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 via 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. 264 265 2664.6 KVM_SET_MEMORY_REGION 267------------------------- 268 269:Capability: basic 270:Architectures: all 271:Type: vm ioctl 272:Parameters: struct kvm_memory_region (in) 273:Returns: 0 on success, -1 on error 274 275This ioctl is obsolete and has been removed. 276 277 2784.7 KVM_CREATE_VCPU 279------------------- 280 281:Capability: basic 282:Architectures: all 283:Type: vm ioctl 284:Parameters: vcpu id (apic id on x86) 285:Returns: vcpu fd on success, -1 on error 286 287This API adds a vcpu to a virtual machine. No more than max_vcpus may be added. 288The vcpu id is an integer in the range [0, max_vcpu_id). 289 290The recommended max_vcpus value can be retrieved using the KVM_CAP_NR_VCPUS of 291the KVM_CHECK_EXTENSION ioctl() at run-time. 292The maximum possible value for max_vcpus can be retrieved using the 293KVM_CAP_MAX_VCPUS of the KVM_CHECK_EXTENSION ioctl() at run-time. 294 295If the KVM_CAP_NR_VCPUS does not exist, you should assume that max_vcpus is 4 296cpus max. 297If the KVM_CAP_MAX_VCPUS does not exist, you should assume that max_vcpus is 298same as the value returned from KVM_CAP_NR_VCPUS. 299 300The maximum possible value for max_vcpu_id can be retrieved using the 301KVM_CAP_MAX_VCPU_ID of the KVM_CHECK_EXTENSION ioctl() at run-time. 302 303If the KVM_CAP_MAX_VCPU_ID does not exist, you should assume that max_vcpu_id 304is the same as the value returned from KVM_CAP_MAX_VCPUS. 305 306On powerpc using book3s_hv mode, the vcpus are mapped onto virtual 307threads in one or more virtual CPU cores. (This is because the 308hardware requires all the hardware threads in a CPU core to be in the 309same partition.) The KVM_CAP_PPC_SMT capability indicates the number 310of vcpus per virtual core (vcore). The vcore id is obtained by 311dividing the vcpu id by the number of vcpus per vcore. The vcpus in a 312given vcore will always be in the same physical core as each other 313(though that might be a different physical core from time to time). 314Userspace can control the threading (SMT) mode of the guest by its 315allocation of vcpu ids. For example, if userspace wants 316single-threaded guest vcpus, it should make all vcpu ids be a multiple 317of the number of vcpus per vcore. 318 319For virtual cpus that have been created with S390 user controlled virtual 320machines, the resulting vcpu fd can be memory mapped at page offset 321KVM_S390_SIE_PAGE_OFFSET in order to obtain a memory map of the virtual 322cpu's hardware control block. 323 324 3254.8 KVM_GET_DIRTY_LOG (vm ioctl) 326-------------------------------- 327 328:Capability: basic 329:Architectures: all 330:Type: vm ioctl 331:Parameters: struct kvm_dirty_log (in/out) 332:Returns: 0 on success, -1 on error 333 334:: 335 336 /* for KVM_GET_DIRTY_LOG */ 337 struct kvm_dirty_log { 338 __u32 slot; 339 __u32 padding; 340 union { 341 void __user *dirty_bitmap; /* one bit per page */ 342 __u64 padding; 343 }; 344 }; 345 346Given a memory slot, return a bitmap containing any pages dirtied 347since the last call to this ioctl. Bit 0 is the first page in the 348memory slot. Ensure the entire structure is cleared to avoid padding 349issues. 350 351If KVM_CAP_MULTI_ADDRESS_SPACE is available, bits 16-31 specifies 352the address space for which you want to return the dirty bitmap. 353They must be less than the value that KVM_CHECK_EXTENSION returns for 354the KVM_CAP_MULTI_ADDRESS_SPACE capability. 355 356The bits in the dirty bitmap are cleared before the ioctl returns, unless 357KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 is enabled. For more information, 358see the description of the capability. 359 3604.9 KVM_SET_MEMORY_ALIAS 361------------------------ 362 363:Capability: basic 364:Architectures: x86 365:Type: vm ioctl 366:Parameters: struct kvm_memory_alias (in) 367:Returns: 0 (success), -1 (error) 368 369This ioctl is obsolete and has been removed. 370 371 3724.10 KVM_RUN 373------------ 374 375:Capability: basic 376:Architectures: all 377:Type: vcpu ioctl 378:Parameters: none 379:Returns: 0 on success, -1 on error 380 381Errors: 382 383 ===== ============================= 384 EINTR an unmasked signal is pending 385 ===== ============================= 386 387This ioctl is used to run a guest virtual cpu. While there are no 388explicit parameters, there is an implicit parameter block that can be 389obtained by mmap()ing the vcpu fd at offset 0, with the size given by 390KVM_GET_VCPU_MMAP_SIZE. The parameter block is formatted as a 'struct 391kvm_run' (see below). 392 393 3944.11 KVM_GET_REGS 395----------------- 396 397:Capability: basic 398:Architectures: all except ARM, arm64 399:Type: vcpu ioctl 400:Parameters: struct kvm_regs (out) 401:Returns: 0 on success, -1 on error 402 403Reads the general purpose registers from the vcpu. 404 405:: 406 407 /* x86 */ 408 struct kvm_regs { 409 /* out (KVM_GET_REGS) / in (KVM_SET_REGS) */ 410 __u64 rax, rbx, rcx, rdx; 411 __u64 rsi, rdi, rsp, rbp; 412 __u64 r8, r9, r10, r11; 413 __u64 r12, r13, r14, r15; 414 __u64 rip, rflags; 415 }; 416 417 /* mips */ 418 struct kvm_regs { 419 /* out (KVM_GET_REGS) / in (KVM_SET_REGS) */ 420 __u64 gpr[32]; 421 __u64 hi; 422 __u64 lo; 423 __u64 pc; 424 }; 425 426 4274.12 KVM_SET_REGS 428----------------- 429 430:Capability: basic 431:Architectures: all except ARM, arm64 432:Type: vcpu ioctl 433:Parameters: struct kvm_regs (in) 434:Returns: 0 on success, -1 on error 435 436Writes the general purpose registers into the vcpu. 437 438See KVM_GET_REGS for the data structure. 439 440 4414.13 KVM_GET_SREGS 442------------------ 443 444:Capability: basic 445:Architectures: x86, ppc 446:Type: vcpu ioctl 447:Parameters: struct kvm_sregs (out) 448:Returns: 0 on success, -1 on error 449 450Reads special registers from the vcpu. 451 452:: 453 454 /* x86 */ 455 struct kvm_sregs { 456 struct kvm_segment cs, ds, es, fs, gs, ss; 457 struct kvm_segment tr, ldt; 458 struct kvm_dtable gdt, idt; 459 __u64 cr0, cr2, cr3, cr4, cr8; 460 __u64 efer; 461 __u64 apic_base; 462 __u64 interrupt_bitmap[(KVM_NR_INTERRUPTS + 63) / 64]; 463 }; 464 465 /* ppc -- see arch/powerpc/include/uapi/asm/kvm.h */ 466 467interrupt_bitmap is a bitmap of pending external interrupts. At most 468one bit may be set. This interrupt has been acknowledged by the APIC 469but not yet injected into the cpu core. 470 471 4724.14 KVM_SET_SREGS 473------------------ 474 475:Capability: basic 476:Architectures: x86, ppc 477:Type: vcpu ioctl 478:Parameters: struct kvm_sregs (in) 479:Returns: 0 on success, -1 on error 480 481Writes special registers into the vcpu. See KVM_GET_SREGS for the 482data structures. 483 484 4854.15 KVM_TRANSLATE 486------------------ 487 488:Capability: basic 489:Architectures: x86 490:Type: vcpu ioctl 491:Parameters: struct kvm_translation (in/out) 492:Returns: 0 on success, -1 on error 493 494Translates a virtual address according to the vcpu's current address 495translation mode. 496 497:: 498 499 struct kvm_translation { 500 /* in */ 501 __u64 linear_address; 502 503 /* out */ 504 __u64 physical_address; 505 __u8 valid; 506 __u8 writeable; 507 __u8 usermode; 508 __u8 pad[5]; 509 }; 510 511 5124.16 KVM_INTERRUPT 513------------------ 514 515:Capability: basic 516:Architectures: x86, ppc, mips 517:Type: vcpu ioctl 518:Parameters: struct kvm_interrupt (in) 519:Returns: 0 on success, negative on failure. 520 521Queues a hardware interrupt vector to be injected. 522 523:: 524 525 /* for KVM_INTERRUPT */ 526 struct kvm_interrupt { 527 /* in */ 528 __u32 irq; 529 }; 530 531X86: 532^^^^ 533 534:Returns: 535 536 ========= =================================== 537 0 on success, 538 -EEXIST if an interrupt is already enqueued 539 -EINVAL the the irq number is invalid 540 -ENXIO if the PIC is in the kernel 541 -EFAULT if the pointer is invalid 542 ========= =================================== 543 544Note 'irq' is an interrupt vector, not an interrupt pin or line. This 545ioctl is useful if the in-kernel PIC is not used. 546 547PPC: 548^^^^ 549 550Queues an external interrupt to be injected. This ioctl is overleaded 551with 3 different irq values: 552 553a) KVM_INTERRUPT_SET 554 555 This injects an edge type external interrupt into the guest once it's ready 556 to receive interrupts. When injected, the interrupt is done. 557 558b) KVM_INTERRUPT_UNSET 559 560 This unsets any pending interrupt. 561 562 Only available with KVM_CAP_PPC_UNSET_IRQ. 563 564c) KVM_INTERRUPT_SET_LEVEL 565 566 This injects a level type external interrupt into the guest context. The 567 interrupt stays pending until a specific ioctl with KVM_INTERRUPT_UNSET 568 is triggered. 569 570 Only available with KVM_CAP_PPC_IRQ_LEVEL. 571 572Note that any value for 'irq' other than the ones stated above is invalid 573and incurs unexpected behavior. 574 575This is an asynchronous vcpu ioctl and can be invoked from any thread. 576 577MIPS: 578^^^^^ 579 580Queues an external interrupt to be injected into the virtual CPU. A negative 581interrupt number dequeues the interrupt. 582 583This is an asynchronous vcpu ioctl and can be invoked from any thread. 584 585 5864.17 KVM_DEBUG_GUEST 587-------------------- 588 589:Capability: basic 590:Architectures: none 591:Type: vcpu ioctl 592:Parameters: none) 593:Returns: -1 on error 594 595Support for this has been removed. Use KVM_SET_GUEST_DEBUG instead. 596 597 5984.18 KVM_GET_MSRS 599----------------- 600 601:Capability: basic (vcpu), KVM_CAP_GET_MSR_FEATURES (system) 602:Architectures: x86 603:Type: system ioctl, vcpu ioctl 604:Parameters: struct kvm_msrs (in/out) 605:Returns: number of msrs successfully returned; 606 -1 on error 607 608When used as a system ioctl: 609Reads the values of MSR-based features that are available for the VM. This 610is similar to KVM_GET_SUPPORTED_CPUID, but it returns MSR indices and values. 611The list of msr-based features can be obtained using KVM_GET_MSR_FEATURE_INDEX_LIST 612in a system ioctl. 613 614When used as a vcpu ioctl: 615Reads model-specific registers from the vcpu. Supported msr indices can 616be obtained using KVM_GET_MSR_INDEX_LIST in a system ioctl. 617 618:: 619 620 struct kvm_msrs { 621 __u32 nmsrs; /* number of msrs in entries */ 622 __u32 pad; 623 624 struct kvm_msr_entry entries[0]; 625 }; 626 627 struct kvm_msr_entry { 628 __u32 index; 629 __u32 reserved; 630 __u64 data; 631 }; 632 633Application code should set the 'nmsrs' member (which indicates the 634size of the entries array) and the 'index' member of each array entry. 635kvm will fill in the 'data' member. 636 637 6384.19 KVM_SET_MSRS 639----------------- 640 641:Capability: basic 642:Architectures: x86 643:Type: vcpu ioctl 644:Parameters: struct kvm_msrs (in) 645:Returns: number of msrs successfully set (see below), -1 on error 646 647Writes model-specific registers to the vcpu. See KVM_GET_MSRS for the 648data structures. 649 650Application code should set the 'nmsrs' member (which indicates the 651size of the entries array), and the 'index' and 'data' members of each 652array entry. 653 654It tries to set the MSRs in array entries[] one by one. If setting an MSR 655fails, e.g., due to setting reserved bits, the MSR isn't supported/emulated 656by KVM, etc..., it stops processing the MSR list and returns the number of 657MSRs that have been set successfully. 658 659 6604.20 KVM_SET_CPUID 661------------------ 662 663:Capability: basic 664:Architectures: x86 665:Type: vcpu ioctl 666:Parameters: struct kvm_cpuid (in) 667:Returns: 0 on success, -1 on error 668 669Defines the vcpu responses to the cpuid instruction. Applications 670should use the KVM_SET_CPUID2 ioctl if available. 671 672:: 673 674 struct kvm_cpuid_entry { 675 __u32 function; 676 __u32 eax; 677 __u32 ebx; 678 __u32 ecx; 679 __u32 edx; 680 __u32 padding; 681 }; 682 683 /* for KVM_SET_CPUID */ 684 struct kvm_cpuid { 685 __u32 nent; 686 __u32 padding; 687 struct kvm_cpuid_entry entries[0]; 688 }; 689 690 6914.21 KVM_SET_SIGNAL_MASK 692------------------------ 693 694:Capability: basic 695:Architectures: all 696:Type: vcpu ioctl 697:Parameters: struct kvm_signal_mask (in) 698:Returns: 0 on success, -1 on error 699 700Defines which signals are blocked during execution of KVM_RUN. This 701signal mask temporarily overrides the threads signal mask. Any 702unblocked signal received (except SIGKILL and SIGSTOP, which retain 703their traditional behaviour) will cause KVM_RUN to return with -EINTR. 704 705Note the signal will only be delivered if not blocked by the original 706signal mask. 707 708:: 709 710 /* for KVM_SET_SIGNAL_MASK */ 711 struct kvm_signal_mask { 712 __u32 len; 713 __u8 sigset[0]; 714 }; 715 716 7174.22 KVM_GET_FPU 718---------------- 719 720:Capability: basic 721:Architectures: x86 722:Type: vcpu ioctl 723:Parameters: struct kvm_fpu (out) 724:Returns: 0 on success, -1 on error 725 726Reads the floating point state from the vcpu. 727 728:: 729 730 /* for KVM_GET_FPU and KVM_SET_FPU */ 731 struct kvm_fpu { 732 __u8 fpr[8][16]; 733 __u16 fcw; 734 __u16 fsw; 735 __u8 ftwx; /* in fxsave format */ 736 __u8 pad1; 737 __u16 last_opcode; 738 __u64 last_ip; 739 __u64 last_dp; 740 __u8 xmm[16][16]; 741 __u32 mxcsr; 742 __u32 pad2; 743 }; 744 745 7464.23 KVM_SET_FPU 747---------------- 748 749:Capability: basic 750:Architectures: x86 751:Type: vcpu ioctl 752:Parameters: struct kvm_fpu (in) 753:Returns: 0 on success, -1 on error 754 755Writes the floating point state to the vcpu. 756 757:: 758 759 /* for KVM_GET_FPU and KVM_SET_FPU */ 760 struct kvm_fpu { 761 __u8 fpr[8][16]; 762 __u16 fcw; 763 __u16 fsw; 764 __u8 ftwx; /* in fxsave format */ 765 __u8 pad1; 766 __u16 last_opcode; 767 __u64 last_ip; 768 __u64 last_dp; 769 __u8 xmm[16][16]; 770 __u32 mxcsr; 771 __u32 pad2; 772 }; 773 774 7754.24 KVM_CREATE_IRQCHIP 776----------------------- 777 778:Capability: KVM_CAP_IRQCHIP, KVM_CAP_S390_IRQCHIP (s390) 779:Architectures: x86, ARM, arm64, s390 780:Type: vm ioctl 781:Parameters: none 782:Returns: 0 on success, -1 on error 783 784Creates an interrupt controller model in the kernel. 785On x86, creates a virtual ioapic, a virtual PIC (two PICs, nested), and sets up 786future vcpus to have a local APIC. IRQ routing for GSIs 0-15 is set to both 787PIC and IOAPIC; GSI 16-23 only go to the IOAPIC. 788On ARM/arm64, a GICv2 is created. Any other GIC versions require the usage of 789KVM_CREATE_DEVICE, which also supports creating a GICv2. Using 790KVM_CREATE_DEVICE is preferred over KVM_CREATE_IRQCHIP for GICv2. 791On s390, a dummy irq routing table is created. 792 793Note that on s390 the KVM_CAP_S390_IRQCHIP vm capability needs to be enabled 794before KVM_CREATE_IRQCHIP can be used. 795 796 7974.25 KVM_IRQ_LINE 798----------------- 799 800:Capability: KVM_CAP_IRQCHIP 801:Architectures: x86, arm, arm64 802:Type: vm ioctl 803:Parameters: struct kvm_irq_level 804:Returns: 0 on success, -1 on error 805 806Sets the level of a GSI input to the interrupt controller model in the kernel. 807On some architectures it is required that an interrupt controller model has 808been previously created with KVM_CREATE_IRQCHIP. Note that edge-triggered 809interrupts require the level to be set to 1 and then back to 0. 810 811On real hardware, interrupt pins can be active-low or active-high. This 812does not matter for the level field of struct kvm_irq_level: 1 always 813means active (asserted), 0 means inactive (deasserted). 814 815x86 allows the operating system to program the interrupt polarity 816(active-low/active-high) for level-triggered interrupts, and KVM used 817to consider the polarity. However, due to bitrot in the handling of 818active-low interrupts, the above convention is now valid on x86 too. 819This is signaled by KVM_CAP_X86_IOAPIC_POLARITY_IGNORED. Userspace 820should not present interrupts to the guest as active-low unless this 821capability is present (or unless it is not using the in-kernel irqchip, 822of course). 823 824 825ARM/arm64 can signal an interrupt either at the CPU level, or at the 826in-kernel irqchip (GIC), and for in-kernel irqchip can tell the GIC to 827use PPIs designated for specific cpus. The irq field is interpreted 828like this:: 829 830 bits: | 31 ... 28 | 27 ... 24 | 23 ... 16 | 15 ... 0 | 831 field: | vcpu2_index | irq_type | vcpu_index | irq_id | 832 833The irq_type field has the following values: 834 835- irq_type[0]: 836 out-of-kernel GIC: irq_id 0 is IRQ, irq_id 1 is FIQ 837- irq_type[1]: 838 in-kernel GIC: SPI, irq_id between 32 and 1019 (incl.) 839 (the vcpu_index field is ignored) 840- irq_type[2]: 841 in-kernel GIC: PPI, irq_id between 16 and 31 (incl.) 842 843(The irq_id field thus corresponds nicely to the IRQ ID in the ARM GIC specs) 844 845In both cases, level is used to assert/deassert the line. 846 847When KVM_CAP_ARM_IRQ_LINE_LAYOUT_2 is supported, the target vcpu is 848identified as (256 * vcpu2_index + vcpu_index). Otherwise, vcpu2_index 849must be zero. 850 851Note that on arm/arm64, the KVM_CAP_IRQCHIP capability only conditions 852injection of interrupts for the in-kernel irqchip. KVM_IRQ_LINE can always 853be used for a userspace interrupt controller. 854 855:: 856 857 struct kvm_irq_level { 858 union { 859 __u32 irq; /* GSI */ 860 __s32 status; /* not used for KVM_IRQ_LEVEL */ 861 }; 862 __u32 level; /* 0 or 1 */ 863 }; 864 865 8664.26 KVM_GET_IRQCHIP 867-------------------- 868 869:Capability: KVM_CAP_IRQCHIP 870:Architectures: x86 871:Type: vm ioctl 872:Parameters: struct kvm_irqchip (in/out) 873:Returns: 0 on success, -1 on error 874 875Reads the state of a kernel interrupt controller created with 876KVM_CREATE_IRQCHIP into a buffer provided by the caller. 877 878:: 879 880 struct kvm_irqchip { 881 __u32 chip_id; /* 0 = PIC1, 1 = PIC2, 2 = IOAPIC */ 882 __u32 pad; 883 union { 884 char dummy[512]; /* reserving space */ 885 struct kvm_pic_state pic; 886 struct kvm_ioapic_state ioapic; 887 } chip; 888 }; 889 890 8914.27 KVM_SET_IRQCHIP 892-------------------- 893 894:Capability: KVM_CAP_IRQCHIP 895:Architectures: x86 896:Type: vm ioctl 897:Parameters: struct kvm_irqchip (in) 898:Returns: 0 on success, -1 on error 899 900Sets the state of a kernel interrupt controller created with 901KVM_CREATE_IRQCHIP from a buffer provided by the caller. 902 903:: 904 905 struct kvm_irqchip { 906 __u32 chip_id; /* 0 = PIC1, 1 = PIC2, 2 = IOAPIC */ 907 __u32 pad; 908 union { 909 char dummy[512]; /* reserving space */ 910 struct kvm_pic_state pic; 911 struct kvm_ioapic_state ioapic; 912 } chip; 913 }; 914 915 9164.28 KVM_XEN_HVM_CONFIG 917----------------------- 918 919:Capability: KVM_CAP_XEN_HVM 920:Architectures: x86 921:Type: vm ioctl 922:Parameters: struct kvm_xen_hvm_config (in) 923:Returns: 0 on success, -1 on error 924 925Sets the MSR that the Xen HVM guest uses to initialize its hypercall 926page, and provides the starting address and size of the hypercall 927blobs in userspace. When the guest writes the MSR, kvm copies one 928page of a blob (32- or 64-bit, depending on the vcpu mode) to guest 929memory. 930 931:: 932 933 struct kvm_xen_hvm_config { 934 __u32 flags; 935 __u32 msr; 936 __u64 blob_addr_32; 937 __u64 blob_addr_64; 938 __u8 blob_size_32; 939 __u8 blob_size_64; 940 __u8 pad2[30]; 941 }; 942 943 9444.29 KVM_GET_CLOCK 945------------------ 946 947:Capability: KVM_CAP_ADJUST_CLOCK 948:Architectures: x86 949:Type: vm ioctl 950:Parameters: struct kvm_clock_data (out) 951:Returns: 0 on success, -1 on error 952 953Gets the current timestamp of kvmclock as seen by the current guest. In 954conjunction with KVM_SET_CLOCK, it is used to ensure monotonicity on scenarios 955such as migration. 956 957When KVM_CAP_ADJUST_CLOCK is passed to KVM_CHECK_EXTENSION, it returns the 958set of bits that KVM can return in struct kvm_clock_data's flag member. 959 960The only flag defined now is KVM_CLOCK_TSC_STABLE. If set, the returned 961value is the exact kvmclock value seen by all VCPUs at the instant 962when KVM_GET_CLOCK was called. If clear, the returned value is simply 963CLOCK_MONOTONIC plus a constant offset; the offset can be modified 964with KVM_SET_CLOCK. KVM will try to make all VCPUs follow this clock, 965but the exact value read by each VCPU could differ, because the host 966TSC is not stable. 967 968:: 969 970 struct kvm_clock_data { 971 __u64 clock; /* kvmclock current value */ 972 __u32 flags; 973 __u32 pad[9]; 974 }; 975 976 9774.30 KVM_SET_CLOCK 978------------------ 979 980:Capability: KVM_CAP_ADJUST_CLOCK 981:Architectures: x86 982:Type: vm ioctl 983:Parameters: struct kvm_clock_data (in) 984:Returns: 0 on success, -1 on error 985 986Sets the current timestamp of kvmclock to the value specified in its parameter. 987In conjunction with KVM_GET_CLOCK, it is used to ensure monotonicity on scenarios 988such as migration. 989 990:: 991 992 struct kvm_clock_data { 993 __u64 clock; /* kvmclock current value */ 994 __u32 flags; 995 __u32 pad[9]; 996 }; 997 998 9994.31 KVM_GET_VCPU_EVENTS 1000------------------------ 1001 1002:Capability: KVM_CAP_VCPU_EVENTS 1003:Extended by: KVM_CAP_INTR_SHADOW 1004:Architectures: x86, arm, arm64 1005:Type: vcpu ioctl 1006:Parameters: struct kvm_vcpu_event (out) 1007:Returns: 0 on success, -1 on error 1008 1009X86: 1010^^^^ 1011 1012Gets currently pending exceptions, interrupts, and NMIs as well as related 1013states of the vcpu. 1014 1015:: 1016 1017 struct kvm_vcpu_events { 1018 struct { 1019 __u8 injected; 1020 __u8 nr; 1021 __u8 has_error_code; 1022 __u8 pending; 1023 __u32 error_code; 1024 } exception; 1025 struct { 1026 __u8 injected; 1027 __u8 nr; 1028 __u8 soft; 1029 __u8 shadow; 1030 } interrupt; 1031 struct { 1032 __u8 injected; 1033 __u8 pending; 1034 __u8 masked; 1035 __u8 pad; 1036 } nmi; 1037 __u32 sipi_vector; 1038 __u32 flags; 1039 struct { 1040 __u8 smm; 1041 __u8 pending; 1042 __u8 smm_inside_nmi; 1043 __u8 latched_init; 1044 } smi; 1045 __u8 reserved[27]; 1046 __u8 exception_has_payload; 1047 __u64 exception_payload; 1048 }; 1049 1050The following bits are defined in the flags field: 1051 1052- KVM_VCPUEVENT_VALID_SHADOW may be set to signal that 1053 interrupt.shadow contains a valid state. 1054 1055- KVM_VCPUEVENT_VALID_SMM may be set to signal that smi contains a 1056 valid state. 1057 1058- KVM_VCPUEVENT_VALID_PAYLOAD may be set to signal that the 1059 exception_has_payload, exception_payload, and exception.pending 1060 fields contain a valid state. This bit will be set whenever 1061 KVM_CAP_EXCEPTION_PAYLOAD is enabled. 1062 1063ARM/ARM64: 1064^^^^^^^^^^ 1065 1066If the guest accesses a device that is being emulated by the host kernel in 1067such a way that a real device would generate a physical SError, KVM may make 1068a virtual SError pending for that VCPU. This system error interrupt remains 1069pending until the guest takes the exception by unmasking PSTATE.A. 1070 1071Running the VCPU may cause it to take a pending SError, or make an access that 1072causes an SError to become pending. The event's description is only valid while 1073the VPCU is not running. 1074 1075This API provides a way to read and write the pending 'event' state that is not 1076visible to the guest. To save, restore or migrate a VCPU the struct representing 1077the state can be read then written using this GET/SET API, along with the other 1078guest-visible registers. It is not possible to 'cancel' an SError that has been 1079made pending. 1080 1081A device being emulated in user-space may also wish to generate an SError. To do 1082this the events structure can be populated by user-space. The current state 1083should be read first, to ensure no existing SError is pending. If an existing 1084SError is pending, the architecture's 'Multiple SError interrupts' rules should 1085be followed. (2.5.3 of DDI0587.a "ARM Reliability, Availability, and 1086Serviceability (RAS) Specification"). 1087 1088SError exceptions always have an ESR value. Some CPUs have the ability to 1089specify what the virtual SError's ESR value should be. These systems will 1090advertise KVM_CAP_ARM_INJECT_SERROR_ESR. In this case exception.has_esr will 1091always have a non-zero value when read, and the agent making an SError pending 1092should specify the ISS field in the lower 24 bits of exception.serror_esr. If 1093the system supports KVM_CAP_ARM_INJECT_SERROR_ESR, but user-space sets the events 1094with exception.has_esr as zero, KVM will choose an ESR. 1095 1096Specifying exception.has_esr on a system that does not support it will return 1097-EINVAL. Setting anything other than the lower 24bits of exception.serror_esr 1098will return -EINVAL. 1099 1100It is not possible to read back a pending external abort (injected via 1101KVM_SET_VCPU_EVENTS or otherwise) because such an exception is always delivered 1102directly to the virtual CPU). 1103 1104:: 1105 1106 struct kvm_vcpu_events { 1107 struct { 1108 __u8 serror_pending; 1109 __u8 serror_has_esr; 1110 __u8 ext_dabt_pending; 1111 /* Align it to 8 bytes */ 1112 __u8 pad[5]; 1113 __u64 serror_esr; 1114 } exception; 1115 __u32 reserved[12]; 1116 }; 1117 11184.32 KVM_SET_VCPU_EVENTS 1119------------------------ 1120 1121:Capability: KVM_CAP_VCPU_EVENTS 1122:Extended by: KVM_CAP_INTR_SHADOW 1123:Architectures: x86, arm, arm64 1124:Type: vcpu ioctl 1125:Parameters: struct kvm_vcpu_event (in) 1126:Returns: 0 on success, -1 on error 1127 1128X86: 1129^^^^ 1130 1131Set pending exceptions, interrupts, and NMIs as well as related states of the 1132vcpu. 1133 1134See KVM_GET_VCPU_EVENTS for the data structure. 1135 1136Fields that may be modified asynchronously by running VCPUs can be excluded 1137from the update. These fields are nmi.pending, sipi_vector, smi.smm, 1138smi.pending. Keep the corresponding bits in the flags field cleared to 1139suppress overwriting the current in-kernel state. The bits are: 1140 1141=============================== ================================== 1142KVM_VCPUEVENT_VALID_NMI_PENDING transfer nmi.pending to the kernel 1143KVM_VCPUEVENT_VALID_SIPI_VECTOR transfer sipi_vector 1144KVM_VCPUEVENT_VALID_SMM transfer the smi sub-struct. 1145=============================== ================================== 1146 1147If KVM_CAP_INTR_SHADOW is available, KVM_VCPUEVENT_VALID_SHADOW can be set in 1148the flags field to signal that interrupt.shadow contains a valid state and 1149shall be written into the VCPU. 1150 1151KVM_VCPUEVENT_VALID_SMM can only be set if KVM_CAP_X86_SMM is available. 1152 1153If KVM_CAP_EXCEPTION_PAYLOAD is enabled, KVM_VCPUEVENT_VALID_PAYLOAD 1154can be set in the flags field to signal that the 1155exception_has_payload, exception_payload, and exception.pending fields 1156contain a valid state and shall be written into the VCPU. 1157 1158ARM/ARM64: 1159^^^^^^^^^^ 1160 1161User space may need to inject several types of events to the guest. 1162 1163Set the pending SError exception state for this VCPU. It is not possible to 1164'cancel' an Serror that has been made pending. 1165 1166If the guest performed an access to I/O memory which could not be handled by 1167userspace, for example because of missing instruction syndrome decode 1168information or because there is no device mapped at the accessed IPA, then 1169userspace can ask the kernel to inject an external abort using the address 1170from the exiting fault on the VCPU. It is a programming error to set 1171ext_dabt_pending after an exit which was not either KVM_EXIT_MMIO or 1172KVM_EXIT_ARM_NISV. This feature is only available if the system supports 1173KVM_CAP_ARM_INJECT_EXT_DABT. This is a helper which provides commonality in 1174how userspace reports accesses for the above cases to guests, across different 1175userspace implementations. Nevertheless, userspace can still emulate all Arm 1176exceptions by manipulating individual registers using the KVM_SET_ONE_REG API. 1177 1178See KVM_GET_VCPU_EVENTS for the data structure. 1179 1180 11814.33 KVM_GET_DEBUGREGS 1182---------------------- 1183 1184:Capability: KVM_CAP_DEBUGREGS 1185:Architectures: x86 1186:Type: vm ioctl 1187:Parameters: struct kvm_debugregs (out) 1188:Returns: 0 on success, -1 on error 1189 1190Reads debug registers from the vcpu. 1191 1192:: 1193 1194 struct kvm_debugregs { 1195 __u64 db[4]; 1196 __u64 dr6; 1197 __u64 dr7; 1198 __u64 flags; 1199 __u64 reserved[9]; 1200 }; 1201 1202 12034.34 KVM_SET_DEBUGREGS 1204---------------------- 1205 1206:Capability: KVM_CAP_DEBUGREGS 1207:Architectures: x86 1208:Type: vm ioctl 1209:Parameters: struct kvm_debugregs (in) 1210:Returns: 0 on success, -1 on error 1211 1212Writes debug registers into the vcpu. 1213 1214See KVM_GET_DEBUGREGS for the data structure. The flags field is unused 1215yet and must be cleared on entry. 1216 1217 12184.35 KVM_SET_USER_MEMORY_REGION 1219------------------------------- 1220 1221:Capability: KVM_CAP_USER_MEMORY 1222:Architectures: all 1223:Type: vm ioctl 1224:Parameters: struct kvm_userspace_memory_region (in) 1225:Returns: 0 on success, -1 on error 1226 1227:: 1228 1229 struct kvm_userspace_memory_region { 1230 __u32 slot; 1231 __u32 flags; 1232 __u64 guest_phys_addr; 1233 __u64 memory_size; /* bytes */ 1234 __u64 userspace_addr; /* start of the userspace allocated memory */ 1235 }; 1236 1237 /* for kvm_memory_region::flags */ 1238 #define KVM_MEM_LOG_DIRTY_PAGES (1UL << 0) 1239 #define KVM_MEM_READONLY (1UL << 1) 1240 1241This ioctl allows the user to create, modify or delete a guest physical 1242memory slot. Bits 0-15 of "slot" specify the slot id and this value 1243should be less than the maximum number of user memory slots supported per 1244VM. The maximum allowed slots can be queried using KVM_CAP_NR_MEMSLOTS. 1245Slots may not overlap in guest physical address space. 1246 1247If KVM_CAP_MULTI_ADDRESS_SPACE is available, bits 16-31 of "slot" 1248specifies the address space which is being modified. They must be 1249less than the value that KVM_CHECK_EXTENSION returns for the 1250KVM_CAP_MULTI_ADDRESS_SPACE capability. Slots in separate address spaces 1251are unrelated; the restriction on overlapping slots only applies within 1252each address space. 1253 1254Deleting a slot is done by passing zero for memory_size. When changing 1255an existing slot, it may be moved in the guest physical memory space, 1256or its flags may be modified, but it may not be resized. 1257 1258Memory for the region is taken starting at the address denoted by the 1259field userspace_addr, which must point at user addressable memory for 1260the entire memory slot size. Any object may back this memory, including 1261anonymous memory, ordinary files, and hugetlbfs. 1262 1263It is recommended that the lower 21 bits of guest_phys_addr and userspace_addr 1264be identical. This allows large pages in the guest to be backed by large 1265pages in the host. 1266 1267The flags field supports two flags: KVM_MEM_LOG_DIRTY_PAGES and 1268KVM_MEM_READONLY. The former can be set to instruct KVM to keep track of 1269writes to memory within the slot. See KVM_GET_DIRTY_LOG ioctl to know how to 1270use it. The latter can be set, if KVM_CAP_READONLY_MEM capability allows it, 1271to make a new slot read-only. In this case, writes to this memory will be 1272posted to userspace as KVM_EXIT_MMIO exits. 1273 1274When the KVM_CAP_SYNC_MMU capability is available, changes in the backing of 1275the memory region are automatically reflected into the guest. For example, an 1276mmap() that affects the region will be made visible immediately. Another 1277example is madvise(MADV_DROP). 1278 1279It is recommended to use this API instead of the KVM_SET_MEMORY_REGION ioctl. 1280The KVM_SET_MEMORY_REGION does not allow fine grained control over memory 1281allocation and is deprecated. 1282 1283 12844.36 KVM_SET_TSS_ADDR 1285--------------------- 1286 1287:Capability: KVM_CAP_SET_TSS_ADDR 1288:Architectures: x86 1289:Type: vm ioctl 1290:Parameters: unsigned long tss_address (in) 1291:Returns: 0 on success, -1 on error 1292 1293This ioctl defines the physical address of a three-page region in the guest 1294physical address space. The region must be within the first 4GB of the 1295guest physical address space and must not conflict with any memory slot 1296or any mmio address. The guest may malfunction if it accesses this memory 1297region. 1298 1299This ioctl is required on Intel-based hosts. This is needed on Intel hardware 1300because of a quirk in the virtualization implementation (see the internals 1301documentation when it pops into existence). 1302 1303 13044.37 KVM_ENABLE_CAP 1305------------------- 1306 1307:Capability: KVM_CAP_ENABLE_CAP 1308:Architectures: mips, ppc, s390 1309:Type: vcpu ioctl 1310:Parameters: struct kvm_enable_cap (in) 1311:Returns: 0 on success; -1 on error 1312 1313:Capability: KVM_CAP_ENABLE_CAP_VM 1314:Architectures: all 1315:Type: vcpu ioctl 1316:Parameters: struct kvm_enable_cap (in) 1317:Returns: 0 on success; -1 on error 1318 1319.. note:: 1320 1321 Not all extensions are enabled by default. Using this ioctl the application 1322 can enable an extension, making it available to the guest. 1323 1324On systems that do not support this ioctl, it always fails. On systems that 1325do support it, it only works for extensions that are supported for enablement. 1326 1327To check if a capability can be enabled, the KVM_CHECK_EXTENSION ioctl should 1328be used. 1329 1330:: 1331 1332 struct kvm_enable_cap { 1333 /* in */ 1334 __u32 cap; 1335 1336The capability that is supposed to get enabled. 1337 1338:: 1339 1340 __u32 flags; 1341 1342A bitfield indicating future enhancements. Has to be 0 for now. 1343 1344:: 1345 1346 __u64 args[4]; 1347 1348Arguments for enabling a feature. If a feature needs initial values to 1349function properly, this is the place to put them. 1350 1351:: 1352 1353 __u8 pad[64]; 1354 }; 1355 1356The vcpu ioctl should be used for vcpu-specific capabilities, the vm ioctl 1357for vm-wide capabilities. 1358 13594.38 KVM_GET_MP_STATE 1360--------------------- 1361 1362:Capability: KVM_CAP_MP_STATE 1363:Architectures: x86, s390, arm, arm64 1364:Type: vcpu ioctl 1365:Parameters: struct kvm_mp_state (out) 1366:Returns: 0 on success; -1 on error 1367 1368:: 1369 1370 struct kvm_mp_state { 1371 __u32 mp_state; 1372 }; 1373 1374Returns the vcpu's current "multiprocessing state" (though also valid on 1375uniprocessor guests). 1376 1377Possible values are: 1378 1379 ========================== =============================================== 1380 KVM_MP_STATE_RUNNABLE the vcpu is currently running [x86,arm/arm64] 1381 KVM_MP_STATE_UNINITIALIZED the vcpu is an application processor (AP) 1382 which has not yet received an INIT signal [x86] 1383 KVM_MP_STATE_INIT_RECEIVED the vcpu has received an INIT signal, and is 1384 now ready for a SIPI [x86] 1385 KVM_MP_STATE_HALTED the vcpu has executed a HLT instruction and 1386 is waiting for an interrupt [x86] 1387 KVM_MP_STATE_SIPI_RECEIVED the vcpu has just received a SIPI (vector 1388 accessible via KVM_GET_VCPU_EVENTS) [x86] 1389 KVM_MP_STATE_STOPPED the vcpu is stopped [s390,arm/arm64] 1390 KVM_MP_STATE_CHECK_STOP the vcpu is in a special error state [s390] 1391 KVM_MP_STATE_OPERATING the vcpu is operating (running or halted) 1392 [s390] 1393 KVM_MP_STATE_LOAD the vcpu is in a special load/startup state 1394 [s390] 1395 ========================== =============================================== 1396 1397On x86, this ioctl is only useful after KVM_CREATE_IRQCHIP. Without an 1398in-kernel irqchip, the multiprocessing state must be maintained by userspace on 1399these architectures. 1400 1401For arm/arm64: 1402^^^^^^^^^^^^^^ 1403 1404The only states that are valid are KVM_MP_STATE_STOPPED and 1405KVM_MP_STATE_RUNNABLE which reflect if the vcpu is paused or not. 1406 14074.39 KVM_SET_MP_STATE 1408--------------------- 1409 1410:Capability: KVM_CAP_MP_STATE 1411:Architectures: x86, s390, arm, arm64 1412:Type: vcpu ioctl 1413:Parameters: struct kvm_mp_state (in) 1414:Returns: 0 on success; -1 on error 1415 1416Sets the vcpu's current "multiprocessing state"; see KVM_GET_MP_STATE for 1417arguments. 1418 1419On x86, this ioctl is only useful after KVM_CREATE_IRQCHIP. Without an 1420in-kernel irqchip, the multiprocessing state must be maintained by userspace on 1421these architectures. 1422 1423For arm/arm64: 1424^^^^^^^^^^^^^^ 1425 1426The only states that are valid are KVM_MP_STATE_STOPPED and 1427KVM_MP_STATE_RUNNABLE which reflect if the vcpu should be paused or not. 1428 14294.40 KVM_SET_IDENTITY_MAP_ADDR 1430------------------------------ 1431 1432:Capability: KVM_CAP_SET_IDENTITY_MAP_ADDR 1433:Architectures: x86 1434:Type: vm ioctl 1435:Parameters: unsigned long identity (in) 1436:Returns: 0 on success, -1 on error 1437 1438This ioctl defines the physical address of a one-page region in the guest 1439physical address space. The region must be within the first 4GB of the 1440guest physical address space and must not conflict with any memory slot 1441or any mmio address. The guest may malfunction if it accesses this memory 1442region. 1443 1444Setting the address to 0 will result in resetting the address to its default 1445(0xfffbc000). 1446 1447This ioctl is required on Intel-based hosts. This is needed on Intel hardware 1448because of a quirk in the virtualization implementation (see the internals 1449documentation when it pops into existence). 1450 1451Fails if any VCPU has already been created. 1452 14534.41 KVM_SET_BOOT_CPU_ID 1454------------------------ 1455 1456:Capability: KVM_CAP_SET_BOOT_CPU_ID 1457:Architectures: x86 1458:Type: vm ioctl 1459:Parameters: unsigned long vcpu_id 1460:Returns: 0 on success, -1 on error 1461 1462Define which vcpu is the Bootstrap Processor (BSP). Values are the same 1463as the vcpu id in KVM_CREATE_VCPU. If this ioctl is not called, the default 1464is vcpu 0. 1465 1466 14674.42 KVM_GET_XSAVE 1468------------------ 1469 1470:Capability: KVM_CAP_XSAVE 1471:Architectures: x86 1472:Type: vcpu ioctl 1473:Parameters: struct kvm_xsave (out) 1474:Returns: 0 on success, -1 on error 1475 1476 1477:: 1478 1479 struct kvm_xsave { 1480 __u32 region[1024]; 1481 }; 1482 1483This ioctl would copy current vcpu's xsave struct to the userspace. 1484 1485 14864.43 KVM_SET_XSAVE 1487------------------ 1488 1489:Capability: KVM_CAP_XSAVE 1490:Architectures: x86 1491:Type: vcpu ioctl 1492:Parameters: struct kvm_xsave (in) 1493:Returns: 0 on success, -1 on error 1494 1495:: 1496 1497 1498 struct kvm_xsave { 1499 __u32 region[1024]; 1500 }; 1501 1502This ioctl would copy userspace's xsave struct to the kernel. 1503 1504 15054.44 KVM_GET_XCRS 1506----------------- 1507 1508:Capability: KVM_CAP_XCRS 1509:Architectures: x86 1510:Type: vcpu ioctl 1511:Parameters: struct kvm_xcrs (out) 1512:Returns: 0 on success, -1 on error 1513 1514:: 1515 1516 struct kvm_xcr { 1517 __u32 xcr; 1518 __u32 reserved; 1519 __u64 value; 1520 }; 1521 1522 struct kvm_xcrs { 1523 __u32 nr_xcrs; 1524 __u32 flags; 1525 struct kvm_xcr xcrs[KVM_MAX_XCRS]; 1526 __u64 padding[16]; 1527 }; 1528 1529This ioctl would copy current vcpu's xcrs to the userspace. 1530 1531 15324.45 KVM_SET_XCRS 1533----------------- 1534 1535:Capability: KVM_CAP_XCRS 1536:Architectures: x86 1537:Type: vcpu ioctl 1538:Parameters: struct kvm_xcrs (in) 1539:Returns: 0 on success, -1 on error 1540 1541:: 1542 1543 struct kvm_xcr { 1544 __u32 xcr; 1545 __u32 reserved; 1546 __u64 value; 1547 }; 1548 1549 struct kvm_xcrs { 1550 __u32 nr_xcrs; 1551 __u32 flags; 1552 struct kvm_xcr xcrs[KVM_MAX_XCRS]; 1553 __u64 padding[16]; 1554 }; 1555 1556This ioctl would set vcpu's xcr to the value userspace specified. 1557 1558 15594.46 KVM_GET_SUPPORTED_CPUID 1560---------------------------- 1561 1562:Capability: KVM_CAP_EXT_CPUID 1563:Architectures: x86 1564:Type: system ioctl 1565:Parameters: struct kvm_cpuid2 (in/out) 1566:Returns: 0 on success, -1 on error 1567 1568:: 1569 1570 struct kvm_cpuid2 { 1571 __u32 nent; 1572 __u32 padding; 1573 struct kvm_cpuid_entry2 entries[0]; 1574 }; 1575 1576 #define KVM_CPUID_FLAG_SIGNIFCANT_INDEX BIT(0) 1577 #define KVM_CPUID_FLAG_STATEFUL_FUNC BIT(1) /* deprecated */ 1578 #define KVM_CPUID_FLAG_STATE_READ_NEXT BIT(2) /* deprecated */ 1579 1580 struct kvm_cpuid_entry2 { 1581 __u32 function; 1582 __u32 index; 1583 __u32 flags; 1584 __u32 eax; 1585 __u32 ebx; 1586 __u32 ecx; 1587 __u32 edx; 1588 __u32 padding[3]; 1589 }; 1590 1591This ioctl returns x86 cpuid features which are supported by both the 1592hardware and kvm in its default configuration. Userspace can use the 1593information returned by this ioctl to construct cpuid information (for 1594KVM_SET_CPUID2) that is consistent with hardware, kernel, and 1595userspace capabilities, and with user requirements (for example, the 1596user may wish to constrain cpuid to emulate older hardware, or for 1597feature consistency across a cluster). 1598 1599Note that certain capabilities, such as KVM_CAP_X86_DISABLE_EXITS, may 1600expose cpuid features (e.g. MONITOR) which are not supported by kvm in 1601its default configuration. If userspace enables such capabilities, it 1602is responsible for modifying the results of this ioctl appropriately. 1603 1604Userspace invokes KVM_GET_SUPPORTED_CPUID by passing a kvm_cpuid2 structure 1605with the 'nent' field indicating the number of entries in the variable-size 1606array 'entries'. If the number of entries is too low to describe the cpu 1607capabilities, an error (E2BIG) is returned. If the number is too high, 1608the 'nent' field is adjusted and an error (ENOMEM) is returned. If the 1609number is just right, the 'nent' field is adjusted to the number of valid 1610entries in the 'entries' array, which is then filled. 1611 1612The entries returned are the host cpuid as returned by the cpuid instruction, 1613with unknown or unsupported features masked out. Some features (for example, 1614x2apic), may not be present in the host cpu, but are exposed by kvm if it can 1615emulate them efficiently. The fields in each entry are defined as follows: 1616 1617 function: 1618 the eax value used to obtain the entry 1619 1620 index: 1621 the ecx value used to obtain the entry (for entries that are 1622 affected by ecx) 1623 1624 flags: 1625 an OR of zero or more of the following: 1626 1627 KVM_CPUID_FLAG_SIGNIFCANT_INDEX: 1628 if the index field is valid 1629 1630 eax, ebx, ecx, edx: 1631 the values returned by the cpuid instruction for 1632 this function/index combination 1633 1634The TSC deadline timer feature (CPUID leaf 1, ecx[24]) is always returned 1635as false, since the feature depends on KVM_CREATE_IRQCHIP for local APIC 1636support. Instead it is reported via:: 1637 1638 ioctl(KVM_CHECK_EXTENSION, KVM_CAP_TSC_DEADLINE_TIMER) 1639 1640if that returns true and you use KVM_CREATE_IRQCHIP, or if you emulate the 1641feature in userspace, then you can enable the feature for KVM_SET_CPUID2. 1642 1643 16444.47 KVM_PPC_GET_PVINFO 1645----------------------- 1646 1647:Capability: KVM_CAP_PPC_GET_PVINFO 1648:Architectures: ppc 1649:Type: vm ioctl 1650:Parameters: struct kvm_ppc_pvinfo (out) 1651:Returns: 0 on success, !0 on error 1652 1653:: 1654 1655 struct kvm_ppc_pvinfo { 1656 __u32 flags; 1657 __u32 hcall[4]; 1658 __u8 pad[108]; 1659 }; 1660 1661This ioctl fetches PV specific information that need to be passed to the guest 1662using the device tree or other means from vm context. 1663 1664The hcall array defines 4 instructions that make up a hypercall. 1665 1666If any additional field gets added to this structure later on, a bit for that 1667additional piece of information will be set in the flags bitmap. 1668 1669The flags bitmap is defined as:: 1670 1671 /* the host supports the ePAPR idle hcall 1672 #define KVM_PPC_PVINFO_FLAGS_EV_IDLE (1<<0) 1673 16744.52 KVM_SET_GSI_ROUTING 1675------------------------ 1676 1677:Capability: KVM_CAP_IRQ_ROUTING 1678:Architectures: x86 s390 arm arm64 1679:Type: vm ioctl 1680:Parameters: struct kvm_irq_routing (in) 1681:Returns: 0 on success, -1 on error 1682 1683Sets the GSI routing table entries, overwriting any previously set entries. 1684 1685On arm/arm64, GSI routing has the following limitation: 1686 1687- GSI routing does not apply to KVM_IRQ_LINE but only to KVM_IRQFD. 1688 1689:: 1690 1691 struct kvm_irq_routing { 1692 __u32 nr; 1693 __u32 flags; 1694 struct kvm_irq_routing_entry entries[0]; 1695 }; 1696 1697No flags are specified so far, the corresponding field must be set to zero. 1698 1699:: 1700 1701 struct kvm_irq_routing_entry { 1702 __u32 gsi; 1703 __u32 type; 1704 __u32 flags; 1705 __u32 pad; 1706 union { 1707 struct kvm_irq_routing_irqchip irqchip; 1708 struct kvm_irq_routing_msi msi; 1709 struct kvm_irq_routing_s390_adapter adapter; 1710 struct kvm_irq_routing_hv_sint hv_sint; 1711 __u32 pad[8]; 1712 } u; 1713 }; 1714 1715 /* gsi routing entry types */ 1716 #define KVM_IRQ_ROUTING_IRQCHIP 1 1717 #define KVM_IRQ_ROUTING_MSI 2 1718 #define KVM_IRQ_ROUTING_S390_ADAPTER 3 1719 #define KVM_IRQ_ROUTING_HV_SINT 4 1720 1721flags: 1722 1723- KVM_MSI_VALID_DEVID: used along with KVM_IRQ_ROUTING_MSI routing entry 1724 type, specifies that the devid field contains a valid value. The per-VM 1725 KVM_CAP_MSI_DEVID capability advertises the requirement to provide 1726 the device ID. If this capability is not available, userspace should 1727 never set the KVM_MSI_VALID_DEVID flag as the ioctl might fail. 1728- zero otherwise 1729 1730:: 1731 1732 struct kvm_irq_routing_irqchip { 1733 __u32 irqchip; 1734 __u32 pin; 1735 }; 1736 1737 struct kvm_irq_routing_msi { 1738 __u32 address_lo; 1739 __u32 address_hi; 1740 __u32 data; 1741 union { 1742 __u32 pad; 1743 __u32 devid; 1744 }; 1745 }; 1746 1747If KVM_MSI_VALID_DEVID is set, devid contains a unique device identifier 1748for the device that wrote the MSI message. For PCI, this is usually a 1749BFD identifier in the lower 16 bits. 1750 1751On x86, address_hi is ignored unless the KVM_X2APIC_API_USE_32BIT_IDS 1752feature of KVM_CAP_X2APIC_API capability is enabled. If it is enabled, 1753address_hi bits 31-8 provide bits 31-8 of the destination id. Bits 7-0 of 1754address_hi must be zero. 1755 1756:: 1757 1758 struct kvm_irq_routing_s390_adapter { 1759 __u64 ind_addr; 1760 __u64 summary_addr; 1761 __u64 ind_offset; 1762 __u32 summary_offset; 1763 __u32 adapter_id; 1764 }; 1765 1766 struct kvm_irq_routing_hv_sint { 1767 __u32 vcpu; 1768 __u32 sint; 1769 }; 1770 1771 17724.55 KVM_SET_TSC_KHZ 1773-------------------- 1774 1775:Capability: KVM_CAP_TSC_CONTROL 1776:Architectures: x86 1777:Type: vcpu ioctl 1778:Parameters: virtual tsc_khz 1779:Returns: 0 on success, -1 on error 1780 1781Specifies the tsc frequency for the virtual machine. The unit of the 1782frequency is KHz. 1783 1784 17854.56 KVM_GET_TSC_KHZ 1786-------------------- 1787 1788:Capability: KVM_CAP_GET_TSC_KHZ 1789:Architectures: x86 1790:Type: vcpu ioctl 1791:Parameters: none 1792:Returns: virtual tsc-khz on success, negative value on error 1793 1794Returns the tsc frequency of the guest. The unit of the return value is 1795KHz. If the host has unstable tsc this ioctl returns -EIO instead as an 1796error. 1797 1798 17994.57 KVM_GET_LAPIC 1800------------------ 1801 1802:Capability: KVM_CAP_IRQCHIP 1803:Architectures: x86 1804:Type: vcpu ioctl 1805:Parameters: struct kvm_lapic_state (out) 1806:Returns: 0 on success, -1 on error 1807 1808:: 1809 1810 #define KVM_APIC_REG_SIZE 0x400 1811 struct kvm_lapic_state { 1812 char regs[KVM_APIC_REG_SIZE]; 1813 }; 1814 1815Reads the Local APIC registers and copies them into the input argument. The 1816data format and layout are the same as documented in the architecture manual. 1817 1818If KVM_X2APIC_API_USE_32BIT_IDS feature of KVM_CAP_X2APIC_API is 1819enabled, then the format of APIC_ID register depends on the APIC mode 1820(reported by MSR_IA32_APICBASE) of its VCPU. x2APIC stores APIC ID in 1821the APIC_ID register (bytes 32-35). xAPIC only allows an 8-bit APIC ID 1822which is stored in bits 31-24 of the APIC register, or equivalently in 1823byte 35 of struct kvm_lapic_state's regs field. KVM_GET_LAPIC must then 1824be called after MSR_IA32_APICBASE has been set with KVM_SET_MSR. 1825 1826If KVM_X2APIC_API_USE_32BIT_IDS feature is disabled, struct kvm_lapic_state 1827always uses xAPIC format. 1828 1829 18304.58 KVM_SET_LAPIC 1831------------------ 1832 1833:Capability: KVM_CAP_IRQCHIP 1834:Architectures: x86 1835:Type: vcpu ioctl 1836:Parameters: struct kvm_lapic_state (in) 1837:Returns: 0 on success, -1 on error 1838 1839:: 1840 1841 #define KVM_APIC_REG_SIZE 0x400 1842 struct kvm_lapic_state { 1843 char regs[KVM_APIC_REG_SIZE]; 1844 }; 1845 1846Copies the input argument into the Local APIC registers. The data format 1847and layout are the same as documented in the architecture manual. 1848 1849The format of the APIC ID register (bytes 32-35 of struct kvm_lapic_state's 1850regs field) depends on the state of the KVM_CAP_X2APIC_API capability. 1851See the note in KVM_GET_LAPIC. 1852 1853 18544.59 KVM_IOEVENTFD 1855------------------ 1856 1857:Capability: KVM_CAP_IOEVENTFD 1858:Architectures: all 1859:Type: vm ioctl 1860:Parameters: struct kvm_ioeventfd (in) 1861:Returns: 0 on success, !0 on error 1862 1863This ioctl attaches or detaches an ioeventfd to a legal pio/mmio address 1864within the guest. A guest write in the registered address will signal the 1865provided event instead of triggering an exit. 1866 1867:: 1868 1869 struct kvm_ioeventfd { 1870 __u64 datamatch; 1871 __u64 addr; /* legal pio/mmio address */ 1872 __u32 len; /* 0, 1, 2, 4, or 8 bytes */ 1873 __s32 fd; 1874 __u32 flags; 1875 __u8 pad[36]; 1876 }; 1877 1878For the special case of virtio-ccw devices on s390, the ioevent is matched 1879to a subchannel/virtqueue tuple instead. 1880 1881The following flags are defined:: 1882 1883 #define KVM_IOEVENTFD_FLAG_DATAMATCH (1 << kvm_ioeventfd_flag_nr_datamatch) 1884 #define KVM_IOEVENTFD_FLAG_PIO (1 << kvm_ioeventfd_flag_nr_pio) 1885 #define KVM_IOEVENTFD_FLAG_DEASSIGN (1 << kvm_ioeventfd_flag_nr_deassign) 1886 #define KVM_IOEVENTFD_FLAG_VIRTIO_CCW_NOTIFY \ 1887 (1 << kvm_ioeventfd_flag_nr_virtio_ccw_notify) 1888 1889If datamatch flag is set, the event will be signaled only if the written value 1890to the registered address is equal to datamatch in struct kvm_ioeventfd. 1891 1892For virtio-ccw devices, addr contains the subchannel id and datamatch the 1893virtqueue index. 1894 1895With KVM_CAP_IOEVENTFD_ANY_LENGTH, a zero length ioeventfd is allowed, and 1896the kernel will ignore the length of guest write and may get a faster vmexit. 1897The speedup may only apply to specific architectures, but the ioeventfd will 1898work anyway. 1899 19004.60 KVM_DIRTY_TLB 1901------------------ 1902 1903:Capability: KVM_CAP_SW_TLB 1904:Architectures: ppc 1905:Type: vcpu ioctl 1906:Parameters: struct kvm_dirty_tlb (in) 1907:Returns: 0 on success, -1 on error 1908 1909:: 1910 1911 struct kvm_dirty_tlb { 1912 __u64 bitmap; 1913 __u32 num_dirty; 1914 }; 1915 1916This must be called whenever userspace has changed an entry in the shared 1917TLB, prior to calling KVM_RUN on the associated vcpu. 1918 1919The "bitmap" field is the userspace address of an array. This array 1920consists of a number of bits, equal to the total number of TLB entries as 1921determined by the last successful call to KVM_CONFIG_TLB, rounded up to the 1922nearest multiple of 64. 1923 1924Each bit corresponds to one TLB entry, ordered the same as in the shared TLB 1925array. 1926 1927The array is little-endian: the bit 0 is the least significant bit of the 1928first byte, bit 8 is the least significant bit of the second byte, etc. 1929This avoids any complications with differing word sizes. 1930 1931The "num_dirty" field is a performance hint for KVM to determine whether it 1932should skip processing the bitmap and just invalidate everything. It must 1933be set to the number of set bits in the bitmap. 1934 1935 19364.62 KVM_CREATE_SPAPR_TCE 1937------------------------- 1938 1939:Capability: KVM_CAP_SPAPR_TCE 1940:Architectures: powerpc 1941:Type: vm ioctl 1942:Parameters: struct kvm_create_spapr_tce (in) 1943:Returns: file descriptor for manipulating the created TCE table 1944 1945This creates a virtual TCE (translation control entry) table, which 1946is an IOMMU for PAPR-style virtual I/O. It is used to translate 1947logical addresses used in virtual I/O into guest physical addresses, 1948and provides a scatter/gather capability for PAPR virtual I/O. 1949 1950:: 1951 1952 /* for KVM_CAP_SPAPR_TCE */ 1953 struct kvm_create_spapr_tce { 1954 __u64 liobn; 1955 __u32 window_size; 1956 }; 1957 1958The liobn field gives the logical IO bus number for which to create a 1959TCE table. The window_size field specifies the size of the DMA window 1960which this TCE table will translate - the table will contain one 64 1961bit TCE entry for every 4kiB of the DMA window. 1962 1963When the guest issues an H_PUT_TCE hcall on a liobn for which a TCE 1964table has been created using this ioctl(), the kernel will handle it 1965in real mode, updating the TCE table. H_PUT_TCE calls for other 1966liobns will cause a vm exit and must be handled by userspace. 1967 1968The return value is a file descriptor which can be passed to mmap(2) 1969to map the created TCE table into userspace. This lets userspace read 1970the entries written by kernel-handled H_PUT_TCE calls, and also lets 1971userspace update the TCE table directly which is useful in some 1972circumstances. 1973 1974 19754.63 KVM_ALLOCATE_RMA 1976--------------------- 1977 1978:Capability: KVM_CAP_PPC_RMA 1979:Architectures: powerpc 1980:Type: vm ioctl 1981:Parameters: struct kvm_allocate_rma (out) 1982:Returns: file descriptor for mapping the allocated RMA 1983 1984This allocates a Real Mode Area (RMA) from the pool allocated at boot 1985time by the kernel. An RMA is a physically-contiguous, aligned region 1986of memory used on older POWER processors to provide the memory which 1987will be accessed by real-mode (MMU off) accesses in a KVM guest. 1988POWER processors support a set of sizes for the RMA that usually 1989includes 64MB, 128MB, 256MB and some larger powers of two. 1990 1991:: 1992 1993 /* for KVM_ALLOCATE_RMA */ 1994 struct kvm_allocate_rma { 1995 __u64 rma_size; 1996 }; 1997 1998The return value is a file descriptor which can be passed to mmap(2) 1999to map the allocated RMA into userspace. The mapped area can then be 2000passed to the KVM_SET_USER_MEMORY_REGION ioctl to establish it as the 2001RMA for a virtual machine. The size of the RMA in bytes (which is 2002fixed at host kernel boot time) is returned in the rma_size field of 2003the argument structure. 2004 2005The KVM_CAP_PPC_RMA capability is 1 or 2 if the KVM_ALLOCATE_RMA ioctl 2006is supported; 2 if the processor requires all virtual machines to have 2007an RMA, or 1 if the processor can use an RMA but doesn't require it, 2008because it supports the Virtual RMA (VRMA) facility. 2009 2010 20114.64 KVM_NMI 2012------------ 2013 2014:Capability: KVM_CAP_USER_NMI 2015:Architectures: x86 2016:Type: vcpu ioctl 2017:Parameters: none 2018:Returns: 0 on success, -1 on error 2019 2020Queues an NMI on the thread's vcpu. Note this is well defined only 2021when KVM_CREATE_IRQCHIP has not been called, since this is an interface 2022between the virtual cpu core and virtual local APIC. After KVM_CREATE_IRQCHIP 2023has been called, this interface is completely emulated within the kernel. 2024 2025To use this to emulate the LINT1 input with KVM_CREATE_IRQCHIP, use the 2026following algorithm: 2027 2028 - pause the vcpu 2029 - read the local APIC's state (KVM_GET_LAPIC) 2030 - check whether changing LINT1 will queue an NMI (see the LVT entry for LINT1) 2031 - if so, issue KVM_NMI 2032 - resume the vcpu 2033 2034Some guests configure the LINT1 NMI input to cause a panic, aiding in 2035debugging. 2036 2037 20384.65 KVM_S390_UCAS_MAP 2039---------------------- 2040 2041:Capability: KVM_CAP_S390_UCONTROL 2042:Architectures: s390 2043:Type: vcpu ioctl 2044:Parameters: struct kvm_s390_ucas_mapping (in) 2045:Returns: 0 in case of success 2046 2047The parameter is defined like this:: 2048 2049 struct kvm_s390_ucas_mapping { 2050 __u64 user_addr; 2051 __u64 vcpu_addr; 2052 __u64 length; 2053 }; 2054 2055This ioctl maps the memory at "user_addr" with the length "length" to 2056the vcpu's address space starting at "vcpu_addr". All parameters need to 2057be aligned by 1 megabyte. 2058 2059 20604.66 KVM_S390_UCAS_UNMAP 2061------------------------ 2062 2063:Capability: KVM_CAP_S390_UCONTROL 2064:Architectures: s390 2065:Type: vcpu ioctl 2066:Parameters: struct kvm_s390_ucas_mapping (in) 2067:Returns: 0 in case of success 2068 2069The parameter is defined like this:: 2070 2071 struct kvm_s390_ucas_mapping { 2072 __u64 user_addr; 2073 __u64 vcpu_addr; 2074 __u64 length; 2075 }; 2076 2077This ioctl unmaps the memory in the vcpu's address space starting at 2078"vcpu_addr" with the length "length". The field "user_addr" is ignored. 2079All parameters need to be aligned by 1 megabyte. 2080 2081 20824.67 KVM_S390_VCPU_FAULT 2083------------------------ 2084 2085:Capability: KVM_CAP_S390_UCONTROL 2086:Architectures: s390 2087:Type: vcpu ioctl 2088:Parameters: vcpu absolute address (in) 2089:Returns: 0 in case of success 2090 2091This call creates a page table entry on the virtual cpu's address space 2092(for user controlled virtual machines) or the virtual machine's address 2093space (for regular virtual machines). This only works for minor faults, 2094thus it's recommended to access subject memory page via the user page 2095table upfront. This is useful to handle validity intercepts for user 2096controlled virtual machines to fault in the virtual cpu's lowcore pages 2097prior to calling the KVM_RUN ioctl. 2098 2099 21004.68 KVM_SET_ONE_REG 2101-------------------- 2102 2103:Capability: KVM_CAP_ONE_REG 2104:Architectures: all 2105:Type: vcpu ioctl 2106:Parameters: struct kvm_one_reg (in) 2107:Returns: 0 on success, negative value on failure 2108 2109Errors: 2110 2111 ====== ============================================================ 2112 ENOENT no such register 2113 EINVAL invalid register ID, or no such register or used with VMs in 2114 protected virtualization mode on s390 2115 EPERM (arm64) register access not allowed before vcpu finalization 2116 ====== ============================================================ 2117 2118(These error codes are indicative only: do not rely on a specific error 2119code being returned in a specific situation.) 2120 2121:: 2122 2123 struct kvm_one_reg { 2124 __u64 id; 2125 __u64 addr; 2126 }; 2127 2128Using this ioctl, a single vcpu register can be set to a specific value 2129defined by user space with the passed in struct kvm_one_reg, where id 2130refers to the register identifier as described below and addr is a pointer 2131to a variable with the respective size. There can be architecture agnostic 2132and architecture specific registers. Each have their own range of operation 2133and their own constants and width. To keep track of the implemented 2134registers, find a list below: 2135 2136 ======= =============================== ============ 2137 Arch Register Width (bits) 2138 ======= =============================== ============ 2139 PPC KVM_REG_PPC_HIOR 64 2140 PPC KVM_REG_PPC_IAC1 64 2141 PPC KVM_REG_PPC_IAC2 64 2142 PPC KVM_REG_PPC_IAC3 64 2143 PPC KVM_REG_PPC_IAC4 64 2144 PPC KVM_REG_PPC_DAC1 64 2145 PPC KVM_REG_PPC_DAC2 64 2146 PPC KVM_REG_PPC_DABR 64 2147 PPC KVM_REG_PPC_DSCR 64 2148 PPC KVM_REG_PPC_PURR 64 2149 PPC KVM_REG_PPC_SPURR 64 2150 PPC KVM_REG_PPC_DAR 64 2151 PPC KVM_REG_PPC_DSISR 32 2152 PPC KVM_REG_PPC_AMR 64 2153 PPC KVM_REG_PPC_UAMOR 64 2154 PPC KVM_REG_PPC_MMCR0 64 2155 PPC KVM_REG_PPC_MMCR1 64 2156 PPC KVM_REG_PPC_MMCRA 64 2157 PPC KVM_REG_PPC_MMCR2 64 2158 PPC KVM_REG_PPC_MMCRS 64 2159 PPC KVM_REG_PPC_SIAR 64 2160 PPC KVM_REG_PPC_SDAR 64 2161 PPC KVM_REG_PPC_SIER 64 2162 PPC KVM_REG_PPC_PMC1 32 2163 PPC KVM_REG_PPC_PMC2 32 2164 PPC KVM_REG_PPC_PMC3 32 2165 PPC KVM_REG_PPC_PMC4 32 2166 PPC KVM_REG_PPC_PMC5 32 2167 PPC KVM_REG_PPC_PMC6 32 2168 PPC KVM_REG_PPC_PMC7 32 2169 PPC KVM_REG_PPC_PMC8 32 2170 PPC KVM_REG_PPC_FPR0 64 2171 ... 2172 PPC KVM_REG_PPC_FPR31 64 2173 PPC KVM_REG_PPC_VR0 128 2174 ... 2175 PPC KVM_REG_PPC_VR31 128 2176 PPC KVM_REG_PPC_VSR0 128 2177 ... 2178 PPC KVM_REG_PPC_VSR31 128 2179 PPC KVM_REG_PPC_FPSCR 64 2180 PPC KVM_REG_PPC_VSCR 32 2181 PPC KVM_REG_PPC_VPA_ADDR 64 2182 PPC KVM_REG_PPC_VPA_SLB 128 2183 PPC KVM_REG_PPC_VPA_DTL 128 2184 PPC KVM_REG_PPC_EPCR 32 2185 PPC KVM_REG_PPC_EPR 32 2186 PPC KVM_REG_PPC_TCR 32 2187 PPC KVM_REG_PPC_TSR 32 2188 PPC KVM_REG_PPC_OR_TSR 32 2189 PPC KVM_REG_PPC_CLEAR_TSR 32 2190 PPC KVM_REG_PPC_MAS0 32 2191 PPC KVM_REG_PPC_MAS1 32 2192 PPC KVM_REG_PPC_MAS2 64 2193 PPC KVM_REG_PPC_MAS7_3 64 2194 PPC KVM_REG_PPC_MAS4 32 2195 PPC KVM_REG_PPC_MAS6 32 2196 PPC KVM_REG_PPC_MMUCFG 32 2197 PPC KVM_REG_PPC_TLB0CFG 32 2198 PPC KVM_REG_PPC_TLB1CFG 32 2199 PPC KVM_REG_PPC_TLB2CFG 32 2200 PPC KVM_REG_PPC_TLB3CFG 32 2201 PPC KVM_REG_PPC_TLB0PS 32 2202 PPC KVM_REG_PPC_TLB1PS 32 2203 PPC KVM_REG_PPC_TLB2PS 32 2204 PPC KVM_REG_PPC_TLB3PS 32 2205 PPC KVM_REG_PPC_EPTCFG 32 2206 PPC KVM_REG_PPC_ICP_STATE 64 2207 PPC KVM_REG_PPC_VP_STATE 128 2208 PPC KVM_REG_PPC_TB_OFFSET 64 2209 PPC KVM_REG_PPC_SPMC1 32 2210 PPC KVM_REG_PPC_SPMC2 32 2211 PPC KVM_REG_PPC_IAMR 64 2212 PPC KVM_REG_PPC_TFHAR 64 2213 PPC KVM_REG_PPC_TFIAR 64 2214 PPC KVM_REG_PPC_TEXASR 64 2215 PPC KVM_REG_PPC_FSCR 64 2216 PPC KVM_REG_PPC_PSPB 32 2217 PPC KVM_REG_PPC_EBBHR 64 2218 PPC KVM_REG_PPC_EBBRR 64 2219 PPC KVM_REG_PPC_BESCR 64 2220 PPC KVM_REG_PPC_TAR 64 2221 PPC KVM_REG_PPC_DPDES 64 2222 PPC KVM_REG_PPC_DAWR 64 2223 PPC KVM_REG_PPC_DAWRX 64 2224 PPC KVM_REG_PPC_CIABR 64 2225 PPC KVM_REG_PPC_IC 64 2226 PPC KVM_REG_PPC_VTB 64 2227 PPC KVM_REG_PPC_CSIGR 64 2228 PPC KVM_REG_PPC_TACR 64 2229 PPC KVM_REG_PPC_TCSCR 64 2230 PPC KVM_REG_PPC_PID 64 2231 PPC KVM_REG_PPC_ACOP 64 2232 PPC KVM_REG_PPC_VRSAVE 32 2233 PPC KVM_REG_PPC_LPCR 32 2234 PPC KVM_REG_PPC_LPCR_64 64 2235 PPC KVM_REG_PPC_PPR 64 2236 PPC KVM_REG_PPC_ARCH_COMPAT 32 2237 PPC KVM_REG_PPC_DABRX 32 2238 PPC KVM_REG_PPC_WORT 64 2239 PPC KVM_REG_PPC_SPRG9 64 2240 PPC KVM_REG_PPC_DBSR 32 2241 PPC KVM_REG_PPC_TIDR 64 2242 PPC KVM_REG_PPC_PSSCR 64 2243 PPC KVM_REG_PPC_DEC_EXPIRY 64 2244 PPC KVM_REG_PPC_PTCR 64 2245 PPC KVM_REG_PPC_TM_GPR0 64 2246 ... 2247 PPC KVM_REG_PPC_TM_GPR31 64 2248 PPC KVM_REG_PPC_TM_VSR0 128 2249 ... 2250 PPC KVM_REG_PPC_TM_VSR63 128 2251 PPC KVM_REG_PPC_TM_CR 64 2252 PPC KVM_REG_PPC_TM_LR 64 2253 PPC KVM_REG_PPC_TM_CTR 64 2254 PPC KVM_REG_PPC_TM_FPSCR 64 2255 PPC KVM_REG_PPC_TM_AMR 64 2256 PPC KVM_REG_PPC_TM_PPR 64 2257 PPC KVM_REG_PPC_TM_VRSAVE 64 2258 PPC KVM_REG_PPC_TM_VSCR 32 2259 PPC KVM_REG_PPC_TM_DSCR 64 2260 PPC KVM_REG_PPC_TM_TAR 64 2261 PPC KVM_REG_PPC_TM_XER 64 2262 2263 MIPS KVM_REG_MIPS_R0 64 2264 ... 2265 MIPS KVM_REG_MIPS_R31 64 2266 MIPS KVM_REG_MIPS_HI 64 2267 MIPS KVM_REG_MIPS_LO 64 2268 MIPS KVM_REG_MIPS_PC 64 2269 MIPS KVM_REG_MIPS_CP0_INDEX 32 2270 MIPS KVM_REG_MIPS_CP0_ENTRYLO0 64 2271 MIPS KVM_REG_MIPS_CP0_ENTRYLO1 64 2272 MIPS KVM_REG_MIPS_CP0_CONTEXT 64 2273 MIPS KVM_REG_MIPS_CP0_CONTEXTCONFIG 32 2274 MIPS KVM_REG_MIPS_CP0_USERLOCAL 64 2275 MIPS KVM_REG_MIPS_CP0_XCONTEXTCONFIG 64 2276 MIPS KVM_REG_MIPS_CP0_PAGEMASK 32 2277 MIPS KVM_REG_MIPS_CP0_PAGEGRAIN 32 2278 MIPS KVM_REG_MIPS_CP0_SEGCTL0 64 2279 MIPS KVM_REG_MIPS_CP0_SEGCTL1 64 2280 MIPS KVM_REG_MIPS_CP0_SEGCTL2 64 2281 MIPS KVM_REG_MIPS_CP0_PWBASE 64 2282 MIPS KVM_REG_MIPS_CP0_PWFIELD 64 2283 MIPS KVM_REG_MIPS_CP0_PWSIZE 64 2284 MIPS KVM_REG_MIPS_CP0_WIRED 32 2285 MIPS KVM_REG_MIPS_CP0_PWCTL 32 2286 MIPS KVM_REG_MIPS_CP0_HWRENA 32 2287 MIPS KVM_REG_MIPS_CP0_BADVADDR 64 2288 MIPS KVM_REG_MIPS_CP0_BADINSTR 32 2289 MIPS KVM_REG_MIPS_CP0_BADINSTRP 32 2290 MIPS KVM_REG_MIPS_CP0_COUNT 32 2291 MIPS KVM_REG_MIPS_CP0_ENTRYHI 64 2292 MIPS KVM_REG_MIPS_CP0_COMPARE 32 2293 MIPS KVM_REG_MIPS_CP0_STATUS 32 2294 MIPS KVM_REG_MIPS_CP0_INTCTL 32 2295 MIPS KVM_REG_MIPS_CP0_CAUSE 32 2296 MIPS KVM_REG_MIPS_CP0_EPC 64 2297 MIPS KVM_REG_MIPS_CP0_PRID 32 2298 MIPS KVM_REG_MIPS_CP0_EBASE 64 2299 MIPS KVM_REG_MIPS_CP0_CONFIG 32 2300 MIPS KVM_REG_MIPS_CP0_CONFIG1 32 2301 MIPS KVM_REG_MIPS_CP0_CONFIG2 32 2302 MIPS KVM_REG_MIPS_CP0_CONFIG3 32 2303 MIPS KVM_REG_MIPS_CP0_CONFIG4 32 2304 MIPS KVM_REG_MIPS_CP0_CONFIG5 32 2305 MIPS KVM_REG_MIPS_CP0_CONFIG7 32 2306 MIPS KVM_REG_MIPS_CP0_XCONTEXT 64 2307 MIPS KVM_REG_MIPS_CP0_ERROREPC 64 2308 MIPS KVM_REG_MIPS_CP0_KSCRATCH1 64 2309 MIPS KVM_REG_MIPS_CP0_KSCRATCH2 64 2310 MIPS KVM_REG_MIPS_CP0_KSCRATCH3 64 2311 MIPS KVM_REG_MIPS_CP0_KSCRATCH4 64 2312 MIPS KVM_REG_MIPS_CP0_KSCRATCH5 64 2313 MIPS KVM_REG_MIPS_CP0_KSCRATCH6 64 2314 MIPS KVM_REG_MIPS_CP0_MAAR(0..63) 64 2315 MIPS KVM_REG_MIPS_COUNT_CTL 64 2316 MIPS KVM_REG_MIPS_COUNT_RESUME 64 2317 MIPS KVM_REG_MIPS_COUNT_HZ 64 2318 MIPS KVM_REG_MIPS_FPR_32(0..31) 32 2319 MIPS KVM_REG_MIPS_FPR_64(0..31) 64 2320 MIPS KVM_REG_MIPS_VEC_128(0..31) 128 2321 MIPS KVM_REG_MIPS_FCR_IR 32 2322 MIPS KVM_REG_MIPS_FCR_CSR 32 2323 MIPS KVM_REG_MIPS_MSA_IR 32 2324 MIPS KVM_REG_MIPS_MSA_CSR 32 2325 ======= =============================== ============ 2326 2327ARM registers are mapped using the lower 32 bits. The upper 16 of that 2328is the register group type, or coprocessor number: 2329 2330ARM core registers have the following id bit patterns:: 2331 2332 0x4020 0000 0010 <index into the kvm_regs struct:16> 2333 2334ARM 32-bit CP15 registers have the following id bit patterns:: 2335 2336 0x4020 0000 000F <zero:1> <crn:4> <crm:4> <opc1:4> <opc2:3> 2337 2338ARM 64-bit CP15 registers have the following id bit patterns:: 2339 2340 0x4030 0000 000F <zero:1> <zero:4> <crm:4> <opc1:4> <zero:3> 2341 2342ARM CCSIDR registers are demultiplexed by CSSELR value:: 2343 2344 0x4020 0000 0011 00 <csselr:8> 2345 2346ARM 32-bit VFP control registers have the following id bit patterns:: 2347 2348 0x4020 0000 0012 1 <regno:12> 2349 2350ARM 64-bit FP registers have the following id bit patterns:: 2351 2352 0x4030 0000 0012 0 <regno:12> 2353 2354ARM firmware pseudo-registers have the following bit pattern:: 2355 2356 0x4030 0000 0014 <regno:16> 2357 2358 2359arm64 registers are mapped using the lower 32 bits. The upper 16 of 2360that is the register group type, or coprocessor number: 2361 2362arm64 core/FP-SIMD registers have the following id bit patterns. Note 2363that the size of the access is variable, as the kvm_regs structure 2364contains elements ranging from 32 to 128 bits. The index is a 32bit 2365value in the kvm_regs structure seen as a 32bit array:: 2366 2367 0x60x0 0000 0010 <index into the kvm_regs struct:16> 2368 2369Specifically: 2370 2371======================= ========= ===== ======================================= 2372 Encoding Register Bits kvm_regs member 2373======================= ========= ===== ======================================= 2374 0x6030 0000 0010 0000 X0 64 regs.regs[0] 2375 0x6030 0000 0010 0002 X1 64 regs.regs[1] 2376 ... 2377 0x6030 0000 0010 003c X30 64 regs.regs[30] 2378 0x6030 0000 0010 003e SP 64 regs.sp 2379 0x6030 0000 0010 0040 PC 64 regs.pc 2380 0x6030 0000 0010 0042 PSTATE 64 regs.pstate 2381 0x6030 0000 0010 0044 SP_EL1 64 sp_el1 2382 0x6030 0000 0010 0046 ELR_EL1 64 elr_el1 2383 0x6030 0000 0010 0048 SPSR_EL1 64 spsr[KVM_SPSR_EL1] (alias SPSR_SVC) 2384 0x6030 0000 0010 004a SPSR_ABT 64 spsr[KVM_SPSR_ABT] 2385 0x6030 0000 0010 004c SPSR_UND 64 spsr[KVM_SPSR_UND] 2386 0x6030 0000 0010 004e SPSR_IRQ 64 spsr[KVM_SPSR_IRQ] 2387 0x6060 0000 0010 0050 SPSR_FIQ 64 spsr[KVM_SPSR_FIQ] 2388 0x6040 0000 0010 0054 V0 128 fp_regs.vregs[0] [1]_ 2389 0x6040 0000 0010 0058 V1 128 fp_regs.vregs[1] [1]_ 2390 ... 2391 0x6040 0000 0010 00d0 V31 128 fp_regs.vregs[31] [1]_ 2392 0x6020 0000 0010 00d4 FPSR 32 fp_regs.fpsr 2393 0x6020 0000 0010 00d5 FPCR 32 fp_regs.fpcr 2394======================= ========= ===== ======================================= 2395 2396.. [1] These encodings are not accepted for SVE-enabled vcpus. See 2397 KVM_ARM_VCPU_INIT. 2398 2399 The equivalent register content can be accessed via bits [127:0] of 2400 the corresponding SVE Zn registers instead for vcpus that have SVE 2401 enabled (see below). 2402 2403arm64 CCSIDR registers are demultiplexed by CSSELR value:: 2404 2405 0x6020 0000 0011 00 <csselr:8> 2406 2407arm64 system registers have the following id bit patterns:: 2408 2409 0x6030 0000 0013 <op0:2> <op1:3> <crn:4> <crm:4> <op2:3> 2410 2411.. warning:: 2412 2413 Two system register IDs do not follow the specified pattern. These 2414 are KVM_REG_ARM_TIMER_CVAL and KVM_REG_ARM_TIMER_CNT, which map to 2415 system registers CNTV_CVAL_EL0 and CNTVCT_EL0 respectively. These 2416 two had their values accidentally swapped, which means TIMER_CVAL is 2417 derived from the register encoding for CNTVCT_EL0 and TIMER_CNT is 2418 derived from the register encoding for CNTV_CVAL_EL0. As this is 2419 API, it must remain this way. 2420 2421arm64 firmware pseudo-registers have the following bit pattern:: 2422 2423 0x6030 0000 0014 <regno:16> 2424 2425arm64 SVE registers have the following bit patterns:: 2426 2427 0x6080 0000 0015 00 <n:5> <slice:5> Zn bits[2048*slice + 2047 : 2048*slice] 2428 0x6050 0000 0015 04 <n:4> <slice:5> Pn bits[256*slice + 255 : 256*slice] 2429 0x6050 0000 0015 060 <slice:5> FFR bits[256*slice + 255 : 256*slice] 2430 0x6060 0000 0015 ffff KVM_REG_ARM64_SVE_VLS pseudo-register 2431 2432Access to register IDs where 2048 * slice >= 128 * max_vq will fail with 2433ENOENT. max_vq is the vcpu's maximum supported vector length in 128-bit 2434quadwords: see [2]_ below. 2435 2436These registers are only accessible on vcpus for which SVE is enabled. 2437See KVM_ARM_VCPU_INIT for details. 2438 2439In addition, except for KVM_REG_ARM64_SVE_VLS, these registers are not 2440accessible until the vcpu's SVE configuration has been finalized 2441using KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE). See KVM_ARM_VCPU_INIT 2442and KVM_ARM_VCPU_FINALIZE for more information about this procedure. 2443 2444KVM_REG_ARM64_SVE_VLS is a pseudo-register that allows the set of vector 2445lengths supported by the vcpu to be discovered and configured by 2446userspace. When transferred to or from user memory via KVM_GET_ONE_REG 2447or KVM_SET_ONE_REG, the value of this register is of type 2448__u64[KVM_ARM64_SVE_VLS_WORDS], and encodes the set of vector lengths as 2449follows:: 2450 2451 __u64 vector_lengths[KVM_ARM64_SVE_VLS_WORDS]; 2452 2453 if (vq >= SVE_VQ_MIN && vq <= SVE_VQ_MAX && 2454 ((vector_lengths[(vq - KVM_ARM64_SVE_VQ_MIN) / 64] >> 2455 ((vq - KVM_ARM64_SVE_VQ_MIN) % 64)) & 1)) 2456 /* Vector length vq * 16 bytes supported */ 2457 else 2458 /* Vector length vq * 16 bytes not supported */ 2459 2460.. [2] The maximum value vq for which the above condition is true is 2461 max_vq. This is the maximum vector length available to the guest on 2462 this vcpu, and determines which register slices are visible through 2463 this ioctl interface. 2464 2465(See Documentation/arm64/sve.rst for an explanation of the "vq" 2466nomenclature.) 2467 2468KVM_REG_ARM64_SVE_VLS is only accessible after KVM_ARM_VCPU_INIT. 2469KVM_ARM_VCPU_INIT initialises it to the best set of vector lengths that 2470the host supports. 2471 2472Userspace may subsequently modify it if desired until the vcpu's SVE 2473configuration is finalized using KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE). 2474 2475Apart from simply removing all vector lengths from the host set that 2476exceed some value, support for arbitrarily chosen sets of vector lengths 2477is hardware-dependent and may not be available. Attempting to configure 2478an invalid set of vector lengths via KVM_SET_ONE_REG will fail with 2479EINVAL. 2480 2481After the vcpu's SVE configuration is finalized, further attempts to 2482write this register will fail with EPERM. 2483 2484 2485MIPS registers are mapped using the lower 32 bits. The upper 16 of that is 2486the register group type: 2487 2488MIPS core registers (see above) have the following id bit patterns:: 2489 2490 0x7030 0000 0000 <reg:16> 2491 2492MIPS CP0 registers (see KVM_REG_MIPS_CP0_* above) have the following id bit 2493patterns depending on whether they're 32-bit or 64-bit registers:: 2494 2495 0x7020 0000 0001 00 <reg:5> <sel:3> (32-bit) 2496 0x7030 0000 0001 00 <reg:5> <sel:3> (64-bit) 2497 2498Note: KVM_REG_MIPS_CP0_ENTRYLO0 and KVM_REG_MIPS_CP0_ENTRYLO1 are the MIPS64 2499versions of the EntryLo registers regardless of the word size of the host 2500hardware, host kernel, guest, and whether XPA is present in the guest, i.e. 2501with the RI and XI bits (if they exist) in bits 63 and 62 respectively, and 2502the PFNX field starting at bit 30. 2503 2504MIPS MAARs (see KVM_REG_MIPS_CP0_MAAR(*) above) have the following id bit 2505patterns:: 2506 2507 0x7030 0000 0001 01 <reg:8> 2508 2509MIPS KVM control registers (see above) have the following id bit patterns:: 2510 2511 0x7030 0000 0002 <reg:16> 2512 2513MIPS FPU registers (see KVM_REG_MIPS_FPR_{32,64}() above) have the following 2514id bit patterns depending on the size of the register being accessed. They are 2515always accessed according to the current guest FPU mode (Status.FR and 2516Config5.FRE), i.e. as the guest would see them, and they become unpredictable 2517if the guest FPU mode is changed. MIPS SIMD Architecture (MSA) vector 2518registers (see KVM_REG_MIPS_VEC_128() above) have similar patterns as they 2519overlap the FPU registers:: 2520 2521 0x7020 0000 0003 00 <0:3> <reg:5> (32-bit FPU registers) 2522 0x7030 0000 0003 00 <0:3> <reg:5> (64-bit FPU registers) 2523 0x7040 0000 0003 00 <0:3> <reg:5> (128-bit MSA vector registers) 2524 2525MIPS FPU control registers (see KVM_REG_MIPS_FCR_{IR,CSR} above) have the 2526following id bit patterns:: 2527 2528 0x7020 0000 0003 01 <0:3> <reg:5> 2529 2530MIPS MSA control registers (see KVM_REG_MIPS_MSA_{IR,CSR} above) have the 2531following id bit patterns:: 2532 2533 0x7020 0000 0003 02 <0:3> <reg:5> 2534 2535 25364.69 KVM_GET_ONE_REG 2537-------------------- 2538 2539:Capability: KVM_CAP_ONE_REG 2540:Architectures: all 2541:Type: vcpu ioctl 2542:Parameters: struct kvm_one_reg (in and out) 2543:Returns: 0 on success, negative value on failure 2544 2545Errors include: 2546 2547 ======== ============================================================ 2548 ENOENT no such register 2549 EINVAL invalid register ID, or no such register or used with VMs in 2550 protected virtualization mode on s390 2551 EPERM (arm64) register access not allowed before vcpu finalization 2552 ======== ============================================================ 2553 2554(These error codes are indicative only: do not rely on a specific error 2555code being returned in a specific situation.) 2556 2557This ioctl allows to receive the value of a single register implemented 2558in a vcpu. The register to read is indicated by the "id" field of the 2559kvm_one_reg struct passed in. On success, the register value can be found 2560at the memory location pointed to by "addr". 2561 2562The list of registers accessible using this interface is identical to the 2563list in 4.68. 2564 2565 25664.70 KVM_KVMCLOCK_CTRL 2567---------------------- 2568 2569:Capability: KVM_CAP_KVMCLOCK_CTRL 2570:Architectures: Any that implement pvclocks (currently x86 only) 2571:Type: vcpu ioctl 2572:Parameters: None 2573:Returns: 0 on success, -1 on error 2574 2575This signals to the host kernel that the specified guest is being paused by 2576userspace. The host will set a flag in the pvclock structure that is checked 2577from the soft lockup watchdog. The flag is part of the pvclock structure that 2578is shared between guest and host, specifically the second bit of the flags 2579field of the pvclock_vcpu_time_info structure. It will be set exclusively by 2580the host and read/cleared exclusively by the guest. The guest operation of 2581checking and clearing the flag must an atomic operation so 2582load-link/store-conditional, or equivalent must be used. There are two cases 2583where the guest will clear the flag: when the soft lockup watchdog timer resets 2584itself or when a soft lockup is detected. This ioctl can be called any time 2585after pausing the vcpu, but before it is resumed. 2586 2587 25884.71 KVM_SIGNAL_MSI 2589------------------- 2590 2591:Capability: KVM_CAP_SIGNAL_MSI 2592:Architectures: x86 arm arm64 2593:Type: vm ioctl 2594:Parameters: struct kvm_msi (in) 2595:Returns: >0 on delivery, 0 if guest blocked the MSI, and -1 on error 2596 2597Directly inject a MSI message. Only valid with in-kernel irqchip that handles 2598MSI messages. 2599 2600:: 2601 2602 struct kvm_msi { 2603 __u32 address_lo; 2604 __u32 address_hi; 2605 __u32 data; 2606 __u32 flags; 2607 __u32 devid; 2608 __u8 pad[12]; 2609 }; 2610 2611flags: 2612 KVM_MSI_VALID_DEVID: devid contains a valid value. The per-VM 2613 KVM_CAP_MSI_DEVID capability advertises the requirement to provide 2614 the device ID. If this capability is not available, userspace 2615 should never set the KVM_MSI_VALID_DEVID flag as the ioctl might fail. 2616 2617If KVM_MSI_VALID_DEVID is set, devid contains a unique device identifier 2618for the device that wrote the MSI message. For PCI, this is usually a 2619BFD identifier in the lower 16 bits. 2620 2621On x86, address_hi is ignored unless the KVM_X2APIC_API_USE_32BIT_IDS 2622feature of KVM_CAP_X2APIC_API capability is enabled. If it is enabled, 2623address_hi bits 31-8 provide bits 31-8 of the destination id. Bits 7-0 of 2624address_hi must be zero. 2625 2626 26274.71 KVM_CREATE_PIT2 2628-------------------- 2629 2630:Capability: KVM_CAP_PIT2 2631:Architectures: x86 2632:Type: vm ioctl 2633:Parameters: struct kvm_pit_config (in) 2634:Returns: 0 on success, -1 on error 2635 2636Creates an in-kernel device model for the i8254 PIT. This call is only valid 2637after enabling in-kernel irqchip support via KVM_CREATE_IRQCHIP. The following 2638parameters have to be passed:: 2639 2640 struct kvm_pit_config { 2641 __u32 flags; 2642 __u32 pad[15]; 2643 }; 2644 2645Valid flags are:: 2646 2647 #define KVM_PIT_SPEAKER_DUMMY 1 /* emulate speaker port stub */ 2648 2649PIT timer interrupts may use a per-VM kernel thread for injection. If it 2650exists, this thread will have a name of the following pattern:: 2651 2652 kvm-pit/<owner-process-pid> 2653 2654When running a guest with elevated priorities, the scheduling parameters of 2655this thread may have to be adjusted accordingly. 2656 2657This IOCTL replaces the obsolete KVM_CREATE_PIT. 2658 2659 26604.72 KVM_GET_PIT2 2661----------------- 2662 2663:Capability: KVM_CAP_PIT_STATE2 2664:Architectures: x86 2665:Type: vm ioctl 2666:Parameters: struct kvm_pit_state2 (out) 2667:Returns: 0 on success, -1 on error 2668 2669Retrieves the state of the in-kernel PIT model. Only valid after 2670KVM_CREATE_PIT2. The state is returned in the following structure:: 2671 2672 struct kvm_pit_state2 { 2673 struct kvm_pit_channel_state channels[3]; 2674 __u32 flags; 2675 __u32 reserved[9]; 2676 }; 2677 2678Valid flags are:: 2679 2680 /* disable PIT in HPET legacy mode */ 2681 #define KVM_PIT_FLAGS_HPET_LEGACY 0x00000001 2682 2683This IOCTL replaces the obsolete KVM_GET_PIT. 2684 2685 26864.73 KVM_SET_PIT2 2687----------------- 2688 2689:Capability: KVM_CAP_PIT_STATE2 2690:Architectures: x86 2691:Type: vm ioctl 2692:Parameters: struct kvm_pit_state2 (in) 2693:Returns: 0 on success, -1 on error 2694 2695Sets the state of the in-kernel PIT model. Only valid after KVM_CREATE_PIT2. 2696See KVM_GET_PIT2 for details on struct kvm_pit_state2. 2697 2698This IOCTL replaces the obsolete KVM_SET_PIT. 2699 2700 27014.74 KVM_PPC_GET_SMMU_INFO 2702-------------------------- 2703 2704:Capability: KVM_CAP_PPC_GET_SMMU_INFO 2705:Architectures: powerpc 2706:Type: vm ioctl 2707:Parameters: None 2708:Returns: 0 on success, -1 on error 2709 2710This populates and returns a structure describing the features of 2711the "Server" class MMU emulation supported by KVM. 2712This can in turn be used by userspace to generate the appropriate 2713device-tree properties for the guest operating system. 2714 2715The structure contains some global information, followed by an 2716array of supported segment page sizes:: 2717 2718 struct kvm_ppc_smmu_info { 2719 __u64 flags; 2720 __u32 slb_size; 2721 __u32 pad; 2722 struct kvm_ppc_one_seg_page_size sps[KVM_PPC_PAGE_SIZES_MAX_SZ]; 2723 }; 2724 2725The supported flags are: 2726 2727 - KVM_PPC_PAGE_SIZES_REAL: 2728 When that flag is set, guest page sizes must "fit" the backing 2729 store page sizes. When not set, any page size in the list can 2730 be used regardless of how they are backed by userspace. 2731 2732 - KVM_PPC_1T_SEGMENTS 2733 The emulated MMU supports 1T segments in addition to the 2734 standard 256M ones. 2735 2736 - KVM_PPC_NO_HASH 2737 This flag indicates that HPT guests are not supported by KVM, 2738 thus all guests must use radix MMU mode. 2739 2740The "slb_size" field indicates how many SLB entries are supported 2741 2742The "sps" array contains 8 entries indicating the supported base 2743page sizes for a segment in increasing order. Each entry is defined 2744as follow:: 2745 2746 struct kvm_ppc_one_seg_page_size { 2747 __u32 page_shift; /* Base page shift of segment (or 0) */ 2748 __u32 slb_enc; /* SLB encoding for BookS */ 2749 struct kvm_ppc_one_page_size enc[KVM_PPC_PAGE_SIZES_MAX_SZ]; 2750 }; 2751 2752An entry with a "page_shift" of 0 is unused. Because the array is 2753organized in increasing order, a lookup can stop when encoutering 2754such an entry. 2755 2756The "slb_enc" field provides the encoding to use in the SLB for the 2757page size. The bits are in positions such as the value can directly 2758be OR'ed into the "vsid" argument of the slbmte instruction. 2759 2760The "enc" array is a list which for each of those segment base page 2761size provides the list of supported actual page sizes (which can be 2762only larger or equal to the base page size), along with the 2763corresponding encoding in the hash PTE. Similarly, the array is 27648 entries sorted by increasing sizes and an entry with a "0" shift 2765is an empty entry and a terminator:: 2766 2767 struct kvm_ppc_one_page_size { 2768 __u32 page_shift; /* Page shift (or 0) */ 2769 __u32 pte_enc; /* Encoding in the HPTE (>>12) */ 2770 }; 2771 2772The "pte_enc" field provides a value that can OR'ed into the hash 2773PTE's RPN field (ie, it needs to be shifted left by 12 to OR it 2774into the hash PTE second double word). 2775 27764.75 KVM_IRQFD 2777-------------- 2778 2779:Capability: KVM_CAP_IRQFD 2780:Architectures: x86 s390 arm arm64 2781:Type: vm ioctl 2782:Parameters: struct kvm_irqfd (in) 2783:Returns: 0 on success, -1 on error 2784 2785Allows setting an eventfd to directly trigger a guest interrupt. 2786kvm_irqfd.fd specifies the file descriptor to use as the eventfd and 2787kvm_irqfd.gsi specifies the irqchip pin toggled by this event. When 2788an event is triggered on the eventfd, an interrupt is injected into 2789the guest using the specified gsi pin. The irqfd is removed using 2790the KVM_IRQFD_FLAG_DEASSIGN flag, specifying both kvm_irqfd.fd 2791and kvm_irqfd.gsi. 2792 2793With KVM_CAP_IRQFD_RESAMPLE, KVM_IRQFD supports a de-assert and notify 2794mechanism allowing emulation of level-triggered, irqfd-based 2795interrupts. When KVM_IRQFD_FLAG_RESAMPLE is set the user must pass an 2796additional eventfd in the kvm_irqfd.resamplefd field. When operating 2797in resample mode, posting of an interrupt through kvm_irq.fd asserts 2798the specified gsi in the irqchip. When the irqchip is resampled, such 2799as from an EOI, the gsi is de-asserted and the user is notified via 2800kvm_irqfd.resamplefd. It is the user's responsibility to re-queue 2801the interrupt if the device making use of it still requires service. 2802Note that closing the resamplefd is not sufficient to disable the 2803irqfd. The KVM_IRQFD_FLAG_RESAMPLE is only necessary on assignment 2804and need not be specified with KVM_IRQFD_FLAG_DEASSIGN. 2805 2806On arm/arm64, gsi routing being supported, the following can happen: 2807 2808- in case no routing entry is associated to this gsi, injection fails 2809- in case the gsi is associated to an irqchip routing entry, 2810 irqchip.pin + 32 corresponds to the injected SPI ID. 2811- in case the gsi is associated to an MSI routing entry, the MSI 2812 message and device ID are translated into an LPI (support restricted 2813 to GICv3 ITS in-kernel emulation). 2814 28154.76 KVM_PPC_ALLOCATE_HTAB 2816-------------------------- 2817 2818:Capability: KVM_CAP_PPC_ALLOC_HTAB 2819:Architectures: powerpc 2820:Type: vm ioctl 2821:Parameters: Pointer to u32 containing hash table order (in/out) 2822:Returns: 0 on success, -1 on error 2823 2824This requests the host kernel to allocate an MMU hash table for a 2825guest using the PAPR paravirtualization interface. This only does 2826anything if the kernel is configured to use the Book 3S HV style of 2827virtualization. Otherwise the capability doesn't exist and the ioctl 2828returns an ENOTTY error. The rest of this description assumes Book 3S 2829HV. 2830 2831There must be no vcpus running when this ioctl is called; if there 2832are, it will do nothing and return an EBUSY error. 2833 2834The parameter is a pointer to a 32-bit unsigned integer variable 2835containing the order (log base 2) of the desired size of the hash 2836table, which must be between 18 and 46. On successful return from the 2837ioctl, the value will not be changed by the kernel. 2838 2839If no hash table has been allocated when any vcpu is asked to run 2840(with the KVM_RUN ioctl), the host kernel will allocate a 2841default-sized hash table (16 MB). 2842 2843If this ioctl is called when a hash table has already been allocated, 2844with a different order from the existing hash table, the existing hash 2845table will be freed and a new one allocated. If this is ioctl is 2846called when a hash table has already been allocated of the same order 2847as specified, the kernel will clear out the existing hash table (zero 2848all HPTEs). In either case, if the guest is using the virtualized 2849real-mode area (VRMA) facility, the kernel will re-create the VMRA 2850HPTEs on the next KVM_RUN of any vcpu. 2851 28524.77 KVM_S390_INTERRUPT 2853----------------------- 2854 2855:Capability: basic 2856:Architectures: s390 2857:Type: vm ioctl, vcpu ioctl 2858:Parameters: struct kvm_s390_interrupt (in) 2859:Returns: 0 on success, -1 on error 2860 2861Allows to inject an interrupt to the guest. Interrupts can be floating 2862(vm ioctl) or per cpu (vcpu ioctl), depending on the interrupt type. 2863 2864Interrupt parameters are passed via kvm_s390_interrupt:: 2865 2866 struct kvm_s390_interrupt { 2867 __u32 type; 2868 __u32 parm; 2869 __u64 parm64; 2870 }; 2871 2872type can be one of the following: 2873 2874KVM_S390_SIGP_STOP (vcpu) 2875 - sigp stop; optional flags in parm 2876KVM_S390_PROGRAM_INT (vcpu) 2877 - program check; code in parm 2878KVM_S390_SIGP_SET_PREFIX (vcpu) 2879 - sigp set prefix; prefix address in parm 2880KVM_S390_RESTART (vcpu) 2881 - restart 2882KVM_S390_INT_CLOCK_COMP (vcpu) 2883 - clock comparator interrupt 2884KVM_S390_INT_CPU_TIMER (vcpu) 2885 - CPU timer interrupt 2886KVM_S390_INT_VIRTIO (vm) 2887 - virtio external interrupt; external interrupt 2888 parameters in parm and parm64 2889KVM_S390_INT_SERVICE (vm) 2890 - sclp external interrupt; sclp parameter in parm 2891KVM_S390_INT_EMERGENCY (vcpu) 2892 - sigp emergency; source cpu in parm 2893KVM_S390_INT_EXTERNAL_CALL (vcpu) 2894 - sigp external call; source cpu in parm 2895KVM_S390_INT_IO(ai,cssid,ssid,schid) (vm) 2896 - compound value to indicate an 2897 I/O interrupt (ai - adapter interrupt; cssid,ssid,schid - subchannel); 2898 I/O interruption parameters in parm (subchannel) and parm64 (intparm, 2899 interruption subclass) 2900KVM_S390_MCHK (vm, vcpu) 2901 - machine check interrupt; cr 14 bits in parm, machine check interrupt 2902 code in parm64 (note that machine checks needing further payload are not 2903 supported by this ioctl) 2904 2905This is an asynchronous vcpu ioctl and can be invoked from any thread. 2906 29074.78 KVM_PPC_GET_HTAB_FD 2908------------------------ 2909 2910:Capability: KVM_CAP_PPC_HTAB_FD 2911:Architectures: powerpc 2912:Type: vm ioctl 2913:Parameters: Pointer to struct kvm_get_htab_fd (in) 2914:Returns: file descriptor number (>= 0) on success, -1 on error 2915 2916This returns a file descriptor that can be used either to read out the 2917entries in the guest's hashed page table (HPT), or to write entries to 2918initialize the HPT. The returned fd can only be written to if the 2919KVM_GET_HTAB_WRITE bit is set in the flags field of the argument, and 2920can only be read if that bit is clear. The argument struct looks like 2921this:: 2922 2923 /* For KVM_PPC_GET_HTAB_FD */ 2924 struct kvm_get_htab_fd { 2925 __u64 flags; 2926 __u64 start_index; 2927 __u64 reserved[2]; 2928 }; 2929 2930 /* Values for kvm_get_htab_fd.flags */ 2931 #define KVM_GET_HTAB_BOLTED_ONLY ((__u64)0x1) 2932 #define KVM_GET_HTAB_WRITE ((__u64)0x2) 2933 2934The 'start_index' field gives the index in the HPT of the entry at 2935which to start reading. It is ignored when writing. 2936 2937Reads on the fd will initially supply information about all 2938"interesting" HPT entries. Interesting entries are those with the 2939bolted bit set, if the KVM_GET_HTAB_BOLTED_ONLY bit is set, otherwise 2940all entries. When the end of the HPT is reached, the read() will 2941return. If read() is called again on the fd, it will start again from 2942the beginning of the HPT, but will only return HPT entries that have 2943changed since they were last read. 2944 2945Data read or written is structured as a header (8 bytes) followed by a 2946series of valid HPT entries (16 bytes) each. The header indicates how 2947many valid HPT entries there are and how many invalid entries follow 2948the valid entries. The invalid entries are not represented explicitly 2949in the stream. The header format is:: 2950 2951 struct kvm_get_htab_header { 2952 __u32 index; 2953 __u16 n_valid; 2954 __u16 n_invalid; 2955 }; 2956 2957Writes to the fd create HPT entries starting at the index given in the 2958header; first 'n_valid' valid entries with contents from the data 2959written, then 'n_invalid' invalid entries, invalidating any previously 2960valid entries found. 2961 29624.79 KVM_CREATE_DEVICE 2963---------------------- 2964 2965:Capability: KVM_CAP_DEVICE_CTRL 2966:Type: vm ioctl 2967:Parameters: struct kvm_create_device (in/out) 2968:Returns: 0 on success, -1 on error 2969 2970Errors: 2971 2972 ====== ======================================================= 2973 ENODEV The device type is unknown or unsupported 2974 EEXIST Device already created, and this type of device may not 2975 be instantiated multiple times 2976 ====== ======================================================= 2977 2978 Other error conditions may be defined by individual device types or 2979 have their standard meanings. 2980 2981Creates an emulated device in the kernel. The file descriptor returned 2982in fd can be used with KVM_SET/GET/HAS_DEVICE_ATTR. 2983 2984If the KVM_CREATE_DEVICE_TEST flag is set, only test whether the 2985device type is supported (not necessarily whether it can be created 2986in the current vm). 2987 2988Individual devices should not define flags. Attributes should be used 2989for specifying any behavior that is not implied by the device type 2990number. 2991 2992:: 2993 2994 struct kvm_create_device { 2995 __u32 type; /* in: KVM_DEV_TYPE_xxx */ 2996 __u32 fd; /* out: device handle */ 2997 __u32 flags; /* in: KVM_CREATE_DEVICE_xxx */ 2998 }; 2999 30004.80 KVM_SET_DEVICE_ATTR/KVM_GET_DEVICE_ATTR 3001-------------------------------------------- 3002 3003:Capability: KVM_CAP_DEVICE_CTRL, KVM_CAP_VM_ATTRIBUTES for vm device, 3004 KVM_CAP_VCPU_ATTRIBUTES for vcpu device 3005:Type: device ioctl, vm ioctl, vcpu ioctl 3006:Parameters: struct kvm_device_attr 3007:Returns: 0 on success, -1 on error 3008 3009Errors: 3010 3011 ===== ============================================================= 3012 ENXIO The group or attribute is unknown/unsupported for this device 3013 or hardware support is missing. 3014 EPERM The attribute cannot (currently) be accessed this way 3015 (e.g. read-only attribute, or attribute that only makes 3016 sense when the device is in a different state) 3017 ===== ============================================================= 3018 3019 Other error conditions may be defined by individual device types. 3020 3021Gets/sets a specified piece of device configuration and/or state. The 3022semantics are device-specific. See individual device documentation in 3023the "devices" directory. As with ONE_REG, the size of the data 3024transferred is defined by the particular attribute. 3025 3026:: 3027 3028 struct kvm_device_attr { 3029 __u32 flags; /* no flags currently defined */ 3030 __u32 group; /* device-defined */ 3031 __u64 attr; /* group-defined */ 3032 __u64 addr; /* userspace address of attr data */ 3033 }; 3034 30354.81 KVM_HAS_DEVICE_ATTR 3036------------------------ 3037 3038:Capability: KVM_CAP_DEVICE_CTRL, KVM_CAP_VM_ATTRIBUTES for vm device, 3039 KVM_CAP_VCPU_ATTRIBUTES for vcpu device 3040:Type: device ioctl, vm ioctl, vcpu ioctl 3041:Parameters: struct kvm_device_attr 3042:Returns: 0 on success, -1 on error 3043 3044Errors: 3045 3046 ===== ============================================================= 3047 ENXIO The group or attribute is unknown/unsupported for this device 3048 or hardware support is missing. 3049 ===== ============================================================= 3050 3051Tests whether a device supports a particular attribute. A successful 3052return indicates the attribute is implemented. It does not necessarily 3053indicate that the attribute can be read or written in the device's 3054current state. "addr" is ignored. 3055 30564.82 KVM_ARM_VCPU_INIT 3057---------------------- 3058 3059:Capability: basic 3060:Architectures: arm, arm64 3061:Type: vcpu ioctl 3062:Parameters: struct kvm_vcpu_init (in) 3063:Returns: 0 on success; -1 on error 3064 3065Errors: 3066 3067 ====== ================================================================= 3068 EINVAL the target is unknown, or the combination of features is invalid. 3069 ENOENT a features bit specified is unknown. 3070 ====== ================================================================= 3071 3072This tells KVM what type of CPU to present to the guest, and what 3073optional features it should have. This will cause a reset of the cpu 3074registers to their initial values. If this is not called, KVM_RUN will 3075return ENOEXEC for that vcpu. 3076 3077Note that because some registers reflect machine topology, all vcpus 3078should be created before this ioctl is invoked. 3079 3080Userspace can call this function multiple times for a given vcpu, including 3081after the vcpu has been run. This will reset the vcpu to its initial 3082state. All calls to this function after the initial call must use the same 3083target and same set of feature flags, otherwise EINVAL will be returned. 3084 3085Possible features: 3086 3087 - KVM_ARM_VCPU_POWER_OFF: Starts the CPU in a power-off state. 3088 Depends on KVM_CAP_ARM_PSCI. If not set, the CPU will be powered on 3089 and execute guest code when KVM_RUN is called. 3090 - KVM_ARM_VCPU_EL1_32BIT: Starts the CPU in a 32bit mode. 3091 Depends on KVM_CAP_ARM_EL1_32BIT (arm64 only). 3092 - KVM_ARM_VCPU_PSCI_0_2: Emulate PSCI v0.2 (or a future revision 3093 backward compatible with v0.2) for the CPU. 3094 Depends on KVM_CAP_ARM_PSCI_0_2. 3095 - KVM_ARM_VCPU_PMU_V3: Emulate PMUv3 for the CPU. 3096 Depends on KVM_CAP_ARM_PMU_V3. 3097 3098 - KVM_ARM_VCPU_PTRAUTH_ADDRESS: Enables Address Pointer authentication 3099 for arm64 only. 3100 Depends on KVM_CAP_ARM_PTRAUTH_ADDRESS. 3101 If KVM_CAP_ARM_PTRAUTH_ADDRESS and KVM_CAP_ARM_PTRAUTH_GENERIC are 3102 both present, then both KVM_ARM_VCPU_PTRAUTH_ADDRESS and 3103 KVM_ARM_VCPU_PTRAUTH_GENERIC must be requested or neither must be 3104 requested. 3105 3106 - KVM_ARM_VCPU_PTRAUTH_GENERIC: Enables Generic Pointer authentication 3107 for arm64 only. 3108 Depends on KVM_CAP_ARM_PTRAUTH_GENERIC. 3109 If KVM_CAP_ARM_PTRAUTH_ADDRESS and KVM_CAP_ARM_PTRAUTH_GENERIC are 3110 both present, then both KVM_ARM_VCPU_PTRAUTH_ADDRESS and 3111 KVM_ARM_VCPU_PTRAUTH_GENERIC must be requested or neither must be 3112 requested. 3113 3114 - KVM_ARM_VCPU_SVE: Enables SVE for the CPU (arm64 only). 3115 Depends on KVM_CAP_ARM_SVE. 3116 Requires KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE): 3117 3118 * After KVM_ARM_VCPU_INIT: 3119 3120 - KVM_REG_ARM64_SVE_VLS may be read using KVM_GET_ONE_REG: the 3121 initial value of this pseudo-register indicates the best set of 3122 vector lengths possible for a vcpu on this host. 3123 3124 * Before KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE): 3125 3126 - KVM_RUN and KVM_GET_REG_LIST are not available; 3127 3128 - KVM_GET_ONE_REG and KVM_SET_ONE_REG cannot be used to access 3129 the scalable archietctural SVE registers 3130 KVM_REG_ARM64_SVE_ZREG(), KVM_REG_ARM64_SVE_PREG() or 3131 KVM_REG_ARM64_SVE_FFR; 3132 3133 - KVM_REG_ARM64_SVE_VLS may optionally be written using 3134 KVM_SET_ONE_REG, to modify the set of vector lengths available 3135 for the vcpu. 3136 3137 * After KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE): 3138 3139 - the KVM_REG_ARM64_SVE_VLS pseudo-register is immutable, and can 3140 no longer be written using KVM_SET_ONE_REG. 3141 31424.83 KVM_ARM_PREFERRED_TARGET 3143----------------------------- 3144 3145:Capability: basic 3146:Architectures: arm, arm64 3147:Type: vm ioctl 3148:Parameters: struct struct kvm_vcpu_init (out) 3149:Returns: 0 on success; -1 on error 3150 3151Errors: 3152 3153 ====== ========================================== 3154 ENODEV no preferred target available for the host 3155 ====== ========================================== 3156 3157This queries KVM for preferred CPU target type which can be emulated 3158by KVM on underlying host. 3159 3160The ioctl returns struct kvm_vcpu_init instance containing information 3161about preferred CPU target type and recommended features for it. The 3162kvm_vcpu_init->features bitmap returned will have feature bits set if 3163the preferred target recommends setting these features, but this is 3164not mandatory. 3165 3166The information returned by this ioctl can be used to prepare an instance 3167of struct kvm_vcpu_init for KVM_ARM_VCPU_INIT ioctl which will result in 3168in VCPU matching underlying host. 3169 3170 31714.84 KVM_GET_REG_LIST 3172--------------------- 3173 3174:Capability: basic 3175:Architectures: arm, arm64, mips 3176:Type: vcpu ioctl 3177:Parameters: struct kvm_reg_list (in/out) 3178:Returns: 0 on success; -1 on error 3179 3180Errors: 3181 3182 ===== ============================================================== 3183 E2BIG the reg index list is too big to fit in the array specified by 3184 the user (the number required will be written into n). 3185 ===== ============================================================== 3186 3187:: 3188 3189 struct kvm_reg_list { 3190 __u64 n; /* number of registers in reg[] */ 3191 __u64 reg[0]; 3192 }; 3193 3194This ioctl returns the guest registers that are supported for the 3195KVM_GET_ONE_REG/KVM_SET_ONE_REG calls. 3196 3197 31984.85 KVM_ARM_SET_DEVICE_ADDR (deprecated) 3199----------------------------------------- 3200 3201:Capability: KVM_CAP_ARM_SET_DEVICE_ADDR 3202:Architectures: arm, arm64 3203:Type: vm ioctl 3204:Parameters: struct kvm_arm_device_address (in) 3205:Returns: 0 on success, -1 on error 3206 3207Errors: 3208 3209 ====== ============================================ 3210 ENODEV The device id is unknown 3211 ENXIO Device not supported on current system 3212 EEXIST Address already set 3213 E2BIG Address outside guest physical address space 3214 EBUSY Address overlaps with other device range 3215 ====== ============================================ 3216 3217:: 3218 3219 struct kvm_arm_device_addr { 3220 __u64 id; 3221 __u64 addr; 3222 }; 3223 3224Specify a device address in the guest's physical address space where guests 3225can access emulated or directly exposed devices, which the host kernel needs 3226to know about. The id field is an architecture specific identifier for a 3227specific device. 3228 3229ARM/arm64 divides the id field into two parts, a device id and an 3230address type id specific to the individual device:: 3231 3232 bits: | 63 ... 32 | 31 ... 16 | 15 ... 0 | 3233 field: | 0x00000000 | device id | addr type id | 3234 3235ARM/arm64 currently only require this when using the in-kernel GIC 3236support for the hardware VGIC features, using KVM_ARM_DEVICE_VGIC_V2 3237as the device id. When setting the base address for the guest's 3238mapping of the VGIC virtual CPU and distributor interface, the ioctl 3239must be called after calling KVM_CREATE_IRQCHIP, but before calling 3240KVM_RUN on any of the VCPUs. Calling this ioctl twice for any of the 3241base addresses will return -EEXIST. 3242 3243Note, this IOCTL is deprecated and the more flexible SET/GET_DEVICE_ATTR API 3244should be used instead. 3245 3246 32474.86 KVM_PPC_RTAS_DEFINE_TOKEN 3248------------------------------ 3249 3250:Capability: KVM_CAP_PPC_RTAS 3251:Architectures: ppc 3252:Type: vm ioctl 3253:Parameters: struct kvm_rtas_token_args 3254:Returns: 0 on success, -1 on error 3255 3256Defines a token value for a RTAS (Run Time Abstraction Services) 3257service in order to allow it to be handled in the kernel. The 3258argument struct gives the name of the service, which must be the name 3259of a service that has a kernel-side implementation. If the token 3260value is non-zero, it will be associated with that service, and 3261subsequent RTAS calls by the guest specifying that token will be 3262handled by the kernel. If the token value is 0, then any token 3263associated with the service will be forgotten, and subsequent RTAS 3264calls by the guest for that service will be passed to userspace to be 3265handled. 3266 32674.87 KVM_SET_GUEST_DEBUG 3268------------------------ 3269 3270:Capability: KVM_CAP_SET_GUEST_DEBUG 3271:Architectures: x86, s390, ppc, arm64 3272:Type: vcpu ioctl 3273:Parameters: struct kvm_guest_debug (in) 3274:Returns: 0 on success; -1 on error 3275 3276:: 3277 3278 struct kvm_guest_debug { 3279 __u32 control; 3280 __u32 pad; 3281 struct kvm_guest_debug_arch arch; 3282 }; 3283 3284Set up the processor specific debug registers and configure vcpu for 3285handling guest debug events. There are two parts to the structure, the 3286first a control bitfield indicates the type of debug events to handle 3287when running. Common control bits are: 3288 3289 - KVM_GUESTDBG_ENABLE: guest debugging is enabled 3290 - KVM_GUESTDBG_SINGLESTEP: the next run should single-step 3291 3292The top 16 bits of the control field are architecture specific control 3293flags which can include the following: 3294 3295 - KVM_GUESTDBG_USE_SW_BP: using software breakpoints [x86, arm64] 3296 - KVM_GUESTDBG_USE_HW_BP: using hardware breakpoints [x86, s390, arm64] 3297 - KVM_GUESTDBG_INJECT_DB: inject DB type exception [x86] 3298 - KVM_GUESTDBG_INJECT_BP: inject BP type exception [x86] 3299 - KVM_GUESTDBG_EXIT_PENDING: trigger an immediate guest exit [s390] 3300 3301For example KVM_GUESTDBG_USE_SW_BP indicates that software breakpoints 3302are enabled in memory so we need to ensure breakpoint exceptions are 3303correctly trapped and the KVM run loop exits at the breakpoint and not 3304running off into the normal guest vector. For KVM_GUESTDBG_USE_HW_BP 3305we need to ensure the guest vCPUs architecture specific registers are 3306updated to the correct (supplied) values. 3307 3308The second part of the structure is architecture specific and 3309typically contains a set of debug registers. 3310 3311For arm64 the number of debug registers is implementation defined and 3312can be determined by querying the KVM_CAP_GUEST_DEBUG_HW_BPS and 3313KVM_CAP_GUEST_DEBUG_HW_WPS capabilities which return a positive number 3314indicating the number of supported registers. 3315 3316For ppc, the KVM_CAP_PPC_GUEST_DEBUG_SSTEP capability indicates whether 3317the single-step debug event (KVM_GUESTDBG_SINGLESTEP) is supported. 3318 3319When debug events exit the main run loop with the reason 3320KVM_EXIT_DEBUG with the kvm_debug_exit_arch part of the kvm_run 3321structure containing architecture specific debug information. 3322 33234.88 KVM_GET_EMULATED_CPUID 3324--------------------------- 3325 3326:Capability: KVM_CAP_EXT_EMUL_CPUID 3327:Architectures: x86 3328:Type: system ioctl 3329:Parameters: struct kvm_cpuid2 (in/out) 3330:Returns: 0 on success, -1 on error 3331 3332:: 3333 3334 struct kvm_cpuid2 { 3335 __u32 nent; 3336 __u32 flags; 3337 struct kvm_cpuid_entry2 entries[0]; 3338 }; 3339 3340The member 'flags' is used for passing flags from userspace. 3341 3342:: 3343 3344 #define KVM_CPUID_FLAG_SIGNIFCANT_INDEX BIT(0) 3345 #define KVM_CPUID_FLAG_STATEFUL_FUNC BIT(1) /* deprecated */ 3346 #define KVM_CPUID_FLAG_STATE_READ_NEXT BIT(2) /* deprecated */ 3347 3348 struct kvm_cpuid_entry2 { 3349 __u32 function; 3350 __u32 index; 3351 __u32 flags; 3352 __u32 eax; 3353 __u32 ebx; 3354 __u32 ecx; 3355 __u32 edx; 3356 __u32 padding[3]; 3357 }; 3358 3359This ioctl returns x86 cpuid features which are emulated by 3360kvm.Userspace can use the information returned by this ioctl to query 3361which features are emulated by kvm instead of being present natively. 3362 3363Userspace invokes KVM_GET_EMULATED_CPUID by passing a kvm_cpuid2 3364structure with the 'nent' field indicating the number of entries in 3365the variable-size array 'entries'. If the number of entries is too low 3366to describe the cpu capabilities, an error (E2BIG) is returned. If the 3367number is too high, the 'nent' field is adjusted and an error (ENOMEM) 3368is returned. If the number is just right, the 'nent' field is adjusted 3369to the number of valid entries in the 'entries' array, which is then 3370filled. 3371 3372The entries returned are the set CPUID bits of the respective features 3373which kvm emulates, as returned by the CPUID instruction, with unknown 3374or unsupported feature bits cleared. 3375 3376Features like x2apic, for example, may not be present in the host cpu 3377but are exposed by kvm in KVM_GET_SUPPORTED_CPUID because they can be 3378emulated efficiently and thus not included here. 3379 3380The fields in each entry are defined as follows: 3381 3382 function: 3383 the eax value used to obtain the entry 3384 index: 3385 the ecx value used to obtain the entry (for entries that are 3386 affected by ecx) 3387 flags: 3388 an OR of zero or more of the following: 3389 3390 KVM_CPUID_FLAG_SIGNIFCANT_INDEX: 3391 if the index field is valid 3392 3393 eax, ebx, ecx, edx: 3394 3395 the values returned by the cpuid instruction for 3396 this function/index combination 3397 33984.89 KVM_S390_MEM_OP 3399-------------------- 3400 3401:Capability: KVM_CAP_S390_MEM_OP 3402:Architectures: s390 3403:Type: vcpu ioctl 3404:Parameters: struct kvm_s390_mem_op (in) 3405:Returns: = 0 on success, 3406 < 0 on generic error (e.g. -EFAULT or -ENOMEM), 3407 > 0 if an exception occurred while walking the page tables 3408 3409Read or write data from/to the logical (virtual) memory of a VCPU. 3410 3411Parameters are specified via the following structure:: 3412 3413 struct kvm_s390_mem_op { 3414 __u64 gaddr; /* the guest address */ 3415 __u64 flags; /* flags */ 3416 __u32 size; /* amount of bytes */ 3417 __u32 op; /* type of operation */ 3418 __u64 buf; /* buffer in userspace */ 3419 __u8 ar; /* the access register number */ 3420 __u8 reserved[31]; /* should be set to 0 */ 3421 }; 3422 3423The type of operation is specified in the "op" field. It is either 3424KVM_S390_MEMOP_LOGICAL_READ for reading from logical memory space or 3425KVM_S390_MEMOP_LOGICAL_WRITE for writing to logical memory space. The 3426KVM_S390_MEMOP_F_CHECK_ONLY flag can be set in the "flags" field to check 3427whether the corresponding memory access would create an access exception 3428(without touching the data in the memory at the destination). In case an 3429access exception occurred while walking the MMU tables of the guest, the 3430ioctl returns a positive error number to indicate the type of exception. 3431This exception is also raised directly at the corresponding VCPU if the 3432flag KVM_S390_MEMOP_F_INJECT_EXCEPTION is set in the "flags" field. 3433 3434The start address of the memory region has to be specified in the "gaddr" 3435field, and the length of the region in the "size" field (which must not 3436be 0). The maximum value for "size" can be obtained by checking the 3437KVM_CAP_S390_MEM_OP capability. "buf" is the buffer supplied by the 3438userspace application where the read data should be written to for 3439KVM_S390_MEMOP_LOGICAL_READ, or where the data that should be written is 3440stored for a KVM_S390_MEMOP_LOGICAL_WRITE. When KVM_S390_MEMOP_F_CHECK_ONLY 3441is specified, "buf" is unused and can be NULL. "ar" designates the access 3442register number to be used; the valid range is 0..15. 3443 3444The "reserved" field is meant for future extensions. It is not used by 3445KVM with the currently defined set of flags. 3446 34474.90 KVM_S390_GET_SKEYS 3448----------------------- 3449 3450:Capability: KVM_CAP_S390_SKEYS 3451:Architectures: s390 3452:Type: vm ioctl 3453:Parameters: struct kvm_s390_skeys 3454:Returns: 0 on success, KVM_S390_GET_KEYS_NONE if guest is not using storage 3455 keys, negative value on error 3456 3457This ioctl is used to get guest storage key values on the s390 3458architecture. The ioctl takes parameters via the kvm_s390_skeys struct:: 3459 3460 struct kvm_s390_skeys { 3461 __u64 start_gfn; 3462 __u64 count; 3463 __u64 skeydata_addr; 3464 __u32 flags; 3465 __u32 reserved[9]; 3466 }; 3467 3468The start_gfn field is the number of the first guest frame whose storage keys 3469you want to get. 3470 3471The count field is the number of consecutive frames (starting from start_gfn) 3472whose storage keys to get. The count field must be at least 1 and the maximum 3473allowed value is defined as KVM_S390_SKEYS_ALLOC_MAX. Values outside this range 3474will cause the ioctl to return -EINVAL. 3475 3476The skeydata_addr field is the address to a buffer large enough to hold count 3477bytes. This buffer will be filled with storage key data by the ioctl. 3478 34794.91 KVM_S390_SET_SKEYS 3480----------------------- 3481 3482:Capability: KVM_CAP_S390_SKEYS 3483:Architectures: s390 3484:Type: vm ioctl 3485:Parameters: struct kvm_s390_skeys 3486:Returns: 0 on success, negative value on error 3487 3488This ioctl is used to set guest storage key values on the s390 3489architecture. The ioctl takes parameters via the kvm_s390_skeys struct. 3490See section on KVM_S390_GET_SKEYS for struct definition. 3491 3492The start_gfn field is the number of the first guest frame whose storage keys 3493you want to set. 3494 3495The count field is the number of consecutive frames (starting from start_gfn) 3496whose storage keys to get. The count field must be at least 1 and the maximum 3497allowed value is defined as KVM_S390_SKEYS_ALLOC_MAX. Values outside this range 3498will cause the ioctl to return -EINVAL. 3499 3500The skeydata_addr field is the address to a buffer containing count bytes of 3501storage keys. Each byte in the buffer will be set as the storage key for a 3502single frame starting at start_gfn for count frames. 3503 3504Note: If any architecturally invalid key value is found in the given data then 3505the ioctl will return -EINVAL. 3506 35074.92 KVM_S390_IRQ 3508----------------- 3509 3510:Capability: KVM_CAP_S390_INJECT_IRQ 3511:Architectures: s390 3512:Type: vcpu ioctl 3513:Parameters: struct kvm_s390_irq (in) 3514:Returns: 0 on success, -1 on error 3515 3516Errors: 3517 3518 3519 ====== ================================================================= 3520 EINVAL interrupt type is invalid 3521 type is KVM_S390_SIGP_STOP and flag parameter is invalid value, 3522 type is KVM_S390_INT_EXTERNAL_CALL and code is bigger 3523 than the maximum of VCPUs 3524 EBUSY type is KVM_S390_SIGP_SET_PREFIX and vcpu is not stopped, 3525 type is KVM_S390_SIGP_STOP and a stop irq is already pending, 3526 type is KVM_S390_INT_EXTERNAL_CALL and an external call interrupt 3527 is already pending 3528 ====== ================================================================= 3529 3530Allows to inject an interrupt to the guest. 3531 3532Using struct kvm_s390_irq as a parameter allows 3533to inject additional payload which is not 3534possible via KVM_S390_INTERRUPT. 3535 3536Interrupt parameters are passed via kvm_s390_irq:: 3537 3538 struct kvm_s390_irq { 3539 __u64 type; 3540 union { 3541 struct kvm_s390_io_info io; 3542 struct kvm_s390_ext_info ext; 3543 struct kvm_s390_pgm_info pgm; 3544 struct kvm_s390_emerg_info emerg; 3545 struct kvm_s390_extcall_info extcall; 3546 struct kvm_s390_prefix_info prefix; 3547 struct kvm_s390_stop_info stop; 3548 struct kvm_s390_mchk_info mchk; 3549 char reserved[64]; 3550 } u; 3551 }; 3552 3553type can be one of the following: 3554 3555- KVM_S390_SIGP_STOP - sigp stop; parameter in .stop 3556- KVM_S390_PROGRAM_INT - program check; parameters in .pgm 3557- KVM_S390_SIGP_SET_PREFIX - sigp set prefix; parameters in .prefix 3558- KVM_S390_RESTART - restart; no parameters 3559- KVM_S390_INT_CLOCK_COMP - clock comparator interrupt; no parameters 3560- KVM_S390_INT_CPU_TIMER - CPU timer interrupt; no parameters 3561- KVM_S390_INT_EMERGENCY - sigp emergency; parameters in .emerg 3562- KVM_S390_INT_EXTERNAL_CALL - sigp external call; parameters in .extcall 3563- KVM_S390_MCHK - machine check interrupt; parameters in .mchk 3564 3565This is an asynchronous vcpu ioctl and can be invoked from any thread. 3566 35674.94 KVM_S390_GET_IRQ_STATE 3568--------------------------- 3569 3570:Capability: KVM_CAP_S390_IRQ_STATE 3571:Architectures: s390 3572:Type: vcpu ioctl 3573:Parameters: struct kvm_s390_irq_state (out) 3574:Returns: >= number of bytes copied into buffer, 3575 -EINVAL if buffer size is 0, 3576 -ENOBUFS if buffer size is too small to fit all pending interrupts, 3577 -EFAULT if the buffer address was invalid 3578 3579This ioctl allows userspace to retrieve the complete state of all currently 3580pending interrupts in a single buffer. Use cases include migration 3581and introspection. The parameter structure contains the address of a 3582userspace buffer and its length:: 3583 3584 struct kvm_s390_irq_state { 3585 __u64 buf; 3586 __u32 flags; /* will stay unused for compatibility reasons */ 3587 __u32 len; 3588 __u32 reserved[4]; /* will stay unused for compatibility reasons */ 3589 }; 3590 3591Userspace passes in the above struct and for each pending interrupt a 3592struct kvm_s390_irq is copied to the provided buffer. 3593 3594The structure contains a flags and a reserved field for future extensions. As 3595the kernel never checked for flags == 0 and QEMU never pre-zeroed flags and 3596reserved, these fields can not be used in the future without breaking 3597compatibility. 3598 3599If -ENOBUFS is returned the buffer provided was too small and userspace 3600may retry with a bigger buffer. 3601 36024.95 KVM_S390_SET_IRQ_STATE 3603--------------------------- 3604 3605:Capability: KVM_CAP_S390_IRQ_STATE 3606:Architectures: s390 3607:Type: vcpu ioctl 3608:Parameters: struct kvm_s390_irq_state (in) 3609:Returns: 0 on success, 3610 -EFAULT if the buffer address was invalid, 3611 -EINVAL for an invalid buffer length (see below), 3612 -EBUSY if there were already interrupts pending, 3613 errors occurring when actually injecting the 3614 interrupt. See KVM_S390_IRQ. 3615 3616This ioctl allows userspace to set the complete state of all cpu-local 3617interrupts currently pending for the vcpu. It is intended for restoring 3618interrupt state after a migration. The input parameter is a userspace buffer 3619containing a struct kvm_s390_irq_state:: 3620 3621 struct kvm_s390_irq_state { 3622 __u64 buf; 3623 __u32 flags; /* will stay unused for compatibility reasons */ 3624 __u32 len; 3625 __u32 reserved[4]; /* will stay unused for compatibility reasons */ 3626 }; 3627 3628The restrictions for flags and reserved apply as well. 3629(see KVM_S390_GET_IRQ_STATE) 3630 3631The userspace memory referenced by buf contains a struct kvm_s390_irq 3632for each interrupt to be injected into the guest. 3633If one of the interrupts could not be injected for some reason the 3634ioctl aborts. 3635 3636len must be a multiple of sizeof(struct kvm_s390_irq). It must be > 0 3637and it must not exceed (max_vcpus + 32) * sizeof(struct kvm_s390_irq), 3638which is the maximum number of possibly pending cpu-local interrupts. 3639 36404.96 KVM_SMI 3641------------ 3642 3643:Capability: KVM_CAP_X86_SMM 3644:Architectures: x86 3645:Type: vcpu ioctl 3646:Parameters: none 3647:Returns: 0 on success, -1 on error 3648 3649Queues an SMI on the thread's vcpu. 3650 36514.97 KVM_CAP_PPC_MULTITCE 3652------------------------- 3653 3654:Capability: KVM_CAP_PPC_MULTITCE 3655:Architectures: ppc 3656:Type: vm 3657 3658This capability means the kernel is capable of handling hypercalls 3659H_PUT_TCE_INDIRECT and H_STUFF_TCE without passing those into the user 3660space. This significantly accelerates DMA operations for PPC KVM guests. 3661User space should expect that its handlers for these hypercalls 3662are not going to be called if user space previously registered LIOBN 3663in KVM (via KVM_CREATE_SPAPR_TCE or similar calls). 3664 3665In order to enable H_PUT_TCE_INDIRECT and H_STUFF_TCE use in the guest, 3666user space might have to advertise it for the guest. For example, 3667IBM pSeries (sPAPR) guest starts using them if "hcall-multi-tce" is 3668present in the "ibm,hypertas-functions" device-tree property. 3669 3670The hypercalls mentioned above may or may not be processed successfully 3671in the kernel based fast path. If they can not be handled by the kernel, 3672they will get passed on to user space. So user space still has to have 3673an implementation for these despite the in kernel acceleration. 3674 3675This capability is always enabled. 3676 36774.98 KVM_CREATE_SPAPR_TCE_64 3678---------------------------- 3679 3680:Capability: KVM_CAP_SPAPR_TCE_64 3681:Architectures: powerpc 3682:Type: vm ioctl 3683:Parameters: struct kvm_create_spapr_tce_64 (in) 3684:Returns: file descriptor for manipulating the created TCE table 3685 3686This is an extension for KVM_CAP_SPAPR_TCE which only supports 32bit 3687windows, described in 4.62 KVM_CREATE_SPAPR_TCE 3688 3689This capability uses extended struct in ioctl interface:: 3690 3691 /* for KVM_CAP_SPAPR_TCE_64 */ 3692 struct kvm_create_spapr_tce_64 { 3693 __u64 liobn; 3694 __u32 page_shift; 3695 __u32 flags; 3696 __u64 offset; /* in pages */ 3697 __u64 size; /* in pages */ 3698 }; 3699 3700The aim of extension is to support an additional bigger DMA window with 3701a variable page size. 3702KVM_CREATE_SPAPR_TCE_64 receives a 64bit window size, an IOMMU page shift and 3703a bus offset of the corresponding DMA window, @size and @offset are numbers 3704of IOMMU pages. 3705 3706@flags are not used at the moment. 3707 3708The rest of functionality is identical to KVM_CREATE_SPAPR_TCE. 3709 37104.99 KVM_REINJECT_CONTROL 3711------------------------- 3712 3713:Capability: KVM_CAP_REINJECT_CONTROL 3714:Architectures: x86 3715:Type: vm ioctl 3716:Parameters: struct kvm_reinject_control (in) 3717:Returns: 0 on success, 3718 -EFAULT if struct kvm_reinject_control cannot be read, 3719 -ENXIO if KVM_CREATE_PIT or KVM_CREATE_PIT2 didn't succeed earlier. 3720 3721i8254 (PIT) has two modes, reinject and !reinject. The default is reinject, 3722where KVM queues elapsed i8254 ticks and monitors completion of interrupt from 3723vector(s) that i8254 injects. Reinject mode dequeues a tick and injects its 3724interrupt whenever there isn't a pending interrupt from i8254. 3725!reinject mode injects an interrupt as soon as a tick arrives. 3726 3727:: 3728 3729 struct kvm_reinject_control { 3730 __u8 pit_reinject; 3731 __u8 reserved[31]; 3732 }; 3733 3734pit_reinject = 0 (!reinject mode) is recommended, unless running an old 3735operating system that uses the PIT for timing (e.g. Linux 2.4.x). 3736 37374.100 KVM_PPC_CONFIGURE_V3_MMU 3738------------------------------ 3739 3740:Capability: KVM_CAP_PPC_RADIX_MMU or KVM_CAP_PPC_HASH_MMU_V3 3741:Architectures: ppc 3742:Type: vm ioctl 3743:Parameters: struct kvm_ppc_mmuv3_cfg (in) 3744:Returns: 0 on success, 3745 -EFAULT if struct kvm_ppc_mmuv3_cfg cannot be read, 3746 -EINVAL if the configuration is invalid 3747 3748This ioctl controls whether the guest will use radix or HPT (hashed 3749page table) translation, and sets the pointer to the process table for 3750the guest. 3751 3752:: 3753 3754 struct kvm_ppc_mmuv3_cfg { 3755 __u64 flags; 3756 __u64 process_table; 3757 }; 3758 3759There are two bits that can be set in flags; KVM_PPC_MMUV3_RADIX and 3760KVM_PPC_MMUV3_GTSE. KVM_PPC_MMUV3_RADIX, if set, configures the guest 3761to use radix tree translation, and if clear, to use HPT translation. 3762KVM_PPC_MMUV3_GTSE, if set and if KVM permits it, configures the guest 3763to be able to use the global TLB and SLB invalidation instructions; 3764if clear, the guest may not use these instructions. 3765 3766The process_table field specifies the address and size of the guest 3767process table, which is in the guest's space. This field is formatted 3768as the second doubleword of the partition table entry, as defined in 3769the Power ISA V3.00, Book III section 5.7.6.1. 3770 37714.101 KVM_PPC_GET_RMMU_INFO 3772--------------------------- 3773 3774:Capability: KVM_CAP_PPC_RADIX_MMU 3775:Architectures: ppc 3776:Type: vm ioctl 3777:Parameters: struct kvm_ppc_rmmu_info (out) 3778:Returns: 0 on success, 3779 -EFAULT if struct kvm_ppc_rmmu_info cannot be written, 3780 -EINVAL if no useful information can be returned 3781 3782This ioctl returns a structure containing two things: (a) a list 3783containing supported radix tree geometries, and (b) a list that maps 3784page sizes to put in the "AP" (actual page size) field for the tlbie 3785(TLB invalidate entry) instruction. 3786 3787:: 3788 3789 struct kvm_ppc_rmmu_info { 3790 struct kvm_ppc_radix_geom { 3791 __u8 page_shift; 3792 __u8 level_bits[4]; 3793 __u8 pad[3]; 3794 } geometries[8]; 3795 __u32 ap_encodings[8]; 3796 }; 3797 3798The geometries[] field gives up to 8 supported geometries for the 3799radix page table, in terms of the log base 2 of the smallest page 3800size, and the number of bits indexed at each level of the tree, from 3801the PTE level up to the PGD level in that order. Any unused entries 3802will have 0 in the page_shift field. 3803 3804The ap_encodings gives the supported page sizes and their AP field 3805encodings, encoded with the AP value in the top 3 bits and the log 3806base 2 of the page size in the bottom 6 bits. 3807 38084.102 KVM_PPC_RESIZE_HPT_PREPARE 3809-------------------------------- 3810 3811:Capability: KVM_CAP_SPAPR_RESIZE_HPT 3812:Architectures: powerpc 3813:Type: vm ioctl 3814:Parameters: struct kvm_ppc_resize_hpt (in) 3815:Returns: 0 on successful completion, 3816 >0 if a new HPT is being prepared, the value is an estimated 3817 number of milliseconds until preparation is complete, 3818 -EFAULT if struct kvm_reinject_control cannot be read, 3819 -EINVAL if the supplied shift or flags are invalid, 3820 -ENOMEM if unable to allocate the new HPT, 3821 -ENOSPC if there was a hash collision 3822 3823:: 3824 3825 struct kvm_ppc_rmmu_info { 3826 struct kvm_ppc_radix_geom { 3827 __u8 page_shift; 3828 __u8 level_bits[4]; 3829 __u8 pad[3]; 3830 } geometries[8]; 3831 __u32 ap_encodings[8]; 3832 }; 3833 3834The geometries[] field gives up to 8 supported geometries for the 3835radix page table, in terms of the log base 2 of the smallest page 3836size, and the number of bits indexed at each level of the tree, from 3837the PTE level up to the PGD level in that order. Any unused entries 3838will have 0 in the page_shift field. 3839 3840The ap_encodings gives the supported page sizes and their AP field 3841encodings, encoded with the AP value in the top 3 bits and the log 3842base 2 of the page size in the bottom 6 bits. 3843 38444.102 KVM_PPC_RESIZE_HPT_PREPARE 3845-------------------------------- 3846 3847:Capability: KVM_CAP_SPAPR_RESIZE_HPT 3848:Architectures: powerpc 3849:Type: vm ioctl 3850:Parameters: struct kvm_ppc_resize_hpt (in) 3851:Returns: 0 on successful completion, 3852 >0 if a new HPT is being prepared, the value is an estimated 3853 number of milliseconds until preparation is complete, 3854 -EFAULT if struct kvm_reinject_control cannot be read, 3855 -EINVAL if the supplied shift or flags are invalid,when moving existing 3856 HPT entries to the new HPT, 3857 -EIO on other error conditions 3858 3859Used to implement the PAPR extension for runtime resizing of a guest's 3860Hashed Page Table (HPT). Specifically this starts, stops or monitors 3861the preparation of a new potential HPT for the guest, essentially 3862implementing the H_RESIZE_HPT_PREPARE hypercall. 3863 3864If called with shift > 0 when there is no pending HPT for the guest, 3865this begins preparation of a new pending HPT of size 2^(shift) bytes. 3866It then returns a positive integer with the estimated number of 3867milliseconds until preparation is complete. 3868 3869If called when there is a pending HPT whose size does not match that 3870requested in the parameters, discards the existing pending HPT and 3871creates a new one as above. 3872 3873If called when there is a pending HPT of the size requested, will: 3874 3875 * If preparation of the pending HPT is already complete, return 0 3876 * If preparation of the pending HPT has failed, return an error 3877 code, then discard the pending HPT. 3878 * If preparation of the pending HPT is still in progress, return an 3879 estimated number of milliseconds until preparation is complete. 3880 3881If called with shift == 0, discards any currently pending HPT and 3882returns 0 (i.e. cancels any in-progress preparation). 3883 3884flags is reserved for future expansion, currently setting any bits in 3885flags will result in an -EINVAL. 3886 3887Normally this will be called repeatedly with the same parameters until 3888it returns <= 0. The first call will initiate preparation, subsequent 3889ones will monitor preparation until it completes or fails. 3890 3891:: 3892 3893 struct kvm_ppc_resize_hpt { 3894 __u64 flags; 3895 __u32 shift; 3896 __u32 pad; 3897 }; 3898 38994.103 KVM_PPC_RESIZE_HPT_COMMIT 3900------------------------------- 3901 3902:Capability: KVM_CAP_SPAPR_RESIZE_HPT 3903:Architectures: powerpc 3904:Type: vm ioctl 3905:Parameters: struct kvm_ppc_resize_hpt (in) 3906:Returns: 0 on successful completion, 3907 -EFAULT if struct kvm_reinject_control cannot be read, 3908 -EINVAL if the supplied shift or flags are invalid, 3909 -ENXIO is there is no pending HPT, or the pending HPT doesn't 3910 have the requested size, 3911 -EBUSY if the pending HPT is not fully prepared, 3912 -ENOSPC if there was a hash collision when moving existing 3913 HPT entries to the new HPT, 3914 -EIO on other error conditions 3915 3916Used to implement the PAPR extension for runtime resizing of a guest's 3917Hashed Page Table (HPT). Specifically this requests that the guest be 3918transferred to working with the new HPT, essentially implementing the 3919H_RESIZE_HPT_COMMIT hypercall. 3920 3921This should only be called after KVM_PPC_RESIZE_HPT_PREPARE has 3922returned 0 with the same parameters. In other cases 3923KVM_PPC_RESIZE_HPT_COMMIT will return an error (usually -ENXIO or 3924-EBUSY, though others may be possible if the preparation was started, 3925but failed). 3926 3927This will have undefined effects on the guest if it has not already 3928placed itself in a quiescent state where no vcpu will make MMU enabled 3929memory accesses. 3930 3931On succsful completion, the pending HPT will become the guest's active 3932HPT and the previous HPT will be discarded. 3933 3934On failure, the guest will still be operating on its previous HPT. 3935 3936:: 3937 3938 struct kvm_ppc_resize_hpt { 3939 __u64 flags; 3940 __u32 shift; 3941 __u32 pad; 3942 }; 3943 39444.104 KVM_X86_GET_MCE_CAP_SUPPORTED 3945----------------------------------- 3946 3947:Capability: KVM_CAP_MCE 3948:Architectures: x86 3949:Type: system ioctl 3950:Parameters: u64 mce_cap (out) 3951:Returns: 0 on success, -1 on error 3952 3953Returns supported MCE capabilities. The u64 mce_cap parameter 3954has the same format as the MSR_IA32_MCG_CAP register. Supported 3955capabilities will have the corresponding bits set. 3956 39574.105 KVM_X86_SETUP_MCE 3958----------------------- 3959 3960:Capability: KVM_CAP_MCE 3961:Architectures: x86 3962:Type: vcpu ioctl 3963:Parameters: u64 mcg_cap (in) 3964:Returns: 0 on success, 3965 -EFAULT if u64 mcg_cap cannot be read, 3966 -EINVAL if the requested number of banks is invalid, 3967 -EINVAL if requested MCE capability is not supported. 3968 3969Initializes MCE support for use. The u64 mcg_cap parameter 3970has the same format as the MSR_IA32_MCG_CAP register and 3971specifies which capabilities should be enabled. The maximum 3972supported number of error-reporting banks can be retrieved when 3973checking for KVM_CAP_MCE. The supported capabilities can be 3974retrieved with KVM_X86_GET_MCE_CAP_SUPPORTED. 3975 39764.106 KVM_X86_SET_MCE 3977--------------------- 3978 3979:Capability: KVM_CAP_MCE 3980:Architectures: x86 3981:Type: vcpu ioctl 3982:Parameters: struct kvm_x86_mce (in) 3983:Returns: 0 on success, 3984 -EFAULT if struct kvm_x86_mce cannot be read, 3985 -EINVAL if the bank number is invalid, 3986 -EINVAL if VAL bit is not set in status field. 3987 3988Inject a machine check error (MCE) into the guest. The input 3989parameter is:: 3990 3991 struct kvm_x86_mce { 3992 __u64 status; 3993 __u64 addr; 3994 __u64 misc; 3995 __u64 mcg_status; 3996 __u8 bank; 3997 __u8 pad1[7]; 3998 __u64 pad2[3]; 3999 }; 4000 4001If the MCE being reported is an uncorrected error, KVM will 4002inject it as an MCE exception into the guest. If the guest 4003MCG_STATUS register reports that an MCE is in progress, KVM 4004causes an KVM_EXIT_SHUTDOWN vmexit. 4005 4006Otherwise, if the MCE is a corrected error, KVM will just 4007store it in the corresponding bank (provided this bank is 4008not holding a previously reported uncorrected error). 4009 40104.107 KVM_S390_GET_CMMA_BITS 4011---------------------------- 4012 4013:Capability: KVM_CAP_S390_CMMA_MIGRATION 4014:Architectures: s390 4015:Type: vm ioctl 4016:Parameters: struct kvm_s390_cmma_log (in, out) 4017:Returns: 0 on success, a negative value on error 4018 4019This ioctl is used to get the values of the CMMA bits on the s390 4020architecture. It is meant to be used in two scenarios: 4021 4022- During live migration to save the CMMA values. Live migration needs 4023 to be enabled via the KVM_REQ_START_MIGRATION VM property. 4024- To non-destructively peek at the CMMA values, with the flag 4025 KVM_S390_CMMA_PEEK set. 4026 4027The ioctl takes parameters via the kvm_s390_cmma_log struct. The desired 4028values are written to a buffer whose location is indicated via the "values" 4029member in the kvm_s390_cmma_log struct. The values in the input struct are 4030also updated as needed. 4031 4032Each CMMA value takes up one byte. 4033 4034:: 4035 4036 struct kvm_s390_cmma_log { 4037 __u64 start_gfn; 4038 __u32 count; 4039 __u32 flags; 4040 union { 4041 __u64 remaining; 4042 __u64 mask; 4043 }; 4044 __u64 values; 4045 }; 4046 4047start_gfn is the number of the first guest frame whose CMMA values are 4048to be retrieved, 4049 4050count is the length of the buffer in bytes, 4051 4052values points to the buffer where the result will be written to. 4053 4054If count is greater than KVM_S390_SKEYS_MAX, then it is considered to be 4055KVM_S390_SKEYS_MAX. KVM_S390_SKEYS_MAX is re-used for consistency with 4056other ioctls. 4057 4058The result is written in the buffer pointed to by the field values, and 4059the values of the input parameter are updated as follows. 4060 4061Depending on the flags, different actions are performed. The only 4062supported flag so far is KVM_S390_CMMA_PEEK. 4063 4064The default behaviour if KVM_S390_CMMA_PEEK is not set is: 4065start_gfn will indicate the first page frame whose CMMA bits were dirty. 4066It is not necessarily the same as the one passed as input, as clean pages 4067are skipped. 4068 4069count will indicate the number of bytes actually written in the buffer. 4070It can (and very often will) be smaller than the input value, since the 4071buffer is only filled until 16 bytes of clean values are found (which 4072are then not copied in the buffer). Since a CMMA migration block needs 4073the base address and the length, for a total of 16 bytes, we will send 4074back some clean data if there is some dirty data afterwards, as long as 4075the size of the clean data does not exceed the size of the header. This 4076allows to minimize the amount of data to be saved or transferred over 4077the network at the expense of more roundtrips to userspace. The next 4078invocation of the ioctl will skip over all the clean values, saving 4079potentially more than just the 16 bytes we found. 4080 4081If KVM_S390_CMMA_PEEK is set: 4082the existing storage attributes are read even when not in migration 4083mode, and no other action is performed; 4084 4085the output start_gfn will be equal to the input start_gfn, 4086 4087the output count will be equal to the input count, except if the end of 4088memory has been reached. 4089 4090In both cases: 4091the field "remaining" will indicate the total number of dirty CMMA values 4092still remaining, or 0 if KVM_S390_CMMA_PEEK is set and migration mode is 4093not enabled. 4094 4095mask is unused. 4096 4097values points to the userspace buffer where the result will be stored. 4098 4099This ioctl can fail with -ENOMEM if not enough memory can be allocated to 4100complete the task, with -ENXIO if CMMA is not enabled, with -EINVAL if 4101KVM_S390_CMMA_PEEK is not set but migration mode was not enabled, with 4102-EFAULT if the userspace address is invalid or if no page table is 4103present for the addresses (e.g. when using hugepages). 4104 41054.108 KVM_S390_SET_CMMA_BITS 4106---------------------------- 4107 4108:Capability: KVM_CAP_S390_CMMA_MIGRATION 4109:Architectures: s390 4110:Type: vm ioctl 4111:Parameters: struct kvm_s390_cmma_log (in) 4112:Returns: 0 on success, a negative value on error 4113 4114This ioctl is used to set the values of the CMMA bits on the s390 4115architecture. It is meant to be used during live migration to restore 4116the CMMA values, but there are no restrictions on its use. 4117The ioctl takes parameters via the kvm_s390_cmma_values struct. 4118Each CMMA value takes up one byte. 4119 4120:: 4121 4122 struct kvm_s390_cmma_log { 4123 __u64 start_gfn; 4124 __u32 count; 4125 __u32 flags; 4126 union { 4127 __u64 remaining; 4128 __u64 mask; 4129 }; 4130 __u64 values; 4131 }; 4132 4133start_gfn indicates the starting guest frame number, 4134 4135count indicates how many values are to be considered in the buffer, 4136 4137flags is not used and must be 0. 4138 4139mask indicates which PGSTE bits are to be considered. 4140 4141remaining is not used. 4142 4143values points to the buffer in userspace where to store the values. 4144 4145This ioctl can fail with -ENOMEM if not enough memory can be allocated to 4146complete the task, with -ENXIO if CMMA is not enabled, with -EINVAL if 4147the count field is too large (e.g. more than KVM_S390_CMMA_SIZE_MAX) or 4148if the flags field was not 0, with -EFAULT if the userspace address is 4149invalid, if invalid pages are written to (e.g. after the end of memory) 4150or if no page table is present for the addresses (e.g. when using 4151hugepages). 4152 41534.109 KVM_PPC_GET_CPU_CHAR 4154-------------------------- 4155 4156:Capability: KVM_CAP_PPC_GET_CPU_CHAR 4157:Architectures: powerpc 4158:Type: vm ioctl 4159:Parameters: struct kvm_ppc_cpu_char (out) 4160:Returns: 0 on successful completion, 4161 -EFAULT if struct kvm_ppc_cpu_char cannot be written 4162 4163This ioctl gives userspace information about certain characteristics 4164of the CPU relating to speculative execution of instructions and 4165possible information leakage resulting from speculative execution (see 4166CVE-2017-5715, CVE-2017-5753 and CVE-2017-5754). The information is 4167returned in struct kvm_ppc_cpu_char, which looks like this:: 4168 4169 struct kvm_ppc_cpu_char { 4170 __u64 character; /* characteristics of the CPU */ 4171 __u64 behaviour; /* recommended software behaviour */ 4172 __u64 character_mask; /* valid bits in character */ 4173 __u64 behaviour_mask; /* valid bits in behaviour */ 4174 }; 4175 4176For extensibility, the character_mask and behaviour_mask fields 4177indicate which bits of character and behaviour have been filled in by 4178the kernel. If the set of defined bits is extended in future then 4179userspace will be able to tell whether it is running on a kernel that 4180knows about the new bits. 4181 4182The character field describes attributes of the CPU which can help 4183with preventing inadvertent information disclosure - specifically, 4184whether there is an instruction to flash-invalidate the L1 data cache 4185(ori 30,30,0 or mtspr SPRN_TRIG2,rN), whether the L1 data cache is set 4186to a mode where entries can only be used by the thread that created 4187them, whether the bcctr[l] instruction prevents speculation, and 4188whether a speculation barrier instruction (ori 31,31,0) is provided. 4189 4190The behaviour field describes actions that software should take to 4191prevent inadvertent information disclosure, and thus describes which 4192vulnerabilities the hardware is subject to; specifically whether the 4193L1 data cache should be flushed when returning to user mode from the 4194kernel, and whether a speculation barrier should be placed between an 4195array bounds check and the array access. 4196 4197These fields use the same bit definitions as the new 4198H_GET_CPU_CHARACTERISTICS hypercall. 4199 42004.110 KVM_MEMORY_ENCRYPT_OP 4201--------------------------- 4202 4203:Capability: basic 4204:Architectures: x86 4205:Type: system 4206:Parameters: an opaque platform specific structure (in/out) 4207:Returns: 0 on success; -1 on error 4208 4209If the platform supports creating encrypted VMs then this ioctl can be used 4210for issuing platform-specific memory encryption commands to manage those 4211encrypted VMs. 4212 4213Currently, this ioctl is used for issuing Secure Encrypted Virtualization 4214(SEV) commands on AMD Processors. The SEV commands are defined in 4215Documentation/virt/kvm/amd-memory-encryption.rst. 4216 42174.111 KVM_MEMORY_ENCRYPT_REG_REGION 4218----------------------------------- 4219 4220:Capability: basic 4221:Architectures: x86 4222:Type: system 4223:Parameters: struct kvm_enc_region (in) 4224:Returns: 0 on success; -1 on error 4225 4226This ioctl can be used to register a guest memory region which may 4227contain encrypted data (e.g. guest RAM, SMRAM etc). 4228 4229It is used in the SEV-enabled guest. When encryption is enabled, a guest 4230memory region may contain encrypted data. The SEV memory encryption 4231engine uses a tweak such that two identical plaintext pages, each at 4232different locations will have differing ciphertexts. So swapping or 4233moving ciphertext of those pages will not result in plaintext being 4234swapped. So relocating (or migrating) physical backing pages for the SEV 4235guest will require some additional steps. 4236 4237Note: The current SEV key management spec does not provide commands to 4238swap or migrate (move) ciphertext pages. Hence, for now we pin the guest 4239memory region registered with the ioctl. 4240 42414.112 KVM_MEMORY_ENCRYPT_UNREG_REGION 4242------------------------------------- 4243 4244:Capability: basic 4245:Architectures: x86 4246:Type: system 4247:Parameters: struct kvm_enc_region (in) 4248:Returns: 0 on success; -1 on error 4249 4250This ioctl can be used to unregister the guest memory region registered 4251with KVM_MEMORY_ENCRYPT_REG_REGION ioctl above. 4252 42534.113 KVM_HYPERV_EVENTFD 4254------------------------ 4255 4256:Capability: KVM_CAP_HYPERV_EVENTFD 4257:Architectures: x86 4258:Type: vm ioctl 4259:Parameters: struct kvm_hyperv_eventfd (in) 4260 4261This ioctl (un)registers an eventfd to receive notifications from the guest on 4262the specified Hyper-V connection id through the SIGNAL_EVENT hypercall, without 4263causing a user exit. SIGNAL_EVENT hypercall with non-zero event flag number 4264(bits 24-31) still triggers a KVM_EXIT_HYPERV_HCALL user exit. 4265 4266:: 4267 4268 struct kvm_hyperv_eventfd { 4269 __u32 conn_id; 4270 __s32 fd; 4271 __u32 flags; 4272 __u32 padding[3]; 4273 }; 4274 4275The conn_id field should fit within 24 bits:: 4276 4277 #define KVM_HYPERV_CONN_ID_MASK 0x00ffffff 4278 4279The acceptable values for the flags field are:: 4280 4281 #define KVM_HYPERV_EVENTFD_DEASSIGN (1 << 0) 4282 4283:Returns: 0 on success, 4284 -EINVAL if conn_id or flags is outside the allowed range, 4285 -ENOENT on deassign if the conn_id isn't registered, 4286 -EEXIST on assign if the conn_id is already registered 4287 42884.114 KVM_GET_NESTED_STATE 4289-------------------------- 4290 4291:Capability: KVM_CAP_NESTED_STATE 4292:Architectures: x86 4293:Type: vcpu ioctl 4294:Parameters: struct kvm_nested_state (in/out) 4295:Returns: 0 on success, -1 on error 4296 4297Errors: 4298 4299 ===== ============================================================= 4300 E2BIG the total state size exceeds the value of 'size' specified by 4301 the user; the size required will be written into size. 4302 ===== ============================================================= 4303 4304:: 4305 4306 struct kvm_nested_state { 4307 __u16 flags; 4308 __u16 format; 4309 __u32 size; 4310 4311 union { 4312 struct kvm_vmx_nested_state_hdr vmx; 4313 struct kvm_svm_nested_state_hdr svm; 4314 4315 /* Pad the header to 128 bytes. */ 4316 __u8 pad[120]; 4317 } hdr; 4318 4319 union { 4320 struct kvm_vmx_nested_state_data vmx[0]; 4321 struct kvm_svm_nested_state_data svm[0]; 4322 } data; 4323 }; 4324 4325 #define KVM_STATE_NESTED_GUEST_MODE 0x00000001 4326 #define KVM_STATE_NESTED_RUN_PENDING 0x00000002 4327 #define KVM_STATE_NESTED_EVMCS 0x00000004 4328 4329 #define KVM_STATE_NESTED_FORMAT_VMX 0 4330 #define KVM_STATE_NESTED_FORMAT_SVM 1 4331 4332 #define KVM_STATE_NESTED_VMX_VMCS_SIZE 0x1000 4333 4334 #define KVM_STATE_NESTED_VMX_SMM_GUEST_MODE 0x00000001 4335 #define KVM_STATE_NESTED_VMX_SMM_VMXON 0x00000002 4336 4337 struct kvm_vmx_nested_state_hdr { 4338 __u64 vmxon_pa; 4339 __u64 vmcs12_pa; 4340 4341 struct { 4342 __u16 flags; 4343 } smm; 4344 }; 4345 4346 struct kvm_vmx_nested_state_data { 4347 __u8 vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE]; 4348 __u8 shadow_vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE]; 4349 }; 4350 4351This ioctl copies the vcpu's nested virtualization state from the kernel to 4352userspace. 4353 4354The maximum size of the state can be retrieved by passing KVM_CAP_NESTED_STATE 4355to the KVM_CHECK_EXTENSION ioctl(). 4356 43574.115 KVM_SET_NESTED_STATE 4358-------------------------- 4359 4360:Capability: KVM_CAP_NESTED_STATE 4361:Architectures: x86 4362:Type: vcpu ioctl 4363:Parameters: struct kvm_nested_state (in) 4364:Returns: 0 on success, -1 on error 4365 4366This copies the vcpu's kvm_nested_state struct from userspace to the kernel. 4367For the definition of struct kvm_nested_state, see KVM_GET_NESTED_STATE. 4368 43694.116 KVM_(UN)REGISTER_COALESCED_MMIO 4370------------------------------------- 4371 4372:Capability: KVM_CAP_COALESCED_MMIO (for coalesced mmio) 4373 KVM_CAP_COALESCED_PIO (for coalesced pio) 4374:Architectures: all 4375:Type: vm ioctl 4376:Parameters: struct kvm_coalesced_mmio_zone 4377:Returns: 0 on success, < 0 on error 4378 4379Coalesced I/O is a performance optimization that defers hardware 4380register write emulation so that userspace exits are avoided. It is 4381typically used to reduce the overhead of emulating frequently accessed 4382hardware registers. 4383 4384When a hardware register is configured for coalesced I/O, write accesses 4385do not exit to userspace and their value is recorded in a ring buffer 4386that is shared between kernel and userspace. 4387 4388Coalesced I/O is used if one or more write accesses to a hardware 4389register can be deferred until a read or a write to another hardware 4390register on the same device. This last access will cause a vmexit and 4391userspace will process accesses from the ring buffer before emulating 4392it. That will avoid exiting to userspace on repeated writes. 4393 4394Coalesced pio is based on coalesced mmio. There is little difference 4395between coalesced mmio and pio except that coalesced pio records accesses 4396to I/O ports. 4397 43984.117 KVM_CLEAR_DIRTY_LOG (vm ioctl) 4399------------------------------------ 4400 4401:Capability: KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 4402:Architectures: x86, arm, arm64, mips 4403:Type: vm ioctl 4404:Parameters: struct kvm_dirty_log (in) 4405:Returns: 0 on success, -1 on error 4406 4407:: 4408 4409 /* for KVM_CLEAR_DIRTY_LOG */ 4410 struct kvm_clear_dirty_log { 4411 __u32 slot; 4412 __u32 num_pages; 4413 __u64 first_page; 4414 union { 4415 void __user *dirty_bitmap; /* one bit per page */ 4416 __u64 padding; 4417 }; 4418 }; 4419 4420The ioctl clears the dirty status of pages in a memory slot, according to 4421the bitmap that is passed in struct kvm_clear_dirty_log's dirty_bitmap 4422field. Bit 0 of the bitmap corresponds to page "first_page" in the 4423memory slot, and num_pages is the size in bits of the input bitmap. 4424first_page must be a multiple of 64; num_pages must also be a multiple of 442564 unless first_page + num_pages is the size of the memory slot. For each 4426bit that is set in the input bitmap, the corresponding page is marked "clean" 4427in KVM's dirty bitmap, and dirty tracking is re-enabled for that page 4428(for example via write-protection, or by clearing the dirty bit in 4429a page table entry). 4430 4431If KVM_CAP_MULTI_ADDRESS_SPACE is available, bits 16-31 specifies 4432the address space for which you want to return the dirty bitmap. 4433They must be less than the value that KVM_CHECK_EXTENSION returns for 4434the KVM_CAP_MULTI_ADDRESS_SPACE capability. 4435 4436This ioctl is mostly useful when KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 4437is enabled; for more information, see the description of the capability. 4438However, it can always be used as long as KVM_CHECK_EXTENSION confirms 4439that KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 is present. 4440 44414.118 KVM_GET_SUPPORTED_HV_CPUID 4442-------------------------------- 4443 4444:Capability: KVM_CAP_HYPERV_CPUID 4445:Architectures: x86 4446:Type: vcpu ioctl 4447:Parameters: struct kvm_cpuid2 (in/out) 4448:Returns: 0 on success, -1 on error 4449 4450:: 4451 4452 struct kvm_cpuid2 { 4453 __u32 nent; 4454 __u32 padding; 4455 struct kvm_cpuid_entry2 entries[0]; 4456 }; 4457 4458 struct kvm_cpuid_entry2 { 4459 __u32 function; 4460 __u32 index; 4461 __u32 flags; 4462 __u32 eax; 4463 __u32 ebx; 4464 __u32 ecx; 4465 __u32 edx; 4466 __u32 padding[3]; 4467 }; 4468 4469This ioctl returns x86 cpuid features leaves related to Hyper-V emulation in 4470KVM. Userspace can use the information returned by this ioctl to construct 4471cpuid information presented to guests consuming Hyper-V enlightenments (e.g. 4472Windows or Hyper-V guests). 4473 4474CPUID feature leaves returned by this ioctl are defined by Hyper-V Top Level 4475Functional Specification (TLFS). These leaves can't be obtained with 4476KVM_GET_SUPPORTED_CPUID ioctl because some of them intersect with KVM feature 4477leaves (0x40000000, 0x40000001). 4478 4479Currently, the following list of CPUID leaves are returned: 4480 - HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS 4481 - HYPERV_CPUID_INTERFACE 4482 - HYPERV_CPUID_VERSION 4483 - HYPERV_CPUID_FEATURES 4484 - HYPERV_CPUID_ENLIGHTMENT_INFO 4485 - HYPERV_CPUID_IMPLEMENT_LIMITS 4486 - HYPERV_CPUID_NESTED_FEATURES 4487 4488HYPERV_CPUID_NESTED_FEATURES leaf is only exposed when Enlightened VMCS was 4489enabled on the corresponding vCPU (KVM_CAP_HYPERV_ENLIGHTENED_VMCS). 4490 4491Userspace invokes KVM_GET_SUPPORTED_CPUID by passing a kvm_cpuid2 structure 4492with the 'nent' field indicating the number of entries in the variable-size 4493array 'entries'. If the number of entries is too low to describe all Hyper-V 4494feature leaves, an error (E2BIG) is returned. If the number is more or equal 4495to the number of Hyper-V feature leaves, the 'nent' field is adjusted to the 4496number of valid entries in the 'entries' array, which is then filled. 4497 4498'index' and 'flags' fields in 'struct kvm_cpuid_entry2' are currently reserved, 4499userspace should not expect to get any particular value there. 4500 45014.119 KVM_ARM_VCPU_FINALIZE 4502--------------------------- 4503 4504:Architectures: arm, arm64 4505:Type: vcpu ioctl 4506:Parameters: int feature (in) 4507:Returns: 0 on success, -1 on error 4508 4509Errors: 4510 4511 ====== ============================================================== 4512 EPERM feature not enabled, needs configuration, or already finalized 4513 EINVAL feature unknown or not present 4514 ====== ============================================================== 4515 4516Recognised values for feature: 4517 4518 ===== =========================================== 4519 arm64 KVM_ARM_VCPU_SVE (requires KVM_CAP_ARM_SVE) 4520 ===== =========================================== 4521 4522Finalizes the configuration of the specified vcpu feature. 4523 4524The vcpu must already have been initialised, enabling the affected feature, by 4525means of a successful KVM_ARM_VCPU_INIT call with the appropriate flag set in 4526features[]. 4527 4528For affected vcpu features, this is a mandatory step that must be performed 4529before the vcpu is fully usable. 4530 4531Between KVM_ARM_VCPU_INIT and KVM_ARM_VCPU_FINALIZE, the feature may be 4532configured by use of ioctls such as KVM_SET_ONE_REG. The exact configuration 4533that should be performaned and how to do it are feature-dependent. 4534 4535Other calls that depend on a particular feature being finalized, such as 4536KVM_RUN, KVM_GET_REG_LIST, KVM_GET_ONE_REG and KVM_SET_ONE_REG, will fail with 4537-EPERM unless the feature has already been finalized by means of a 4538KVM_ARM_VCPU_FINALIZE call. 4539 4540See KVM_ARM_VCPU_INIT for details of vcpu features that require finalization 4541using this ioctl. 4542 45434.120 KVM_SET_PMU_EVENT_FILTER 4544------------------------------ 4545 4546:Capability: KVM_CAP_PMU_EVENT_FILTER 4547:Architectures: x86 4548:Type: vm ioctl 4549:Parameters: struct kvm_pmu_event_filter (in) 4550:Returns: 0 on success, -1 on error 4551 4552:: 4553 4554 struct kvm_pmu_event_filter { 4555 __u32 action; 4556 __u32 nevents; 4557 __u32 fixed_counter_bitmap; 4558 __u32 flags; 4559 __u32 pad[4]; 4560 __u64 events[0]; 4561 }; 4562 4563This ioctl restricts the set of PMU events that the guest can program. 4564The argument holds a list of events which will be allowed or denied. 4565The eventsel+umask of each event the guest attempts to program is compared 4566against the events field to determine whether the guest should have access. 4567The events field only controls general purpose counters; fixed purpose 4568counters are controlled by the fixed_counter_bitmap. 4569 4570No flags are defined yet, the field must be zero. 4571 4572Valid values for 'action':: 4573 4574 #define KVM_PMU_EVENT_ALLOW 0 4575 #define KVM_PMU_EVENT_DENY 1 4576 45774.121 KVM_PPC_SVM_OFF 4578--------------------- 4579 4580:Capability: basic 4581:Architectures: powerpc 4582:Type: vm ioctl 4583:Parameters: none 4584:Returns: 0 on successful completion, 4585 4586Errors: 4587 4588 ====== ================================================================ 4589 EINVAL if ultravisor failed to terminate the secure guest 4590 ENOMEM if hypervisor failed to allocate new radix page tables for guest 4591 ====== ================================================================ 4592 4593This ioctl is used to turn off the secure mode of the guest or transition 4594the guest from secure mode to normal mode. This is invoked when the guest 4595is reset. This has no effect if called for a normal guest. 4596 4597This ioctl issues an ultravisor call to terminate the secure guest, 4598unpins the VPA pages and releases all the device pages that are used to 4599track the secure pages by hypervisor. 4600 46014.122 KVM_S390_NORMAL_RESET 4602--------------------------- 4603 4604:Capability: KVM_CAP_S390_VCPU_RESETS 4605:Architectures: s390 4606:Type: vcpu ioctl 4607:Parameters: none 4608:Returns: 0 4609 4610This ioctl resets VCPU registers and control structures according to 4611the cpu reset definition in the POP (Principles Of Operation). 4612 46134.123 KVM_S390_INITIAL_RESET 4614---------------------------- 4615 4616:Capability: none 4617:Architectures: s390 4618:Type: vcpu ioctl 4619:Parameters: none 4620:Returns: 0 4621 4622This ioctl resets VCPU registers and control structures according to 4623the initial cpu reset definition in the POP. However, the cpu is not 4624put into ESA mode. This reset is a superset of the normal reset. 4625 46264.124 KVM_S390_CLEAR_RESET 4627-------------------------- 4628 4629:Capability: KVM_CAP_S390_VCPU_RESETS 4630:Architectures: s390 4631:Type: vcpu ioctl 4632:Parameters: none 4633:Returns: 0 4634 4635This ioctl resets VCPU registers and control structures according to 4636the clear cpu reset definition in the POP. However, the cpu is not put 4637into ESA mode. This reset is a superset of the initial reset. 4638 4639 46404.125 KVM_S390_PV_COMMAND 4641------------------------- 4642 4643:Capability: KVM_CAP_S390_PROTECTED 4644:Architectures: s390 4645:Type: vm ioctl 4646:Parameters: struct kvm_pv_cmd 4647:Returns: 0 on success, < 0 on error 4648 4649:: 4650 4651 struct kvm_pv_cmd { 4652 __u32 cmd; /* Command to be executed */ 4653 __u16 rc; /* Ultravisor return code */ 4654 __u16 rrc; /* Ultravisor return reason code */ 4655 __u64 data; /* Data or address */ 4656 __u32 flags; /* flags for future extensions. Must be 0 for now */ 4657 __u32 reserved[3]; 4658 }; 4659 4660cmd values: 4661 4662KVM_PV_ENABLE 4663 Allocate memory and register the VM with the Ultravisor, thereby 4664 donating memory to the Ultravisor that will become inaccessible to 4665 KVM. All existing CPUs are converted to protected ones. After this 4666 command has succeeded, any CPU added via hotplug will become 4667 protected during its creation as well. 4668 4669 Errors: 4670 4671 ===== ============================= 4672 EINTR an unmasked signal is pending 4673 ===== ============================= 4674 4675KVM_PV_DISABLE 4676 4677 Deregister the VM from the Ultravisor and reclaim the memory that 4678 had been donated to the Ultravisor, making it usable by the kernel 4679 again. All registered VCPUs are converted back to non-protected 4680 ones. 4681 4682KVM_PV_VM_SET_SEC_PARMS 4683 Pass the image header from VM memory to the Ultravisor in 4684 preparation of image unpacking and verification. 4685 4686KVM_PV_VM_UNPACK 4687 Unpack (protect and decrypt) a page of the encrypted boot image. 4688 4689KVM_PV_VM_VERIFY 4690 Verify the integrity of the unpacked image. Only if this succeeds, 4691 KVM is allowed to start protected VCPUs. 4692 4693 46945. The kvm_run structure 4695======================== 4696 4697Application code obtains a pointer to the kvm_run structure by 4698mmap()ing a vcpu fd. From that point, application code can control 4699execution by changing fields in kvm_run prior to calling the KVM_RUN 4700ioctl, and obtain information about the reason KVM_RUN returned by 4701looking up structure members. 4702 4703:: 4704 4705 struct kvm_run { 4706 /* in */ 4707 __u8 request_interrupt_window; 4708 4709Request that KVM_RUN return when it becomes possible to inject external 4710interrupts into the guest. Useful in conjunction with KVM_INTERRUPT. 4711 4712:: 4713 4714 __u8 immediate_exit; 4715 4716This field is polled once when KVM_RUN starts; if non-zero, KVM_RUN 4717exits immediately, returning -EINTR. In the common scenario where a 4718signal is used to "kick" a VCPU out of KVM_RUN, this field can be used 4719to avoid usage of KVM_SET_SIGNAL_MASK, which has worse scalability. 4720Rather than blocking the signal outside KVM_RUN, userspace can set up 4721a signal handler that sets run->immediate_exit to a non-zero value. 4722 4723This field is ignored if KVM_CAP_IMMEDIATE_EXIT is not available. 4724 4725:: 4726 4727 __u8 padding1[6]; 4728 4729 /* out */ 4730 __u32 exit_reason; 4731 4732When KVM_RUN has returned successfully (return value 0), this informs 4733application code why KVM_RUN has returned. Allowable values for this 4734field are detailed below. 4735 4736:: 4737 4738 __u8 ready_for_interrupt_injection; 4739 4740If request_interrupt_window has been specified, this field indicates 4741an interrupt can be injected now with KVM_INTERRUPT. 4742 4743:: 4744 4745 __u8 if_flag; 4746 4747The value of the current interrupt flag. Only valid if in-kernel 4748local APIC is not used. 4749 4750:: 4751 4752 __u16 flags; 4753 4754More architecture-specific flags detailing state of the VCPU that may 4755affect the device's behavior. The only currently defined flag is 4756KVM_RUN_X86_SMM, which is valid on x86 machines and is set if the 4757VCPU is in system management mode. 4758 4759:: 4760 4761 /* in (pre_kvm_run), out (post_kvm_run) */ 4762 __u64 cr8; 4763 4764The value of the cr8 register. Only valid if in-kernel local APIC is 4765not used. Both input and output. 4766 4767:: 4768 4769 __u64 apic_base; 4770 4771The value of the APIC BASE msr. Only valid if in-kernel local 4772APIC is not used. Both input and output. 4773 4774:: 4775 4776 union { 4777 /* KVM_EXIT_UNKNOWN */ 4778 struct { 4779 __u64 hardware_exit_reason; 4780 } hw; 4781 4782If exit_reason is KVM_EXIT_UNKNOWN, the vcpu has exited due to unknown 4783reasons. Further architecture-specific information is available in 4784hardware_exit_reason. 4785 4786:: 4787 4788 /* KVM_EXIT_FAIL_ENTRY */ 4789 struct { 4790 __u64 hardware_entry_failure_reason; 4791 } fail_entry; 4792 4793If exit_reason is KVM_EXIT_FAIL_ENTRY, the vcpu could not be run due 4794to unknown reasons. Further architecture-specific information is 4795available in hardware_entry_failure_reason. 4796 4797:: 4798 4799 /* KVM_EXIT_EXCEPTION */ 4800 struct { 4801 __u32 exception; 4802 __u32 error_code; 4803 } ex; 4804 4805Unused. 4806 4807:: 4808 4809 /* KVM_EXIT_IO */ 4810 struct { 4811 #define KVM_EXIT_IO_IN 0 4812 #define KVM_EXIT_IO_OUT 1 4813 __u8 direction; 4814 __u8 size; /* bytes */ 4815 __u16 port; 4816 __u32 count; 4817 __u64 data_offset; /* relative to kvm_run start */ 4818 } io; 4819 4820If exit_reason is KVM_EXIT_IO, then the vcpu has 4821executed a port I/O instruction which could not be satisfied by kvm. 4822data_offset describes where the data is located (KVM_EXIT_IO_OUT) or 4823where kvm expects application code to place the data for the next 4824KVM_RUN invocation (KVM_EXIT_IO_IN). Data format is a packed array. 4825 4826:: 4827 4828 /* KVM_EXIT_DEBUG */ 4829 struct { 4830 struct kvm_debug_exit_arch arch; 4831 } debug; 4832 4833If the exit_reason is KVM_EXIT_DEBUG, then a vcpu is processing a debug event 4834for which architecture specific information is returned. 4835 4836:: 4837 4838 /* KVM_EXIT_MMIO */ 4839 struct { 4840 __u64 phys_addr; 4841 __u8 data[8]; 4842 __u32 len; 4843 __u8 is_write; 4844 } mmio; 4845 4846If exit_reason is KVM_EXIT_MMIO, then the vcpu has 4847executed a memory-mapped I/O instruction which could not be satisfied 4848by kvm. The 'data' member contains the written data if 'is_write' is 4849true, and should be filled by application code otherwise. 4850 4851The 'data' member contains, in its first 'len' bytes, the value as it would 4852appear if the VCPU performed a load or store of the appropriate width directly 4853to the byte array. 4854 4855.. note:: 4856 4857 For KVM_EXIT_IO, KVM_EXIT_MMIO, KVM_EXIT_OSI, KVM_EXIT_PAPR and 4858 KVM_EXIT_EPR the corresponding 4859 4860operations are complete (and guest state is consistent) only after userspace 4861has re-entered the kernel with KVM_RUN. The kernel side will first finish 4862incomplete operations and then check for pending signals. Userspace 4863can re-enter the guest with an unmasked signal pending to complete 4864pending operations. 4865 4866:: 4867 4868 /* KVM_EXIT_HYPERCALL */ 4869 struct { 4870 __u64 nr; 4871 __u64 args[6]; 4872 __u64 ret; 4873 __u32 longmode; 4874 __u32 pad; 4875 } hypercall; 4876 4877Unused. This was once used for 'hypercall to userspace'. To implement 4878such functionality, use KVM_EXIT_IO (x86) or KVM_EXIT_MMIO (all except s390). 4879 4880.. note:: KVM_EXIT_IO is significantly faster than KVM_EXIT_MMIO. 4881 4882:: 4883 4884 /* KVM_EXIT_TPR_ACCESS */ 4885 struct { 4886 __u64 rip; 4887 __u32 is_write; 4888 __u32 pad; 4889 } tpr_access; 4890 4891To be documented (KVM_TPR_ACCESS_REPORTING). 4892 4893:: 4894 4895 /* KVM_EXIT_S390_SIEIC */ 4896 struct { 4897 __u8 icptcode; 4898 __u64 mask; /* psw upper half */ 4899 __u64 addr; /* psw lower half */ 4900 __u16 ipa; 4901 __u32 ipb; 4902 } s390_sieic; 4903 4904s390 specific. 4905 4906:: 4907 4908 /* KVM_EXIT_S390_RESET */ 4909 #define KVM_S390_RESET_POR 1 4910 #define KVM_S390_RESET_CLEAR 2 4911 #define KVM_S390_RESET_SUBSYSTEM 4 4912 #define KVM_S390_RESET_CPU_INIT 8 4913 #define KVM_S390_RESET_IPL 16 4914 __u64 s390_reset_flags; 4915 4916s390 specific. 4917 4918:: 4919 4920 /* KVM_EXIT_S390_UCONTROL */ 4921 struct { 4922 __u64 trans_exc_code; 4923 __u32 pgm_code; 4924 } s390_ucontrol; 4925 4926s390 specific. A page fault has occurred for a user controlled virtual 4927machine (KVM_VM_S390_UNCONTROL) on it's host page table that cannot be 4928resolved by the kernel. 4929The program code and the translation exception code that were placed 4930in the cpu's lowcore are presented here as defined by the z Architecture 4931Principles of Operation Book in the Chapter for Dynamic Address Translation 4932(DAT) 4933 4934:: 4935 4936 /* KVM_EXIT_DCR */ 4937 struct { 4938 __u32 dcrn; 4939 __u32 data; 4940 __u8 is_write; 4941 } dcr; 4942 4943Deprecated - was used for 440 KVM. 4944 4945:: 4946 4947 /* KVM_EXIT_OSI */ 4948 struct { 4949 __u64 gprs[32]; 4950 } osi; 4951 4952MOL uses a special hypercall interface it calls 'OSI'. To enable it, we catch 4953hypercalls and exit with this exit struct that contains all the guest gprs. 4954 4955If exit_reason is KVM_EXIT_OSI, then the vcpu has triggered such a hypercall. 4956Userspace can now handle the hypercall and when it's done modify the gprs as 4957necessary. Upon guest entry all guest GPRs will then be replaced by the values 4958in this struct. 4959 4960:: 4961 4962 /* KVM_EXIT_PAPR_HCALL */ 4963 struct { 4964 __u64 nr; 4965 __u64 ret; 4966 __u64 args[9]; 4967 } papr_hcall; 4968 4969This is used on 64-bit PowerPC when emulating a pSeries partition, 4970e.g. with the 'pseries' machine type in qemu. It occurs when the 4971guest does a hypercall using the 'sc 1' instruction. The 'nr' field 4972contains the hypercall number (from the guest R3), and 'args' contains 4973the arguments (from the guest R4 - R12). Userspace should put the 4974return code in 'ret' and any extra returned values in args[]. 4975The possible hypercalls are defined in the Power Architecture Platform 4976Requirements (PAPR) document available from www.power.org (free 4977developer registration required to access it). 4978 4979:: 4980 4981 /* KVM_EXIT_S390_TSCH */ 4982 struct { 4983 __u16 subchannel_id; 4984 __u16 subchannel_nr; 4985 __u32 io_int_parm; 4986 __u32 io_int_word; 4987 __u32 ipb; 4988 __u8 dequeued; 4989 } s390_tsch; 4990 4991s390 specific. This exit occurs when KVM_CAP_S390_CSS_SUPPORT has been enabled 4992and TEST SUBCHANNEL was intercepted. If dequeued is set, a pending I/O 4993interrupt for the target subchannel has been dequeued and subchannel_id, 4994subchannel_nr, io_int_parm and io_int_word contain the parameters for that 4995interrupt. ipb is needed for instruction parameter decoding. 4996 4997:: 4998 4999 /* KVM_EXIT_EPR */ 5000 struct { 5001 __u32 epr; 5002 } epr; 5003 5004On FSL BookE PowerPC chips, the interrupt controller has a fast patch 5005interrupt acknowledge path to the core. When the core successfully 5006delivers an interrupt, it automatically populates the EPR register with 5007the interrupt vector number and acknowledges the interrupt inside 5008the interrupt controller. 5009 5010In case the interrupt controller lives in user space, we need to do 5011the interrupt acknowledge cycle through it to fetch the next to be 5012delivered interrupt vector using this exit. 5013 5014It gets triggered whenever both KVM_CAP_PPC_EPR are enabled and an 5015external interrupt has just been delivered into the guest. User space 5016should put the acknowledged interrupt vector into the 'epr' field. 5017 5018:: 5019 5020 /* KVM_EXIT_SYSTEM_EVENT */ 5021 struct { 5022 #define KVM_SYSTEM_EVENT_SHUTDOWN 1 5023 #define KVM_SYSTEM_EVENT_RESET 2 5024 #define KVM_SYSTEM_EVENT_CRASH 3 5025 __u32 type; 5026 __u64 flags; 5027 } system_event; 5028 5029If exit_reason is KVM_EXIT_SYSTEM_EVENT then the vcpu has triggered 5030a system-level event using some architecture specific mechanism (hypercall 5031or some special instruction). In case of ARM/ARM64, this is triggered using 5032HVC instruction based PSCI call from the vcpu. The 'type' field describes 5033the system-level event type. The 'flags' field describes architecture 5034specific flags for the system-level event. 5035 5036Valid values for 'type' are: 5037 5038 - KVM_SYSTEM_EVENT_SHUTDOWN -- the guest has requested a shutdown of the 5039 VM. Userspace is not obliged to honour this, and if it does honour 5040 this does not need to destroy the VM synchronously (ie it may call 5041 KVM_RUN again before shutdown finally occurs). 5042 - KVM_SYSTEM_EVENT_RESET -- the guest has requested a reset of the VM. 5043 As with SHUTDOWN, userspace can choose to ignore the request, or 5044 to schedule the reset to occur in the future and may call KVM_RUN again. 5045 - KVM_SYSTEM_EVENT_CRASH -- the guest crash occurred and the guest 5046 has requested a crash condition maintenance. Userspace can choose 5047 to ignore the request, or to gather VM memory core dump and/or 5048 reset/shutdown of the VM. 5049 5050:: 5051 5052 /* KVM_EXIT_IOAPIC_EOI */ 5053 struct { 5054 __u8 vector; 5055 } eoi; 5056 5057Indicates that the VCPU's in-kernel local APIC received an EOI for a 5058level-triggered IOAPIC interrupt. This exit only triggers when the 5059IOAPIC is implemented in userspace (i.e. KVM_CAP_SPLIT_IRQCHIP is enabled); 5060the userspace IOAPIC should process the EOI and retrigger the interrupt if 5061it is still asserted. Vector is the LAPIC interrupt vector for which the 5062EOI was received. 5063 5064:: 5065 5066 struct kvm_hyperv_exit { 5067 #define KVM_EXIT_HYPERV_SYNIC 1 5068 #define KVM_EXIT_HYPERV_HCALL 2 5069 __u32 type; 5070 union { 5071 struct { 5072 __u32 msr; 5073 __u64 control; 5074 __u64 evt_page; 5075 __u64 msg_page; 5076 } synic; 5077 struct { 5078 __u64 input; 5079 __u64 result; 5080 __u64 params[2]; 5081 } hcall; 5082 } u; 5083 }; 5084 /* KVM_EXIT_HYPERV */ 5085 struct kvm_hyperv_exit hyperv; 5086 5087Indicates that the VCPU exits into userspace to process some tasks 5088related to Hyper-V emulation. 5089 5090Valid values for 'type' are: 5091 5092 - KVM_EXIT_HYPERV_SYNIC -- synchronously notify user-space about 5093 5094Hyper-V SynIC state change. Notification is used to remap SynIC 5095event/message pages and to enable/disable SynIC messages/events processing 5096in userspace. 5097 5098:: 5099 5100 /* KVM_EXIT_ARM_NISV */ 5101 struct { 5102 __u64 esr_iss; 5103 __u64 fault_ipa; 5104 } arm_nisv; 5105 5106Used on arm and arm64 systems. If a guest accesses memory not in a memslot, 5107KVM will typically return to userspace and ask it to do MMIO emulation on its 5108behalf. However, for certain classes of instructions, no instruction decode 5109(direction, length of memory access) is provided, and fetching and decoding 5110the instruction from the VM is overly complicated to live in the kernel. 5111 5112Historically, when this situation occurred, KVM would print a warning and kill 5113the VM. KVM assumed that if the guest accessed non-memslot memory, it was 5114trying to do I/O, which just couldn't be emulated, and the warning message was 5115phrased accordingly. However, what happened more often was that a guest bug 5116caused access outside the guest memory areas which should lead to a more 5117meaningful warning message and an external abort in the guest, if the access 5118did not fall within an I/O window. 5119 5120Userspace implementations can query for KVM_CAP_ARM_NISV_TO_USER, and enable 5121this capability at VM creation. Once this is done, these types of errors will 5122instead return to userspace with KVM_EXIT_ARM_NISV, with the valid bits from 5123the HSR (arm) and ESR_EL2 (arm64) in the esr_iss field, and the faulting IPA 5124in the fault_ipa field. Userspace can either fix up the access if it's 5125actually an I/O access by decoding the instruction from guest memory (if it's 5126very brave) and continue executing the guest, or it can decide to suspend, 5127dump, or restart the guest. 5128 5129Note that KVM does not skip the faulting instruction as it does for 5130KVM_EXIT_MMIO, but userspace has to emulate any change to the processing state 5131if it decides to decode and emulate the instruction. 5132 5133:: 5134 5135 /* Fix the size of the union. */ 5136 char padding[256]; 5137 }; 5138 5139 /* 5140 * shared registers between kvm and userspace. 5141 * kvm_valid_regs specifies the register classes set by the host 5142 * kvm_dirty_regs specified the register classes dirtied by userspace 5143 * struct kvm_sync_regs is architecture specific, as well as the 5144 * bits for kvm_valid_regs and kvm_dirty_regs 5145 */ 5146 __u64 kvm_valid_regs; 5147 __u64 kvm_dirty_regs; 5148 union { 5149 struct kvm_sync_regs regs; 5150 char padding[SYNC_REGS_SIZE_BYTES]; 5151 } s; 5152 5153If KVM_CAP_SYNC_REGS is defined, these fields allow userspace to access 5154certain guest registers without having to call SET/GET_*REGS. Thus we can 5155avoid some system call overhead if userspace has to handle the exit. 5156Userspace can query the validity of the structure by checking 5157kvm_valid_regs for specific bits. These bits are architecture specific 5158and usually define the validity of a groups of registers. (e.g. one bit 5159for general purpose registers) 5160 5161Please note that the kernel is allowed to use the kvm_run structure as the 5162primary storage for certain register types. Therefore, the kernel may use the 5163values in kvm_run even if the corresponding bit in kvm_dirty_regs is not set. 5164 5165:: 5166 5167 }; 5168 5169 5170 51716. Capabilities that can be enabled on vCPUs 5172============================================ 5173 5174There are certain capabilities that change the behavior of the virtual CPU or 5175the virtual machine when enabled. To enable them, please see section 4.37. 5176Below you can find a list of capabilities and what their effect on the vCPU or 5177the virtual machine is when enabling them. 5178 5179The following information is provided along with the description: 5180 5181 Architectures: 5182 which instruction set architectures provide this ioctl. 5183 x86 includes both i386 and x86_64. 5184 5185 Target: 5186 whether this is a per-vcpu or per-vm capability. 5187 5188 Parameters: 5189 what parameters are accepted by the capability. 5190 5191 Returns: 5192 the return value. General error numbers (EBADF, ENOMEM, EINVAL) 5193 are not detailed, but errors with specific meanings are. 5194 5195 51966.1 KVM_CAP_PPC_OSI 5197------------------- 5198 5199:Architectures: ppc 5200:Target: vcpu 5201:Parameters: none 5202:Returns: 0 on success; -1 on error 5203 5204This capability enables interception of OSI hypercalls that otherwise would 5205be treated as normal system calls to be injected into the guest. OSI hypercalls 5206were invented by Mac-on-Linux to have a standardized communication mechanism 5207between the guest and the host. 5208 5209When this capability is enabled, KVM_EXIT_OSI can occur. 5210 5211 52126.2 KVM_CAP_PPC_PAPR 5213-------------------- 5214 5215:Architectures: ppc 5216:Target: vcpu 5217:Parameters: none 5218:Returns: 0 on success; -1 on error 5219 5220This capability enables interception of PAPR hypercalls. PAPR hypercalls are 5221done using the hypercall instruction "sc 1". 5222 5223It also sets the guest privilege level to "supervisor" mode. Usually the guest 5224runs in "hypervisor" privilege mode with a few missing features. 5225 5226In addition to the above, it changes the semantics of SDR1. In this mode, the 5227HTAB address part of SDR1 contains an HVA instead of a GPA, as PAPR keeps the 5228HTAB invisible to the guest. 5229 5230When this capability is enabled, KVM_EXIT_PAPR_HCALL can occur. 5231 5232 52336.3 KVM_CAP_SW_TLB 5234------------------ 5235 5236:Architectures: ppc 5237:Target: vcpu 5238:Parameters: args[0] is the address of a struct kvm_config_tlb 5239:Returns: 0 on success; -1 on error 5240 5241:: 5242 5243 struct kvm_config_tlb { 5244 __u64 params; 5245 __u64 array; 5246 __u32 mmu_type; 5247 __u32 array_len; 5248 }; 5249 5250Configures the virtual CPU's TLB array, establishing a shared memory area 5251between userspace and KVM. The "params" and "array" fields are userspace 5252addresses of mmu-type-specific data structures. The "array_len" field is an 5253safety mechanism, and should be set to the size in bytes of the memory that 5254userspace has reserved for the array. It must be at least the size dictated 5255by "mmu_type" and "params". 5256 5257While KVM_RUN is active, the shared region is under control of KVM. Its 5258contents are undefined, and any modification by userspace results in 5259boundedly undefined behavior. 5260 5261On return from KVM_RUN, the shared region will reflect the current state of 5262the guest's TLB. If userspace makes any changes, it must call KVM_DIRTY_TLB 5263to tell KVM which entries have been changed, prior to calling KVM_RUN again 5264on this vcpu. 5265 5266For mmu types KVM_MMU_FSL_BOOKE_NOHV and KVM_MMU_FSL_BOOKE_HV: 5267 5268 - The "params" field is of type "struct kvm_book3e_206_tlb_params". 5269 - The "array" field points to an array of type "struct 5270 kvm_book3e_206_tlb_entry". 5271 - The array consists of all entries in the first TLB, followed by all 5272 entries in the second TLB. 5273 - Within a TLB, entries are ordered first by increasing set number. Within a 5274 set, entries are ordered by way (increasing ESEL). 5275 - The hash for determining set number in TLB0 is: (MAS2 >> 12) & (num_sets - 1) 5276 where "num_sets" is the tlb_sizes[] value divided by the tlb_ways[] value. 5277 - The tsize field of mas1 shall be set to 4K on TLB0, even though the 5278 hardware ignores this value for TLB0. 5279 52806.4 KVM_CAP_S390_CSS_SUPPORT 5281---------------------------- 5282 5283:Architectures: s390 5284:Target: vcpu 5285:Parameters: none 5286:Returns: 0 on success; -1 on error 5287 5288This capability enables support for handling of channel I/O instructions. 5289 5290TEST PENDING INTERRUPTION and the interrupt portion of TEST SUBCHANNEL are 5291handled in-kernel, while the other I/O instructions are passed to userspace. 5292 5293When this capability is enabled, KVM_EXIT_S390_TSCH will occur on TEST 5294SUBCHANNEL intercepts. 5295 5296Note that even though this capability is enabled per-vcpu, the complete 5297virtual machine is affected. 5298 52996.5 KVM_CAP_PPC_EPR 5300------------------- 5301 5302:Architectures: ppc 5303:Target: vcpu 5304:Parameters: args[0] defines whether the proxy facility is active 5305:Returns: 0 on success; -1 on error 5306 5307This capability enables or disables the delivery of interrupts through the 5308external proxy facility. 5309 5310When enabled (args[0] != 0), every time the guest gets an external interrupt 5311delivered, it automatically exits into user space with a KVM_EXIT_EPR exit 5312to receive the topmost interrupt vector. 5313 5314When disabled (args[0] == 0), behavior is as if this facility is unsupported. 5315 5316When this capability is enabled, KVM_EXIT_EPR can occur. 5317 53186.6 KVM_CAP_IRQ_MPIC 5319-------------------- 5320 5321:Architectures: ppc 5322:Parameters: args[0] is the MPIC device fd; 5323 args[1] is the MPIC CPU number for this vcpu 5324 5325This capability connects the vcpu to an in-kernel MPIC device. 5326 53276.7 KVM_CAP_IRQ_XICS 5328-------------------- 5329 5330:Architectures: ppc 5331:Target: vcpu 5332:Parameters: args[0] is the XICS device fd; 5333 args[1] is the XICS CPU number (server ID) for this vcpu 5334 5335This capability connects the vcpu to an in-kernel XICS device. 5336 53376.8 KVM_CAP_S390_IRQCHIP 5338------------------------ 5339 5340:Architectures: s390 5341:Target: vm 5342:Parameters: none 5343 5344This capability enables the in-kernel irqchip for s390. Please refer to 5345"4.24 KVM_CREATE_IRQCHIP" for details. 5346 53476.9 KVM_CAP_MIPS_FPU 5348-------------------- 5349 5350:Architectures: mips 5351:Target: vcpu 5352:Parameters: args[0] is reserved for future use (should be 0). 5353 5354This capability allows the use of the host Floating Point Unit by the guest. It 5355allows the Config1.FP bit to be set to enable the FPU in the guest. Once this is 5356done the ``KVM_REG_MIPS_FPR_*`` and ``KVM_REG_MIPS_FCR_*`` registers can be 5357accessed (depending on the current guest FPU register mode), and the Status.FR, 5358Config5.FRE bits are accessible via the KVM API and also from the guest, 5359depending on them being supported by the FPU. 5360 53616.10 KVM_CAP_MIPS_MSA 5362--------------------- 5363 5364:Architectures: mips 5365:Target: vcpu 5366:Parameters: args[0] is reserved for future use (should be 0). 5367 5368This capability allows the use of the MIPS SIMD Architecture (MSA) by the guest. 5369It allows the Config3.MSAP bit to be set to enable the use of MSA by the guest. 5370Once this is done the ``KVM_REG_MIPS_VEC_*`` and ``KVM_REG_MIPS_MSA_*`` 5371registers can be accessed, and the Config5.MSAEn bit is accessible via the 5372KVM API and also from the guest. 5373 53746.74 KVM_CAP_SYNC_REGS 5375---------------------- 5376 5377:Architectures: s390, x86 5378:Target: s390: always enabled, x86: vcpu 5379:Parameters: none 5380:Returns: x86: KVM_CHECK_EXTENSION returns a bit-array indicating which register 5381 sets are supported 5382 (bitfields defined in arch/x86/include/uapi/asm/kvm.h). 5383 5384As described above in the kvm_sync_regs struct info in section 5 (kvm_run): 5385KVM_CAP_SYNC_REGS "allow[s] userspace to access certain guest registers 5386without having to call SET/GET_*REGS". This reduces overhead by eliminating 5387repeated ioctl calls for setting and/or getting register values. This is 5388particularly important when userspace is making synchronous guest state 5389modifications, e.g. when emulating and/or intercepting instructions in 5390userspace. 5391 5392For s390 specifics, please refer to the source code. 5393 5394For x86: 5395 5396- the register sets to be copied out to kvm_run are selectable 5397 by userspace (rather that all sets being copied out for every exit). 5398- vcpu_events are available in addition to regs and sregs. 5399 5400For x86, the 'kvm_valid_regs' field of struct kvm_run is overloaded to 5401function as an input bit-array field set by userspace to indicate the 5402specific register sets to be copied out on the next exit. 5403 5404To indicate when userspace has modified values that should be copied into 5405the vCPU, the all architecture bitarray field, 'kvm_dirty_regs' must be set. 5406This is done using the same bitflags as for the 'kvm_valid_regs' field. 5407If the dirty bit is not set, then the register set values will not be copied 5408into the vCPU even if they've been modified. 5409 5410Unused bitfields in the bitarrays must be set to zero. 5411 5412:: 5413 5414 struct kvm_sync_regs { 5415 struct kvm_regs regs; 5416 struct kvm_sregs sregs; 5417 struct kvm_vcpu_events events; 5418 }; 5419 54206.75 KVM_CAP_PPC_IRQ_XIVE 5421------------------------- 5422 5423:Architectures: ppc 5424:Target: vcpu 5425:Parameters: args[0] is the XIVE device fd; 5426 args[1] is the XIVE CPU number (server ID) for this vcpu 5427 5428This capability connects the vcpu to an in-kernel XIVE device. 5429 54307. Capabilities that can be enabled on VMs 5431========================================== 5432 5433There are certain capabilities that change the behavior of the virtual 5434machine when enabled. To enable them, please see section 4.37. Below 5435you can find a list of capabilities and what their effect on the VM 5436is when enabling them. 5437 5438The following information is provided along with the description: 5439 5440 Architectures: 5441 which instruction set architectures provide this ioctl. 5442 x86 includes both i386 and x86_64. 5443 5444 Parameters: 5445 what parameters are accepted by the capability. 5446 5447 Returns: 5448 the return value. General error numbers (EBADF, ENOMEM, EINVAL) 5449 are not detailed, but errors with specific meanings are. 5450 5451 54527.1 KVM_CAP_PPC_ENABLE_HCALL 5453---------------------------- 5454 5455:Architectures: ppc 5456:Parameters: args[0] is the sPAPR hcall number; 5457 args[1] is 0 to disable, 1 to enable in-kernel handling 5458 5459This capability controls whether individual sPAPR hypercalls (hcalls) 5460get handled by the kernel or not. Enabling or disabling in-kernel 5461handling of an hcall is effective across the VM. On creation, an 5462initial set of hcalls are enabled for in-kernel handling, which 5463consists of those hcalls for which in-kernel handlers were implemented 5464before this capability was implemented. If disabled, the kernel will 5465not to attempt to handle the hcall, but will always exit to userspace 5466to handle it. Note that it may not make sense to enable some and 5467disable others of a group of related hcalls, but KVM does not prevent 5468userspace from doing that. 5469 5470If the hcall number specified is not one that has an in-kernel 5471implementation, the KVM_ENABLE_CAP ioctl will fail with an EINVAL 5472error. 5473 54747.2 KVM_CAP_S390_USER_SIGP 5475-------------------------- 5476 5477:Architectures: s390 5478:Parameters: none 5479 5480This capability controls which SIGP orders will be handled completely in user 5481space. With this capability enabled, all fast orders will be handled completely 5482in the kernel: 5483 5484- SENSE 5485- SENSE RUNNING 5486- EXTERNAL CALL 5487- EMERGENCY SIGNAL 5488- CONDITIONAL EMERGENCY SIGNAL 5489 5490All other orders will be handled completely in user space. 5491 5492Only privileged operation exceptions will be checked for in the kernel (or even 5493in the hardware prior to interception). If this capability is not enabled, the 5494old way of handling SIGP orders is used (partially in kernel and user space). 5495 54967.3 KVM_CAP_S390_VECTOR_REGISTERS 5497--------------------------------- 5498 5499:Architectures: s390 5500:Parameters: none 5501:Returns: 0 on success, negative value on error 5502 5503Allows use of the vector registers introduced with z13 processor, and 5504provides for the synchronization between host and user space. Will 5505return -EINVAL if the machine does not support vectors. 5506 55077.4 KVM_CAP_S390_USER_STSI 5508-------------------------- 5509 5510:Architectures: s390 5511:Parameters: none 5512 5513This capability allows post-handlers for the STSI instruction. After 5514initial handling in the kernel, KVM exits to user space with 5515KVM_EXIT_S390_STSI to allow user space to insert further data. 5516 5517Before exiting to userspace, kvm handlers should fill in s390_stsi field of 5518vcpu->run:: 5519 5520 struct { 5521 __u64 addr; 5522 __u8 ar; 5523 __u8 reserved; 5524 __u8 fc; 5525 __u8 sel1; 5526 __u16 sel2; 5527 } s390_stsi; 5528 5529 @addr - guest address of STSI SYSIB 5530 @fc - function code 5531 @sel1 - selector 1 5532 @sel2 - selector 2 5533 @ar - access register number 5534 5535KVM handlers should exit to userspace with rc = -EREMOTE. 5536 55377.5 KVM_CAP_SPLIT_IRQCHIP 5538------------------------- 5539 5540:Architectures: x86 5541:Parameters: args[0] - number of routes reserved for userspace IOAPICs 5542:Returns: 0 on success, -1 on error 5543 5544Create a local apic for each processor in the kernel. This can be used 5545instead of KVM_CREATE_IRQCHIP if the userspace VMM wishes to emulate the 5546IOAPIC and PIC (and also the PIT, even though this has to be enabled 5547separately). 5548 5549This capability also enables in kernel routing of interrupt requests; 5550when KVM_CAP_SPLIT_IRQCHIP only routes of KVM_IRQ_ROUTING_MSI type are 5551used in the IRQ routing table. The first args[0] MSI routes are reserved 5552for the IOAPIC pins. Whenever the LAPIC receives an EOI for these routes, 5553a KVM_EXIT_IOAPIC_EOI vmexit will be reported to userspace. 5554 5555Fails if VCPU has already been created, or if the irqchip is already in the 5556kernel (i.e. KVM_CREATE_IRQCHIP has already been called). 5557 55587.6 KVM_CAP_S390_RI 5559------------------- 5560 5561:Architectures: s390 5562:Parameters: none 5563 5564Allows use of runtime-instrumentation introduced with zEC12 processor. 5565Will return -EINVAL if the machine does not support runtime-instrumentation. 5566Will return -EBUSY if a VCPU has already been created. 5567 55687.7 KVM_CAP_X2APIC_API 5569---------------------- 5570 5571:Architectures: x86 5572:Parameters: args[0] - features that should be enabled 5573:Returns: 0 on success, -EINVAL when args[0] contains invalid features 5574 5575Valid feature flags in args[0] are:: 5576 5577 #define KVM_X2APIC_API_USE_32BIT_IDS (1ULL << 0) 5578 #define KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK (1ULL << 1) 5579 5580Enabling KVM_X2APIC_API_USE_32BIT_IDS changes the behavior of 5581KVM_SET_GSI_ROUTING, KVM_SIGNAL_MSI, KVM_SET_LAPIC, and KVM_GET_LAPIC, 5582allowing the use of 32-bit APIC IDs. See KVM_CAP_X2APIC_API in their 5583respective sections. 5584 5585KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK must be enabled for x2APIC to work 5586in logical mode or with more than 255 VCPUs. Otherwise, KVM treats 0xff 5587as a broadcast even in x2APIC mode in order to support physical x2APIC 5588without interrupt remapping. This is undesirable in logical mode, 5589where 0xff represents CPUs 0-7 in cluster 0. 5590 55917.8 KVM_CAP_S390_USER_INSTR0 5592---------------------------- 5593 5594:Architectures: s390 5595:Parameters: none 5596 5597With this capability enabled, all illegal instructions 0x0000 (2 bytes) will 5598be intercepted and forwarded to user space. User space can use this 5599mechanism e.g. to realize 2-byte software breakpoints. The kernel will 5600not inject an operating exception for these instructions, user space has 5601to take care of that. 5602 5603This capability can be enabled dynamically even if VCPUs were already 5604created and are running. 5605 56067.9 KVM_CAP_S390_GS 5607------------------- 5608 5609:Architectures: s390 5610:Parameters: none 5611:Returns: 0 on success; -EINVAL if the machine does not support 5612 guarded storage; -EBUSY if a VCPU has already been created. 5613 5614Allows use of guarded storage for the KVM guest. 5615 56167.10 KVM_CAP_S390_AIS 5617--------------------- 5618 5619:Architectures: s390 5620:Parameters: none 5621 5622Allow use of adapter-interruption suppression. 5623:Returns: 0 on success; -EBUSY if a VCPU has already been created. 5624 56257.11 KVM_CAP_PPC_SMT 5626-------------------- 5627 5628:Architectures: ppc 5629:Parameters: vsmt_mode, flags 5630 5631Enabling this capability on a VM provides userspace with a way to set 5632the desired virtual SMT mode (i.e. the number of virtual CPUs per 5633virtual core). The virtual SMT mode, vsmt_mode, must be a power of 2 5634between 1 and 8. On POWER8, vsmt_mode must also be no greater than 5635the number of threads per subcore for the host. Currently flags must 5636be 0. A successful call to enable this capability will result in 5637vsmt_mode being returned when the KVM_CAP_PPC_SMT capability is 5638subsequently queried for the VM. This capability is only supported by 5639HV KVM, and can only be set before any VCPUs have been created. 5640The KVM_CAP_PPC_SMT_POSSIBLE capability indicates which virtual SMT 5641modes are available. 5642 56437.12 KVM_CAP_PPC_FWNMI 5644---------------------- 5645 5646:Architectures: ppc 5647:Parameters: none 5648 5649With this capability a machine check exception in the guest address 5650space will cause KVM to exit the guest with NMI exit reason. This 5651enables QEMU to build error log and branch to guest kernel registered 5652machine check handling routine. Without this capability KVM will 5653branch to guests' 0x200 interrupt vector. 5654 56557.13 KVM_CAP_X86_DISABLE_EXITS 5656------------------------------ 5657 5658:Architectures: x86 5659:Parameters: args[0] defines which exits are disabled 5660:Returns: 0 on success, -EINVAL when args[0] contains invalid exits 5661 5662Valid bits in args[0] are:: 5663 5664 #define KVM_X86_DISABLE_EXITS_MWAIT (1 << 0) 5665 #define KVM_X86_DISABLE_EXITS_HLT (1 << 1) 5666 #define KVM_X86_DISABLE_EXITS_PAUSE (1 << 2) 5667 #define KVM_X86_DISABLE_EXITS_CSTATE (1 << 3) 5668 5669Enabling this capability on a VM provides userspace with a way to no 5670longer intercept some instructions for improved latency in some 5671workloads, and is suggested when vCPUs are associated to dedicated 5672physical CPUs. More bits can be added in the future; userspace can 5673just pass the KVM_CHECK_EXTENSION result to KVM_ENABLE_CAP to disable 5674all such vmexits. 5675 5676Do not enable KVM_FEATURE_PV_UNHALT if you disable HLT exits. 5677 56787.14 KVM_CAP_S390_HPAGE_1M 5679-------------------------- 5680 5681:Architectures: s390 5682:Parameters: none 5683:Returns: 0 on success, -EINVAL if hpage module parameter was not set 5684 or cmma is enabled, or the VM has the KVM_VM_S390_UCONTROL 5685 flag set 5686 5687With this capability the KVM support for memory backing with 1m pages 5688through hugetlbfs can be enabled for a VM. After the capability is 5689enabled, cmma can't be enabled anymore and pfmfi and the storage key 5690interpretation are disabled. If cmma has already been enabled or the 5691hpage module parameter is not set to 1, -EINVAL is returned. 5692 5693While it is generally possible to create a huge page backed VM without 5694this capability, the VM will not be able to run. 5695 56967.15 KVM_CAP_MSR_PLATFORM_INFO 5697------------------------------ 5698 5699:Architectures: x86 5700:Parameters: args[0] whether feature should be enabled or not 5701 5702With this capability, a guest may read the MSR_PLATFORM_INFO MSR. Otherwise, 5703a #GP would be raised when the guest tries to access. Currently, this 5704capability does not enable write permissions of this MSR for the guest. 5705 57067.16 KVM_CAP_PPC_NESTED_HV 5707-------------------------- 5708 5709:Architectures: ppc 5710:Parameters: none 5711:Returns: 0 on success, -EINVAL when the implementation doesn't support 5712 nested-HV virtualization. 5713 5714HV-KVM on POWER9 and later systems allows for "nested-HV" 5715virtualization, which provides a way for a guest VM to run guests that 5716can run using the CPU's supervisor mode (privileged non-hypervisor 5717state). Enabling this capability on a VM depends on the CPU having 5718the necessary functionality and on the facility being enabled with a 5719kvm-hv module parameter. 5720 57217.17 KVM_CAP_EXCEPTION_PAYLOAD 5722------------------------------ 5723 5724:Architectures: x86 5725:Parameters: args[0] whether feature should be enabled or not 5726 5727With this capability enabled, CR2 will not be modified prior to the 5728emulated VM-exit when L1 intercepts a #PF exception that occurs in 5729L2. Similarly, for kvm-intel only, DR6 will not be modified prior to 5730the emulated VM-exit when L1 intercepts a #DB exception that occurs in 5731L2. As a result, when KVM_GET_VCPU_EVENTS reports a pending #PF (or 5732#DB) exception for L2, exception.has_payload will be set and the 5733faulting address (or the new DR6 bits*) will be reported in the 5734exception_payload field. Similarly, when userspace injects a #PF (or 5735#DB) into L2 using KVM_SET_VCPU_EVENTS, it is expected to set 5736exception.has_payload and to put the faulting address - or the new DR6 5737bits\ [#]_ - in the exception_payload field. 5738 5739This capability also enables exception.pending in struct 5740kvm_vcpu_events, which allows userspace to distinguish between pending 5741and injected exceptions. 5742 5743 5744.. [#] For the new DR6 bits, note that bit 16 is set iff the #DB exception 5745 will clear DR6.RTM. 5746 57477.18 KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 5748 5749:Architectures: x86, arm, arm64, mips 5750:Parameters: args[0] whether feature should be enabled or not 5751 5752Valid flags are:: 5753 5754 #define KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE (1 << 0) 5755 #define KVM_DIRTY_LOG_INITIALLY_SET (1 << 1) 5756 5757With KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE is set, KVM_GET_DIRTY_LOG will not 5758automatically clear and write-protect all pages that are returned as dirty. 5759Rather, userspace will have to do this operation separately using 5760KVM_CLEAR_DIRTY_LOG. 5761 5762At the cost of a slightly more complicated operation, this provides better 5763scalability and responsiveness for two reasons. First, 5764KVM_CLEAR_DIRTY_LOG ioctl can operate on a 64-page granularity rather 5765than requiring to sync a full memslot; this ensures that KVM does not 5766take spinlocks for an extended period of time. Second, in some cases a 5767large amount of time can pass between a call to KVM_GET_DIRTY_LOG and 5768userspace actually using the data in the page. Pages can be modified 5769during this time, which is inefficient for both the guest and userspace: 5770the guest will incur a higher penalty due to write protection faults, 5771while userspace can see false reports of dirty pages. Manual reprotection 5772helps reducing this time, improving guest performance and reducing the 5773number of dirty log false positives. 5774 5775With KVM_DIRTY_LOG_INITIALLY_SET set, all the bits of the dirty bitmap 5776will be initialized to 1 when created. This also improves performance because 5777dirty logging can be enabled gradually in small chunks on the first call 5778to KVM_CLEAR_DIRTY_LOG. KVM_DIRTY_LOG_INITIALLY_SET depends on 5779KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE (it is also only available on 5780x86 for now). 5781 5782KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 was previously available under the name 5783KVM_CAP_MANUAL_DIRTY_LOG_PROTECT, but the implementation had bugs that make 5784it hard or impossible to use it correctly. The availability of 5785KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 signals that those bugs are fixed. 5786Userspace should not try to use KVM_CAP_MANUAL_DIRTY_LOG_PROTECT. 5787 57887.19 KVM_CAP_PPC_SECURE_GUEST 5789------------------------------ 5790 5791:Architectures: ppc 5792 5793This capability indicates that KVM is running on a host that has 5794ultravisor firmware and thus can support a secure guest. On such a 5795system, a guest can ask the ultravisor to make it a secure guest, 5796one whose memory is inaccessible to the host except for pages which 5797are explicitly requested to be shared with the host. The ultravisor 5798notifies KVM when a guest requests to become a secure guest, and KVM 5799has the opportunity to veto the transition. 5800 5801If present, this capability can be enabled for a VM, meaning that KVM 5802will allow the transition to secure guest mode. Otherwise KVM will 5803veto the transition. 5804 58058. Other capabilities. 5806====================== 5807 5808This section lists capabilities that give information about other 5809features of the KVM implementation. 5810 58118.1 KVM_CAP_PPC_HWRNG 5812--------------------- 5813 5814:Architectures: ppc 5815 5816This capability, if KVM_CHECK_EXTENSION indicates that it is 5817available, means that that the kernel has an implementation of the 5818H_RANDOM hypercall backed by a hardware random-number generator. 5819If present, the kernel H_RANDOM handler can be enabled for guest use 5820with the KVM_CAP_PPC_ENABLE_HCALL capability. 5821 58228.2 KVM_CAP_HYPERV_SYNIC 5823------------------------ 5824 5825:Architectures: x86 5826 5827This capability, if KVM_CHECK_EXTENSION indicates that it is 5828available, means that that the kernel has an implementation of the 5829Hyper-V Synthetic interrupt controller(SynIC). Hyper-V SynIC is 5830used to support Windows Hyper-V based guest paravirt drivers(VMBus). 5831 5832In order to use SynIC, it has to be activated by setting this 5833capability via KVM_ENABLE_CAP ioctl on the vcpu fd. Note that this 5834will disable the use of APIC hardware virtualization even if supported 5835by the CPU, as it's incompatible with SynIC auto-EOI behavior. 5836 58378.3 KVM_CAP_PPC_RADIX_MMU 5838------------------------- 5839 5840:Architectures: ppc 5841 5842This capability, if KVM_CHECK_EXTENSION indicates that it is 5843available, means that that the kernel can support guests using the 5844radix MMU defined in Power ISA V3.00 (as implemented in the POWER9 5845processor). 5846 58478.4 KVM_CAP_PPC_HASH_MMU_V3 5848--------------------------- 5849 5850:Architectures: ppc 5851 5852This capability, if KVM_CHECK_EXTENSION indicates that it is 5853available, means that that the kernel can support guests using the 5854hashed page table MMU defined in Power ISA V3.00 (as implemented in 5855the POWER9 processor), including in-memory segment tables. 5856 58578.5 KVM_CAP_MIPS_VZ 5858------------------- 5859 5860:Architectures: mips 5861 5862This capability, if KVM_CHECK_EXTENSION on the main kvm handle indicates that 5863it is available, means that full hardware assisted virtualization capabilities 5864of the hardware are available for use through KVM. An appropriate 5865KVM_VM_MIPS_* type must be passed to KVM_CREATE_VM to create a VM which 5866utilises it. 5867 5868If KVM_CHECK_EXTENSION on a kvm VM handle indicates that this capability is 5869available, it means that the VM is using full hardware assisted virtualization 5870capabilities of the hardware. This is useful to check after creating a VM with 5871KVM_VM_MIPS_DEFAULT. 5872 5873The value returned by KVM_CHECK_EXTENSION should be compared against known 5874values (see below). All other values are reserved. This is to allow for the 5875possibility of other hardware assisted virtualization implementations which 5876may be incompatible with the MIPS VZ ASE. 5877 5878== ========================================================================== 5879 0 The trap & emulate implementation is in use to run guest code in user 5880 mode. Guest virtual memory segments are rearranged to fit the guest in the 5881 user mode address space. 5882 5883 1 The MIPS VZ ASE is in use, providing full hardware assisted 5884 virtualization, including standard guest virtual memory segments. 5885== ========================================================================== 5886 58878.6 KVM_CAP_MIPS_TE 5888------------------- 5889 5890:Architectures: mips 5891 5892This capability, if KVM_CHECK_EXTENSION on the main kvm handle indicates that 5893it is available, means that the trap & emulate implementation is available to 5894run guest code in user mode, even if KVM_CAP_MIPS_VZ indicates that hardware 5895assisted virtualisation is also available. KVM_VM_MIPS_TE (0) must be passed 5896to KVM_CREATE_VM to create a VM which utilises it. 5897 5898If KVM_CHECK_EXTENSION on a kvm VM handle indicates that this capability is 5899available, it means that the VM is using trap & emulate. 5900 59018.7 KVM_CAP_MIPS_64BIT 5902---------------------- 5903 5904:Architectures: mips 5905 5906This capability indicates the supported architecture type of the guest, i.e. the 5907supported register and address width. 5908 5909The values returned when this capability is checked by KVM_CHECK_EXTENSION on a 5910kvm VM handle correspond roughly to the CP0_Config.AT register field, and should 5911be checked specifically against known values (see below). All other values are 5912reserved. 5913 5914== ======================================================================== 5915 0 MIPS32 or microMIPS32. 5916 Both registers and addresses are 32-bits wide. 5917 It will only be possible to run 32-bit guest code. 5918 5919 1 MIPS64 or microMIPS64 with access only to 32-bit compatibility segments. 5920 Registers are 64-bits wide, but addresses are 32-bits wide. 5921 64-bit guest code may run but cannot access MIPS64 memory segments. 5922 It will also be possible to run 32-bit guest code. 5923 5924 2 MIPS64 or microMIPS64 with access to all address segments. 5925 Both registers and addresses are 64-bits wide. 5926 It will be possible to run 64-bit or 32-bit guest code. 5927== ======================================================================== 5928 59298.9 KVM_CAP_ARM_USER_IRQ 5930------------------------ 5931 5932:Architectures: arm, arm64 5933 5934This capability, if KVM_CHECK_EXTENSION indicates that it is available, means 5935that if userspace creates a VM without an in-kernel interrupt controller, it 5936will be notified of changes to the output level of in-kernel emulated devices, 5937which can generate virtual interrupts, presented to the VM. 5938For such VMs, on every return to userspace, the kernel 5939updates the vcpu's run->s.regs.device_irq_level field to represent the actual 5940output level of the device. 5941 5942Whenever kvm detects a change in the device output level, kvm guarantees at 5943least one return to userspace before running the VM. This exit could either 5944be a KVM_EXIT_INTR or any other exit event, like KVM_EXIT_MMIO. This way, 5945userspace can always sample the device output level and re-compute the state of 5946the userspace interrupt controller. Userspace should always check the state 5947of run->s.regs.device_irq_level on every kvm exit. 5948The value in run->s.regs.device_irq_level can represent both level and edge 5949triggered interrupt signals, depending on the device. Edge triggered interrupt 5950signals will exit to userspace with the bit in run->s.regs.device_irq_level 5951set exactly once per edge signal. 5952 5953The field run->s.regs.device_irq_level is available independent of 5954run->kvm_valid_regs or run->kvm_dirty_regs bits. 5955 5956If KVM_CAP_ARM_USER_IRQ is supported, the KVM_CHECK_EXTENSION ioctl returns a 5957number larger than 0 indicating the version of this capability is implemented 5958and thereby which bits in in run->s.regs.device_irq_level can signal values. 5959 5960Currently the following bits are defined for the device_irq_level bitmap:: 5961 5962 KVM_CAP_ARM_USER_IRQ >= 1: 5963 5964 KVM_ARM_DEV_EL1_VTIMER - EL1 virtual timer 5965 KVM_ARM_DEV_EL1_PTIMER - EL1 physical timer 5966 KVM_ARM_DEV_PMU - ARM PMU overflow interrupt signal 5967 5968Future versions of kvm may implement additional events. These will get 5969indicated by returning a higher number from KVM_CHECK_EXTENSION and will be 5970listed above. 5971 59728.10 KVM_CAP_PPC_SMT_POSSIBLE 5973----------------------------- 5974 5975:Architectures: ppc 5976 5977Querying this capability returns a bitmap indicating the possible 5978virtual SMT modes that can be set using KVM_CAP_PPC_SMT. If bit N 5979(counting from the right) is set, then a virtual SMT mode of 2^N is 5980available. 5981 59828.11 KVM_CAP_HYPERV_SYNIC2 5983-------------------------- 5984 5985:Architectures: x86 5986 5987This capability enables a newer version of Hyper-V Synthetic interrupt 5988controller (SynIC). The only difference with KVM_CAP_HYPERV_SYNIC is that KVM 5989doesn't clear SynIC message and event flags pages when they are enabled by 5990writing to the respective MSRs. 5991 59928.12 KVM_CAP_HYPERV_VP_INDEX 5993---------------------------- 5994 5995:Architectures: x86 5996 5997This capability indicates that userspace can load HV_X64_MSR_VP_INDEX msr. Its 5998value is used to denote the target vcpu for a SynIC interrupt. For 5999compatibilty, KVM initializes this msr to KVM's internal vcpu index. When this 6000capability is absent, userspace can still query this msr's value. 6001 60028.13 KVM_CAP_S390_AIS_MIGRATION 6003------------------------------- 6004 6005:Architectures: s390 6006:Parameters: none 6007 6008This capability indicates if the flic device will be able to get/set the 6009AIS states for migration via the KVM_DEV_FLIC_AISM_ALL attribute and allows 6010to discover this without having to create a flic device. 6011 60128.14 KVM_CAP_S390_PSW 6013--------------------- 6014 6015:Architectures: s390 6016 6017This capability indicates that the PSW is exposed via the kvm_run structure. 6018 60198.15 KVM_CAP_S390_GMAP 6020---------------------- 6021 6022:Architectures: s390 6023 6024This capability indicates that the user space memory used as guest mapping can 6025be anywhere in the user memory address space, as long as the memory slots are 6026aligned and sized to a segment (1MB) boundary. 6027 60288.16 KVM_CAP_S390_COW 6029--------------------- 6030 6031:Architectures: s390 6032 6033This capability indicates that the user space memory used as guest mapping can 6034use copy-on-write semantics as well as dirty pages tracking via read-only page 6035tables. 6036 60378.17 KVM_CAP_S390_BPB 6038--------------------- 6039 6040:Architectures: s390 6041 6042This capability indicates that kvm will implement the interfaces to handle 6043reset, migration and nested KVM for branch prediction blocking. The stfle 6044facility 82 should not be provided to the guest without this capability. 6045 60468.18 KVM_CAP_HYPERV_TLBFLUSH 6047---------------------------- 6048 6049:Architectures: x86 6050 6051This capability indicates that KVM supports paravirtualized Hyper-V TLB Flush 6052hypercalls: 6053HvFlushVirtualAddressSpace, HvFlushVirtualAddressSpaceEx, 6054HvFlushVirtualAddressList, HvFlushVirtualAddressListEx. 6055 60568.19 KVM_CAP_ARM_INJECT_SERROR_ESR 6057---------------------------------- 6058 6059:Architectures: arm, arm64 6060 6061This capability indicates that userspace can specify (via the 6062KVM_SET_VCPU_EVENTS ioctl) the syndrome value reported to the guest when it 6063takes a virtual SError interrupt exception. 6064If KVM advertises this capability, userspace can only specify the ISS field for 6065the ESR syndrome. Other parts of the ESR, such as the EC are generated by the 6066CPU when the exception is taken. If this virtual SError is taken to EL1 using 6067AArch64, this value will be reported in the ISS field of ESR_ELx. 6068 6069See KVM_CAP_VCPU_EVENTS for more details. 6070 60718.20 KVM_CAP_HYPERV_SEND_IPI 6072---------------------------- 6073 6074:Architectures: x86 6075 6076This capability indicates that KVM supports paravirtualized Hyper-V IPI send 6077hypercalls: 6078HvCallSendSyntheticClusterIpi, HvCallSendSyntheticClusterIpiEx. 6079 60808.21 KVM_CAP_HYPERV_DIRECT_TLBFLUSH 6081----------------------------------- 6082 6083:Architecture: x86 6084 6085This capability indicates that KVM running on top of Hyper-V hypervisor 6086enables Direct TLB flush for its guests meaning that TLB flush 6087hypercalls are handled by Level 0 hypervisor (Hyper-V) bypassing KVM. 6088Due to the different ABI for hypercall parameters between Hyper-V and 6089KVM, enabling this capability effectively disables all hypercall 6090handling by KVM (as some KVM hypercall may be mistakenly treated as TLB 6091flush hypercalls by Hyper-V) so userspace should disable KVM identification 6092in CPUID and only exposes Hyper-V identification. In this case, guest 6093thinks it's running on Hyper-V and only use Hyper-V hypercalls. 6094 60958.22 KVM_CAP_S390_VCPU_RESETS 6096 6097Architectures: s390 6098 6099This capability indicates that the KVM_S390_NORMAL_RESET and 6100KVM_S390_CLEAR_RESET ioctls are available. 6101 61028.23 KVM_CAP_S390_PROTECTED 6103 6104Architecture: s390 6105 6106 6107This capability indicates that the Ultravisor has been initialized and 6108KVM can therefore start protected VMs. 6109This capability governs the KVM_S390_PV_COMMAND ioctl and the 6110KVM_MP_STATE_LOAD MP_STATE. KVM_SET_MP_STATE can fail for protected 6111guests when the state change is invalid. 6112