to userspace with KVM_EXIT_ARM_NISV, with the valid bits from 5281the HSR (arm) and ESR_EL2 (arm64) in the esr_iss field, and the faulting IPA 5282in the fault_ipa field. Userspace can either fix up the access if it's 5283actually an I/O access by decoding the instruction from guest memory (if it's 5284very brave) and continue executing the guest, or it can decide to suspend, 5285dump, or restart the guest. 5286 5287Note that KVM does not skip the faulting instruction as it does for 5288KVM_EXIT_MMIO, but userspace has to emulate any change to the processing state 5289if it decides to decode and emulate the instruction. 5290 5291:: 5292 5293 /* KVM_EXIT_X86_RDMSR / KVM_EXIT_X86_WRMSR */ 5294 struct { 5295 __u8 error; /* user -> kernel */ 5296 __u8 pad[7]; 5297 __u32 reason; /* kernel -> user */ 5298 __u32 index; /* kernel -> user */ 5299 __u64 data; /* kernel <-> user */ 5300 } msr; 5301 5302Used on x86 systems. When the VM capability KVM_CAP_X86_USER_SPACE_MSR is 5303enabled, MSR accesses to registers that would invoke a #GP by KVM kernel code 5304will instead trigger a KVM_EXIT_X86_RDMSR exit for reads and KVM_EXIT_X86_WRMSR 5305exit for writes. 5306 5307The "reason" field specifies why the MSR trap occurred. User space will only 5308receive MSR exit traps when a particular reason was requested during through 5309ENABLE_CAP. Currently valid exit reasons are: 5310 5311 KVM_MSR_EXIT_REASON_UNKNOWN - access to MSR that is unknown to KVM 5312 KVM_MSR_EXIT_REASON_INVAL - access to invalid MSRs or reserved bits 5313 KVM_MSR_EXIT_REASON_FILTER - access blocked by KVM_X86_SET_MSR_FILTER 5314 5315For KVM_EXIT_X86_RDMSR, the "index" field tells user space which MSR the guest 5316wants to read. To respond to this request with a successful read, user space 5317writes the respective data into the "data" field and must continue guest 5318execution to ensure the read data is transferred into guest register state. 5319 5320If the RDMSR request was unsuccessful, user space indicates that with a "1" in 5321the "error" field. This will inject a #GP into the guest when the VCPU is 5322executed again. 5323 5324For KVM_EXIT_X86_WRMSR, the "index" field tells user space which MSR the guest 5325wants to write. Once finished processing the event, user space must continue 5326vCPU execution. If the MSR write was unsuccessful, user space also sets the 5327"error" field to "1". 5328 5329:: 5330 5331 /* Fix the size of the union. */ 5332 char padding[256]; 5333 }; 5334 5335 /* 5336 * shared registers between kvm and userspace. 5337 * kvm_valid_regs specifies the register classes set by the host 5338 * kvm_dirty_regs specified the register classes dirtied by userspace 5339 * struct kvm_sync_regs is architecture specific, as well as the 5340 * bits for kvm_valid_regs and kvm_dirty_regs 5341 */ 5342 __u64 kvm_valid_regs; 5343 __u64 kvm_dirty_regs; 5344 union { 5345 struct kvm_sync_regs regs; 5346 char padding[SYNC_REGS_SIZE_BYTES]; 5347 } s; 5348 5349If KVM_CAP_SYNC_REGS is defined, these fields allow userspace to access 5350certain guest registers without having to call SET/GET_*REGS. Thus we can 5351avoid some system call overhead if userspace has to handle the exit. 5352Userspace can query the validity of the structure by checking 5353kvm_valid_regs for specific bits. These bits are architecture specific 5354and usually define the validity of a groups of registers. (e.g. one bit 5355for general purpose registers) 5356 5357Please note that the kernel is allowed to use the kvm_run structure as the 5358primary storage for certain register types. Therefore, the kernel may use the 5359values in kvm_run even if the corresponding bit in kvm_dirty_regs is not set. 5360 5361:: 5362 5363 }; 5364 5365 5366 53676. Capabilities that can be enabled on vCPUs 5368============================================ 5369 5370There are certain capabilities that change the behavior of the virtual CPU or 5371the virtual machine when enabled. To enable them, please see section 4.37. 5372Below you can find a list of capabilities and what their effect on the vCPU or 5373the virtual machine is when enabling them. 5374 5375The following information is provided along with the description: 5376 5377 Architectures: 5378 which instruction set architectures provide this ioctl. 5379 x86 includes both i386 and x86_64. 5380 5381 Target: 5382 whether this is a per-vcpu or per-vm capability. 5383 5384 Parameters: 5385 what parameters are accepted by the capability. 5386 5387 Returns: 5388 the return value. General error numbers (EBADF, ENOMEM, EINVAL) 5389 are not detailed, but errors with specific meanings are. 5390 5391 53926.1 KVM_CAP_PPC_OSI 5393------------------- 5394 5395:Architectures: ppc 5396:Target: vcpu 5397:Parameters: none 5398:Returns: 0 on success; -1 on error 5399 5400This capability enables interception of OSI hypercalls that otherwise would 5401be treated as normal system calls to be injected into the guest. OSI hypercalls 5402were invented by Mac-on-Linux to have a standardized communication mechanism 5403between the guest and the host. 5404 5405When this capability is enabled, KVM_EXIT_OSI can occur. 5406 5407 54086.2 KVM_CAP_PPC_PAPR 5409-------------------- 5410 5411:Architectures: ppc 5412:Target: vcpu 5413:Parameters: none 5414:Returns: 0 on success; -1 on error 5415 5416This capability enables interception of PAPR hypercalls. PAPR hypercalls are 5417done using the hypercall instruction "sc 1". 5418 5419It also sets the guest privilege level to "supervisor" mode. Usually the guest 5420runs in "hypervisor" privilege mode with a few missing features. 5421 5422In addition to the above, it changes the semantics of SDR1. In this mode, the 5423HTAB address part of SDR1 contains an HVA instead of a GPA, as PAPR keeps the 5424HTAB invisible to the guest. 5425 5426When this capability is enabled, KVM_EXIT_PAPR_HCALL can occur. 5427 5428 54296.3 KVM_CAP_SW_TLB 5430------------------ 5431 5432:Architectures: ppc 5433:Target: vcpu 5434:Parameters: args[0] is the address of a struct kvm_config_tlb 5435:Returns: 0 on success; -1 on error 5436 5437:: 5438 5439 struct kvm_config_tlb { 5440 __u64 params; 5441 __u64 array; 5442 __u32 mmu_type; 5443 __u32 array_len; 5444 }; 5445 5446Configures the virtual CPU's TLB array, establishing a shared memory area 5447between userspace and KVM. The "params" and "array" fields are userspace 5448addresses of mmu-type-specific data structures. The "array_len" field is an 5449safety mechanism, and should be set to the size in bytes of the memory that 5450userspace has reserved for the array. It must be at least the size dictated 5451by "mmu_type" and "params". 5452 5453While KVM_RUN is active, the shared region is under control of KVM. Its 5454contents are undefined, and any modification by userspace results in 5455boundedly undefined behavior. 5456 5457On return from KVM_RUN, the shared region will reflect the current state of 5458the guest's TLB. If userspace makes any changes, it must call KVM_DIRTY_TLB 5459to tell KVM which entries have been changed, prior to calling KVM_RUN again 5460on this vcpu. 5461 5462For mmu types KVM_MMU_FSL_BOOKE_NOHV and KVM_MMU_FSL_BOOKE_HV: 5463 5464 - The "params" field is of type "struct kvm_book3e_206_tlb_params". 5465 - The "array" field points to an array of type "struct 5466 kvm_book3e_206_tlb_entry". 5467 - The array consists of all entries in the first TLB, followed by all 5468 entries in the second TLB. 5469 - Within a TLB, entries are ordered first by increasing set number. Within a 5470 set, entries are ordered by way (increasing ESEL). 5471 - The hash for determining set number in TLB0 is: (MAS2 >> 12) & (num_sets - 1) 5472 where "num_sets" is the tlb_sizes[] value divided by the tlb_ways[] value. 5473 - The tsize field of mas1 shall be set to 4K on TLB0, even though the 5474 hardware ignores this value for TLB0. 5475 54766.4 KVM_CAP_S390_CSS_SUPPORT 5477---------------------------- 5478 5479:Architectures: s390 5480:Target: vcpu 5481:Parameters: none 5482:Returns: 0 on success; -1 on error 5483 5484This capability enables support for handling of channel I/O instructions. 5485 5486TEST PENDING INTERRUPTION and the interrupt portion of TEST SUBCHANNEL are 5487handled in-kernel, while the other I/O instructions are passed to userspace. 5488 5489When this capability is enabled, KVM_EXIT_S390_TSCH will occur on TEST 5490SUBCHANNEL intercepts. 5491 5492Note that even though this capability is enabled per-vcpu, the complete 5493virtual machine is affected. 5494 54956.5 KVM_CAP_PPC_EPR 5496------------------- 5497 5498:Architectures: ppc 5499:Target: vcpu 5500:Parameters: args[0] defines whether the proxy facility is active 5501:Returns: 0 on success; -1 on error 5502 5503This capability enables or disables the delivery of interrupts through the 5504external proxy facility. 5505 5506When enabled (args[0] != 0), every time the guest gets an external interrupt 5507delivered, it automatically exits into user space with a KVM_EXIT_EPR exit 5508to receive the topmost interrupt vector. 5509 5510When disabled (args[0] == 0), behavior is as if this facility is unsupported. 5511 5512When this capability is enabled, KVM_EXIT_EPR can occur. 5513 55146.6 KVM_CAP_IRQ_MPIC 5515-------------------- 5516 5517:Architectures: ppc 5518:Parameters: args[0] is the MPIC device fd; 5519 args[1] is the MPIC CPU number for this vcpu 5520 5521This capability connects the vcpu to an in-kernel MPIC device. 5522 55236.7 KVM_CAP_IRQ_XICS 5524-------------------- 5525 5526:Architectures: ppc 5527:Target: vcpu 5528:Parameters: args[0] is the XICS device fd; 5529 args[1] is the XICS CPU number (server ID) for this vcpu 5530 5531This capability connects the vcpu to an in-kernel XICS device. 5532 55336.8 KVM_CAP_S390_IRQCHIP 5534------------------------ 5535 5536:Architectures: s390 5537:Target: vm 5538:Parameters: none 5539 5540This capability enables the in-kernel irqchip for s390. Please refer to 5541"4.24 KVM_CREATE_IRQCHIP" for details. 5542 55436.9 KVM_CAP_MIPS_FPU 5544-------------------- 5545 5546:Architectures: mips 5547:Target: vcpu 5548:Parameters: args[0] is reserved for future use (should be 0). 5549 5550This capability allows the use of the host Floating Point Unit by the guest. It 5551allows the Config1.FP bit to be set to enable the FPU in the guest. Once this is 5552done the ``KVM_REG_MIPS_FPR_*`` and ``KVM_REG_MIPS_FCR_*`` registers can be 5553accessed (depending on the current guest FPU register mode), and the Status.FR, 5554Config5.FRE bits are accessible via the KVM API and also from the guest, 5555depending on them being supported by the FPU. 5556 55576.10 KVM_CAP_MIPS_MSA 5558--------------------- 5559 5560:Architectures: mips 5561:Target: vcpu 5562:Parameters: args[0] is reserved for future use (should be 0). 5563 5564This capability allows the use of the MIPS SIMD Architecture (MSA) by the guest. 5565It allows the Config3.MSAP bit to be set to enable the use of MSA by the guest. 5566Once this is done the ``KVM_REG_MIPS_VEC_*`` and ``KVM_REG_MIPS_MSA_*`` 5567registers can be accessed, and the Config5.MSAEn bit is accessible via the 5568KVM API and also from the guest. 5569 55706.74 KVM_CAP_SYNC_REGS 5571---------------------- 5572 5573:Architectures: s390, x86 5574:Target: s390: always enabled, x86: vcpu 5575:Parameters: none 5576:Returns: x86: KVM_CHECK_EXTENSION returns a bit-array indicating which register 5577 sets are supported 5578 (bitfields defined in arch/x86/include/uapi/asm/kvm.h). 5579 5580As described above in the kvm_sync_regs struct info in section 5 (kvm_run): 5581KVM_CAP_SYNC_REGS "allow[s] userspace to access certain guest registers 5582without having to call SET/GET_*REGS". This reduces overhead by eliminating 5583repeated ioctl calls for setting and/or getting register values. This is 5584particularly important when userspace is making synchronous guest state 5585modifications, e.g. when emulating and/or intercepting instructions in 5586userspace. 5587 5588For s390 specifics, please refer to the source code. 5589 5590For x86: 5591 5592- the register sets to be copied out to kvm_run are selectable 5593 by userspace (rather that all sets being copied out for every exit). 5594- vcpu_events are available in addition to regs and sregs. 5595 5596For x86, the 'kvm_valid_regs' field of struct kvm_run is overloaded to 5597function as an input bit-array field set by userspace to indicate the 5598specific register sets to be copied out on the next exit. 5599 5600To indicate when userspace has modified values that should be copied into 5601the vCPU, the all architecture bitarray field, 'kvm_dirty_regs' must be set. 5602This is done using the same bitflags as for the 'kvm_valid_regs' field. 5603If the dirty bit is not set, then the register set values will not be copied 5604into the vCPU even if they've been modified. 5605 5606Unused bitfields in the bitarrays must be set to zero. 5607 5608:: 5609 5610 struct kvm_sync_regs { 5611 struct kvm_regs regs; 5612 struct kvm_sregs sregs; 5613 struct kvm_vcpu_events events; 5614 }; 5615 56166.75 KVM_CAP_PPC_IRQ_XIVE 5617------------------------- 5618 5619:Architectures: ppc 5620:Target: vcpu 5621:Parameters: args[0] is the XIVE device fd; 5622 args[1] is the XIVE CPU number (server ID) for this vcpu 5623 5624This capability connects the vcpu to an in-kernel XIVE device. 5625 56267. Capabilities that can be enabled on VMs 5627========================================== 5628 5629There are certain capabilities that change the behavior of the virtual 5630machine when enabled. To enable them, please see section 4.37. Below 5631you can find a list of capabilities and what their effect on the VM 5632is when enabling them. 5633 5634The following information is provided along with the description: 5635 5636 Architectures: 5637 which instruction set architectures provide this ioctl. 5638 x86 includes both i386 and x86_64. 5639 5640 Parameters: 5641 what parameters are accepted by the capability. 5642 5643 Returns: 5644 the return value. General error numbers (EBADF, ENOMEM, EINVAL) 5645 are not detailed, but errors with specific meanings are. 5646 5647 56487.1 KVM_CAP_PPC_ENABLE_HCALL 5649---------------------------- 5650 5651:Architectures: ppc 5652:Parameters: args[0] is the sPAPR hcall number; 5653 args[1] is 0 to disable, 1 to enable in-kernel handling 5654 5655This capability controls whether individual sPAPR hypercalls (hcalls) 5656get handled by the kernel or not. Enabling or disabling in-kernel 5657handling of an hcall is effective across the VM. On creation, an 5658initial set of hcalls are enabled for in-kernel handling, which 5659consists of those hcalls for which in-kernel handlers were implemented 5660before this capability was implemented. If disabled, the kernel will 5661not to attempt to handle the hcall, but will always exit to userspace 5662to handle it. Note that it may not make sense to enable some and 5663disable others of a group of related hcalls, but KVM does not prevent 5664userspace from doing that. 5665 5666If the hcall number specified is not one that has an in-kernel 5667implementation, the KVM_ENABLE_CAP ioctl will fail with an EINVAL 5668error. 5669 56707.2 KVM_CAP_S390_USER_SIGP 5671-------------------------- 5672 5673:Architectures: s390 5674:Parameters: none 5675 5676This capability controls which SIGP orders will be handled completely in user 5677space. With this capability enabled, all fast orders will be handled completely 5678in the kernel: 5679 5680- SENSE 5681- SENSE RUNNING 5682- EXTERNAL CALL 5683- EMERGENCY SIGNAL 5684- CONDITIONAL EMERGENCY SIGNAL 5685 5686All other orders will be handled completely in user space. 5687 5688Only privileged operation exceptions will be checked for in the kernel (or even 5689in the hardware prior to interception). If this capability is not enabled, the 5690old way of handling SIGP orders is used (partially in kernel and user space). 5691 56927.3 KVM_CAP_S390_VECTOR_REGISTERS 5693--------------------------------- 5694 5695:Architectures: s390 5696:Parameters: none 5697:Returns: 0 on success, negative value on error 5698 5699Allows use of the vector registers introduced with z13 processor, and 5700provides for the synchronization between host and user space. Will 5701return -EINVAL if the machine does not support vectors. 5702 57037.4 KVM_CAP_S390_USER_STSI 5704-------------------------- 5705 5706:Architectures: s390 5707:Parameters: none 5708 5709This capability allows post-handlers for the STSI instruction. After 5710initial handling in the kernel, KVM exits to user space with 5711KVM_EXIT_S390_STSI to allow user space to insert further data. 5712 5713Before exiting to userspace, kvm handlers should fill in s390_stsi field of 5714vcpu->run:: 5715 5716 struct { 5717 __u64 addr; 5718 __u8 ar; 5719 __u8 reserved; 5720 __u8 fc; 5721 __u8 sel1; 5722 __u16 sel2; 5723 } s390_stsi; 5724 5725 @addr - guest address of STSI SYSIB 5726 @fc - function code 5727 @sel1 - selector 1 5728 @sel2 - selector 2 5729 @ar - access register number 5730 5731KVM handlers should exit to userspace with rc = -EREMOTE. 5732 57337.5 KVM_CAP_SPLIT_IRQCHIP 5734------------------------- 5735 5736:Architectures: x86 5737:Parameters: args[0] - number of routes reserved for userspace IOAPICs 5738:Returns: 0 on success, -1 on error 5739 5740Create a local apic for each processor in the kernel. This can be used 5741instead of KVM_CREATE_IRQCHIP if the userspace VMM wishes to emulate the 5742IOAPIC and PIC (and also the PIT, even though this has to be enabled 5743separately). 5744 5745This capability also enables in kernel routing of interrupt requests; 5746when KVM_CAP_SPLIT_IRQCHIP only routes of KVM_IRQ_ROUTING_MSI type are 5747used in the IRQ routing table. The first args[0] MSI routes are reserved 5748for the IOAPIC pins. Whenever the LAPIC receives an EOI for these routes, 5749a KVM_EXIT_IOAPIC_EOI vmexit will be reported to userspace. 5750 5751Fails if VCPU has already been created, or if the irqchip is already in the 5752kernel (i.e. KVM_CREATE_IRQCHIP has already been called). 5753 57547.6 KVM_CAP_S390_RI 5755------------------- 5756 5757:Architectures: s390 5758:Parameters: none 5759 5760Allows use of runtime-instrumentation introduced with zEC12 processor. 5761Will return -EINVAL if the machine does not support runtime-instrumentation. 5762Will return -EBUSY if a VCPU has already been created. 5763 57647.7 KVM_CAP_X2APIC_API 5765---------------------- 5766 5767:Architectures: x86 5768:Parameters: args[0] - features that should be enabled 5769:Returns: 0 on success, -EINVAL when args[0] contains invalid features 5770 5771Valid feature flags in args[0] are:: 5772 5773 #define KVM_X2APIC_API_USE_32BIT_IDS (1ULL << 0) 5774 #define KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK (1ULL << 1) 5775 5776Enabling KVM_X2APIC_API_USE_32BIT_IDS changes the behavior of 5777KVM_SET_GSI_ROUTING, KVM_SIGNAL_MSI, KVM_SET_LAPIC, and KVM_GET_LAPIC, 5778allowing the use of 32-bit APIC IDs. See KVM_CAP_X2APIC_API in their 5779respective sections. 5780 5781KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK must be enabled for x2APIC to work 5782in logical mode or with more than 255 VCPUs. Otherwise, KVM treats 0xff 5783as a broadcast even in x2APIC mode in order to support physical x2APIC 5784without interrupt remapping. This is undesirable in logical mode, 5785where 0xff represents CPUs 0-7 in cluster 0. 5786 57877.8 KVM_CAP_S390_USER_INSTR0 5788---------------------------- 5789 5790:Architectures: s390 5791:Parameters: none 5792 5793With this capability enabled, all illegal instructions 0x0000 (2 bytes) will 5794be intercepted and forwarded to user space. User space can use this 5795mechanism e.g. to realize 2-byte software breakpoints. The kernel will 5796not inject an operating exception for these instructions, user space has 5797to take care of that. 5798 5799This capability can be enabled dynamically even if VCPUs were already 5800created and are running. 5801 58027.9 KVM_CAP_S390_GS 5803------------------- 5804 5805:Architectures: s390 5806:Parameters: none 5807:Returns: 0 on success; -EINVAL if the machine does not support 5808 guarded storage; -EBUSY if a VCPU has already been created. 5809 5810Allows use of guarded storage for the KVM guest. 5811 58127.10 KVM_CAP_S390_AIS 5813--------------------- 5814 5815:Architectures: s390 5816:Parameters: none 5817 5818Allow use of adapter-interruption suppression. 5819:Returns: 0 on success; -EBUSY if a VCPU has already been created. 5820 58217.11 KVM_CAP_PPC_SMT 5822-------------------- 5823 5824:Architectures: ppc 5825:Parameters: vsmt_mode, flags 5826 5827Enabling this capability on a VM provides userspace with a way to set 5828the desired virtual SMT mode (i.e. the number of virtual CPUs per 5829virtual core). The virtual SMT mode, vsmt_mode, must be a power of 2 5830between 1 and 8. On POWER8, vsmt_mode must also be no greater than 5831the number of threads per subcore for the host. Currently flags must 5832be 0. A successful call to enable this capability will result in 5833vsmt_mode being returned when the KVM_CAP_PPC_SMT capability is 5834subsequently queried for the VM. This capability is only supported by 5835HV KVM, and can only be set before any VCPUs have been created. 5836The KVM_CAP_PPC_SMT_POSSIBLE capability indicates which virtual SMT 5837modes are available. 5838 58397.12 KVM_CAP_PPC_FWNMI 5840---------------------- 5841 5842:Architectures: ppc 5843:Parameters: none 5844 5845With this capability a machine check exception in the guest address 5846space will cause KVM to exit the guest with NMI exit reason. This 5847enables QEMU to build error log and branch to guest kernel registered 5848machine check handling routine. Without this capability KVM will 5849branch to guests' 0x200 interrupt vector. 5850 58517.13 KVM_CAP_X86_DISABLE_EXITS 5852------------------------------ 5853 5854:Architectures: x86 5855:Parameters: args[0] defines which exits are disabled 5856:Returns: 0 on success, -EINVAL when args[0] contains invalid exits 5857 5858Valid bits in args[0] are:: 5859 5860 #define KVM_X86_DISABLE_EXITS_MWAIT (1 << 0) 5861 #define KVM_X86_DISABLE_EXITS_HLT (1 << 1) 5862 #define KVM_X86_DISABLE_EXITS_PAUSE (1 << 2) 5863 #define KVM_X86_DISABLE_EXITS_CSTATE (1 << 3) 5864 5865Enabling this capability on a VM provides userspace with a way to no 5866longer intercept some instructions for improved latency in some 5867workloads, and is suggested when vCPUs are associated to dedicated 5868physical CPUs. More bits can be added in the future; userspace can 5869just pass the KVM_CHECK_EXTENSION result to KVM_ENABLE_CAP to disable 5870all such vmexits. 5871 5872Do not enable KVM_FEATURE_PV_UNHALT if you disable HLT exits. 5873 58747.14 KVM_CAP_S390_HPAGE_1M 5875-------------------------- 5876 5877:Architectures: s390 5878:Parameters: none 5879:Returns: 0 on success, -EINVAL if hpage module parameter was not set 5880 or cmma is enabled, or the VM has the KVM_VM_S390_UCONTROL 5881 flag set 5882 5883With this capability the KVM support for memory backing with 1m pages 5884through hugetlbfs can be enabled for a VM. After the capability is 5885enabled, cmma can't be enabled anymore and pfmfi and the storage key 5886interpretation are disabled. If cmma has already been enabled or the 5887hpage module parameter is not set to 1, -EINVAL is returned. 5888 5889While it is generally possible to create a huge page backed VM without 5890this capability, the VM will not be able to run. 5891 58927.15 KVM_CAP_MSR_PLATFORM_INFO 5893------------------------------ 5894 5895:Architectures: x86 5896:Parameters: args[0] whether feature should be enabled or not 5897 5898With this capability, a guest may read the MSR_PLATFORM_INFO MSR. Otherwise, 5899a #GP would be raised when the guest tries to access. Currently, this 5900capability does not enable write permissions of this MSR for the guest. 5901 59027.16 KVM_CAP_PPC_NESTED_HV 5903-------------------------- 5904 5905:Architectures: ppc 5906:Parameters: none 5907:Returns: 0 on success, -EINVAL when the implementation doesn't support 5908 nested-HV virtualization. 5909 5910HV-KVM on POWER9 and later systems allows for "nested-HV" 5911virtualization, which provides a way for a guest VM to run guests that 5912can run using the CPU's supervisor mode (privileged non-hypervisor 5913state). Enabling this capability on a VM depends on the CPU having 5914the necessary functionality and on the facility being enabled with a 5915kvm-hv module parameter. 5916 59177.17 KVM_CAP_EXCEPTION_PAYLOAD 5918------------------------------ 5919 5920:Architectures: x86 5921:Parameters: args[0] whether feature should be enabled or not 5922 5923With this capability enabled, CR2 will not be modified prior to the 5924emulated VM-exit when L1 intercepts a #PF exception that occurs in 5925L2. Similarly, for kvm-intel only, DR6 will not be modified prior to 5926the emulated VM-exit when L1 intercepts a #DB exception that occurs in 5927L2. As a result, when KVM_GET_VCPU_EVENTS reports a pending #PF (or 5928#DB) exception for L2, exception.has_payload will be set and the 5929faulting address (or the new DR6 bits*) will be reported in the 5930exception_payload field. Similarly, when userspace injects a #PF (or 5931#DB) into L2 using KVM_SET_VCPU_EVENTS, it is expected to set 5932exception.has_payload and to put the faulting address - or the new DR6 5933bits\ [#]_ - in the exception_payload field. 5934 5935This capability also enables exception.pending in struct 5936kvm_vcpu_events, which allows userspace to distinguish between pending 5937and injected exceptions. 5938 5939 5940.. [#] For the new DR6 bits, note that bit 16 is set iff the #DB exception 5941 will clear DR6.RTM. 5942 59437.18 KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 5944 5945:Architectures: x86, arm, arm64, mips 5946:Parameters: args[0] whether feature should be enabled or not 5947 5948Valid flags are:: 5949 5950 #define KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE (1 << 0) 5951 #define KVM_DIRTY_LOG_INITIALLY_SET (1 << 1) 5952 5953With KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE is set, KVM_GET_DIRTY_LOG will not 5954automatically clear and write-protect all pages that are returned as dirty. 5955Rather, userspace will have to do this operation separately using 5956KVM_CLEAR_DIRTY_LOG. 5957 5958At the cost of a slightly more complicated operation, this provides better 5959scalability and responsiveness for two reasons. First, 5960KVM_CLEAR_DIRTY_LOG ioctl can operate on a 64-page granularity rather 5961than requiring to sync a full memslot; this ensures that KVM does not 5962take spinlocks for an extended period of time. Second, in some cases a 5963large amount of time can pass between a call to KVM_GET_DIRTY_LOG and 5964userspace actually using the data in the page. Pages can be modified 5965during this time, which is inefficient for both the guest and userspace: 5966the guest will incur a higher penalty due to write protection faults, 5967while userspace can see false reports of dirty pages. Manual reprotection 5968helps reducing this time, improving guest performance and reducing the 5969number of dirty log false positives. 5970 5971With KVM_DIRTY_LOG_INITIALLY_SET set, all the bits of the dirty bitmap 5972will be initialized to 1 when created. This also improves performance because 5973dirty logging can be enabled gradually in small chunks on the first call 5974to KVM_CLEAR_DIRTY_LOG. KVM_DIRTY_LOG_INITIALLY_SET depends on 5975KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE (it is also only available on 5976x86 and arm64 for now). 5977 5978KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 was previously available under the name 5979KVM_CAP_MANUAL_DIRTY_LOG_PROTECT, but the implementation had bugs that make 5980it hard or impossible to use it correctly. The availability of 5981KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 signals that those bugs are fixed. 5982Userspace should not try to use KVM_CAP_MANUAL_DIRTY_LOG_PROTECT. 5983 59847.19 KVM_CAP_PPC_SECURE_GUEST 5985------------------------------ 5986 5987:Architectures: ppc 5988 5989This capability indicates that KVM is running on a host that has 5990ultravisor firmware and thus can support a secure guest. On such a 5991system, a guest can ask the ultravisor to make it a secure guest, 5992one whose memory is inaccessible to the host except for pages which 5993are explicitly requested to be shared with the host. The ultravisor 5994notifies KVM when a guest requests to become a secure guest, and KVM 5995has the opportunity to veto the transition. 5996 5997If present, this capability can be enabled for a VM, meaning that KVM 5998will allow the transition to secure guest mode. Otherwise KVM will 5999veto the transition. 6000 60017.20 KVM_CAP_HALT_POLL 6002---------------------- 6003 6004:Architectures: all 6005:Target: VM 6006:Parameters: args[0] is the maximum poll time in nanoseconds 6007:Returns: 0 on success; -1 on error 6008 6009This capability overrides the kvm module parameter halt_poll_ns for the 6010target VM. 6011 6012VCPU polling allows a VCPU to poll for wakeup events instead of immediately 6013scheduling during guest halts. The maximum time a VCPU can spend polling is 6014controlled by the kvm module parameter halt_poll_ns. This capability allows 6015the maximum halt time to specified on a per-VM basis, effectively overriding 6016the module parameter for the target VM. 6017 60187.21 KVM_CAP_X86_USER_SPACE_MSR 6019------------------------------- 6020 6021:Architectures: x86 6022:Target: VM 6023:Parameters: args[0] contains the mask of KVM_MSR_EXIT_REASON_* events to report 6024:Returns: 0 on success; -1 on error 6025 6026This capability enables trapping of #GP invoking RDMSR and WRMSR instructions 6027into user space. 6028 6029When a guest requests to read or write an MSR, KVM may not implement all MSRs 6030that are relevant to a respective system. It also does not differentiate by 6031CPU type. 6032 6033To allow more fine grained control over MSR handling, user space may enable 6034this capability. With it enabled, MSR accesses that match the mask specified in 6035args[0] and trigger a #GP event inside the guest by KVM will instead trigger 6036KVM_EXIT_X86_RDMSR and KVM_EXIT_X86_WRMSR exit notifications which user space 6037can then handle to implement model specific MSR handling and/or user notifications 6038to inform a user that an MSR was not handled. 6039 60408. Other capabilities. 6041====================== 6042 6043This section lists capabilities that give information about other 6044features of the KVM implementation. 6045 60468.1 KVM_CAP_PPC_HWRNG 6047--------------------- 6048 6049:Architectures: ppc 6050 6051This capability, if KVM_CHECK_EXTENSION indicates that it is 6052available, means that the kernel has an implementation of the 6053H_RANDOM hypercall backed by a hardware random-number generator. 6054If present, the kernel H_RANDOM handler can be enabled for guest use 6055with the KVM_CAP_PPC_ENABLE_HCALL capability. 6056 60578.2 KVM_CAP_HYPERV_SYNIC 6058------------------------ 6059 6060:Architectures: x86 6061 6062This capability, if KVM_CHECK_EXTENSION indicates that it is 6063available, means that the kernel has an implementation of the 6064Hyper-V Synthetic interrupt controller(SynIC). Hyper-V SynIC is 6065used to support Windows Hyper-V based guest paravirt drivers(VMBus). 6066 6067In order to use SynIC, it has to be activated by setting this 6068capability via KVM_ENABLE_CAP ioctl on the vcpu fd. Note that this 6069will disable the use of APIC hardware virtualization even if supported 6070by the CPU, as it's incompatible with SynIC auto-EOI behavior. 6071 60728.3 KVM_CAP_PPC_RADIX_MMU 6073------------------------- 6074 6075:Architectures: ppc 6076 6077This capability, if KVM_CHECK_EXTENSION indicates that it is 6078available, means that the kernel can support guests using the 6079radix MMU defined in Power ISA V3.00 (as implemented in the POWER9 6080processor). 6081 60828.4 KVM_CAP_PPC_HASH_MMU_V3 6083--------------------------- 6084 6085:Architectures: ppc 6086 6087This capability, if KVM_CHECK_EXTENSION indicates that it is 6088available, means that the kernel can support guests using the 6089hashed page table MMU defined in Power ISA V3.00 (as implemented in 6090the POWER9 processor), including in-memory segment tables. 6091 60928.5 KVM_CAP_MIPS_VZ 6093------------------- 6094 6095:Architectures: mips 6096 6097This capability, if KVM_CHECK_EXTENSION on the main kvm handle indicates that 6098it is available, means that full hardware assisted virtualization capabilities 6099of the hardware are available for use through KVM. An appropriate 6100KVM_VM_MIPS_* type must be passed to KVM_CREATE_VM to create a VM which 6101utilises it. 6102 6103If KVM_CHECK_EXTENSION on a kvm VM handle indicates that this capability is 6104available, it means that the VM is using full hardware assisted virtualization 6105capabilities of the hardware. This is useful to check after creating a VM with 6106KVM_VM_MIPS_DEFAULT. 6107 6108The value returned by KVM_CHECK_EXTENSION should be compared against known 6109values (see below). All other values are reserved. This is to allow for the 6110possibility of other hardware assisted virtualization implementations which 6111may be incompatible with the MIPS VZ ASE. 6112 6113== ========================================================================== 6114 0 The trap & emulate implementation is in use to run guest code in user 6115 mode. Guest virtual memory segments are rearranged to fit the guest in the 6116 user mode address space. 6117 6118 1 The MIPS VZ ASE is in use, providing full hardware assisted 6119 virtualization, including standard guest virtual memory segments. 6120== ========================================================================== 6121 61228.6 KVM_CAP_MIPS_TE 6123------------------- 6124 6125:Architectures: mips 6126 6127This capability, if KVM_CHECK_EXTENSION on the main kvm handle indicates that 6128it is available, means that the trap & emulate implementation is available to 6129run guest code in user mode, even if KVM_CAP_MIPS_VZ indicates that hardware 6130assisted virtualisation is also available. KVM_VM_MIPS_TE (0) must be passed 6131to KVM_CREATE_VM to create a VM which utilises it. 6132 6133If KVM_CHECK_EXTENSION on a kvm VM handle indicates that this capability is 6134available, it means that the VM is using trap & emulate. 6135 61368.7 KVM_CAP_MIPS_64BIT 6137---------------------- 6138 6139:Architectures: mips 6140 6141This capability indicates the supported architecture type of the guest, i.e. the 6142supported register and address width. 6143 6144The values returned when this capability is checked by KVM_CHECK_EXTENSION on a 6145kvm VM handle correspond roughly to the CP0_Config.AT register field, and should 6146be checked specifically against known values (see below). All other values are 6147reserved. 6148 6149== ======================================================================== 6150 0 MIPS32 or microMIPS32. 6151 Both registers and addresses are 32-bits wide. 6152 It will only be possible to run 32-bit guest code. 6153 6154 1 MIPS64 or microMIPS64 with access only to 32-bit compatibility segments. 6155 Registers are 64-bits wide, but addresses are 32-bits wide. 6156 64-bit guest code may run but cannot access MIPS64 memory segments. 6157 It will also be possible to run 32-bit guest code. 6158 6159 2 MIPS64 or microMIPS64 with access to all address segments. 6160 Both registers and addresses are 64-bits wide. 6161 It will be possible to run 64-bit or 32-bit guest code. 6162== ======================================================================== 6163 61648.9 KVM_CAP_ARM_USER_IRQ 6165------------------------ 6166 6167:Architectures: arm, arm64 6168 6169This capability, if KVM_CHECK_EXTENSION indicates that it is available, means 6170that if userspace creates a VM without an in-kernel interrupt controller, it 6171will be notified of changes to the output level of in-kernel emulated devices, 6172which can generate virtual interrupts, presented to the VM. 6173For such VMs, on every return to userspace, the kernel 6174updates the vcpu's run->s.regs.device_irq_level field to represent the actual 6175output level of the device. 6176 6177Whenever kvm detects a change in the device output level, kvm guarantees at 6178least one return to userspace before running the VM. This exit could either 6179be a KVM_EXIT_INTR or any other exit event, like KVM_EXIT_MMIO. This way, 6180userspace can always sample the device output level and re-compute the state of 6181the userspace interrupt controller. Userspace should always check the state 6182of run->s.regs.device_irq_level on every kvm exit. 6183The value in run->s.regs.device_irq_level can represent both level and edge 6184triggered interrupt signals, depending on the device. Edge triggered interrupt 6185signals will exit to userspace with the bit in run->s.regs.device_irq_level 6186set exactly once per edge signal. 6187 6188The field run->s.regs.device_irq_level is available independent of 6189run->kvm_valid_regs or run->kvm_dirty_regs bits. 6190 6191If KVM_CAP_ARM_USER_IRQ is supported, the KVM_CHECK_EXTENSION ioctl returns a 6192number larger than 0 indicating the version of this capability is implemented 6193and thereby which bits in run->s.regs.device_irq_level can signal values. 6194 6195Currently the following bits are defined for the device_irq_level bitmap:: 6196 6197 KVM_CAP_ARM_USER_IRQ >= 1: 6198 6199 KVM_ARM_DEV_EL1_VTIMER - EL1 virtual timer 6200 KVM_ARM_DEV_EL1_PTIMER - EL1 physical timer 6201 KVM_ARM_DEV_PMU - ARM PMU overflow interrupt signal 6202 6203Future versions of kvm may implement additional events. These will get 6204indicated by returning a higher number from KVM_CHECK_EXTENSION and will be 6205listed above. 6206 62078.10 KVM_CAP_PPC_SMT_POSSIBLE 6208----------------------------- 6209 6210:Architectures: ppc 6211 6212Querying this capability returns a bitmap indicating the possible 6213virtual SMT modes that can be set using KVM_CAP_PPC_SMT. If bit N 6214(counting from the right) is set, then a virtual SMT mode of 2^N is 6215available. 6216 62178.11 KVM_CAP_HYPERV_SYNIC2 6218-------------------------- 6219 6220:Architectures: x86 6221 6222This capability enables a newer version of Hyper-V Synthetic interrupt 6223controller (SynIC). The only difference with KVM_CAP_HYPERV_SYNIC is that KVM 6224doesn't clear SynIC message and event flags pages when they are enabled by 6225writing to the respective MSRs. 6226 62278.12 KVM_CAP_HYPERV_VP_INDEX 6228---------------------------- 6229 6230:Architectures: x86 6231 6232This capability indicates that userspace can load HV_X64_MSR_VP_INDEX msr. Its 6233value is used to denote the target vcpu for a SynIC interrupt. For 6234compatibilty, KVM initializes this msr to KVM's internal vcpu index. When this 6235capability is absent, userspace can still query this msr's value. 6236 62378.13 KVM_CAP_S390_AIS_MIGRATION 6238------------------------------- 6239 6240:Architectures: s390 6241:Parameters: none 6242 6243This capability indicates if the flic device will be able to get/set the 6244AIS states for migration via the KVM_DEV_FLIC_AISM_ALL attribute and allows 6245to discover this without having to create a flic device. 6246 62478.14 KVM_CAP_S390_PSW 6248--------------------- 6249 6250:Architectures: s390 6251 6252This capability indicates that the PSW is exposed via the kvm_run structure. 6253 62548.15 KVM_CAP_S390_GMAP 6255---------------------- 6256 6257:Architectures: s390 6258 6259This capability indicates that the user space memory used as guest mapping can 6260be anywhere in the user memory address space, as long as the memory slots are 6261aligned and sized to a segment (1MB) boundary. 6262 62638.16 KVM_CAP_S390_COW 6264--------------------- 6265 6266:Architectures: s390 6267 6268This capability indicates that the user space memory used as guest mapping can 6269use copy-on-write semantics as well as dirty pages tracking via read-only page 6270tables. 6271 62728.17 KVM_CAP_S390_BPB 6273--------------------- 6274 6275:Architectures: s390 6276 6277This capability indicates that kvm will implement the interfaces to handle 6278reset, migration and nested KVM for branch prediction blocking. The stfle 6279facility 82 should not be provided to the guest without this capability. 6280 62818.18 KVM_CAP_HYPERV_TLBFLUSH 6282---------------------------- 6283 6284:Architectures: x86 6285 6286This capability indicates that KVM supports paravirtualized Hyper-V TLB Flush 6287hypercalls: 6288HvFlushVirtualAddressSpace, HvFlushVirtualAddressSpaceEx, 6289HvFlushVirtualAddressList, HvFlushVirtualAddressListEx. 6290 62918.19 KVM_CAP_ARM_INJECT_SERROR_ESR 6292---------------------------------- 6293 6294:Architectures: arm, arm64 6295 6296This capability indicates that userspace can specify (via the 6297KVM_SET_VCPU_EVENTS ioctl) the syndrome value reported to the guest when it 6298takes a virtual SError interrupt exception. 6299If KVM advertises this capability, userspace can only specify the ISS field for 6300the ESR syndrome. Other parts of the ESR, such as the EC are generated by the 6301CPU when the exception is taken. If this virtual SError is taken to EL1 using 6302AArch64, this value will be reported in the ISS field of ESR_ELx. 6303 6304See KVM_CAP_VCPU_EVENTS for more details. 6305 63068.20 KVM_CAP_HYPERV_SEND_IPI 6307---------------------------- 6308 6309:Architectures: x86 6310 6311This capability indicates that KVM supports paravirtualized Hyper-V IPI send 6312hypercalls: 6313HvCallSendSyntheticClusterIpi, HvCallSendSyntheticClusterIpiEx. 6314 63158.21 KVM_CAP_HYPERV_DIRECT_TLBFLUSH 6316----------------------------------- 6317 6318:Architectures: x86 6319 6320This capability indicates that KVM running on top of Hyper-V hypervisor 6321enables Direct TLB flush for its guests meaning that TLB flush 6322hypercalls are handled by Level 0 hypervisor (Hyper-V) bypassing KVM. 6323Due to the different ABI for hypercall parameters between Hyper-V and 6324KVM, enabling this capability effectively disables all hypercall 6325handling by KVM (as some KVM hypercall may be mistakenly treated as TLB 6326flush hypercalls by Hyper-V) so userspace should disable KVM identification 6327in CPUID and only exposes Hyper-V identification. In this case, guest 6328thinks it's running on Hyper-V and only use Hyper-V hypercalls. 6329 63308.22 KVM_CAP_S390_VCPU_RESETS 6331----------------------------- 6332 6333:Architectures: s390 6334 6335This capability indicates that the KVM_S390_NORMAL_RESET and 6336KVM_S390_CLEAR_RESET ioctls are available. 6337 63388.23 KVM_CAP_S390_PROTECTED 6339--------------------------- 6340 6341:Architectures: s390 6342 6343This capability indicates that the Ultravisor has been initialized and 6344KVM can therefore start protected VMs. 6345This capability governs the KVM_S390_PV_COMMAND ioctl and the 6346KVM_MP_STATE_LOAD MP_STATE. KVM_SET_MP_STATE can fail for protected 6347guests when the state change is invalid. 6348 63498.24 KVM_CAP_STEAL_TIME 6350----------------------- 6351 6352:Architectures: arm64, x86 6353 6354This capability indicates that KVM supports steal time accounting. 6355When steal time accounting is supported it may be enabled with 6356architecture-specific interfaces. This capability and the architecture- 6357specific interfaces must be consistent, i.e. if one says the feature 6358is supported, than the other should as well and vice versa. For arm64 6359see Documentation/virt/kvm/devices/vcpu.rst "KVM_ARM_VCPU_PVTIME_CTRL". 6360For x86 see Documentation/virt/kvm/msr.rst "MSR_KVM_STEAL_TIME". 6361 63628.25 KVM_CAP_S390_DIAG318 6363------------------------- 6364 6365:Architectures: s390 6366 6367This capability enables a guest to set information about its control program 6368(i.e. guest kernel type and version). The information is helpful during 6369system/firmware service events, providing additional data about the guest 6370environments running on the machine. 6371 6372The information is associated with the DIAGNOSE 0x318 instruction, which sets 6373an 8-byte value consisting of a one-byte Control Program Name Code (CPNC) and 6374a 7-byte Control Program Version Code (CPVC). The CPNC determines what 6375environment the control program is running in (e.g. Linux, z/VM...), and the 6376CPVC is used for information specific to OS (e.g. Linux version, Linux 6377distribution...) 6378 6379If this capability is available, then the CPNC and CPVC can be synchronized 6380between KVM and userspace via the sync regs mechanism (KVM_SYNC_DIAG318). 6381 63828.26 KVM_CAP_X86_USER_SPACE_MSR 6383------------------------------- 6384 6385:Architectures: x86 6386 6387This capability indicates that KVM supports deflection of MSR reads and 6388writes to user space. It can be enabled on a VM level. If enabled, MSR 6389accesses that would usually trigger a #GP by KVM into the guest will 6390instead get bounced to user space through the KVM_EXIT_X86_RDMSR and 6391KVM_EXIT_X86_WRMSR exit notifications. 6392 63938.27 KVM_X86_SET_MSR_FILTER 6394--------------------------- 6395 6396:Architectures: x86 6397 6398This capability indicates that KVM supports that accesses to user defined MSRs 6399may be rejected. With this capability exposed, KVM exports new VM ioctl 6400KVM_X86_SET_MSR_FILTER which user space can call to specify bitmaps of MSR 6401ranges that KVM should reject access to. 6402 6403In combination with KVM_CAP_X86_USER_SPACE_MSR, this allows user space to 6404trap and emulate MSRs that are outside of the scope of KVM as well as 6405limit the attack surface on KVM's MSR emulation code. 6406 64078.28 KVM_CAP_ENFORCE_PV_CPUID 6408----------------------------- 6409 6410Architectures: x86 6411 6412When enabled, KVM will disable paravirtual features provided to the 6413guest according to the bits in the KVM_CPUID_FEATURES CPUID leaf 6414(0x40000001). Otherwise, a guest may use the paravirtual features 6415regardless of what has actually been exposed through the CPUID leaf. 6416 6417 64188.29 KVM_CAP_DIRTY_LOG_RING 6419--------------------------- 6420 6421:Architectures: x86 6422:Parameters: args[0] - size of the dirty log ring 6423 6424KVM is capable of tracking dirty memory using ring buffers that are 6425mmaped into userspace; there is one dirty ring per vcpu. 6426 6427The dirty ring is available to userspace as an array of 6428``struct kvm_dirty_gfn``. Each dirty entry it's defined as:: 6429 6430 struct kvm_dirty_gfn { 6431 __u32 flags; 6432 __u32 slot; /* as_id | slot_id */ 6433 __u64 offset; 6434 }; 6435 6436The following values are defined for the flags field to define the 6437current state of the entry:: 6438 6439 #define KVM_DIRTY_GFN_F_DIRTY BIT(0) 6440 #define KVM_DIRTY_GFN_F_RESET BIT(1) 6441 #define KVM_DIRTY_GFN_F_MASK 0x3 6442 6443Userspace should call KVM_ENABLE_CAP ioctl right after KVM_CREATE_VM 6444ioctl to enable this capability for the new guest and set the size of 6445the rings. Enabling the capability is only allowed before creating any 6446vCPU, and the size of the ring must be a power of two. The larger the 6447ring buffer, the less likely the ring is full and the VM is forced to 6448exit to userspace. The optimal size depends on the workload, but it is 6449recommended that it be at least 64 KiB (4096 entries). 6450 6451Just like for dirty page bitmaps, the buffer tracks writes to 6452all user memory regions for which the KVM_MEM_LOG_DIRTY_PAGES flag was 6453set in KVM_SET_USER_MEMORY_REGION. Once a memory region is registered 6454with the flag set, userspace can start harvesting dirty pages from the 6455ring buffer. 6456 6457An entry in the ring buffer can be unused (flag bits ``00``), 6458dirty (flag bits ``01``) or harvested (flag bits ``1X``). The 6459state machine for the entry is as follows:: 6460 6461 dirtied harvested reset 6462 00 -----------> 01 -------------> 1X -------+ 6463 ^ | 6464 | | 6465 +------------------------------------------+ 6466 6467To harvest the dirty pages, userspace accesses the mmaped ring buffer 6468to read the dirty GFNs. If the flags has the DIRTY bit set (at this stage 6469the RESET bit must be cleared), then it means this GFN is a dirty GFN. 6470The userspace should harvest this GFN and mark the flags from state 6471``01b`` to ``1Xb`` (bit 0 will be ignored by KVM, but bit 1 must be set 6472to show that this GFN is harvested and waiting for a reset), and move 6473on to the next GFN. The userspace should continue to do this until the 6474flags of a GFN have the DIRTY bit cleared, meaning that it has harvested 6475all the dirty GFNs that were available. 6476 6477It's not necessary for userspace to harvest the all dirty GFNs at once. 6478However it must collect the dirty GFNs in sequence, i.e., the userspace 6479program cannot skip one dirty GFN to collect the one next to it. 6480 6481After processing one or more entries in the ring buffer, userspace 6482calls the VM ioctl KVM_RESET_DIRTY_RINGS to notify the kernel about 6483it, so that the kernel will reprotect those collected GFNs. 6484Therefore, the ioctl must be called *before* reading the content of 6485the dirty pages. 6486 6487The dirty ring can get full. When it happens, the KVM_RUN of the 6488vcpu will return with exit reason KVM_EXIT_DIRTY_LOG_FULL. 6489 6490The dirty ring interface has a major difference comparing to the 6491KVM_GET_DIRTY_LOG interface in that, when reading the dirty ring from 6492userspace, it's still possible that the kernel has not yet flushed the 6493processor's dirty page buffers into the kernel buffer (with dirty bitmaps, the 6494flushing is done by the KVM_GET_DIRTY_LOG ioctl). To achieve that, one 6495needs to kick the vcpu out of KVM_RUN using a signal. The resulting 6496vmexit ensures that all dirty GFNs are flushed to the dirty rings. 6497 6498NOTE: the capability KVM_CAP_DIRTY_LOG_RING and the corresponding 6499ioctl KVM_RESET_DIRTY_RINGS are mutual exclusive to the existing ioctls 6500KVM_GET_DIRTY_LOG and KVM_CLEAR_DIRTY_LOG. After enabling 6501KVM_CAP_DIRTY_LOG_RING with an acceptable dirty ring size, the virtual 6502machine will switch to ring-buffer dirty page tracking and further 6503KVM_GET_DIRTY_LOG or KVM_CLEAR_DIRTY_LOG ioctls will fail. 6504