1.. SPDX-License-Identifier: GPL-2.0 2 3=================================================================== 4The Definitive KVM (Kernel-based Virtual Machine) API Documentation 5=================================================================== 6 71. General description 8====================== 9 10The kvm API is a set of ioctls that are issued to control various aspects 11of a virtual machine. The ioctls belong to the following classes: 12 13 - System ioctls: These query and set global attributes which affect the 14 whole kvm subsystem. In addition a system ioctl is used to create 15 virtual machines. 16 17 - VM ioctls: These query and set attributes that affect an entire virtual 18 machine, for example memory layout. In addition a VM ioctl is used to 19 create virtual cpus (vcpus) and devices. 20 21 VM ioctls must be issued from the same process (address space) that was 22 used to create the VM. 23 24 - vcpu ioctls: These query and set attributes that control the operation 25 of a single virtual cpu. 26 27 vcpu ioctls should be issued from the same thread that was used to create 28 the vcpu, except for asynchronous vcpu ioctl that are marked as such in 29 the documentation. Otherwise, the first ioctl after switching threads 30 could see a performance impact. 31 32 - device ioctls: These query and set attributes that control the operation 33 of a single device. 34 35 device ioctls must be issued from the same process (address space) that 36 was used to create the VM. 37 382. File descriptors 39=================== 40 41The kvm API is centered around file descriptors. An initial 42open("/dev/kvm") obtains a handle to the kvm subsystem; this handle 43can be used to issue system ioctls. A KVM_CREATE_VM ioctl on this 44handle will create a VM file descriptor which can be used to issue VM 45ioctls. A KVM_CREATE_VCPU or KVM_CREATE_DEVICE ioctl on a VM fd will 46create a virtual cpu or device and return a file descriptor pointing to 47the new resource. Finally, ioctls on a vcpu or device fd can be used 48to control the vcpu or device. For vcpus, this includes the important 49task of actually running guest code. 50 51In general file descriptors can be migrated among processes by means 52of fork() and the SCM_RIGHTS facility of unix domain socket. These 53kinds of tricks are explicitly not supported by kvm. While they will 54not cause harm to the host, their actual behavior is not guaranteed by 55the API. See "General description" for details on the ioctl usage 56model that is supported by KVM. 57 58It is important to note that althought VM ioctls may only be issued from 59the process that created the VM, a VM's lifecycle is associated with its 60file descriptor, not its creator (process). In other words, the VM and 61its resources, *including the associated address space*, are not freed 62until the last reference to the VM's file descriptor has been released. 63For example, if fork() is issued after ioctl(KVM_CREATE_VM), the VM will 64not be freed until both the parent (original) process and its child have 65put their references to the VM's file descriptor. 66 67Because a VM's resources are not freed until the last reference to its 68file descriptor is released, creating additional references to a VM 69via fork(), dup(), etc... without careful consideration is strongly 70discouraged and may have unwanted side effects, e.g. memory allocated 71by and on behalf of the VM's process may not be freed/unaccounted when 72the VM is shut down. 73 74 753. Extensions 76============= 77 78As of Linux 2.6.22, the KVM ABI has been stabilized: no backward 79incompatible change are allowed. However, there is an extension 80facility that allows backward-compatible extensions to the API to be 81queried and used. 82 83The extension mechanism is not based on the Linux version number. 84Instead, kvm defines extension identifiers and a facility to query 85whether a particular extension identifier is available. If it is, a 86set of ioctls is available for application use. 87 88 894. API description 90================== 91 92This section describes ioctls that can be used to control kvm guests. 93For each ioctl, the following information is provided along with a 94description: 95 96 Capability: 97 which KVM extension provides this ioctl. Can be 'basic', 98 which means that is will be provided by any kernel that supports 99 API version 12 (see section 4.1), a KVM_CAP_xyz constant, which 100 means availability needs to be checked with KVM_CHECK_EXTENSION 101 (see section 4.4), or 'none' which means that while not all kernels 102 support this ioctl, there's no capability bit to check its 103 availability: for kernels that don't support the ioctl, 104 the ioctl returns -ENOTTY. 105 106 Architectures: 107 which instruction set architectures provide this ioctl. 108 x86 includes both i386 and x86_64. 109 110 Type: 111 system, vm, or vcpu. 112 113 Parameters: 114 what parameters are accepted by the ioctl. 115 116 Returns: 117 the return value. General error numbers (EBADF, ENOMEM, EINVAL) 118 are not detailed, but errors with specific meanings are. 119 120 1214.1 KVM_GET_API_VERSION 122----------------------- 123 124:Capability: basic 125:Architectures: all 126:Type: system ioctl 127:Parameters: none 128:Returns: the constant KVM_API_VERSION (=12) 129 130This identifies the API version as the stable kvm API. It is not 131expected that this number will change. However, Linux 2.6.20 and 1322.6.21 report earlier versions; these are not documented and not 133supported. Applications should refuse to run if KVM_GET_API_VERSION 134returns a value other than 12. If this check passes, all ioctls 135described as 'basic' will be available. 136 137 1384.2 KVM_CREATE_VM 139----------------- 140 141:Capability: basic 142:Architectures: all 143:Type: system ioctl 144:Parameters: machine type identifier (KVM_VM_*) 145:Returns: a VM fd that can be used to control the new virtual machine. 146 147The new VM has no virtual cpus and no memory. 148You probably want to use 0 as machine type. 149 150In order to create user controlled virtual machines on S390, check 151KVM_CAP_S390_UCONTROL and use the flag KVM_VM_S390_UCONTROL as 152privileged user (CAP_SYS_ADMIN). 153 154To use hardware assisted virtualization on MIPS (VZ ASE) rather than 155the default trap & emulate implementation (which changes the virtual 156memory layout to fit in user mode), check KVM_CAP_MIPS_VZ and use the 157flag KVM_VM_MIPS_VZ. 158 159 160On arm64, the physical address size for a VM (IPA Size limit) is limited 161to 40bits by default. The limit can be configured if the host supports the 162extension KVM_CAP_ARM_VM_IPA_SIZE. When supported, use 163KVM_VM_TYPE_ARM_IPA_SIZE(IPA_Bits) to set the size in the machine type 164identifier, where IPA_Bits is the maximum width of any physical 165address used by the VM. The IPA_Bits is encoded in bits[7-0] of the 166machine type identifier. 167 168e.g, to configure a guest to use 48bit physical address size:: 169 170 vm_fd = ioctl(dev_fd, KVM_CREATE_VM, KVM_VM_TYPE_ARM_IPA_SIZE(48)); 171 172The requested size (IPA_Bits) must be: 173 174 == ========================================================= 175 0 Implies default size, 40bits (for backward compatibility) 176 N Implies N bits, where N is a positive integer such that, 177 32 <= N <= Host_IPA_Limit 178 == ========================================================= 179 180Host_IPA_Limit is the maximum possible value for IPA_Bits on the host and 181is dependent on the CPU capability and the kernel configuration. The limit can 182be retrieved using KVM_CAP_ARM_VM_IPA_SIZE of the KVM_CHECK_EXTENSION 183ioctl() at run-time. 184 185Creation of the VM will fail if the requested IPA size (whether it is 186implicit or explicit) is unsupported on the host. 187 188Please note that configuring the IPA size does not affect the capability 189exposed by the guest CPUs in ID_AA64MMFR0_EL1[PARange]. It only affects 190size of the address translated by the stage2 level (guest physical to 191host physical address translations). 192 193 1944.3 KVM_GET_MSR_INDEX_LIST, KVM_GET_MSR_FEATURE_INDEX_LIST 195---------------------------------------------------------- 196 197:Capability: basic, KVM_CAP_GET_MSR_FEATURES for KVM_GET_MSR_FEATURE_INDEX_LIST 198:Architectures: x86 199:Type: system ioctl 200:Parameters: struct kvm_msr_list (in/out) 201:Returns: 0 on success; -1 on error 202 203Errors: 204 205 ====== ============================================================ 206 EFAULT the msr index list cannot be read from or written to 207 E2BIG the msr index list is to be to fit in the array specified by 208 the user. 209 ====== ============================================================ 210 211:: 212 213 struct kvm_msr_list { 214 __u32 nmsrs; /* number of msrs in entries */ 215 __u32 indices[0]; 216 }; 217 218The user fills in the size of the indices array in nmsrs, and in return 219kvm adjusts nmsrs to reflect the actual number of msrs and fills in the 220indices array with their numbers. 221 222KVM_GET_MSR_INDEX_LIST returns the guest msrs that are supported. The list 223varies by kvm version and host processor, but does not change otherwise. 224 225Note: if kvm indicates supports MCE (KVM_CAP_MCE), then the MCE bank MSRs are 226not returned in the MSR list, as different vcpus can have a different number 227of banks, as set via the KVM_X86_SETUP_MCE ioctl. 228 229KVM_GET_MSR_FEATURE_INDEX_LIST returns the list of MSRs that can be passed 230to the KVM_GET_MSRS system ioctl. This lets userspace probe host capabilities 231and processor features that are exposed via MSRs (e.g., VMX capabilities). 232This list also varies by kvm version and host processor, but does not change 233otherwise. 234 235 2364.4 KVM_CHECK_EXTENSION 237----------------------- 238 239:Capability: basic, KVM_CAP_CHECK_EXTENSION_VM for vm ioctl 240:Architectures: all 241:Type: system ioctl, vm ioctl 242:Parameters: extension identifier (KVM_CAP_*) 243:Returns: 0 if unsupported; 1 (or some other positive integer) if supported 244 245The API allows the application to query about extensions to the core 246kvm API. Userspace passes an extension identifier (an integer) and 247receives an integer that describes the extension availability. 248Generally 0 means no and 1 means yes, but some extensions may report 249additional information in the integer return value. 250 251Based on their initialization different VMs may have different capabilities. 252It is thus encouraged to use the vm ioctl to query for capabilities (available 253with KVM_CAP_CHECK_EXTENSION_VM on the vm fd) 254 2554.5 KVM_GET_VCPU_MMAP_SIZE 256-------------------------- 257 258:Capability: basic 259:Architectures: all 260:Type: system ioctl 261:Parameters: none 262:Returns: size of vcpu mmap area, in bytes 263 264The KVM_RUN ioctl (cf.) communicates with userspace via a shared 265memory region. This ioctl returns the size of that region. See the 266KVM_RUN documentation for details. 267 268Besides the size of the KVM_RUN communication region, other areas of 269the VCPU file descriptor can be mmap-ed, including: 270 271- if KVM_CAP_COALESCED_MMIO is available, a page at 272 KVM_COALESCED_MMIO_PAGE_OFFSET * PAGE_SIZE; for historical reasons, 273 this page is included in the result of KVM_GET_VCPU_MMAP_SIZE. 274 KVM_CAP_COALESCED_MMIO is not documented yet. 275 276- if KVM_CAP_DIRTY_LOG_RING is available, a number of pages at 277 KVM_DIRTY_LOG_PAGE_OFFSET * PAGE_SIZE. For more information on 278 KVM_CAP_DIRTY_LOG_RING, see section 8.3. 279 280 2814.6 KVM_SET_MEMORY_REGION 282------------------------- 283 284:Capability: basic 285:Architectures: all 286:Type: vm ioctl 287:Parameters: struct kvm_memory_region (in) 288:Returns: 0 on success, -1 on error 289 290This ioctl is obsolete and has been removed. 291 292 2934.7 KVM_CREATE_VCPU 294------------------- 295 296:Capability: basic 297:Architectures: all 298:Type: vm ioctl 299:Parameters: vcpu id (apic id on x86) 300:Returns: vcpu fd on success, -1 on error 301 302This API adds a vcpu to a virtual machine. No more than max_vcpus may be added. 303The vcpu id is an integer in the range [0, max_vcpu_id). 304 305The recommended max_vcpus value can be retrieved using the KVM_CAP_NR_VCPUS of 306the KVM_CHECK_EXTENSION ioctl() at run-time. 307The maximum possible value for max_vcpus can be retrieved using the 308KVM_CAP_MAX_VCPUS of the KVM_CHECK_EXTENSION ioctl() at run-time. 309 310If the KVM_CAP_NR_VCPUS does not exist, you should assume that max_vcpus is 4 311cpus max. 312If the KVM_CAP_MAX_VCPUS does not exist, you should assume that max_vcpus is 313same as the value returned from KVM_CAP_NR_VCPUS. 314 315The maximum possible value for max_vcpu_id can be retrieved using the 316KVM_CAP_MAX_VCPU_ID of the KVM_CHECK_EXTENSION ioctl() at run-time. 317 318If the KVM_CAP_MAX_VCPU_ID does not exist, you should assume that max_vcpu_id 319is the same as the value returned from KVM_CAP_MAX_VCPUS. 320 321On powerpc using book3s_hv mode, the vcpus are mapped onto virtual 322threads in one or more virtual CPU cores. (This is because the 323hardware requires all the hardware threads in a CPU core to be in the 324same partition.) The KVM_CAP_PPC_SMT capability indicates the number 325of vcpus per virtual core (vcore). The vcore id is obtained by 326dividing the vcpu id by the number of vcpus per vcore. The vcpus in a 327given vcore will always be in the same physical core as each other 328(though that might be a different physical core from time to time). 329Userspace can control the threading (SMT) mode of the guest by its 330allocation of vcpu ids. For example, if userspace wants 331single-threaded guest vcpus, it should make all vcpu ids be a multiple 332of the number of vcpus per vcore. 333 334For virtual cpus that have been created with S390 user controlled virtual 335machines, the resulting vcpu fd can be memory mapped at page offset 336KVM_S390_SIE_PAGE_OFFSET in order to obtain a memory map of the virtual 337cpu's hardware control block. 338 339 3404.8 KVM_GET_DIRTY_LOG (vm ioctl) 341-------------------------------- 342 343:Capability: basic 344:Architectures: all 345:Type: vm ioctl 346:Parameters: struct kvm_dirty_log (in/out) 347:Returns: 0 on success, -1 on error 348 349:: 350 351 /* for KVM_GET_DIRTY_LOG */ 352 struct kvm_dirty_log { 353 __u32 slot; 354 __u32 padding; 355 union { 356 void __user *dirty_bitmap; /* one bit per page */ 357 __u64 padding; 358 }; 359 }; 360 361Given a memory slot, return a bitmap containing any pages dirtied 362since the last call to this ioctl. Bit 0 is the first page in the 363memory slot. Ensure the entire structure is cleared to avoid padding 364issues. 365 366If KVM_CAP_MULTI_ADDRESS_SPACE is available, bits 16-31 of slot field specifies 367the address space for which you want to return the dirty bitmap. See 368KVM_SET_USER_MEMORY_REGION for details on the usage of slot field. 369 370The bits in the dirty bitmap are cleared before the ioctl returns, unless 371KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 is enabled. For more information, 372see the description of the capability. 373 3744.9 KVM_SET_MEMORY_ALIAS 375------------------------ 376 377:Capability: basic 378:Architectures: x86 379:Type: vm ioctl 380:Parameters: struct kvm_memory_alias (in) 381:Returns: 0 (success), -1 (error) 382 383This ioctl is obsolete and has been removed. 384 385 3864.10 KVM_RUN 387------------ 388 389:Capability: basic 390:Architectures: all 391:Type: vcpu ioctl 392:Parameters: none 393:Returns: 0 on success, -1 on error 394 395Errors: 396 397 ======= ============================================================== 398 EINTR an unmasked signal is pending 399 ENOEXEC the vcpu hasn't been initialized or the guest tried to execute 400 instructions from device memory (arm64) 401 ENOSYS data abort outside memslots with no syndrome info and 402 KVM_CAP_ARM_NISV_TO_USER not enabled (arm64) 403 EPERM SVE feature set but not finalized (arm64) 404 ======= ============================================================== 405 406This ioctl is used to run a guest virtual cpu. While there are no 407explicit parameters, there is an implicit parameter block that can be 408obtained by mmap()ing the vcpu fd at offset 0, with the size given by 409KVM_GET_VCPU_MMAP_SIZE. The parameter block is formatted as a 'struct 410kvm_run' (see below). 411 412 4134.11 KVM_GET_REGS 414----------------- 415 416:Capability: basic 417:Architectures: all except ARM, arm64 418:Type: vcpu ioctl 419:Parameters: struct kvm_regs (out) 420:Returns: 0 on success, -1 on error 421 422Reads the general purpose registers from the vcpu. 423 424:: 425 426 /* x86 */ 427 struct kvm_regs { 428 /* out (KVM_GET_REGS) / in (KVM_SET_REGS) */ 429 __u64 rax, rbx, rcx, rdx; 430 __u64 rsi, rdi, rsp, rbp; 431 __u64 r8, r9, r10, r11; 432 __u64 r12, r13, r14, r15; 433 __u64 rip, rflags; 434 }; 435 436 /* mips */ 437 struct kvm_regs { 438 /* out (KVM_GET_REGS) / in (KVM_SET_REGS) */ 439 __u64 gpr[32]; 440 __u64 hi; 441 __u64 lo; 442 __u64 pc; 443 }; 444 445 4464.12 KVM_SET_REGS 447----------------- 448 449:Capability: basic 450:Architectures: all except ARM, arm64 451:Type: vcpu ioctl 452:Parameters: struct kvm_regs (in) 453:Returns: 0 on success, -1 on error 454 455Writes the general purpose registers into the vcpu. 456 457See KVM_GET_REGS for the data structure. 458 459 4604.13 KVM_GET_SREGS 461------------------ 462 463:Capability: basic 464:Architectures: x86, ppc 465:Type: vcpu ioctl 466:Parameters: struct kvm_sregs (out) 467:Returns: 0 on success, -1 on error 468 469Reads special registers from the vcpu. 470 471:: 472 473 /* x86 */ 474 struct kvm_sregs { 475 struct kvm_segment cs, ds, es, fs, gs, ss; 476 struct kvm_segment tr, ldt; 477 struct kvm_dtable gdt, idt; 478 __u64 cr0, cr2, cr3, cr4, cr8; 479 __u64 efer; 480 __u64 apic_base; 481 __u64 interrupt_bitmap[(KVM_NR_INTERRUPTS + 63) / 64]; 482 }; 483 484 /* ppc -- see arch/powerpc/include/uapi/asm/kvm.h */ 485 486interrupt_bitmap is a bitmap of pending external interrupts. At most 487one bit may be set. This interrupt has been acknowledged by the APIC 488but not yet injected into the cpu core. 489 490 4914.14 KVM_SET_SREGS 492------------------ 493 494:Capability: basic 495:Architectures: x86, ppc 496:Type: vcpu ioctl 497:Parameters: struct kvm_sregs (in) 498:Returns: 0 on success, -1 on error 499 500Writes special registers into the vcpu. See KVM_GET_SREGS for the 501data structures. 502 503 5044.15 KVM_TRANSLATE 505------------------ 506 507:Capability: basic 508:Architectures: x86 509:Type: vcpu ioctl 510:Parameters: struct kvm_translation (in/out) 511:Returns: 0 on success, -1 on error 512 513Translates a virtual address according to the vcpu's current address 514translation mode. 515 516:: 517 518 struct kvm_translation { 519 /* in */ 520 __u64 linear_address; 521 522 /* out */ 523 __u64 physical_address; 524 __u8 valid; 525 __u8 writeable; 526 __u8 usermode; 527 __u8 pad[5]; 528 }; 529 530 5314.16 KVM_INTERRUPT 532------------------ 533 534:Capability: basic 535:Architectures: x86, ppc, mips 536:Type: vcpu ioctl 537:Parameters: struct kvm_interrupt (in) 538:Returns: 0 on success, negative on failure. 539 540Queues a hardware interrupt vector to be injected. 541 542:: 543 544 /* for KVM_INTERRUPT */ 545 struct kvm_interrupt { 546 /* in */ 547 __u32 irq; 548 }; 549 550X86: 551^^^^ 552 553:Returns: 554 555 ========= =================================== 556 0 on success, 557 -EEXIST if an interrupt is already enqueued 558 -EINVAL the irq number is invalid 559 -ENXIO if the PIC is in the kernel 560 -EFAULT if the pointer is invalid 561 ========= =================================== 562 563Note 'irq' is an interrupt vector, not an interrupt pin or line. This 564ioctl is useful if the in-kernel PIC is not used. 565 566PPC: 567^^^^ 568 569Queues an external interrupt to be injected. This ioctl is overleaded 570with 3 different irq values: 571 572a) KVM_INTERRUPT_SET 573 574 This injects an edge type external interrupt into the guest once it's ready 575 to receive interrupts. When injected, the interrupt is done. 576 577b) KVM_INTERRUPT_UNSET 578 579 This unsets any pending interrupt. 580 581 Only available with KVM_CAP_PPC_UNSET_IRQ. 582 583c) KVM_INTERRUPT_SET_LEVEL 584 585 This injects a level type external interrupt into the guest context. The 586 interrupt stays pending until a specific ioctl with KVM_INTERRUPT_UNSET 587 is triggered. 588 589 Only available with KVM_CAP_PPC_IRQ_LEVEL. 590 591Note that any value for 'irq' other than the ones stated above is invalid 592and incurs unexpected behavior. 593 594This is an asynchronous vcpu ioctl and can be invoked from any thread. 595 596MIPS: 597^^^^^ 598 599Queues an external interrupt to be injected into the virtual CPU. A negative 600interrupt number dequeues the interrupt. 601 602This is an asynchronous vcpu ioctl and can be invoked from any thread. 603 604 6054.17 KVM_DEBUG_GUEST 606-------------------- 607 608:Capability: basic 609:Architectures: none 610:Type: vcpu ioctl 611:Parameters: none) 612:Returns: -1 on error 613 614Support for this has been removed. Use KVM_SET_GUEST_DEBUG instead. 615 616 6174.18 KVM_GET_MSRS 618----------------- 619 620:Capability: basic (vcpu), KVM_CAP_GET_MSR_FEATURES (system) 621:Architectures: x86 622:Type: system ioctl, vcpu ioctl 623:Parameters: struct kvm_msrs (in/out) 624:Returns: number of msrs successfully returned; 625 -1 on error 626 627When used as a system ioctl: 628Reads the values of MSR-based features that are available for the VM. This 629is similar to KVM_GET_SUPPORTED_CPUID, but it returns MSR indices and values. 630The list of msr-based features can be obtained using KVM_GET_MSR_FEATURE_INDEX_LIST 631in a system ioctl. 632 633When used as a vcpu ioctl: 634Reads model-specific registers from the vcpu. Supported msr indices can 635be obtained using KVM_GET_MSR_INDEX_LIST in a system ioctl. 636 637:: 638 639 struct kvm_msrs { 640 __u32 nmsrs; /* number of msrs in entries */ 641 __u32 pad; 642 643 struct kvm_msr_entry entries[0]; 644 }; 645 646 struct kvm_msr_entry { 647 __u32 index; 648 __u32 reserved; 649 __u64 data; 650 }; 651 652Application code should set the 'nmsrs' member (which indicates the 653size of the entries array) and the 'index' member of each array entry. 654kvm will fill in the 'data' member. 655 656 6574.19 KVM_SET_MSRS 658----------------- 659 660:Capability: basic 661:Architectures: x86 662:Type: vcpu ioctl 663:Parameters: struct kvm_msrs (in) 664:Returns: number of msrs successfully set (see below), -1 on error 665 666Writes model-specific registers to the vcpu. See KVM_GET_MSRS for the 667data structures. 668 669Application code should set the 'nmsrs' member (which indicates the 670size of the entries array), and the 'index' and 'data' members of each 671array entry. 672 673It tries to set the MSRs in array entries[] one by one. If setting an MSR 674fails, e.g., due to setting reserved bits, the MSR isn't supported/emulated 675by KVM, etc..., it stops processing the MSR list and returns the number of 676MSRs that have been set successfully. 677 678 6794.20 KVM_SET_CPUID 680------------------ 681 682:Capability: basic 683:Architectures: x86 684:Type: vcpu ioctl 685:Parameters: struct kvm_cpuid (in) 686:Returns: 0 on success, -1 on error 687 688Defines the vcpu responses to the cpuid instruction. Applications 689should use the KVM_SET_CPUID2 ioctl if available. 690 691Note, when this IOCTL fails, KVM gives no guarantees that previous valid CPUID 692configuration (if there is) is not corrupted. Userspace can get a copy of the 693resulting CPUID configuration through KVM_GET_CPUID2 in case. 694 695:: 696 697 struct kvm_cpuid_entry { 698 __u32 function; 699 __u32 eax; 700 __u32 ebx; 701 __u32 ecx; 702 __u32 edx; 703 __u32 padding; 704 }; 705 706 /* for KVM_SET_CPUID */ 707 struct kvm_cpuid { 708 __u32 nent; 709 __u32 padding; 710 struct kvm_cpuid_entry entries[0]; 711 }; 712 713 7144.21 KVM_SET_SIGNAL_MASK 715------------------------ 716 717:Capability: basic 718:Architectures: all 719:Type: vcpu ioctl 720:Parameters: struct kvm_signal_mask (in) 721:Returns: 0 on success, -1 on error 722 723Defines which signals are blocked during execution of KVM_RUN. This 724signal mask temporarily overrides the threads signal mask. Any 725unblocked signal received (except SIGKILL and SIGSTOP, which retain 726their traditional behaviour) will cause KVM_RUN to return with -EINTR. 727 728Note the signal will only be delivered if not blocked by the original 729signal mask. 730 731:: 732 733 /* for KVM_SET_SIGNAL_MASK */ 734 struct kvm_signal_mask { 735 __u32 len; 736 __u8 sigset[0]; 737 }; 738 739 7404.22 KVM_GET_FPU 741---------------- 742 743:Capability: basic 744:Architectures: x86 745:Type: vcpu ioctl 746:Parameters: struct kvm_fpu (out) 747:Returns: 0 on success, -1 on error 748 749Reads the floating point state from the vcpu. 750 751:: 752 753 /* for KVM_GET_FPU and KVM_SET_FPU */ 754 struct kvm_fpu { 755 __u8 fpr[8][16]; 756 __u16 fcw; 757 __u16 fsw; 758 __u8 ftwx; /* in fxsave format */ 759 __u8 pad1; 760 __u16 last_opcode; 761 __u64 last_ip; 762 __u64 last_dp; 763 __u8 xmm[16][16]; 764 __u32 mxcsr; 765 __u32 pad2; 766 }; 767 768 7694.23 KVM_SET_FPU 770---------------- 771 772:Capability: basic 773:Architectures: x86 774:Type: vcpu ioctl 775:Parameters: struct kvm_fpu (in) 776:Returns: 0 on success, -1 on error 777 778Writes the floating point state to the vcpu. 779 780:: 781 782 /* for KVM_GET_FPU and KVM_SET_FPU */ 783 struct kvm_fpu { 784 __u8 fpr[8][16]; 785 __u16 fcw; 786 __u16 fsw; 787 __u8 ftwx; /* in fxsave format */ 788 __u8 pad1; 789 __u16 last_opcode; 790 __u64 last_ip; 791 __u64 last_dp; 792 __u8 xmm[16][16]; 793 __u32 mxcsr; 794 __u32 pad2; 795 }; 796 797 7984.24 KVM_CREATE_IRQCHIP 799----------------------- 800 801:Capability: KVM_CAP_IRQCHIP, KVM_CAP_S390_IRQCHIP (s390) 802:Architectures: x86, ARM, arm64, s390 803:Type: vm ioctl 804:Parameters: none 805:Returns: 0 on success, -1 on error 806 807Creates an interrupt controller model in the kernel. 808On x86, creates a virtual ioapic, a virtual PIC (two PICs, nested), and sets up 809future vcpus to have a local APIC. IRQ routing for GSIs 0-15 is set to both 810PIC and IOAPIC; GSI 16-23 only go to the IOAPIC. 811On ARM/arm64, a GICv2 is created. Any other GIC versions require the usage of 812KVM_CREATE_DEVICE, which also supports creating a GICv2. Using 813KVM_CREATE_DEVICE is preferred over KVM_CREATE_IRQCHIP for GICv2. 814On s390, a dummy irq routing table is created. 815 816Note that on s390 the KVM_CAP_S390_IRQCHIP vm capability needs to be enabled 817before KVM_CREATE_IRQCHIP can be used. 818 819 8204.25 KVM_IRQ_LINE 821----------------- 822 823:Capability: KVM_CAP_IRQCHIP 824:Architectures: x86, arm, arm64 825:Type: vm ioctl 826:Parameters: struct kvm_irq_level 827:Returns: 0 on success, -1 on error 828 829Sets the level of a GSI input to the interrupt controller model in the kernel. 830On some architectures it is required that an interrupt controller model has 831been previously created with KVM_CREATE_IRQCHIP. Note that edge-triggered 832interrupts require the level to be set to 1 and then back to 0. 833 834On real hardware, interrupt pins can be active-low or active-high. This 835does not matter for the level field of struct kvm_irq_level: 1 always 836means active (asserted), 0 means inactive (deasserted). 837 838x86 allows the operating system to program the interrupt polarity 839(active-low/active-high) for level-triggered interrupts, and KVM used 840to consider the polarity. However, due to bitrot in the handling of 841active-low interrupts, the above convention is now valid on x86 too. 842This is signaled by KVM_CAP_X86_IOAPIC_POLARITY_IGNORED. Userspace 843should not present interrupts to the guest as active-low unless this 844capability is present (or unless it is not using the in-kernel irqchip, 845of course). 846 847 848ARM/arm64 can signal an interrupt either at the CPU level, or at the 849in-kernel irqchip (GIC), and for in-kernel irqchip can tell the GIC to 850use PPIs designated for specific cpus. The irq field is interpreted 851like this:: 852 853 bits: | 31 ... 28 | 27 ... 24 | 23 ... 16 | 15 ... 0 | 854 field: | vcpu2_index | irq_type | vcpu_index | irq_id | 855 856The irq_type field has the following values: 857 858- irq_type[0]: 859 out-of-kernel GIC: irq_id 0 is IRQ, irq_id 1 is FIQ 860- irq_type[1]: 861 in-kernel GIC: SPI, irq_id between 32 and 1019 (incl.) 862 (the vcpu_index field is ignored) 863- irq_type[2]: 864 in-kernel GIC: PPI, irq_id between 16 and 31 (incl.) 865 866(The irq_id field thus corresponds nicely to the IRQ ID in the ARM GIC specs) 867 868In both cases, level is used to assert/deassert the line. 869 870When KVM_CAP_ARM_IRQ_LINE_LAYOUT_2 is supported, the target vcpu is 871identified as (256 * vcpu2_index + vcpu_index). Otherwise, vcpu2_index 872must be zero. 873 874Note that on arm/arm64, the KVM_CAP_IRQCHIP capability only conditions 875injection of interrupts for the in-kernel irqchip. KVM_IRQ_LINE can always 876be used for a userspace interrupt controller. 877 878:: 879 880 struct kvm_irq_level { 881 union { 882 __u32 irq; /* GSI */ 883 __s32 status; /* not used for KVM_IRQ_LEVEL */ 884 }; 885 __u32 level; /* 0 or 1 */ 886 }; 887 888 8894.26 KVM_GET_IRQCHIP 890-------------------- 891 892:Capability: KVM_CAP_IRQCHIP 893:Architectures: x86 894:Type: vm ioctl 895:Parameters: struct kvm_irqchip (in/out) 896:Returns: 0 on success, -1 on error 897 898Reads the state of a kernel interrupt controller created with 899KVM_CREATE_IRQCHIP into a buffer provided by the caller. 900 901:: 902 903 struct kvm_irqchip { 904 __u32 chip_id; /* 0 = PIC1, 1 = PIC2, 2 = IOAPIC */ 905 __u32 pad; 906 union { 907 char dummy[512]; /* reserving space */ 908 struct kvm_pic_state pic; 909 struct kvm_ioapic_state ioapic; 910 } chip; 911 }; 912 913 9144.27 KVM_SET_IRQCHIP 915-------------------- 916 917:Capability: KVM_CAP_IRQCHIP 918:Architectures: x86 919:Type: vm ioctl 920:Parameters: struct kvm_irqchip (in) 921:Returns: 0 on success, -1 on error 922 923Sets the state of a kernel interrupt controller created with 924KVM_CREATE_IRQCHIP from a buffer provided by the caller. 925 926:: 927 928 struct kvm_irqchip { 929 __u32 chip_id; /* 0 = PIC1, 1 = PIC2, 2 = IOAPIC */ 930 __u32 pad; 931 union { 932 char dummy[512]; /* reserving space */ 933 struct kvm_pic_state pic; 934 struct kvm_ioapic_state ioapic; 935 } chip; 936 }; 937 938 9394.28 KVM_XEN_HVM_CONFIG 940----------------------- 941 942:Capability: KVM_CAP_XEN_HVM 943:Architectures: x86 944:Type: vm ioctl 945:Parameters: struct kvm_xen_hvm_config (in) 946:Returns: 0 on success, -1 on error 947 948Sets the MSR that the Xen HVM guest uses to initialize its hypercall 949page, and provides the starting address and size of the hypercall 950blobs in userspace. When the guest writes the MSR, kvm copies one 951page of a blob (32- or 64-bit, depending on the vcpu mode) to guest 952memory. 953 954:: 955 956 struct kvm_xen_hvm_config { 957 __u32 flags; 958 __u32 msr; 959 __u64 blob_addr_32; 960 __u64 blob_addr_64; 961 __u8 blob_size_32; 962 __u8 blob_size_64; 963 __u8 pad2[30]; 964 }; 965 966If the KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL flag is returned from the 967KVM_CAP_XEN_HVM check, it may be set in the flags field of this ioctl. 968This requests KVM to generate the contents of the hypercall page 969automatically; hypercalls will be intercepted and passed to userspace 970through KVM_EXIT_XEN. In this case, all of the blob size and address 971fields must be zero. 972 973No other flags are currently valid in the struct kvm_xen_hvm_config. 974 9754.29 KVM_GET_CLOCK 976------------------ 977 978:Capability: KVM_CAP_ADJUST_CLOCK 979:Architectures: x86 980:Type: vm ioctl 981:Parameters: struct kvm_clock_data (out) 982:Returns: 0 on success, -1 on error 983 984Gets the current timestamp of kvmclock as seen by the current guest. In 985conjunction with KVM_SET_CLOCK, it is used to ensure monotonicity on scenarios 986such as migration. 987 988When KVM_CAP_ADJUST_CLOCK is passed to KVM_CHECK_EXTENSION, it returns the 989set of bits that KVM can return in struct kvm_clock_data's flag member. 990 991The only flag defined now is KVM_CLOCK_TSC_STABLE. If set, the returned 992value is the exact kvmclock value seen by all VCPUs at the instant 993when KVM_GET_CLOCK was called. If clear, the returned value is simply 994CLOCK_MONOTONIC plus a constant offset; the offset can be modified 995with KVM_SET_CLOCK. KVM will try to make all VCPUs follow this clock, 996but the exact value read by each VCPU could differ, because the host 997TSC is not stable. 998 999:: 1000 1001 struct kvm_clock_data { 1002 __u64 clock; /* kvmclock current value */ 1003 __u32 flags; 1004 __u32 pad[9]; 1005 }; 1006 1007 10084.30 KVM_SET_CLOCK 1009------------------ 1010 1011:Capability: KVM_CAP_ADJUST_CLOCK 1012:Architectures: x86 1013:Type: vm ioctl 1014:Parameters: struct kvm_clock_data (in) 1015:Returns: 0 on success, -1 on error 1016 1017Sets the current timestamp of kvmclock to the value specified in its parameter. 1018In conjunction with KVM_GET_CLOCK, it is used to ensure monotonicity on scenarios 1019such as migration. 1020 1021:: 1022 1023 struct kvm_clock_data { 1024 __u64 clock; /* kvmclock current value */ 1025 __u32 flags; 1026 __u32 pad[9]; 1027 }; 1028 1029 10304.31 KVM_GET_VCPU_EVENTS 1031------------------------ 1032 1033:Capability: KVM_CAP_VCPU_EVENTS 1034:Extended by: KVM_CAP_INTR_SHADOW 1035:Architectures: x86, arm, arm64 1036:Type: vcpu ioctl 1037:Parameters: struct kvm_vcpu_event (out) 1038:Returns: 0 on success, -1 on error 1039 1040X86: 1041^^^^ 1042 1043Gets currently pending exceptions, interrupts, and NMIs as well as related 1044states of the vcpu. 1045 1046:: 1047 1048 struct kvm_vcpu_events { 1049 struct { 1050 __u8 injected; 1051 __u8 nr; 1052 __u8 has_error_code; 1053 __u8 pending; 1054 __u32 error_code; 1055 } exception; 1056 struct { 1057 __u8 injected; 1058 __u8 nr; 1059 __u8 soft; 1060 __u8 shadow; 1061 } interrupt; 1062 struct { 1063 __u8 injected; 1064 __u8 pending; 1065 __u8 masked; 1066 __u8 pad; 1067 } nmi; 1068 __u32 sipi_vector; 1069 __u32 flags; 1070 struct { 1071 __u8 smm; 1072 __u8 pending; 1073 __u8 smm_inside_nmi; 1074 __u8 latched_init; 1075 } smi; 1076 __u8 reserved[27]; 1077 __u8 exception_has_payload; 1078 __u64 exception_payload; 1079 }; 1080 1081The following bits are defined in the flags field: 1082 1083- KVM_VCPUEVENT_VALID_SHADOW may be set to signal that 1084 interrupt.shadow contains a valid state. 1085 1086- KVM_VCPUEVENT_VALID_SMM may be set to signal that smi contains a 1087 valid state. 1088 1089- KVM_VCPUEVENT_VALID_PAYLOAD may be set to signal that the 1090 exception_has_payload, exception_payload, and exception.pending 1091 fields contain a valid state. This bit will be set whenever 1092 KVM_CAP_EXCEPTION_PAYLOAD is enabled. 1093 1094ARM/ARM64: 1095^^^^^^^^^^ 1096 1097If the guest accesses a device that is being emulated by the host kernel in 1098such a way that a real device would generate a physical SError, KVM may make 1099a virtual SError pending for that VCPU. This system error interrupt remains 1100pending until the guest takes the exception by unmasking PSTATE.A. 1101 1102Running the VCPU may cause it to take a pending SError, or make an access that 1103causes an SError to become pending. The event's description is only valid while 1104the VPCU is not running. 1105 1106This API provides a way to read and write the pending 'event' state that is not 1107visible to the guest. To save, restore or migrate a VCPU the struct representing 1108the state can be read then written using this GET/SET API, along with the other 1109guest-visible registers. It is not possible to 'cancel' an SError that has been 1110made pending. 1111 1112A device being emulated in user-space may also wish to generate an SError. To do 1113this the events structure can be populated by user-space. The current state 1114should be read first, to ensure no existing SError is pending. If an existing 1115SError is pending, the architecture's 'Multiple SError interrupts' rules should 1116be followed. (2.5.3 of DDI0587.a "ARM Reliability, Availability, and 1117Serviceability (RAS) Specification"). 1118 1119SError exceptions always have an ESR value. Some CPUs have the ability to 1120specify what the virtual SError's ESR value should be. These systems will 1121advertise KVM_CAP_ARM_INJECT_SERROR_ESR. In this case exception.has_esr will 1122always have a non-zero value when read, and the agent making an SError pending 1123should specify the ISS field in the lower 24 bits of exception.serror_esr. If 1124the system supports KVM_CAP_ARM_INJECT_SERROR_ESR, but user-space sets the events 1125with exception.has_esr as zero, KVM will choose an ESR. 1126 1127Specifying exception.has_esr on a system that does not support it will return 1128-EINVAL. Setting anything other than the lower 24bits of exception.serror_esr 1129will return -EINVAL. 1130 1131It is not possible to read back a pending external abort (injected via 1132KVM_SET_VCPU_EVENTS or otherwise) because such an exception is always delivered 1133directly to the virtual CPU). 1134 1135:: 1136 1137 struct kvm_vcpu_events { 1138 struct { 1139 __u8 serror_pending; 1140 __u8 serror_has_esr; 1141 __u8 ext_dabt_pending; 1142 /* Align it to 8 bytes */ 1143 __u8 pad[5]; 1144 __u64 serror_esr; 1145 } exception; 1146 __u32 reserved[12]; 1147 }; 1148 11494.32 KVM_SET_VCPU_EVENTS 1150------------------------ 1151 1152:Capability: KVM_CAP_VCPU_EVENTS 1153:Extended by: KVM_CAP_INTR_SHADOW 1154:Architectures: x86, arm, arm64 1155:Type: vcpu ioctl 1156:Parameters: struct kvm_vcpu_event (in) 1157:Returns: 0 on success, -1 on error 1158 1159X86: 1160^^^^ 1161 1162Set pending exceptions, interrupts, and NMIs as well as related states of the 1163vcpu. 1164 1165See KVM_GET_VCPU_EVENTS for the data structure. 1166 1167Fields that may be modified asynchronously by running VCPUs can be excluded 1168from the update. These fields are nmi.pending, sipi_vector, smi.smm, 1169smi.pending. Keep the corresponding bits in the flags field cleared to 1170suppress overwriting the current in-kernel state. The bits are: 1171 1172=============================== ================================== 1173KVM_VCPUEVENT_VALID_NMI_PENDING transfer nmi.pending to the kernel 1174KVM_VCPUEVENT_VALID_SIPI_VECTOR transfer sipi_vector 1175KVM_VCPUEVENT_VALID_SMM transfer the smi sub-struct. 1176=============================== ================================== 1177 1178If KVM_CAP_INTR_SHADOW is available, KVM_VCPUEVENT_VALID_SHADOW can be set in 1179the flags field to signal that interrupt.shadow contains a valid state and 1180shall be written into the VCPU. 1181 1182KVM_VCPUEVENT_VALID_SMM can only be set if KVM_CAP_X86_SMM is available. 1183 1184If KVM_CAP_EXCEPTION_PAYLOAD is enabled, KVM_VCPUEVENT_VALID_PAYLOAD 1185can be set in the flags field to signal that the 1186exception_has_payload, exception_payload, and exception.pending fields 1187contain a valid state and shall be written into the VCPU. 1188 1189ARM/ARM64: 1190^^^^^^^^^^ 1191 1192User space may need to inject several types of events to the guest. 1193 1194Set the pending SError exception state for this VCPU. It is not possible to 1195'cancel' an Serror that has been made pending. 1196 1197If the guest performed an access to I/O memory which could not be handled by 1198userspace, for example because of missing instruction syndrome decode 1199information or because there is no device mapped at the accessed IPA, then 1200userspace can ask the kernel to inject an external abort using the address 1201from the exiting fault on the VCPU. It is a programming error to set 1202ext_dabt_pending after an exit which was not either KVM_EXIT_MMIO or 1203KVM_EXIT_ARM_NISV. This feature is only available if the system supports 1204KVM_CAP_ARM_INJECT_EXT_DABT. This is a helper which provides commonality in 1205how userspace reports accesses for the above cases to guests, across different 1206userspace implementations. Nevertheless, userspace can still emulate all Arm 1207exceptions by manipulating individual registers using the KVM_SET_ONE_REG API. 1208 1209See KVM_GET_VCPU_EVENTS for the data structure. 1210 1211 12124.33 KVM_GET_DEBUGREGS 1213---------------------- 1214 1215:Capability: KVM_CAP_DEBUGREGS 1216:Architectures: x86 1217:Type: vm ioctl 1218:Parameters: struct kvm_debugregs (out) 1219:Returns: 0 on success, -1 on error 1220 1221Reads debug registers from the vcpu. 1222 1223:: 1224 1225 struct kvm_debugregs { 1226 __u64 db[4]; 1227 __u64 dr6; 1228 __u64 dr7; 1229 __u64 flags; 1230 __u64 reserved[9]; 1231 }; 1232 1233 12344.34 KVM_SET_DEBUGREGS 1235---------------------- 1236 1237:Capability: KVM_CAP_DEBUGREGS 1238:Architectures: x86 1239:Type: vm ioctl 1240:Parameters: struct kvm_debugregs (in) 1241:Returns: 0 on success, -1 on error 1242 1243Writes debug registers into the vcpu. 1244 1245See KVM_GET_DEBUGREGS for the data structure. The flags field is unused 1246yet and must be cleared on entry. 1247 1248 12494.35 KVM_SET_USER_MEMORY_REGION 1250------------------------------- 1251 1252:Capability: KVM_CAP_USER_MEMORY 1253:Architectures: all 1254:Type: vm ioctl 1255:Parameters: struct kvm_userspace_memory_region (in) 1256:Returns: 0 on success, -1 on error 1257 1258:: 1259 1260 struct kvm_userspace_memory_region { 1261 __u32 slot; 1262 __u32 flags; 1263 __u64 guest_phys_addr; 1264 __u64 memory_size; /* bytes */ 1265 __u64 userspace_addr; /* start of the userspace allocated memory */ 1266 }; 1267 1268 /* for kvm_memory_region::flags */ 1269 #define KVM_MEM_LOG_DIRTY_PAGES (1UL << 0) 1270 #define KVM_MEM_READONLY (1UL << 1) 1271 1272This ioctl allows the user to create, modify or delete a guest physical 1273memory slot. Bits 0-15 of "slot" specify the slot id and this value 1274should be less than the maximum number of user memory slots supported per 1275VM. The maximum allowed slots can be queried using KVM_CAP_NR_MEMSLOTS. 1276Slots may not overlap in guest physical address space. 1277 1278If KVM_CAP_MULTI_ADDRESS_SPACE is available, bits 16-31 of "slot" 1279specifies the address space which is being modified. They must be 1280less than the value that KVM_CHECK_EXTENSION returns for the 1281KVM_CAP_MULTI_ADDRESS_SPACE capability. Slots in separate address spaces 1282are unrelated; the restriction on overlapping slots only applies within 1283each address space. 1284 1285Deleting a slot is done by passing zero for memory_size. When changing 1286an existing slot, it may be moved in the guest physical memory space, 1287or its flags may be modified, but it may not be resized. 1288 1289Memory for the region is taken starting at the address denoted by the 1290field userspace_addr, which must point at user addressable memory for 1291the entire memory slot size. Any object may back this memory, including 1292anonymous memory, ordinary files, and hugetlbfs. 1293 1294On architectures that support a form of address tagging, userspace_addr must 1295be an untagged address. 1296 1297It is recommended that the lower 21 bits of guest_phys_addr and userspace_addr 1298be identical. This allows large pages in the guest to be backed by large 1299pages in the host. 1300 1301The flags field supports two flags: KVM_MEM_LOG_DIRTY_PAGES and 1302KVM_MEM_READONLY. The former can be set to instruct KVM to keep track of 1303writes to memory within the slot. See KVM_GET_DIRTY_LOG ioctl to know how to 1304use it. The latter can be set, if KVM_CAP_READONLY_MEM capability allows it, 1305to make a new slot read-only. In this case, writes to this memory will be 1306posted to userspace as KVM_EXIT_MMIO exits. 1307 1308When the KVM_CAP_SYNC_MMU capability is available, changes in the backing of 1309the memory region are automatically reflected into the guest. For example, an 1310mmap() that affects the region will be made visible immediately. Another 1311example is madvise(MADV_DROP). 1312 1313It is recommended to use this API instead of the KVM_SET_MEMORY_REGION ioctl. 1314The KVM_SET_MEMORY_REGION does not allow fine grained control over memory 1315allocation and is deprecated. 1316 1317 13184.36 KVM_SET_TSS_ADDR 1319--------------------- 1320 1321:Capability: KVM_CAP_SET_TSS_ADDR 1322:Architectures: x86 1323:Type: vm ioctl 1324:Parameters: unsigned long tss_address (in) 1325:Returns: 0 on success, -1 on error 1326 1327This ioctl defines the physical address of a three-page region in the guest 1328physical address space. The region must be within the first 4GB of the 1329guest physical address space and must not conflict with any memory slot 1330or any mmio address. The guest may malfunction if it accesses this memory 1331region. 1332 1333This ioctl is required on Intel-based hosts. This is needed on Intel hardware 1334because of a quirk in the virtualization implementation (see the internals 1335documentation when it pops into existence). 1336 1337 13384.37 KVM_ENABLE_CAP 1339------------------- 1340 1341:Capability: KVM_CAP_ENABLE_CAP 1342:Architectures: mips, ppc, s390 1343:Type: vcpu ioctl 1344:Parameters: struct kvm_enable_cap (in) 1345:Returns: 0 on success; -1 on error 1346 1347:Capability: KVM_CAP_ENABLE_CAP_VM 1348:Architectures: all 1349:Type: vm ioctl 1350:Parameters: struct kvm_enable_cap (in) 1351:Returns: 0 on success; -1 on error 1352 1353.. note:: 1354 1355 Not all extensions are enabled by default. Using this ioctl the application 1356 can enable an extension, making it available to the guest. 1357 1358On systems that do not support this ioctl, it always fails. On systems that 1359do support it, it only works for extensions that are supported for enablement. 1360 1361To check if a capability can be enabled, the KVM_CHECK_EXTENSION ioctl should 1362be used. 1363 1364:: 1365 1366 struct kvm_enable_cap { 1367 /* in */ 1368 __u32 cap; 1369 1370The capability that is supposed to get enabled. 1371 1372:: 1373 1374 __u32 flags; 1375 1376A bitfield indicating future enhancements. Has to be 0 for now. 1377 1378:: 1379 1380 __u64 args[4]; 1381 1382Arguments for enabling a feature. If a feature needs initial values to 1383function properly, this is the place to put them. 1384 1385:: 1386 1387 __u8 pad[64]; 1388 }; 1389 1390The vcpu ioctl should be used for vcpu-specific capabilities, the vm ioctl 1391for vm-wide capabilities. 1392 13934.38 KVM_GET_MP_STATE 1394--------------------- 1395 1396:Capability: KVM_CAP_MP_STATE 1397:Architectures: x86, s390, arm, arm64 1398:Type: vcpu ioctl 1399:Parameters: struct kvm_mp_state (out) 1400:Returns: 0 on success; -1 on error 1401 1402:: 1403 1404 struct kvm_mp_state { 1405 __u32 mp_state; 1406 }; 1407 1408Returns the vcpu's current "multiprocessing state" (though also valid on 1409uniprocessor guests). 1410 1411Possible values are: 1412 1413 ========================== =============================================== 1414 KVM_MP_STATE_RUNNABLE the vcpu is currently running [x86,arm/arm64] 1415 KVM_MP_STATE_UNINITIALIZED the vcpu is an application processor (AP) 1416 which has not yet received an INIT signal [x86] 1417 KVM_MP_STATE_INIT_RECEIVED the vcpu has received an INIT signal, and is 1418 now ready for a SIPI [x86] 1419 KVM_MP_STATE_HALTED the vcpu has executed a HLT instruction and 1420 is waiting for an interrupt [x86] 1421 KVM_MP_STATE_SIPI_RECEIVED the vcpu has just received a SIPI (vector 1422 accessible via KVM_GET_VCPU_EVENTS) [x86] 1423 KVM_MP_STATE_STOPPED the vcpu is stopped [s390,arm/arm64] 1424 KVM_MP_STATE_CHECK_STOP the vcpu is in a special error state [s390] 1425 KVM_MP_STATE_OPERATING the vcpu is operating (running or halted) 1426 [s390] 1427 KVM_MP_STATE_LOAD the vcpu is in a special load/startup state 1428 [s390] 1429 ========================== =============================================== 1430 1431On x86, this ioctl is only useful after KVM_CREATE_IRQCHIP. Without an 1432in-kernel irqchip, the multiprocessing state must be maintained by userspace on 1433these architectures. 1434 1435For arm/arm64: 1436^^^^^^^^^^^^^^ 1437 1438The only states that are valid are KVM_MP_STATE_STOPPED and 1439KVM_MP_STATE_RUNNABLE which reflect if the vcpu is paused or not. 1440 14414.39 KVM_SET_MP_STATE 1442--------------------- 1443 1444:Capability: KVM_CAP_MP_STATE 1445:Architectures: x86, s390, arm, arm64 1446:Type: vcpu ioctl 1447:Parameters: struct kvm_mp_state (in) 1448:Returns: 0 on success; -1 on error 1449 1450Sets the vcpu's current "multiprocessing state"; see KVM_GET_MP_STATE for 1451arguments. 1452 1453On x86, this ioctl is only useful after KVM_CREATE_IRQCHIP. Without an 1454in-kernel irqchip, the multiprocessing state must be maintained by userspace on 1455these architectures. 1456 1457For arm/arm64: 1458^^^^^^^^^^^^^^ 1459 1460The only states that are valid are KVM_MP_STATE_STOPPED and 1461KVM_MP_STATE_RUNNABLE which reflect if the vcpu should be paused or not. 1462 14634.40 KVM_SET_IDENTITY_MAP_ADDR 1464------------------------------ 1465 1466:Capability: KVM_CAP_SET_IDENTITY_MAP_ADDR 1467:Architectures: x86 1468:Type: vm ioctl 1469:Parameters: unsigned long identity (in) 1470:Returns: 0 on success, -1 on error 1471 1472This ioctl defines the physical address of a one-page region in the guest 1473physical address space. The region must be within the first 4GB of the 1474guest physical address space and must not conflict with any memory slot 1475or any mmio address. The guest may malfunction if it accesses this memory 1476region. 1477 1478Setting the address to 0 will result in resetting the address to its default 1479(0xfffbc000). 1480 1481This ioctl is required on Intel-based hosts. This is needed on Intel hardware 1482because of a quirk in the virtualization implementation (see the internals 1483documentation when it pops into existence). 1484 1485Fails if any VCPU has already been created. 1486 14874.41 KVM_SET_BOOT_CPU_ID 1488------------------------ 1489 1490:Capability: KVM_CAP_SET_BOOT_CPU_ID 1491:Architectures: x86 1492:Type: vm ioctl 1493:Parameters: unsigned long vcpu_id 1494:Returns: 0 on success, -1 on error 1495 1496Define which vcpu is the Bootstrap Processor (BSP). Values are the same 1497as the vcpu id in KVM_CREATE_VCPU. If this ioctl is not called, the default 1498is vcpu 0. This ioctl has to be called before vcpu creation, 1499otherwise it will return EBUSY error. 1500 1501 15024.42 KVM_GET_XSAVE 1503------------------ 1504 1505:Capability: KVM_CAP_XSAVE 1506:Architectures: x86 1507:Type: vcpu ioctl 1508:Parameters: struct kvm_xsave (out) 1509:Returns: 0 on success, -1 on error 1510 1511 1512:: 1513 1514 struct kvm_xsave { 1515 __u32 region[1024]; 1516 }; 1517 1518This ioctl would copy current vcpu's xsave struct to the userspace. 1519 1520 15214.43 KVM_SET_XSAVE 1522------------------ 1523 1524:Capability: KVM_CAP_XSAVE 1525:Architectures: x86 1526:Type: vcpu ioctl 1527:Parameters: struct kvm_xsave (in) 1528:Returns: 0 on success, -1 on error 1529 1530:: 1531 1532 1533 struct kvm_xsave { 1534 __u32 region[1024]; 1535 }; 1536 1537This ioctl would copy userspace's xsave struct to the kernel. 1538 1539 15404.44 KVM_GET_XCRS 1541----------------- 1542 1543:Capability: KVM_CAP_XCRS 1544:Architectures: x86 1545:Type: vcpu ioctl 1546:Parameters: struct kvm_xcrs (out) 1547:Returns: 0 on success, -1 on error 1548 1549:: 1550 1551 struct kvm_xcr { 1552 __u32 xcr; 1553 __u32 reserved; 1554 __u64 value; 1555 }; 1556 1557 struct kvm_xcrs { 1558 __u32 nr_xcrs; 1559 __u32 flags; 1560 struct kvm_xcr xcrs[KVM_MAX_XCRS]; 1561 __u64 padding[16]; 1562 }; 1563 1564This ioctl would copy current vcpu's xcrs to the userspace. 1565 1566 15674.45 KVM_SET_XCRS 1568----------------- 1569 1570:Capability: KVM_CAP_XCRS 1571:Architectures: x86 1572:Type: vcpu ioctl 1573:Parameters: struct kvm_xcrs (in) 1574:Returns: 0 on success, -1 on error 1575 1576:: 1577 1578 struct kvm_xcr { 1579 __u32 xcr; 1580 __u32 reserved; 1581 __u64 value; 1582 }; 1583 1584 struct kvm_xcrs { 1585 __u32 nr_xcrs; 1586 __u32 flags; 1587 struct kvm_xcr xcrs[KVM_MAX_XCRS]; 1588 __u64 padding[16]; 1589 }; 1590 1591This ioctl would set vcpu's xcr to the value userspace specified. 1592 1593 15944.46 KVM_GET_SUPPORTED_CPUID 1595---------------------------- 1596 1597:Capability: KVM_CAP_EXT_CPUID 1598:Architectures: x86 1599:Type: system ioctl 1600:Parameters: struct kvm_cpuid2 (in/out) 1601:Returns: 0 on success, -1 on error 1602 1603:: 1604 1605 struct kvm_cpuid2 { 1606 __u32 nent; 1607 __u32 padding; 1608 struct kvm_cpuid_entry2 entries[0]; 1609 }; 1610 1611 #define KVM_CPUID_FLAG_SIGNIFCANT_INDEX BIT(0) 1612 #define KVM_CPUID_FLAG_STATEFUL_FUNC BIT(1) /* deprecated */ 1613 #define KVM_CPUID_FLAG_STATE_READ_NEXT BIT(2) /* deprecated */ 1614 1615 struct kvm_cpuid_entry2 { 1616 __u32 function; 1617 __u32 index; 1618 __u32 flags; 1619 __u32 eax; 1620 __u32 ebx; 1621 __u32 ecx; 1622 __u32 edx; 1623 __u32 padding[3]; 1624 }; 1625 1626This ioctl returns x86 cpuid features which are supported by both the 1627hardware and kvm in its default configuration. Userspace can use the 1628information returned by this ioctl to construct cpuid information (for 1629KVM_SET_CPUID2) that is consistent with hardware, kernel, and 1630userspace capabilities, and with user requirements (for example, the 1631user may wish to constrain cpuid to emulate older hardware, or for 1632feature consistency across a cluster). 1633 1634Note that certain capabilities, such as KVM_CAP_X86_DISABLE_EXITS, may 1635expose cpuid features (e.g. MONITOR) which are not supported by kvm in 1636its default configuration. If userspace enables such capabilities, it 1637is responsible for modifying the results of this ioctl appropriately. 1638 1639Userspace invokes KVM_GET_SUPPORTED_CPUID by passing a kvm_cpuid2 structure 1640with the 'nent' field indicating the number of entries in the variable-size 1641array 'entries'. If the number of entries is too low to describe the cpu 1642capabilities, an error (E2BIG) is returned. If the number is too high, 1643the 'nent' field is adjusted and an error (ENOMEM) is returned. If the 1644number is just right, the 'nent' field is adjusted to the number of valid 1645entries in the 'entries' array, which is then filled. 1646 1647The entries returned are the host cpuid as returned by the cpuid instruction, 1648with unknown or unsupported features masked out. Some features (for example, 1649x2apic), may not be present in the host cpu, but are exposed by kvm if it can 1650emulate them efficiently. The fields in each entry are defined as follows: 1651 1652 function: 1653 the eax value used to obtain the entry 1654 1655 index: 1656 the ecx value used to obtain the entry (for entries that are 1657 affected by ecx) 1658 1659 flags: 1660 an OR of zero or more of the following: 1661 1662 KVM_CPUID_FLAG_SIGNIFCANT_INDEX: 1663 if the index field is valid 1664 1665 eax, ebx, ecx, edx: 1666 the values returned by the cpuid instruction for 1667 this function/index combination 1668 1669The TSC deadline timer feature (CPUID leaf 1, ecx[24]) is always returned 1670as false, since the feature depends on KVM_CREATE_IRQCHIP for local APIC 1671support. Instead it is reported via:: 1672 1673 ioctl(KVM_CHECK_EXTENSION, KVM_CAP_TSC_DEADLINE_TIMER) 1674 1675if that returns true and you use KVM_CREATE_IRQCHIP, or if you emulate the 1676feature in userspace, then you can enable the feature for KVM_SET_CPUID2. 1677 1678 16794.47 KVM_PPC_GET_PVINFO 1680----------------------- 1681 1682:Capability: KVM_CAP_PPC_GET_PVINFO 1683:Architectures: ppc 1684:Type: vm ioctl 1685:Parameters: struct kvm_ppc_pvinfo (out) 1686:Returns: 0 on success, !0 on error 1687 1688:: 1689 1690 struct kvm_ppc_pvinfo { 1691 __u32 flags; 1692 __u32 hcall[4]; 1693 __u8 pad[108]; 1694 }; 1695 1696This ioctl fetches PV specific information that need to be passed to the guest 1697using the device tree or other means from vm context. 1698 1699The hcall array defines 4 instructions that make up a hypercall. 1700 1701If any additional field gets added to this structure later on, a bit for that 1702additional piece of information will be set in the flags bitmap. 1703 1704The flags bitmap is defined as:: 1705 1706 /* the host supports the ePAPR idle hcall 1707 #define KVM_PPC_PVINFO_FLAGS_EV_IDLE (1<<0) 1708 17094.52 KVM_SET_GSI_ROUTING 1710------------------------ 1711 1712:Capability: KVM_CAP_IRQ_ROUTING 1713:Architectures: x86 s390 arm arm64 1714:Type: vm ioctl 1715:Parameters: struct kvm_irq_routing (in) 1716:Returns: 0 on success, -1 on error 1717 1718Sets the GSI routing table entries, overwriting any previously set entries. 1719 1720On arm/arm64, GSI routing has the following limitation: 1721 1722- GSI routing does not apply to KVM_IRQ_LINE but only to KVM_IRQFD. 1723 1724:: 1725 1726 struct kvm_irq_routing { 1727 __u32 nr; 1728 __u32 flags; 1729 struct kvm_irq_routing_entry entries[0]; 1730 }; 1731 1732No flags are specified so far, the corresponding field must be set to zero. 1733 1734:: 1735 1736 struct kvm_irq_routing_entry { 1737 __u32 gsi; 1738 __u32 type; 1739 __u32 flags; 1740 __u32 pad; 1741 union { 1742 struct kvm_irq_routing_irqchip irqchip; 1743 struct kvm_irq_routing_msi msi; 1744 struct kvm_irq_routing_s390_adapter adapter; 1745 struct kvm_irq_routing_hv_sint hv_sint; 1746 __u32 pad[8]; 1747 } u; 1748 }; 1749 1750 /* gsi routing entry types */ 1751 #define KVM_IRQ_ROUTING_IRQCHIP 1 1752 #define KVM_IRQ_ROUTING_MSI 2 1753 #define KVM_IRQ_ROUTING_S390_ADAPTER 3 1754 #define KVM_IRQ_ROUTING_HV_SINT 4 1755 1756flags: 1757 1758- KVM_MSI_VALID_DEVID: used along with KVM_IRQ_ROUTING_MSI routing entry 1759 type, specifies that the devid field contains a valid value. The per-VM 1760 KVM_CAP_MSI_DEVID capability advertises the requirement to provide 1761 the device ID. If this capability is not available, userspace should 1762 never set the KVM_MSI_VALID_DEVID flag as the ioctl might fail. 1763- zero otherwise 1764 1765:: 1766 1767 struct kvm_irq_routing_irqchip { 1768 __u32 irqchip; 1769 __u32 pin; 1770 }; 1771 1772 struct kvm_irq_routing_msi { 1773 __u32 address_lo; 1774 __u32 address_hi; 1775 __u32 data; 1776 union { 1777 __u32 pad; 1778 __u32 devid; 1779 }; 1780 }; 1781 1782If KVM_MSI_VALID_DEVID is set, devid contains a unique device identifier 1783for the device that wrote the MSI message. For PCI, this is usually a 1784BFD identifier in the lower 16 bits. 1785 1786On x86, address_hi is ignored unless the KVM_X2APIC_API_USE_32BIT_IDS 1787feature of KVM_CAP_X2APIC_API capability is enabled. If it is enabled, 1788address_hi bits 31-8 provide bits 31-8 of the destination id. Bits 7-0 of 1789address_hi must be zero. 1790 1791:: 1792 1793 struct kvm_irq_routing_s390_adapter { 1794 __u64 ind_addr; 1795 __u64 summary_addr; 1796 __u64 ind_offset; 1797 __u32 summary_offset; 1798 __u32 adapter_id; 1799 }; 1800 1801 struct kvm_irq_routing_hv_sint { 1802 __u32 vcpu; 1803 __u32 sint; 1804 }; 1805 1806 18074.55 KVM_SET_TSC_KHZ 1808-------------------- 1809 1810:Capability: KVM_CAP_TSC_CONTROL 1811:Architectures: x86 1812:Type: vcpu ioctl 1813:Parameters: virtual tsc_khz 1814:Returns: 0 on success, -1 on error 1815 1816Specifies the tsc frequency for the virtual machine. The unit of the 1817frequency is KHz. 1818 1819 18204.56 KVM_GET_TSC_KHZ 1821-------------------- 1822 1823:Capability: KVM_CAP_GET_TSC_KHZ 1824:Architectures: x86 1825:Type: vcpu ioctl 1826:Parameters: none 1827:Returns: virtual tsc-khz on success, negative value on error 1828 1829Returns the tsc frequency of the guest. The unit of the return value is 1830KHz. If the host has unstable tsc this ioctl returns -EIO instead as an 1831error. 1832 1833 18344.57 KVM_GET_LAPIC 1835------------------ 1836 1837:Capability: KVM_CAP_IRQCHIP 1838:Architectures: x86 1839:Type: vcpu ioctl 1840:Parameters: struct kvm_lapic_state (out) 1841:Returns: 0 on success, -1 on error 1842 1843:: 1844 1845 #define KVM_APIC_REG_SIZE 0x400 1846 struct kvm_lapic_state { 1847 char regs[KVM_APIC_REG_SIZE]; 1848 }; 1849 1850Reads the Local APIC registers and copies them into the input argument. The 1851data format and layout are the same as documented in the architecture manual. 1852 1853If KVM_X2APIC_API_USE_32BIT_IDS feature of KVM_CAP_X2APIC_API is 1854enabled, then the format of APIC_ID register depends on the APIC mode 1855(reported by MSR_IA32_APICBASE) of its VCPU. x2APIC stores APIC ID in 1856the APIC_ID register (bytes 32-35). xAPIC only allows an 8-bit APIC ID 1857which is stored in bits 31-24 of the APIC register, or equivalently in 1858byte 35 of struct kvm_lapic_state's regs field. KVM_GET_LAPIC must then 1859be called after MSR_IA32_APICBASE has been set with KVM_SET_MSR. 1860 1861If KVM_X2APIC_API_USE_32BIT_IDS feature is disabled, struct kvm_lapic_state 1862always uses xAPIC format. 1863 1864 18654.58 KVM_SET_LAPIC 1866------------------ 1867 1868:Capability: KVM_CAP_IRQCHIP 1869:Architectures: x86 1870:Type: vcpu ioctl 1871:Parameters: struct kvm_lapic_state (in) 1872:Returns: 0 on success, -1 on error 1873 1874:: 1875 1876 #define KVM_APIC_REG_SIZE 0x400 1877 struct kvm_lapic_state { 1878 char regs[KVM_APIC_REG_SIZE]; 1879 }; 1880 1881Copies the input argument into the Local APIC registers. The data format 1882and layout are the same as documented in the architecture manual. 1883 1884The format of the APIC ID register (bytes 32-35 of struct kvm_lapic_state's 1885regs field) depends on the state of the KVM_CAP_X2APIC_API capability. 1886See the note in KVM_GET_LAPIC. 1887 1888 18894.59 KVM_IOEVENTFD 1890------------------ 1891 1892:Capability: KVM_CAP_IOEVENTFD 1893:Architectures: all 1894:Type: vm ioctl 1895:Parameters: struct kvm_ioeventfd (in) 1896:Returns: 0 on success, !0 on error 1897 1898This ioctl attaches or detaches an ioeventfd to a legal pio/mmio address 1899within the guest. A guest write in the registered address will signal the 1900provided event instead of triggering an exit. 1901 1902:: 1903 1904 struct kvm_ioeventfd { 1905 __u64 datamatch; 1906 __u64 addr; /* legal pio/mmio address */ 1907 __u32 len; /* 0, 1, 2, 4, or 8 bytes */ 1908 __s32 fd; 1909 __u32 flags; 1910 __u8 pad[36]; 1911 }; 1912 1913For the special case of virtio-ccw devices on s390, the ioevent is matched 1914to a subchannel/virtqueue tuple instead. 1915 1916The following flags are defined:: 1917 1918 #define KVM_IOEVENTFD_FLAG_DATAMATCH (1 << kvm_ioeventfd_flag_nr_datamatch) 1919 #define KVM_IOEVENTFD_FLAG_PIO (1 << kvm_ioeventfd_flag_nr_pio) 1920 #define KVM_IOEVENTFD_FLAG_DEASSIGN (1 << kvm_ioeventfd_flag_nr_deassign) 1921 #define KVM_IOEVENTFD_FLAG_VIRTIO_CCW_NOTIFY \ 1922 (1 << kvm_ioeventfd_flag_nr_virtio_ccw_notify) 1923 1924If datamatch flag is set, the event will be signaled only if the written value 1925to the registered address is equal to datamatch in struct kvm_ioeventfd. 1926 1927For virtio-ccw devices, addr contains the subchannel id and datamatch the 1928virtqueue index. 1929 1930With KVM_CAP_IOEVENTFD_ANY_LENGTH, a zero length ioeventfd is allowed, and 1931the kernel will ignore the length of guest write and may get a faster vmexit. 1932The speedup may only apply to specific architectures, but the ioeventfd will 1933work anyway. 1934 19354.60 KVM_DIRTY_TLB 1936------------------ 1937 1938:Capability: KVM_CAP_SW_TLB 1939:Architectures: ppc 1940:Type: vcpu ioctl 1941:Parameters: struct kvm_dirty_tlb (in) 1942:Returns: 0 on success, -1 on error 1943 1944:: 1945 1946 struct kvm_dirty_tlb { 1947 __u64 bitmap; 1948 __u32 num_dirty; 1949 }; 1950 1951This must be called whenever userspace has changed an entry in the shared 1952TLB, prior to calling KVM_RUN on the associated vcpu. 1953 1954The "bitmap" field is the userspace address of an array. This array 1955consists of a number of bits, equal to the total number of TLB entries as 1956determined by the last successful call to KVM_CONFIG_TLB, rounded up to the 1957nearest multiple of 64. 1958 1959Each bit corresponds to one TLB entry, ordered the same as in the shared TLB 1960array. 1961 1962The array is little-endian: the bit 0 is the least significant bit of the 1963first byte, bit 8 is the least significant bit of the second byte, etc. 1964This avoids any complications with differing word sizes. 1965 1966The "num_dirty" field is a performance hint for KVM to determine whether it 1967should skip processing the bitmap and just invalidate everything. It must 1968be set to the number of set bits in the bitmap. 1969 1970 19714.62 KVM_CREATE_SPAPR_TCE 1972------------------------- 1973 1974:Capability: KVM_CAP_SPAPR_TCE 1975:Architectures: powerpc 1976:Type: vm ioctl 1977:Parameters: struct kvm_create_spapr_tce (in) 1978:Returns: file descriptor for manipulating the created TCE table 1979 1980This creates a virtual TCE (translation control entry) table, which 1981is an IOMMU for PAPR-style virtual I/O. It is used to translate 1982logical addresses used in virtual I/O into guest physical addresses, 1983and provides a scatter/gather capability for PAPR virtual I/O. 1984 1985:: 1986 1987 /* for KVM_CAP_SPAPR_TCE */ 1988 struct kvm_create_spapr_tce { 1989 __u64 liobn; 1990 __u32 window_size; 1991 }; 1992 1993The liobn field gives the logical IO bus number for which to create a 1994TCE table. The window_size field specifies the size of the DMA window 1995which this TCE table will translate - the table will contain one 64 1996bit TCE entry for every 4kiB of the DMA window. 1997 1998When the guest issues an H_PUT_TCE hcall on a liobn for which a TCE 1999table has been created using this ioctl(), the kernel will handle it 2000in real mode, updating the TCE table. H_PUT_TCE calls for other 2001liobns will cause a vm exit and must be handled by userspace. 2002 2003The return value is a file descriptor which can be passed to mmap(2) 2004to map the created TCE table into userspace. This lets userspace read 2005the entries written by kernel-handled H_PUT_TCE calls, and also lets 2006userspace update the TCE table directly which is useful in some 2007circumstances. 2008 2009 20104.63 KVM_ALLOCATE_RMA 2011--------------------- 2012 2013:Capability: KVM_CAP_PPC_RMA 2014:Architectures: powerpc 2015:Type: vm ioctl 2016:Parameters: struct kvm_allocate_rma (out) 2017:Returns: file descriptor for mapping the allocated RMA 2018 2019This allocates a Real Mode Area (RMA) from the pool allocated at boot 2020time by the kernel. An RMA is a physically-contiguous, aligned region 2021of memory used on older POWER processors to provide the memory which 2022will be accessed by real-mode (MMU off) accesses in a KVM guest. 2023POWER processors support a set of sizes for the RMA that usually 2024includes 64MB, 128MB, 256MB and some larger powers of two. 2025 2026:: 2027 2028 /* for KVM_ALLOCATE_RMA */ 2029 struct kvm_allocate_rma { 2030 __u64 rma_size; 2031 }; 2032 2033The return value is a file descriptor which can be passed to mmap(2) 2034to map the allocated RMA into userspace. The mapped area can then be 2035passed to the KVM_SET_USER_MEMORY_REGION ioctl to establish it as the 2036RMA for a virtual machine. The size of the RMA in bytes (which is 2037fixed at host kernel boot time) is returned in the rma_size field of 2038the argument structure. 2039 2040The KVM_CAP_PPC_RMA capability is 1 or 2 if the KVM_ALLOCATE_RMA ioctl 2041is supported; 2 if the processor requires all virtual machines to have 2042an RMA, or 1 if the processor can use an RMA but doesn't require it, 2043because it supports the Virtual RMA (VRMA) facility. 2044 2045 20464.64 KVM_NMI 2047------------ 2048 2049:Capability: KVM_CAP_USER_NMI 2050:Architectures: x86 2051:Type: vcpu ioctl 2052:Parameters: none 2053:Returns: 0 on success, -1 on error 2054 2055Queues an NMI on the thread's vcpu. Note this is well defined only 2056when KVM_CREATE_IRQCHIP has not been called, since this is an interface 2057between the virtual cpu core and virtual local APIC. After KVM_CREATE_IRQCHIP 2058has been called, this interface is completely emulated within the kernel. 2059 2060To use this to emulate the LINT1 input with KVM_CREATE_IRQCHIP, use the 2061following algorithm: 2062 2063 - pause the vcpu 2064 - read the local APIC's state (KVM_GET_LAPIC) 2065 - check whether changing LINT1 will queue an NMI (see the LVT entry for LINT1) 2066 - if so, issue KVM_NMI 2067 - resume the vcpu 2068 2069Some guests configure the LINT1 NMI input to cause a panic, aiding in 2070debugging. 2071 2072 20734.65 KVM_S390_UCAS_MAP 2074---------------------- 2075 2076:Capability: KVM_CAP_S390_UCONTROL 2077:Architectures: s390 2078:Type: vcpu ioctl 2079:Parameters: struct kvm_s390_ucas_mapping (in) 2080:Returns: 0 in case of success 2081 2082The parameter is defined like this:: 2083 2084 struct kvm_s390_ucas_mapping { 2085 __u64 user_addr; 2086 __u64 vcpu_addr; 2087 __u64 length; 2088 }; 2089 2090This ioctl maps the memory at "user_addr" with the length "length" to 2091the vcpu's address space starting at "vcpu_addr". All parameters need to 2092be aligned by 1 megabyte. 2093 2094 20954.66 KVM_S390_UCAS_UNMAP 2096------------------------ 2097 2098:Capability: KVM_CAP_S390_UCONTROL 2099:Architectures: s390 2100:Type: vcpu ioctl 2101:Parameters: struct kvm_s390_ucas_mapping (in) 2102:Returns: 0 in case of success 2103 2104The parameter is defined like this:: 2105 2106 struct kvm_s390_ucas_mapping { 2107 __u64 user_addr; 2108 __u64 vcpu_addr; 2109 __u64 length; 2110 }; 2111 2112This ioctl unmaps the memory in the vcpu's address space starting at 2113"vcpu_addr" with the length "length". The field "user_addr" is ignored. 2114All parameters need to be aligned by 1 megabyte. 2115 2116 21174.67 KVM_S390_VCPU_FAULT 2118------------------------ 2119 2120:Capability: KVM_CAP_S390_UCONTROL 2121:Architectures: s390 2122:Type: vcpu ioctl 2123:Parameters: vcpu absolute address (in) 2124:Returns: 0 in case of success 2125 2126This call creates a page table entry on the virtual cpu's address space 2127(for user controlled virtual machines) or the virtual machine's address 2128space (for regular virtual machines). This only works for minor faults, 2129thus it's recommended to access subject memory page via the user page 2130table upfront. This is useful to handle validity intercepts for user 2131controlled virtual machines to fault in the virtual cpu's lowcore pages 2132prior to calling the KVM_RUN ioctl. 2133 2134 21354.68 KVM_SET_ONE_REG 2136-------------------- 2137 2138:Capability: KVM_CAP_ONE_REG 2139:Architectures: all 2140:Type: vcpu ioctl 2141:Parameters: struct kvm_one_reg (in) 2142:Returns: 0 on success, negative value on failure 2143 2144Errors: 2145 2146 ====== ============================================================ 2147 ENOENT no such register 2148 EINVAL invalid register ID, or no such register or used with VMs in 2149 protected virtualization mode on s390 2150 EPERM (arm64) register access not allowed before vcpu finalization 2151 ====== ============================================================ 2152 2153(These error codes are indicative only: do not rely on a specific error 2154code being returned in a specific situation.) 2155 2156:: 2157 2158 struct kvm_one_reg { 2159 __u64 id; 2160 __u64 addr; 2161 }; 2162 2163Using this ioctl, a single vcpu register can be set to a specific value 2164defined by user space with the passed in struct kvm_one_reg, where id 2165refers to the register identifier as described below and addr is a pointer 2166to a variable with the respective size. There can be architecture agnostic 2167and architecture specific registers. Each have their own range of operation 2168and their own constants and width. To keep track of the implemented 2169registers, find a list below: 2170 2171 ======= =============================== ============ 2172 Arch Register Width (bits) 2173 ======= =============================== ============ 2174 PPC KVM_REG_PPC_HIOR 64 2175 PPC KVM_REG_PPC_IAC1 64 2176 PPC KVM_REG_PPC_IAC2 64 2177 PPC KVM_REG_PPC_IAC3 64 2178 PPC KVM_REG_PPC_IAC4 64 2179 PPC KVM_REG_PPC_DAC1 64 2180 PPC KVM_REG_PPC_DAC2 64 2181 PPC KVM_REG_PPC_DABR 64 2182 PPC KVM_REG_PPC_DSCR 64 2183 PPC KVM_REG_PPC_PURR 64 2184 PPC KVM_REG_PPC_SPURR 64 2185 PPC KVM_REG_PPC_DAR 64 2186 PPC KVM_REG_PPC_DSISR 32 2187 PPC KVM_REG_PPC_AMR 64 2188 PPC KVM_REG_PPC_UAMOR 64 2189 PPC KVM_REG_PPC_MMCR0 64 2190 PPC KVM_REG_PPC_MMCR1 64 2191 PPC KVM_REG_PPC_MMCRA 64 2192 PPC KVM_REG_PPC_MMCR2 64 2193 PPC KVM_REG_PPC_MMCRS 64 2194 PPC KVM_REG_PPC_MMCR3 64 2195 PPC KVM_REG_PPC_SIAR 64 2196 PPC KVM_REG_PPC_SDAR 64 2197 PPC KVM_REG_PPC_SIER 64 2198 PPC KVM_REG_PPC_SIER2 64 2199 PPC KVM_REG_PPC_SIER3 64 2200 PPC KVM_REG_PPC_PMC1 32 2201 PPC KVM_REG_PPC_PMC2 32 2202 PPC KVM_REG_PPC_PMC3 32 2203 PPC KVM_REG_PPC_PMC4 32 2204 PPC KVM_REG_PPC_PMC5 32 2205 PPC KVM_REG_PPC_PMC6 32 2206 PPC KVM_REG_PPC_PMC7 32 2207 PPC KVM_REG_PPC_PMC8 32 2208 PPC KVM_REG_PPC_FPR0 64 2209 ... 2210 PPC KVM_REG_PPC_FPR31 64 2211 PPC KVM_REG_PPC_VR0 128 2212 ... 2213 PPC KVM_REG_PPC_VR31 128 2214 PPC KVM_REG_PPC_VSR0 128 2215 ... 2216 PPC KVM_REG_PPC_VSR31 128 2217 PPC KVM_REG_PPC_FPSCR 64 2218 PPC KVM_REG_PPC_VSCR 32 2219 PPC KVM_REG_PPC_VPA_ADDR 64 2220 PPC KVM_REG_PPC_VPA_SLB 128 2221 PPC KVM_REG_PPC_VPA_DTL 128 2222 PPC KVM_REG_PPC_EPCR 32 2223 PPC KVM_REG_PPC_EPR 32 2224 PPC KVM_REG_PPC_TCR 32 2225 PPC KVM_REG_PPC_TSR 32 2226 PPC KVM_REG_PPC_OR_TSR 32 2227 PPC KVM_REG_PPC_CLEAR_TSR 32 2228 PPC KVM_REG_PPC_MAS0 32 2229 PPC KVM_REG_PPC_MAS1 32 2230 PPC KVM_REG_PPC_MAS2 64 2231 PPC KVM_REG_PPC_MAS7_3 64 2232 PPC KVM_REG_PPC_MAS4 32 2233 PPC KVM_REG_PPC_MAS6 32 2234 PPC KVM_REG_PPC_MMUCFG 32 2235 PPC KVM_REG_PPC_TLB0CFG 32 2236 PPC KVM_REG_PPC_TLB1CFG 32 2237 PPC KVM_REG_PPC_TLB2CFG 32 2238 PPC KVM_REG_PPC_TLB3CFG 32 2239 PPC KVM_REG_PPC_TLB0PS 32 2240 PPC KVM_REG_PPC_TLB1PS 32 2241 PPC KVM_REG_PPC_TLB2PS 32 2242 PPC KVM_REG_PPC_TLB3PS 32 2243 PPC KVM_REG_PPC_EPTCFG 32 2244 PPC KVM_REG_PPC_ICP_STATE 64 2245 PPC KVM_REG_PPC_VP_STATE 128 2246 PPC KVM_REG_PPC_TB_OFFSET 64 2247 PPC KVM_REG_PPC_SPMC1 32 2248 PPC KVM_REG_PPC_SPMC2 32 2249 PPC KVM_REG_PPC_IAMR 64 2250 PPC KVM_REG_PPC_TFHAR 64 2251 PPC KVM_REG_PPC_TFIAR 64 2252 PPC KVM_REG_PPC_TEXASR 64 2253 PPC KVM_REG_PPC_FSCR 64 2254 PPC KVM_REG_PPC_PSPB 32 2255 PPC KVM_REG_PPC_EBBHR 64 2256 PPC KVM_REG_PPC_EBBRR 64 2257 PPC KVM_REG_PPC_BESCR 64 2258 PPC KVM_REG_PPC_TAR 64 2259 PPC KVM_REG_PPC_DPDES 64 2260 PPC KVM_REG_PPC_DAWR 64 2261 PPC KVM_REG_PPC_DAWRX 64 2262 PPC KVM_REG_PPC_CIABR 64 2263 PPC KVM_REG_PPC_IC 64 2264 PPC KVM_REG_PPC_VTB 64 2265 PPC KVM_REG_PPC_CSIGR 64 2266 PPC KVM_REG_PPC_TACR 64 2267 PPC KVM_REG_PPC_TCSCR 64 2268 PPC KVM_REG_PPC_PID 64 2269 PPC KVM_REG_PPC_ACOP 64 2270 PPC KVM_REG_PPC_VRSAVE 32 2271 PPC KVM_REG_PPC_LPCR 32 2272 PPC KVM_REG_PPC_LPCR_64 64 2273 PPC KVM_REG_PPC_PPR 64 2274 PPC KVM_REG_PPC_ARCH_COMPAT 32 2275 PPC KVM_REG_PPC_DABRX 32 2276 PPC KVM_REG_PPC_WORT 64 2277 PPC KVM_REG_PPC_SPRG9 64 2278 PPC KVM_REG_PPC_DBSR 32 2279 PPC KVM_REG_PPC_TIDR 64 2280 PPC KVM_REG_PPC_PSSCR 64 2281 PPC KVM_REG_PPC_DEC_EXPIRY 64 2282 PPC KVM_REG_PPC_PTCR 64 2283 PPC KVM_REG_PPC_DAWR1 64 2284 PPC KVM_REG_PPC_DAWRX1 64 2285 PPC KVM_REG_PPC_TM_GPR0 64 2286 ... 2287 PPC KVM_REG_PPC_TM_GPR31 64 2288 PPC KVM_REG_PPC_TM_VSR0 128 2289 ... 2290 PPC KVM_REG_PPC_TM_VSR63 128 2291 PPC KVM_REG_PPC_TM_CR 64 2292 PPC KVM_REG_PPC_TM_LR 64 2293 PPC KVM_REG_PPC_TM_CTR 64 2294 PPC KVM_REG_PPC_TM_FPSCR 64 2295 PPC KVM_REG_PPC_TM_AMR 64 2296 PPC KVM_REG_PPC_TM_PPR 64 2297 PPC KVM_REG_PPC_TM_VRSAVE 64 2298 PPC KVM_REG_PPC_TM_VSCR 32 2299 PPC KVM_REG_PPC_TM_DSCR 64 2300 PPC KVM_REG_PPC_TM_TAR 64 2301 PPC KVM_REG_PPC_TM_XER 64 2302 2303 MIPS KVM_REG_MIPS_R0 64 2304 ... 2305 MIPS KVM_REG_MIPS_R31 64 2306 MIPS KVM_REG_MIPS_HI 64 2307 MIPS KVM_REG_MIPS_LO 64 2308 MIPS KVM_REG_MIPS_PC 64 2309 MIPS KVM_REG_MIPS_CP0_INDEX 32 2310 MIPS KVM_REG_MIPS_CP0_ENTRYLO0 64 2311 MIPS KVM_REG_MIPS_CP0_ENTRYLO1 64 2312 MIPS KVM_REG_MIPS_CP0_CONTEXT 64 2313 MIPS KVM_REG_MIPS_CP0_CONTEXTCONFIG 32 2314 MIPS KVM_REG_MIPS_CP0_USERLOCAL 64 2315 MIPS KVM_REG_MIPS_CP0_XCONTEXTCONFIG 64 2316 MIPS KVM_REG_MIPS_CP0_PAGEMASK 32 2317 MIPS KVM_REG_MIPS_CP0_PAGEGRAIN 32 2318 MIPS KVM_REG_MIPS_CP0_SEGCTL0 64 2319 MIPS KVM_REG_MIPS_CP0_SEGCTL1 64 2320 MIPS KVM_REG_MIPS_CP0_SEGCTL2 64 2321 MIPS KVM_REG_MIPS_CP0_PWBASE 64 2322 MIPS KVM_REG_MIPS_CP0_PWFIELD 64 2323 MIPS KVM_REG_MIPS_CP0_PWSIZE 64 2324 MIPS KVM_REG_MIPS_CP0_WIRED 32 2325 MIPS KVM_REG_MIPS_CP0_PWCTL 32 2326 MIPS KVM_REG_MIPS_CP0_HWRENA 32 2327 MIPS KVM_REG_MIPS_CP0_BADVADDR 64 2328 MIPS KVM_REG_MIPS_CP0_BADINSTR 32 2329 MIPS KVM_REG_MIPS_CP0_BADINSTRP 32 2330 MIPS KVM_REG_MIPS_CP0_COUNT 32 2331 MIPS KVM_REG_MIPS_CP0_ENTRYHI 64 2332 MIPS KVM_REG_MIPS_CP0_COMPARE 32 2333 MIPS KVM_REG_MIPS_CP0_STATUS 32 2334 MIPS KVM_REG_MIPS_CP0_INTCTL 32 2335 MIPS KVM_REG_MIPS_CP0_CAUSE 32 2336 MIPS KVM_REG_MIPS_CP0_EPC 64 2337 MIPS KVM_REG_MIPS_CP0_PRID 32 2338 MIPS KVM_REG_MIPS_CP0_EBASE 64 2339 MIPS KVM_REG_MIPS_CP0_CONFIG 32 2340 MIPS KVM_REG_MIPS_CP0_CONFIG1 32 2341 MIPS KVM_REG_MIPS_CP0_CONFIG2 32 2342 MIPS KVM_REG_MIPS_CP0_CONFIG3 32 2343 MIPS KVM_REG_MIPS_CP0_CONFIG4 32 2344 MIPS KVM_REG_MIPS_CP0_CONFIG5 32 2345 MIPS KVM_REG_MIPS_CP0_CONFIG7 32 2346 MIPS KVM_REG_MIPS_CP0_XCONTEXT 64 2347 MIPS KVM_REG_MIPS_CP0_ERROREPC 64 2348 MIPS KVM_REG_MIPS_CP0_KSCRATCH1 64 2349 MIPS KVM_REG_MIPS_CP0_KSCRATCH2 64 2350 MIPS KVM_REG_MIPS_CP0_KSCRATCH3 64 2351 MIPS KVM_REG_MIPS_CP0_KSCRATCH4 64 2352 MIPS KVM_REG_MIPS_CP0_KSCRATCH5 64 2353 MIPS KVM_REG_MIPS_CP0_KSCRATCH6 64 2354 MIPS KVM_REG_MIPS_CP0_MAAR(0..63) 64 2355 MIPS KVM_REG_MIPS_COUNT_CTL 64 2356 MIPS KVM_REG_MIPS_COUNT_RESUME 64 2357 MIPS KVM_REG_MIPS_COUNT_HZ 64 2358 MIPS KVM_REG_MIPS_FPR_32(0..31) 32 2359 MIPS KVM_REG_MIPS_FPR_64(0..31) 64 2360 MIPS KVM_REG_MIPS_VEC_128(0..31) 128 2361 MIPS KVM_REG_MIPS_FCR_IR 32 2362 MIPS KVM_REG_MIPS_FCR_CSR 32 2363 MIPS KVM_REG_MIPS_MSA_IR 32 2364 MIPS KVM_REG_MIPS_MSA_CSR 32 2365 ======= =============================== ============ 2366 2367ARM registers are mapped using the lower 32 bits. The upper 16 of that 2368is the register group type, or coprocessor number: 2369 2370ARM core registers have the following id bit patterns:: 2371 2372 0x4020 0000 0010 <index into the kvm_regs struct:16> 2373 2374ARM 32-bit CP15 registers have the following id bit patterns:: 2375 2376 0x4020 0000 000F <zero:1> <crn:4> <crm:4> <opc1:4> <opc2:3> 2377 2378ARM 64-bit CP15 registers have the following id bit patterns:: 2379 2380 0x4030 0000 000F <zero:1> <zero:4> <crm:4> <opc1:4> <zero:3> 2381 2382ARM CCSIDR registers are demultiplexed by CSSELR value:: 2383 2384 0x4020 0000 0011 00 <csselr:8> 2385 2386ARM 32-bit VFP control registers have the following id bit patterns:: 2387 2388 0x4020 0000 0012 1 <regno:12> 2389 2390ARM 64-bit FP registers have the following id bit patterns:: 2391 2392 0x4030 0000 0012 0 <regno:12> 2393 2394ARM firmware pseudo-registers have the following bit pattern:: 2395 2396 0x4030 0000 0014 <regno:16> 2397 2398 2399arm64 registers are mapped using the lower 32 bits. The upper 16 of 2400that is the register group type, or coprocessor number: 2401 2402arm64 core/FP-SIMD registers have the following id bit patterns. Note 2403that the size of the access is variable, as the kvm_regs structure 2404contains elements ranging from 32 to 128 bits. The index is a 32bit 2405value in the kvm_regs structure seen as a 32bit array:: 2406 2407 0x60x0 0000 0010 <index into the kvm_regs struct:16> 2408 2409Specifically: 2410 2411======================= ========= ===== ======================================= 2412 Encoding Register Bits kvm_regs member 2413======================= ========= ===== ======================================= 2414 0x6030 0000 0010 0000 X0 64 regs.regs[0] 2415 0x6030 0000 0010 0002 X1 64 regs.regs[1] 2416 ... 2417 0x6030 0000 0010 003c X30 64 regs.regs[30] 2418 0x6030 0000 0010 003e SP 64 regs.sp 2419 0x6030 0000 0010 0040 PC 64 regs.pc 2420 0x6030 0000 0010 0042 PSTATE 64 regs.pstate 2421 0x6030 0000 0010 0044 SP_EL1 64 sp_el1 2422 0x6030 0000 0010 0046 ELR_EL1 64 elr_el1 2423 0x6030 0000 0010 0048 SPSR_EL1 64 spsr[KVM_SPSR_EL1] (alias SPSR_SVC) 2424 0x6030 0000 0010 004a SPSR_ABT 64 spsr[KVM_SPSR_ABT] 2425 0x6030 0000 0010 004c SPSR_UND 64 spsr[KVM_SPSR_UND] 2426 0x6030 0000 0010 004e SPSR_IRQ 64 spsr[KVM_SPSR_IRQ] 2427 0x6060 0000 0010 0050 SPSR_FIQ 64 spsr[KVM_SPSR_FIQ] 2428 0x6040 0000 0010 0054 V0 128 fp_regs.vregs[0] [1]_ 2429 0x6040 0000 0010 0058 V1 128 fp_regs.vregs[1] [1]_ 2430 ... 2431 0x6040 0000 0010 00d0 V31 128 fp_regs.vregs[31] [1]_ 2432 0x6020 0000 0010 00d4 FPSR 32 fp_regs.fpsr 2433 0x6020 0000 0010 00d5 FPCR 32 fp_regs.fpcr 2434======================= ========= ===== ======================================= 2435 2436.. [1] These encodings are not accepted for SVE-enabled vcpus. See 2437 KVM_ARM_VCPU_INIT. 2438 2439 The equivalent register content can be accessed via bits [127:0] of 2440 the corresponding SVE Zn registers instead for vcpus that have SVE 2441 enabled (see below). 2442 2443arm64 CCSIDR registers are demultiplexed by CSSELR value:: 2444 2445 0x6020 0000 0011 00 <csselr:8> 2446 2447arm64 system registers have the following id bit patterns:: 2448 2449 0x6030 0000 0013 <op0:2> <op1:3> <crn:4> <crm:4> <op2:3> 2450 2451.. warning:: 2452 2453 Two system register IDs do not follow the specified pattern. These 2454 are KVM_REG_ARM_TIMER_CVAL and KVM_REG_ARM_TIMER_CNT, which map to 2455 system registers CNTV_CVAL_EL0 and CNTVCT_EL0 respectively. These 2456 two had their values accidentally swapped, which means TIMER_CVAL is 2457 derived from the register encoding for CNTVCT_EL0 and TIMER_CNT is 2458 derived from the register encoding for CNTV_CVAL_EL0. As this is 2459 API, it must remain this way. 2460 2461arm64 firmware pseudo-registers have the following bit pattern:: 2462 2463 0x6030 0000 0014 <regno:16> 2464 2465arm64 SVE registers have the following bit patterns:: 2466 2467 0x6080 0000 0015 00 <n:5> <slice:5> Zn bits[2048*slice + 2047 : 2048*slice] 2468 0x6050 0000 0015 04 <n:4> <slice:5> Pn bits[256*slice + 255 : 256*slice] 2469 0x6050 0000 0015 060 <slice:5> FFR bits[256*slice + 255 : 256*slice] 2470 0x6060 0000 0015 ffff KVM_REG_ARM64_SVE_VLS pseudo-register 2471 2472Access to register IDs where 2048 * slice >= 128 * max_vq will fail with 2473ENOENT. max_vq is the vcpu's maximum supported vector length in 128-bit 2474quadwords: see [2]_ below. 2475 2476These registers are only accessible on vcpus for which SVE is enabled. 2477See KVM_ARM_VCPU_INIT for details. 2478 2479In addition, except for KVM_REG_ARM64_SVE_VLS, these registers are not 2480accessible until the vcpu's SVE configuration has been finalized 2481using KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE). See KVM_ARM_VCPU_INIT 2482and KVM_ARM_VCPU_FINALIZE for more information about this procedure. 2483 2484KVM_REG_ARM64_SVE_VLS is a pseudo-register that allows the set of vector 2485lengths supported by the vcpu to be discovered and configured by 2486userspace. When transferred to or from user memory via KVM_GET_ONE_REG 2487or KVM_SET_ONE_REG, the value of this register is of type 2488__u64[KVM_ARM64_SVE_VLS_WORDS], and encodes the set of vector lengths as 2489follows:: 2490 2491 __u64 vector_lengths[KVM_ARM64_SVE_VLS_WORDS]; 2492 2493 if (vq >= SVE_VQ_MIN && vq <= SVE_VQ_MAX && 2494 ((vector_lengths[(vq - KVM_ARM64_SVE_VQ_MIN) / 64] >> 2495 ((vq - KVM_ARM64_SVE_VQ_MIN) % 64)) & 1)) 2496 /* Vector length vq * 16 bytes supported */ 2497 else 2498 /* Vector length vq * 16 bytes not supported */ 2499 2500.. [2] The maximum value vq for which the above condition is true is 2501 max_vq. This is the maximum vector length available to the guest on 2502 this vcpu, and determines which register slices are visible through 2503 this ioctl interface. 2504 2505(See Documentation/arm64/sve.rst for an explanation of the "vq" 2506nomenclature.) 2507 2508KVM_REG_ARM64_SVE_VLS is only accessible after KVM_ARM_VCPU_INIT. 2509KVM_ARM_VCPU_INIT initialises it to the best set of vector lengths that 2510the host supports. 2511 2512Userspace may subsequently modify it if desired until the vcpu's SVE 2513configuration is finalized using KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE). 2514 2515Apart from simply removing all vector lengths from the host set that 2516exceed some value, support for arbitrarily chosen sets of vector lengths 2517is hardware-dependent and may not be available. Attempting to configure 2518an invalid set of vector lengths via KVM_SET_ONE_REG will fail with 2519EINVAL. 2520 2521After the vcpu's SVE configuration is finalized, further attempts to 2522write this register will fail with EPERM. 2523 2524 2525MIPS registers are mapped using the lower 32 bits. The upper 16 of that is 2526the register group type: 2527 2528MIPS core registers (see above) have the following id bit patterns:: 2529 2530 0x7030 0000 0000 <reg:16> 2531 2532MIPS CP0 registers (see KVM_REG_MIPS_CP0_* above) have the following id bit 2533patterns depending on whether they're 32-bit or 64-bit registers:: 2534 2535 0x7020 0000 0001 00 <reg:5> <sel:3> (32-bit) 2536 0x7030 0000 0001 00 <reg:5> <sel:3> (64-bit) 2537 2538Note: KVM_REG_MIPS_CP0_ENTRYLO0 and KVM_REG_MIPS_CP0_ENTRYLO1 are the MIPS64 2539versions of the EntryLo registers regardless of the word size of the host 2540hardware, host kernel, guest, and whether XPA is present in the guest, i.e. 2541with the RI and XI bits (if they exist) in bits 63 and 62 respectively, and 2542the PFNX field starting at bit 30. 2543 2544MIPS MAARs (see KVM_REG_MIPS_CP0_MAAR(*) above) have the following id bit 2545patterns:: 2546 2547 0x7030 0000 0001 01 <reg:8> 2548 2549MIPS KVM control registers (see above) have the following id bit patterns:: 2550 2551 0x7030 0000 0002 <reg:16> 2552 2553MIPS FPU registers (see KVM_REG_MIPS_FPR_{32,64}() above) have the following 2554id bit patterns depending on the size of the register being accessed. They are 2555always accessed according to the current guest FPU mode (Status.FR and 2556Config5.FRE), i.e. as the guest would see them, and they become unpredictable 2557if the guest FPU mode is changed. MIPS SIMD Architecture (MSA) vector 2558registers (see KVM_REG_MIPS_VEC_128() above) have similar patterns as they 2559overlap the FPU registers:: 2560 2561 0x7020 0000 0003 00 <0:3> <reg:5> (32-bit FPU registers) 2562 0x7030 0000 0003 00 <0:3> <reg:5> (64-bit FPU registers) 2563 0x7040 0000 0003 00 <0:3> <reg:5> (128-bit MSA vector registers) 2564 2565MIPS FPU control registers (see KVM_REG_MIPS_FCR_{IR,CSR} above) have the 2566following id bit patterns:: 2567 2568 0x7020 0000 0003 01 <0:3> <reg:5> 2569 2570MIPS MSA control registers (see KVM_REG_MIPS_MSA_{IR,CSR} above) have the 2571following id bit patterns:: 2572 2573 0x7020 0000 0003 02 <0:3> <reg:5> 2574 2575 25764.69 KVM_GET_ONE_REG 2577-------------------- 2578 2579:Capability: KVM_CAP_ONE_REG 2580:Architectures: all 2581:Type: vcpu ioctl 2582:Parameters: struct kvm_one_reg (in and out) 2583:Returns: 0 on success, negative value on failure 2584 2585Errors include: 2586 2587 ======== ============================================================ 2588 ENOENT no such register 2589 EINVAL invalid register ID, or no such register or used with VMs in 2590 protected virtualization mode on s390 2591 EPERM (arm64) register access not allowed before vcpu finalization 2592 ======== ============================================================ 2593 2594(These error codes are indicative only: do not rely on a specific error 2595code being returned in a specific situation.) 2596 2597This ioctl allows to receive the value of a single register implemented 2598in a vcpu. The register to read is indicated by the "id" field of the 2599kvm_one_reg struct passed in. On success, the register value can be found 2600at the memory location pointed to by "addr". 2601 2602The list of registers accessible using this interface is identical to the 2603list in 4.68. 2604 2605 26064.70 KVM_KVMCLOCK_CTRL 2607---------------------- 2608 2609:Capability: KVM_CAP_KVMCLOCK_CTRL 2610:Architectures: Any that implement pvclocks (currently x86 only) 2611:Type: vcpu ioctl 2612:Parameters: None 2613:Returns: 0 on success, -1 on error 2614 2615This ioctl sets a flag accessible to the guest indicating that the specified 2616vCPU has been paused by the host userspace. 2617 2618The host will set a flag in the pvclock structure that is checked from the 2619soft lockup watchdog. The flag is part of the pvclock structure that is 2620shared between guest and host, specifically the second bit of the flags 2621field of the pvclock_vcpu_time_info structure. It will be set exclusively by 2622the host and read/cleared exclusively by the guest. The guest operation of 2623checking and clearing the flag must be an atomic operation so 2624load-link/store-conditional, or equivalent must be used. There are two cases 2625where the guest will clear the flag: when the soft lockup watchdog timer resets 2626itself or when a soft lockup is detected. This ioctl can be called any time 2627after pausing the vcpu, but before it is resumed. 2628 2629 26304.71 KVM_SIGNAL_MSI 2631------------------- 2632 2633:Capability: KVM_CAP_SIGNAL_MSI 2634:Architectures: x86 arm arm64 2635:Type: vm ioctl 2636:Parameters: struct kvm_msi (in) 2637:Returns: >0 on delivery, 0 if guest blocked the MSI, and -1 on error 2638 2639Directly inject a MSI message. Only valid with in-kernel irqchip that handles 2640MSI messages. 2641 2642:: 2643 2644 struct kvm_msi { 2645 __u32 address_lo; 2646 __u32 address_hi; 2647 __u32 data; 2648 __u32 flags; 2649 __u32 devid; 2650 __u8 pad[12]; 2651 }; 2652 2653flags: 2654 KVM_MSI_VALID_DEVID: devid contains a valid value. The per-VM 2655 KVM_CAP_MSI_DEVID capability advertises the requirement to provide 2656 the device ID. If this capability is not available, userspace 2657 should never set the KVM_MSI_VALID_DEVID flag as the ioctl might fail. 2658 2659If KVM_MSI_VALID_DEVID is set, devid contains a unique device identifier 2660for the device that wrote the MSI message. For PCI, this is usually a 2661BFD identifier in the lower 16 bits. 2662 2663On x86, address_hi is ignored unless the KVM_X2APIC_API_USE_32BIT_IDS 2664feature of KVM_CAP_X2APIC_API capability is enabled. If it is enabled, 2665address_hi bits 31-8 provide bits 31-8 of the destination id. Bits 7-0 of 2666address_hi must be zero. 2667 2668 26694.71 KVM_CREATE_PIT2 2670-------------------- 2671 2672:Capability: KVM_CAP_PIT2 2673:Architectures: x86 2674:Type: vm ioctl 2675:Parameters: struct kvm_pit_config (in) 2676:Returns: 0 on success, -1 on error 2677 2678Creates an in-kernel device model for the i8254 PIT. This call is only valid 2679after enabling in-kernel irqchip support via KVM_CREATE_IRQCHIP. The following 2680parameters have to be passed:: 2681 2682 struct kvm_pit_config { 2683 __u32 flags; 2684 __u32 pad[15]; 2685 }; 2686 2687Valid flags are:: 2688 2689 #define KVM_PIT_SPEAKER_DUMMY 1 /* emulate speaker port stub */ 2690 2691PIT timer interrupts may use a per-VM kernel thread for injection. If it 2692exists, this thread will have a name of the following pattern:: 2693 2694 kvm-pit/<owner-process-pid> 2695 2696When running a guest with elevated priorities, the scheduling parameters of 2697this thread may have to be adjusted accordingly. 2698 2699This IOCTL replaces the obsolete KVM_CREATE_PIT. 2700 2701 27024.72 KVM_GET_PIT2 2703----------------- 2704 2705:Capability: KVM_CAP_PIT_STATE2 2706:Architectures: x86 2707:Type: vm ioctl 2708:Parameters: struct kvm_pit_state2 (out) 2709:Returns: 0 on success, -1 on error 2710 2711Retrieves the state of the in-kernel PIT model. Only valid after 2712KVM_CREATE_PIT2. The state is returned in the following structure:: 2713 2714 struct kvm_pit_state2 { 2715 struct kvm_pit_channel_state channels[3]; 2716 __u32 flags; 2717 __u32 reserved[9]; 2718 }; 2719 2720Valid flags are:: 2721 2722 /* disable PIT in HPET legacy mode */ 2723 #define KVM_PIT_FLAGS_HPET_LEGACY 0x00000001 2724 2725This IOCTL replaces the obsolete KVM_GET_PIT. 2726 2727 27284.73 KVM_SET_PIT2 2729----------------- 2730 2731:Capability: KVM_CAP_PIT_STATE2 2732:Architectures: x86 2733:Type: vm ioctl 2734:Parameters: struct kvm_pit_state2 (in) 2735:Returns: 0 on success, -1 on error 2736 2737Sets the state of the in-kernel PIT model. Only valid after KVM_CREATE_PIT2. 2738See KVM_GET_PIT2 for details on struct kvm_pit_state2. 2739 2740This IOCTL replaces the obsolete KVM_SET_PIT. 2741 2742 27434.74 KVM_PPC_GET_SMMU_INFO 2744-------------------------- 2745 2746:Capability: KVM_CAP_PPC_GET_SMMU_INFO 2747:Architectures: powerpc 2748:Type: vm ioctl 2749:Parameters: None 2750:Returns: 0 on success, -1 on error 2751 2752This populates and returns a structure describing the features of 2753the "Server" class MMU emulation supported by KVM. 2754This can in turn be used by userspace to generate the appropriate 2755device-tree properties for the guest operating system. 2756 2757The structure contains some global information, followed by an 2758array of supported segment page sizes:: 2759 2760 struct kvm_ppc_smmu_info { 2761 __u64 flags; 2762 __u32 slb_size; 2763 __u32 pad; 2764 struct kvm_ppc_one_seg_page_size sps[KVM_PPC_PAGE_SIZES_MAX_SZ]; 2765 }; 2766 2767The supported flags are: 2768 2769 - KVM_PPC_PAGE_SIZES_REAL: 2770 When that flag is set, guest page sizes must "fit" the backing 2771 store page sizes. When not set, any page size in the list can 2772 be used regardless of how they are backed by userspace. 2773 2774 - KVM_PPC_1T_SEGMENTS 2775 The emulated MMU supports 1T segments in addition to the 2776 standard 256M ones. 2777 2778 - KVM_PPC_NO_HASH 2779 This flag indicates that HPT guests are not supported by KVM, 2780 thus all guests must use radix MMU mode. 2781 2782The "slb_size" field indicates how many SLB entries are supported 2783 2784The "sps" array contains 8 entries indicating the supported base 2785page sizes for a segment in increasing order. Each entry is defined 2786as follow:: 2787 2788 struct kvm_ppc_one_seg_page_size { 2789 __u32 page_shift; /* Base page shift of segment (or 0) */ 2790 __u32 slb_enc; /* SLB encoding for BookS */ 2791 struct kvm_ppc_one_page_size enc[KVM_PPC_PAGE_SIZES_MAX_SZ]; 2792 }; 2793 2794An entry with a "page_shift" of 0 is unused. Because the array is 2795organized in increasing order, a lookup can stop when encoutering 2796such an entry. 2797 2798The "slb_enc" field provides the encoding to use in the SLB for the 2799page size. The bits are in positions such as the value can directly 2800be OR'ed into the "vsid" argument of the slbmte instruction. 2801 2802The "enc" array is a list which for each of those segment base page 2803size provides the list of supported actual page sizes (which can be 2804only larger or equal to the base page size), along with the 2805corresponding encoding in the hash PTE. Similarly, the array is 28068 entries sorted by increasing sizes and an entry with a "0" shift 2807is an empty entry and a terminator:: 2808 2809 struct kvm_ppc_one_page_size { 2810 __u32 page_shift; /* Page shift (or 0) */ 2811 __u32 pte_enc; /* Encoding in the HPTE (>>12) */ 2812 }; 2813 2814The "pte_enc" field provides a value that can OR'ed into the hash 2815PTE's RPN field (ie, it needs to be shifted left by 12 to OR it 2816into the hash PTE second double word). 2817 28184.75 KVM_IRQFD 2819-------------- 2820 2821:Capability: KVM_CAP_IRQFD 2822:Architectures: x86 s390 arm arm64 2823:Type: vm ioctl 2824:Parameters: struct kvm_irqfd (in) 2825:Returns: 0 on success, -1 on error 2826 2827Allows setting an eventfd to directly trigger a guest interrupt. 2828kvm_irqfd.fd specifies the file descriptor to use as the eventfd and 2829kvm_irqfd.gsi specifies the irqchip pin toggled by this event. When 2830an event is triggered on the eventfd, an interrupt is injected into 2831the guest using the specified gsi pin. The irqfd is removed using 2832the KVM_IRQFD_FLAG_DEASSIGN flag, specifying both kvm_irqfd.fd 2833and kvm_irqfd.gsi. 2834 2835With KVM_CAP_IRQFD_RESAMPLE, KVM_IRQFD supports a de-assert and notify 2836mechanism allowing emulation of level-triggered, irqfd-based 2837interrupts. When KVM_IRQFD_FLAG_RESAMPLE is set the user must pass an 2838additional eventfd in the kvm_irqfd.resamplefd field. When operating 2839in resample mode, posting of an interrupt through kvm_irq.fd asserts 2840the specified gsi in the irqchip. When the irqchip is resampled, such 2841as from an EOI, the gsi is de-asserted and the user is notified via 2842kvm_irqfd.resamplefd. It is the user's responsibility to re-queue 2843the interrupt if the device making use of it still requires service. 2844Note that closing the resamplefd is not sufficient to disable the 2845irqfd. The KVM_IRQFD_FLAG_RESAMPLE is only necessary on assignment 2846and need not be specified with KVM_IRQFD_FLAG_DEASSIGN. 2847 2848On arm/arm64, gsi routing being supported, the following can happen: 2849 2850- in case no routing entry is associated to this gsi, injection fails 2851- in case the gsi is associated to an irqchip routing entry, 2852 irqchip.pin + 32 corresponds to the injected SPI ID. 2853- in case the gsi is associated to an MSI routing entry, the MSI 2854 message and device ID are translated into an LPI (support restricted 2855 to GICv3 ITS in-kernel emulation). 2856 28574.76 KVM_PPC_ALLOCATE_HTAB 2858-------------------------- 2859 2860:Capability: KVM_CAP_PPC_ALLOC_HTAB 2861:Architectures: powerpc 2862:Type: vm ioctl 2863:Parameters: Pointer to u32 containing hash table order (in/out) 2864:Returns: 0 on success, -1 on error 2865 2866This requests the host kernel to allocate an MMU hash table for a 2867guest using the PAPR paravirtualization interface. This only does 2868anything if the kernel is configured to use the Book 3S HV style of 2869virtualization. Otherwise the capability doesn't exist and the ioctl 2870returns an ENOTTY error. The rest of this description assumes Book 3S 2871HV. 2872 2873There must be no vcpus running when this ioctl is called; if there 2874are, it will do nothing and return an EBUSY error. 2875 2876The parameter is a pointer to a 32-bit unsigned integer variable 2877containing the order (log base 2) of the desired size of the hash 2878table, which must be between 18 and 46. On successful return from the 2879ioctl, the value will not be changed by the kernel. 2880 2881If no hash table has been allocated when any vcpu is asked to run 2882(with the KVM_RUN ioctl), the host kernel will allocate a 2883default-sized hash table (16 MB). 2884 2885If this ioctl is called when a hash table has already been allocated, 2886with a different order from the existing hash table, the existing hash 2887table will be freed and a new one allocated. If this is ioctl is 2888called when a hash table has already been allocated of the same order 2889as specified, the kernel will clear out the existing hash table (zero 2890all HPTEs). In either case, if the guest is using the virtualized 2891real-mode area (VRMA) facility, the kernel will re-create the VMRA 2892HPTEs on the next KVM_RUN of any vcpu. 2893 28944.77 KVM_S390_INTERRUPT 2895----------------------- 2896 2897:Capability: basic 2898:Architectures: s390 2899:Type: vm ioctl, vcpu ioctl 2900:Parameters: struct kvm_s390_interrupt (in) 2901:Returns: 0 on success, -1 on error 2902 2903Allows to inject an interrupt to the guest. Interrupts can be floating 2904(vm ioctl) or per cpu (vcpu ioctl), depending on the interrupt type. 2905 2906Interrupt parameters are passed via kvm_s390_interrupt:: 2907 2908 struct kvm_s390_interrupt { 2909 __u32 type; 2910 __u32 parm; 2911 __u64 parm64; 2912 }; 2913 2914type can be one of the following: 2915 2916KVM_S390_SIGP_STOP (vcpu) 2917 - sigp stop; optional flags in parm 2918KVM_S390_PROGRAM_INT (vcpu) 2919 - program check; code in parm 2920KVM_S390_SIGP_SET_PREFIX (vcpu) 2921 - sigp set prefix; prefix address in parm 2922KVM_S390_RESTART (vcpu) 2923 - restart 2924KVM_S390_INT_CLOCK_COMP (vcpu) 2925 - clock comparator interrupt 2926KVM_S390_INT_CPU_TIMER (vcpu) 2927 - CPU timer interrupt 2928KVM_S390_INT_VIRTIO (vm) 2929 - virtio external interrupt; external interrupt 2930 parameters in parm and parm64 2931KVM_S390_INT_SERVICE (vm) 2932 - sclp external interrupt; sclp parameter in parm 2933KVM_S390_INT_EMERGENCY (vcpu) 2934 - sigp emergency; source cpu in parm 2935KVM_S390_INT_EXTERNAL_CALL (vcpu) 2936 - sigp external call; source cpu in parm 2937KVM_S390_INT_IO(ai,cssid,ssid,schid) (vm) 2938 - compound value to indicate an 2939 I/O interrupt (ai - adapter interrupt; cssid,ssid,schid - subchannel); 2940 I/O interruption parameters in parm (subchannel) and parm64 (intparm, 2941 interruption subclass) 2942KVM_S390_MCHK (vm, vcpu) 2943 - machine check interrupt; cr 14 bits in parm, machine check interrupt 2944 code in parm64 (note that machine checks needing further payload are not 2945 supported by this ioctl) 2946 2947This is an asynchronous vcpu ioctl and can be invoked from any thread. 2948 29494.78 KVM_PPC_GET_HTAB_FD 2950------------------------ 2951 2952:Capability: KVM_CAP_PPC_HTAB_FD 2953:Architectures: powerpc 2954:Type: vm ioctl 2955:Parameters: Pointer to struct kvm_get_htab_fd (in) 2956:Returns: file descriptor number (>= 0) on success, -1 on error 2957 2958This returns a file descriptor that can be used either to read out the 2959entries in the guest's hashed page table (HPT), or to write entries to 2960initialize the HPT. The returned fd can only be written to if the 2961KVM_GET_HTAB_WRITE bit is set in the flags field of the argument, and 2962can only be read if that bit is clear. The argument struct looks like 2963this:: 2964 2965 /* For KVM_PPC_GET_HTAB_FD */ 2966 struct kvm_get_htab_fd { 2967 __u64 flags; 2968 __u64 start_index; 2969 __u64 reserved[2]; 2970 }; 2971 2972 /* Values for kvm_get_htab_fd.flags */ 2973 #define KVM_GET_HTAB_BOLTED_ONLY ((__u64)0x1) 2974 #define KVM_GET_HTAB_WRITE ((__u64)0x2) 2975 2976The 'start_index' field gives the index in the HPT of the entry at 2977which to start reading. It is ignored when writing. 2978 2979Reads on the fd will initially supply information about all 2980"interesting" HPT entries. Interesting entries are those with the 2981bolted bit set, if the KVM_GET_HTAB_BOLTED_ONLY bit is set, otherwise 2982all entries. When the end of the HPT is reached, the read() will 2983return. If read() is called again on the fd, it will start again from 2984the beginning of the HPT, but will only return HPT entries that have 2985changed since they were last read. 2986 2987Data read or written is structured as a header (8 bytes) followed by a 2988series of valid HPT entries (16 bytes) each. The header indicates how 2989many valid HPT entries there are and how many invalid entries follow 2990the valid entries. The invalid entries are not represented explicitly 2991in the stream. The header format is:: 2992 2993 struct kvm_get_htab_header { 2994 __u32 index; 2995 __u16 n_valid; 2996 __u16 n_invalid; 2997 }; 2998 2999Writes to the fd create HPT entries starting at the index given in the 3000header; first 'n_valid' valid entries with contents from the data 3001written, then 'n_invalid' invalid entries, invalidating any previously 3002valid entries found. 3003 30044.79 KVM_CREATE_DEVICE 3005---------------------- 3006 3007:Capability: KVM_CAP_DEVICE_CTRL 3008:Type: vm ioctl 3009:Parameters: struct kvm_create_device (in/out) 3010:Returns: 0 on success, -1 on error 3011 3012Errors: 3013 3014 ====== ======================================================= 3015 ENODEV The device type is unknown or unsupported 3016 EEXIST Device already created, and this type of device may not 3017 be instantiated multiple times 3018 ====== ======================================================= 3019 3020 Other error conditions may be defined by individual device types or 3021 have their standard meanings. 3022 3023Creates an emulated device in the kernel. The file descriptor returned 3024in fd can be used with KVM_SET/GET/HAS_DEVICE_ATTR. 3025 3026If the KVM_CREATE_DEVICE_TEST flag is set, only test whether the 3027device type is supported (not necessarily whether it can be created 3028in the current vm). 3029 3030Individual devices should not define flags. Attributes should be used 3031for specifying any behavior that is not implied by the device type 3032number. 3033 3034:: 3035 3036 struct kvm_create_device { 3037 __u32 type; /* in: KVM_DEV_TYPE_xxx */ 3038 __u32 fd; /* out: device handle */ 3039 __u32 flags; /* in: KVM_CREATE_DEVICE_xxx */ 3040 }; 3041 30424.80 KVM_SET_DEVICE_ATTR/KVM_GET_DEVICE_ATTR 3043-------------------------------------------- 3044 3045:Capability: KVM_CAP_DEVICE_CTRL, KVM_CAP_VM_ATTRIBUTES for vm device, 3046 KVM_CAP_VCPU_ATTRIBUTES for vcpu device 3047:Type: device ioctl, vm ioctl, vcpu ioctl 3048:Parameters: struct kvm_device_attr 3049:Returns: 0 on success, -1 on error 3050 3051Errors: 3052 3053 ===== ============================================================= 3054 ENXIO The group or attribute is unknown/unsupported for this device 3055 or hardware support is missing. 3056 EPERM The attribute cannot (currently) be accessed this way 3057 (e.g. read-only attribute, or attribute that only makes 3058 sense when the device is in a different state) 3059 ===== ============================================================= 3060 3061 Other error conditions may be defined by individual device types. 3062 3063Gets/sets a specified piece of device configuration and/or state. The 3064semantics are device-specific. See individual device documentation in 3065the "devices" directory. As with ONE_REG, the size of the data 3066transferred is defined by the particular attribute. 3067 3068:: 3069 3070 struct kvm_device_attr { 3071 __u32 flags; /* no flags currently defined */ 3072 __u32 group; /* device-defined */ 3073 __u64 attr; /* group-defined */ 3074 __u64 addr; /* userspace address of attr data */ 3075 }; 3076 30774.81 KVM_HAS_DEVICE_ATTR 3078------------------------ 3079 3080:Capability: KVM_CAP_DEVICE_CTRL, KVM_CAP_VM_ATTRIBUTES for vm device, 3081 KVM_CAP_VCPU_ATTRIBUTES for vcpu device 3082:Type: device ioctl, vm ioctl, vcpu ioctl 3083:Parameters: struct kvm_device_attr 3084:Returns: 0 on success, -1 on error 3085 3086Errors: 3087 3088 ===== ============================================================= 3089 ENXIO The group or attribute is unknown/unsupported for this device 3090 or hardware support is missing. 3091 ===== ============================================================= 3092 3093Tests whether a device supports a particular attribute. A successful 3094return indicates the attribute is implemented. It does not necessarily 3095indicate that the attribute can be read or written in the device's 3096current state. "addr" is ignored. 3097 30984.82 KVM_ARM_VCPU_INIT 3099---------------------- 3100 3101:Capability: basic 3102:Architectures: arm, arm64 3103:Type: vcpu ioctl 3104:Parameters: struct kvm_vcpu_init (in) 3105:Returns: 0 on success; -1 on error 3106 3107Errors: 3108 3109 ====== ================================================================= 3110 EINVAL the target is unknown, or the combination of features is invalid. 3111 ENOENT a features bit specified is unknown. 3112 ====== ================================================================= 3113 3114This tells KVM what type of CPU to present to the guest, and what 3115optional features it should have. This will cause a reset of the cpu 3116registers to their initial values. If this is not called, KVM_RUN will 3117return ENOEXEC for that vcpu. 3118 3119Note that because some registers reflect machine topology, all vcpus 3120should be created before this ioctl is invoked. 3121 3122Userspace can call this function multiple times for a given vcpu, including 3123after the vcpu has been run. This will reset the vcpu to its initial 3124state. All calls to this function after the initial call must use the same 3125target and same set of feature flags, otherwise EINVAL will be returned. 3126 3127Possible features: 3128 3129 - KVM_ARM_VCPU_POWER_OFF: Starts the CPU in a power-off state. 3130 Depends on KVM_CAP_ARM_PSCI. If not set, the CPU will be powered on 3131 and execute guest code when KVM_RUN is called. 3132 - KVM_ARM_VCPU_EL1_32BIT: Starts the CPU in a 32bit mode. 3133 Depends on KVM_CAP_ARM_EL1_32BIT (arm64 only). 3134 - KVM_ARM_VCPU_PSCI_0_2: Emulate PSCI v0.2 (or a future revision 3135 backward compatible with v0.2) for the CPU. 3136 Depends on KVM_CAP_ARM_PSCI_0_2. 3137 - KVM_ARM_VCPU_PMU_V3: Emulate PMUv3 for the CPU. 3138 Depends on KVM_CAP_ARM_PMU_V3. 3139 3140 - KVM_ARM_VCPU_PTRAUTH_ADDRESS: Enables Address Pointer authentication 3141 for arm64 only. 3142 Depends on KVM_CAP_ARM_PTRAUTH_ADDRESS. 3143 If KVM_CAP_ARM_PTRAUTH_ADDRESS and KVM_CAP_ARM_PTRAUTH_GENERIC are 3144 both present, then both KVM_ARM_VCPU_PTRAUTH_ADDRESS and 3145 KVM_ARM_VCPU_PTRAUTH_GENERIC must be requested or neither must be 3146 requested. 3147 3148 - KVM_ARM_VCPU_PTRAUTH_GENERIC: Enables Generic Pointer authentication 3149 for arm64 only. 3150 Depends on KVM_CAP_ARM_PTRAUTH_GENERIC. 3151 If KVM_CAP_ARM_PTRAUTH_ADDRESS and KVM_CAP_ARM_PTRAUTH_GENERIC are 3152 both present, then both KVM_ARM_VCPU_PTRAUTH_ADDRESS and 3153 KVM_ARM_VCPU_PTRAUTH_GENERIC must be requested or neither must be 3154 requested. 3155 3156 - KVM_ARM_VCPU_SVE: Enables SVE for the CPU (arm64 only). 3157 Depends on KVM_CAP_ARM_SVE. 3158 Requires KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE): 3159 3160 * After KVM_ARM_VCPU_INIT: 3161 3162 - KVM_REG_ARM64_SVE_VLS may be read using KVM_GET_ONE_REG: the 3163 initial value of this pseudo-register indicates the best set of 3164 vector lengths possible for a vcpu on this host. 3165 3166 * Before KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE): 3167 3168 - KVM_RUN and KVM_GET_REG_LIST are not available; 3169 3170 - KVM_GET_ONE_REG and KVM_SET_ONE_REG cannot be used to access 3171 the scalable archietctural SVE registers 3172 KVM_REG_ARM64_SVE_ZREG(), KVM_REG_ARM64_SVE_PREG() or 3173 KVM_REG_ARM64_SVE_FFR; 3174 3175 - KVM_REG_ARM64_SVE_VLS may optionally be written using 3176 KVM_SET_ONE_REG, to modify the set of vector lengths available 3177 for the vcpu. 3178 3179 * After KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE): 3180 3181 - the KVM_REG_ARM64_SVE_VLS pseudo-register is immutable, and can 3182 no longer be written using KVM_SET_ONE_REG. 3183 31844.83 KVM_ARM_PREFERRED_TARGET 3185----------------------------- 3186 3187:Capability: basic 3188:Architectures: arm, arm64 3189:Type: vm ioctl 3190:Parameters: struct kvm_vcpu_init (out) 3191:Returns: 0 on success; -1 on error 3192 3193Errors: 3194 3195 ====== ========================================== 3196 ENODEV no preferred target available for the host 3197 ====== ========================================== 3198 3199This queries KVM for preferred CPU target type which can be emulated 3200by KVM on underlying host. 3201 3202The ioctl returns struct kvm_vcpu_init instance containing information 3203about preferred CPU target type and recommended features for it. The 3204kvm_vcpu_init->features bitmap returned will have feature bits set if 3205the preferred target recommends setting these features, but this is 3206not mandatory. 3207 3208The information returned by this ioctl can be used to prepare an instance 3209of struct kvm_vcpu_init for KVM_ARM_VCPU_INIT ioctl which will result in 3210VCPU matching underlying host. 3211 3212 32134.84 KVM_GET_REG_LIST 3214--------------------- 3215 3216:Capability: basic 3217:Architectures: arm, arm64, mips 3218:Type: vcpu ioctl 3219:Parameters: struct kvm_reg_list (in/out) 3220:Returns: 0 on success; -1 on error 3221 3222Errors: 3223 3224 ===== ============================================================== 3225 E2BIG the reg index list is too big to fit in the array specified by 3226 the user (the number required will be written into n). 3227 ===== ============================================================== 3228 3229:: 3230 3231 struct kvm_reg_list { 3232 __u64 n; /* number of registers in reg[] */ 3233 __u64 reg[0]; 3234 }; 3235 3236This ioctl returns the guest registers that are supported for the 3237KVM_GET_ONE_REG/KVM_SET_ONE_REG calls. 3238 3239 32404.85 KVM_ARM_SET_DEVICE_ADDR (deprecated) 3241----------------------------------------- 3242 3243:Capability: KVM_CAP_ARM_SET_DEVICE_ADDR 3244:Architectures: arm, arm64 3245:Type: vm ioctl 3246:Parameters: struct kvm_arm_device_address (in) 3247:Returns: 0 on success, -1 on error 3248 3249Errors: 3250 3251 ====== ============================================ 3252 ENODEV The device id is unknown 3253 ENXIO Device not supported on current system 3254 EEXIST Address already set 3255 E2BIG Address outside guest physical address space 3256 EBUSY Address overlaps with other device range 3257 ====== ============================================ 3258 3259:: 3260 3261 struct kvm_arm_device_addr { 3262 __u64 id; 3263 __u64 addr; 3264 }; 3265 3266Specify a device address in the guest's physical address space where guests 3267can access emulated or directly exposed devices, which the host kernel needs 3268to know about. The id field is an architecture specific identifier for a 3269specific device. 3270 3271ARM/arm64 divides the id field into two parts, a device id and an 3272address type id specific to the individual device:: 3273 3274 bits: | 63 ... 32 | 31 ... 16 | 15 ... 0 | 3275 field: | 0x00000000 | device id | addr type id | 3276 3277ARM/arm64 currently only require this when using the in-kernel GIC 3278support for the hardware VGIC features, using KVM_ARM_DEVICE_VGIC_V2 3279as the device id. When setting the base address for the guest's 3280mapping of the VGIC virtual CPU and distributor interface, the ioctl 3281must be called after calling KVM_CREATE_IRQCHIP, but before calling 3282KVM_RUN on any of the VCPUs. Calling this ioctl twice for any of the 3283base addresses will return -EEXIST. 3284 3285Note, this IOCTL is deprecated and the more flexible SET/GET_DEVICE_ATTR API 3286should be used instead. 3287 3288 32894.86 KVM_PPC_RTAS_DEFINE_TOKEN 3290------------------------------ 3291 3292:Capability: KVM_CAP_PPC_RTAS 3293:Architectures: ppc 3294:Type: vm ioctl 3295:Parameters: struct kvm_rtas_token_args 3296:Returns: 0 on success, -1 on error 3297 3298Defines a token value for a RTAS (Run Time Abstraction Services) 3299service in order to allow it to be handled in the kernel. The 3300argument struct gives the name of the service, which must be the name 3301of a service that has a kernel-side implementation. If the token 3302value is non-zero, it will be associated with that service, and 3303subsequent RTAS calls by the guest specifying that token will be 3304handled by the kernel. If the token value is 0, then any token 3305associated with the service will be forgotten, and subsequent RTAS 3306calls by the guest for that service will be passed to userspace to be 3307handled. 3308 33094.87 KVM_SET_GUEST_DEBUG 3310------------------------ 3311 3312:Capability: KVM_CAP_SET_GUEST_DEBUG 3313:Architectures: x86, s390, ppc, arm64 3314:Type: vcpu ioctl 3315:Parameters: struct kvm_guest_debug (in) 3316:Returns: 0 on success; -1 on error 3317 3318:: 3319 3320 struct kvm_guest_debug { 3321 __u32 control; 3322 __u32 pad; 3323 struct kvm_guest_debug_arch arch; 3324 }; 3325 3326Set up the processor specific debug registers and configure vcpu for 3327handling guest debug events. There are two parts to the structure, the 3328first a control bitfield indicates the type of debug events to handle 3329when running. Common control bits are: 3330 3331 - KVM_GUESTDBG_ENABLE: guest debugging is enabled 3332 - KVM_GUESTDBG_SINGLESTEP: the next run should single-step 3333 3334The top 16 bits of the control field are architecture specific control 3335flags which can include the following: 3336 3337 - KVM_GUESTDBG_USE_SW_BP: using software breakpoints [x86, arm64] 3338 - KVM_GUESTDBG_USE_HW_BP: using hardware breakpoints [x86, s390, arm64] 3339 - KVM_GUESTDBG_INJECT_DB: inject DB type exception [x86] 3340 - KVM_GUESTDBG_INJECT_BP: inject BP type exception [x86] 3341 - KVM_GUESTDBG_EXIT_PENDING: trigger an immediate guest exit [s390] 3342 3343For example KVM_GUESTDBG_USE_SW_BP indicates that software breakpoints 3344are enabled in memory so we need to ensure breakpoint exceptions are 3345correctly trapped and the KVM run loop exits at the breakpoint and not 3346running off into the normal guest vector. For KVM_GUESTDBG_USE_HW_BP 3347we need to ensure the guest vCPUs architecture specific registers are 3348updated to the correct (supplied) values. 3349 3350The second part of the structure is architecture specific and 3351typically contains a set of debug registers. 3352 3353For arm64 the number of debug registers is implementation defined and 3354can be determined by querying the KVM_CAP_GUEST_DEBUG_HW_BPS and 3355KVM_CAP_GUEST_DEBUG_HW_WPS capabilities which return a positive number 3356indicating the number of supported registers. 3357 3358For ppc, the KVM_CAP_PPC_GUEST_DEBUG_SSTEP capability indicates whether 3359the single-step debug event (KVM_GUESTDBG_SINGLESTEP) is supported. 3360 3361When debug events exit the main run loop with the reason 3362KVM_EXIT_DEBUG with the kvm_debug_exit_arch part of the kvm_run 3363structure containing architecture specific debug information. 3364 33654.88 KVM_GET_EMULATED_CPUID 3366--------------------------- 3367 3368:Capability: KVM_CAP_EXT_EMUL_CPUID 3369:Architectures: x86 3370:Type: system ioctl 3371:Parameters: struct kvm_cpuid2 (in/out) 3372:Returns: 0 on success, -1 on error 3373 3374:: 3375 3376 struct kvm_cpuid2 { 3377 __u32 nent; 3378 __u32 flags; 3379 struct kvm_cpuid_entry2 entries[0]; 3380 }; 3381 3382The member 'flags' is used for passing flags from userspace. 3383 3384:: 3385 3386 #define KVM_CPUID_FLAG_SIGNIFCANT_INDEX BIT(0) 3387 #define KVM_CPUID_FLAG_STATEFUL_FUNC BIT(1) /* deprecated */ 3388 #define KVM_CPUID_FLAG_STATE_READ_NEXT BIT(2) /* deprecated */ 3389 3390 struct kvm_cpuid_entry2 { 3391 __u32 function; 3392 __u32 index; 3393 __u32 flags; 3394 __u32 eax; 3395 __u32 ebx; 3396 __u32 ecx; 3397 __u32 edx; 3398 __u32 padding[3]; 3399 }; 3400 3401This ioctl returns x86 cpuid features which are emulated by 3402kvm.Userspace can use the information returned by this ioctl to query 3403which features are emulated by kvm instead of being present natively. 3404 3405Userspace invokes KVM_GET_EMULATED_CPUID by passing a kvm_cpuid2 3406structure with the 'nent' field indicating the number of entries in 3407the variable-size array 'entries'. If the number of entries is too low 3408to describe the cpu capabilities, an error (E2BIG) is returned. If the 3409number is too high, the 'nent' field is adjusted and an error (ENOMEM) 3410is returned. If the number is just right, the 'nent' field is adjusted 3411to the number of valid entries in the 'entries' array, which is then 3412filled. 3413 3414The entries returned are the set CPUID bits of the respective features 3415which kvm emulates, as returned by the CPUID instruction, with unknown 3416or unsupported feature bits cleared. 3417 3418Features like x2apic, for example, may not be present in the host cpu 3419but are exposed by kvm in KVM_GET_SUPPORTED_CPUID because they can be 3420emulated efficiently and thus not included here. 3421 3422The fields in each entry are defined as follows: 3423 3424 function: 3425 the eax value used to obtain the entry 3426 index: 3427 the ecx value used to obtain the entry (for entries that are 3428 affected by ecx) 3429 flags: 3430 an OR of zero or more of the following: 3431 3432 KVM_CPUID_FLAG_SIGNIFCANT_INDEX: 3433 if the index field is valid 3434 3435 eax, ebx, ecx, edx: 3436 3437 the values returned by the cpuid instruction for 3438 this function/index combination 3439 34404.89 KVM_S390_MEM_OP 3441-------------------- 3442 3443:Capability: KVM_CAP_S390_MEM_OP 3444:Architectures: s390 3445:Type: vcpu ioctl 3446:Parameters: struct kvm_s390_mem_op (in) 3447:Returns: = 0 on success, 3448 < 0 on generic error (e.g. -EFAULT or -ENOMEM), 3449 > 0 if an exception occurred while walking the page tables 3450 3451Read or write data from/to the logical (virtual) memory of a VCPU. 3452 3453Parameters are specified via the following structure:: 3454 3455 struct kvm_s390_mem_op { 3456 __u64 gaddr; /* the guest address */ 3457 __u64 flags; /* flags */ 3458 __u32 size; /* amount of bytes */ 3459 __u32 op; /* type of operation */ 3460 __u64 buf; /* buffer in userspace */ 3461 __u8 ar; /* the access register number */ 3462 __u8 reserved[31]; /* should be set to 0 */ 3463 }; 3464 3465The type of operation is specified in the "op" field. It is either 3466KVM_S390_MEMOP_LOGICAL_READ for reading from logical memory space or 3467KVM_S390_MEMOP_LOGICAL_WRITE for writing to logical memory space. The 3468KVM_S390_MEMOP_F_CHECK_ONLY flag can be set in the "flags" field to check 3469whether the corresponding memory access would create an access exception 3470(without touching the data in the memory at the destination). In case an 3471access exception occurred while walking the MMU tables of the guest, the 3472ioctl returns a positive error number to indicate the type of exception. 3473This exception is also raised directly at the corresponding VCPU if the 3474flag KVM_S390_MEMOP_F_INJECT_EXCEPTION is set in the "flags" field. 3475 3476The start address of the memory region has to be specified in the "gaddr" 3477field, and the length of the region in the "size" field (which must not 3478be 0). The maximum value for "size" can be obtained by checking the 3479KVM_CAP_S390_MEM_OP capability. "buf" is the buffer supplied by the 3480userspace application where the read data should be written to for 3481KVM_S390_MEMOP_LOGICAL_READ, or where the data that should be written is 3482stored for a KVM_S390_MEMOP_LOGICAL_WRITE. When KVM_S390_MEMOP_F_CHECK_ONLY 3483is specified, "buf" is unused and can be NULL. "ar" designates the access 3484register number to be used; the valid range is 0..15. 3485 3486The "reserved" field is meant for future extensions. It is not used by 3487KVM with the currently defined set of flags. 3488 34894.90 KVM_S390_GET_SKEYS 3490----------------------- 3491 3492:Capability: KVM_CAP_S390_SKEYS 3493:Architectures: s390 3494:Type: vm ioctl 3495:Parameters: struct kvm_s390_skeys 3496:Returns: 0 on success, KVM_S390_GET_KEYS_NONE if guest is not using storage 3497 keys, negative value on error 3498 3499This ioctl is used to get guest storage key values on the s390 3500architecture. The ioctl takes parameters via the kvm_s390_skeys struct:: 3501 3502 struct kvm_s390_skeys { 3503 __u64 start_gfn; 3504 __u64 count; 3505 __u64 skeydata_addr; 3506 __u32 flags; 3507 __u32 reserved[9]; 3508 }; 3509 3510The start_gfn field is the number of the first guest frame whose storage keys 3511you want to get. 3512 3513The count field is the number of consecutive frames (starting from start_gfn) 3514whose storage keys to get. The count field must be at least 1 and the maximum 3515allowed value is defined as KVM_S390_SKEYS_ALLOC_MAX. Values outside this range 3516will cause the ioctl to return -EINVAL. 3517 3518The skeydata_addr field is the address to a buffer large enough to hold count 3519bytes. This buffer will be filled with storage key data by the ioctl. 3520 35214.91 KVM_S390_SET_SKEYS 3522----------------------- 3523 3524:Capability: KVM_CAP_S390_SKEYS 3525:Architectures: s390 3526:Type: vm ioctl 3527:Parameters: struct kvm_s390_skeys 3528:Returns: 0 on success, negative value on error 3529 3530This ioctl is used to set guest storage key values on the s390 3531architecture. The ioctl takes parameters via the kvm_s390_skeys struct. 3532See section on KVM_S390_GET_SKEYS for struct definition. 3533 3534The start_gfn field is the number of the first guest frame whose storage keys 3535you want to set. 3536 3537The count field is the number of consecutive frames (starting from start_gfn) 3538whose storage keys to get. The count field must be at least 1 and the maximum 3539allowed value is defined as KVM_S390_SKEYS_ALLOC_MAX. Values outside this range 3540will cause the ioctl to return -EINVAL. 3541 3542The skeydata_addr field is the address to a buffer containing count bytes of 3543storage keys. Each byte in the buffer will be set as the storage key for a 3544single frame starting at start_gfn for count frames. 3545 3546Note: If any architecturally invalid key value is found in the given data then 3547the ioctl will return -EINVAL. 3548 35494.92 KVM_S390_IRQ 3550----------------- 3551 3552:Capability: KVM_CAP_S390_INJECT_IRQ 3553:Architectures: s390 3554:Type: vcpu ioctl 3555:Parameters: struct kvm_s390_irq (in) 3556:Returns: 0 on success, -1 on error 3557 3558Errors: 3559 3560 3561 ====== ================================================================= 3562 EINVAL interrupt type is invalid 3563 type is KVM_S390_SIGP_STOP and flag parameter is invalid value, 3564 type is KVM_S390_INT_EXTERNAL_CALL and code is bigger 3565 than the maximum of VCPUs 3566 EBUSY type is KVM_S390_SIGP_SET_PREFIX and vcpu is not stopped, 3567 type is KVM_S390_SIGP_STOP and a stop irq is already pending, 3568 type is KVM_S390_INT_EXTERNAL_CALL and an external call interrupt 3569 is already pending 3570 ====== ================================================================= 3571 3572Allows to inject an interrupt to the guest. 3573 3574Using struct kvm_s390_irq as a parameter allows 3575to inject additional payload which is not 3576possible via KVM_S390_INTERRUPT. 3577 3578Interrupt parameters are passed via kvm_s390_irq:: 3579 3580 struct kvm_s390_irq { 3581 __u64 type; 3582 union { 3583 struct kvm_s390_io_info io; 3584 struct kvm_s390_ext_info ext; 3585 struct kvm_s390_pgm_info pgm; 3586 struct kvm_s390_emerg_info emerg; 3587 struct kvm_s390_extcall_info extcall; 3588 struct kvm_s390_prefix_info prefix; 3589 struct kvm_s390_stop_info stop; 3590 struct kvm_s390_mchk_info mchk; 3591 char reserved[64]; 3592 } u; 3593 }; 3594 3595type can be one of the following: 3596 3597- KVM_S390_SIGP_STOP - sigp stop; parameter in .stop 3598- KVM_S390_PROGRAM_INT - program check; parameters in .pgm 3599- KVM_S390_SIGP_SET_PREFIX - sigp set prefix; parameters in .prefix 3600- KVM_S390_RESTART - restart; no parameters 3601- KVM_S390_INT_CLOCK_COMP - clock comparator interrupt; no parameters 3602- KVM_S390_INT_CPU_TIMER - CPU timer interrupt; no parameters 3603- KVM_S390_INT_EMERGENCY - sigp emergency; parameters in .emerg 3604- KVM_S390_INT_EXTERNAL_CALL - sigp external call; parameters in .extcall 3605- KVM_S390_MCHK - machine check interrupt; parameters in .mchk 3606 3607This is an asynchronous vcpu ioctl and can be invoked from any thread. 3608 36094.94 KVM_S390_GET_IRQ_STATE 3610--------------------------- 3611 3612:Capability: KVM_CAP_S390_IRQ_STATE 3613:Architectures: s390 3614:Type: vcpu ioctl 3615:Parameters: struct kvm_s390_irq_state (out) 3616:Returns: >= number of bytes copied into buffer, 3617 -EINVAL if buffer size is 0, 3618 -ENOBUFS if buffer size is too small to fit all pending interrupts, 3619 -EFAULT if the buffer address was invalid 3620 3621This ioctl allows userspace to retrieve the complete state of all currently 3622pending interrupts in a single buffer. Use cases include migration 3623and introspection. The parameter structure contains the address of a 3624userspace buffer and its length:: 3625 3626 struct kvm_s390_irq_state { 3627 __u64 buf; 3628 __u32 flags; /* will stay unused for compatibility reasons */ 3629 __u32 len; 3630 __u32 reserved[4]; /* will stay unused for compatibility reasons */ 3631 }; 3632 3633Userspace passes in the above struct and for each pending interrupt a 3634struct kvm_s390_irq is copied to the provided buffer. 3635 3636The structure contains a flags and a reserved field for future extensions. As 3637the kernel never checked for flags == 0 and QEMU never pre-zeroed flags and 3638reserved, these fields can not be used in the future without breaking 3639compatibility. 3640 3641If -ENOBUFS is returned the buffer provided was too small and userspace 3642may retry with a bigger buffer. 3643 36444.95 KVM_S390_SET_IRQ_STATE 3645--------------------------- 3646 3647:Capability: KVM_CAP_S390_IRQ_STATE 3648:Architectures: s390 3649:Type: vcpu ioctl 3650:Parameters: struct kvm_s390_irq_state (in) 3651:Returns: 0 on success, 3652 -EFAULT if the buffer address was invalid, 3653 -EINVAL for an invalid buffer length (see below), 3654 -EBUSY if there were already interrupts pending, 3655 errors occurring when actually injecting the 3656 interrupt. See KVM_S390_IRQ. 3657 3658This ioctl allows userspace to set the complete state of all cpu-local 3659interrupts currently pending for the vcpu. It is intended for restoring 3660interrupt state after a migration. The input parameter is a userspace buffer 3661containing a struct kvm_s390_irq_state:: 3662 3663 struct kvm_s390_irq_state { 3664 __u64 buf; 3665 __u32 flags; /* will stay unused for compatibility reasons */ 3666 __u32 len; 3667 __u32 reserved[4]; /* will stay unused for compatibility reasons */ 3668 }; 3669 3670The restrictions for flags and reserved apply as well. 3671(see KVM_S390_GET_IRQ_STATE) 3672 3673The userspace memory referenced by buf contains a struct kvm_s390_irq 3674for each interrupt to be injected into the guest. 3675If one of the interrupts could not be injected for some reason the 3676ioctl aborts. 3677 3678len must be a multiple of sizeof(struct kvm_s390_irq). It must be > 0 3679and it must not exceed (max_vcpus + 32) * sizeof(struct kvm_s390_irq), 3680which is the maximum number of possibly pending cpu-local interrupts. 3681 36824.96 KVM_SMI 3683------------ 3684 3685:Capability: KVM_CAP_X86_SMM 3686:Architectures: x86 3687:Type: vcpu ioctl 3688:Parameters: none 3689:Returns: 0 on success, -1 on error 3690 3691Queues an SMI on the thread's vcpu. 3692 36934.97 KVM_CAP_PPC_MULTITCE 3694------------------------- 3695 3696:Capability: KVM_CAP_PPC_MULTITCE 3697:Architectures: ppc 3698:Type: vm 3699 3700This capability means the kernel is capable of handling hypercalls 3701H_PUT_TCE_INDIRECT and H_STUFF_TCE without passing those into the user 3702space. This significantly accelerates DMA operations for PPC KVM guests. 3703User space should expect that its handlers for these hypercalls 3704are not going to be called if user space previously registered LIOBN 3705in KVM (via KVM_CREATE_SPAPR_TCE or similar calls). 3706 3707In order to enable H_PUT_TCE_INDIRECT and H_STUFF_TCE use in the guest, 3708user space might have to advertise it for the guest. For example, 3709IBM pSeries (sPAPR) guest starts using them if "hcall-multi-tce" is 3710present in the "ibm,hypertas-functions" device-tree property. 3711 3712The hypercalls mentioned above may or may not be processed successfully 3713in the kernel based fast path. If they can not be handled by the kernel, 3714they will get passed on to user space. So user space still has to have 3715an implementation for these despite the in kernel acceleration. 3716 3717This capability is always enabled. 3718 37194.98 KVM_CREATE_SPAPR_TCE_64 3720---------------------------- 3721 3722:Capability: KVM_CAP_SPAPR_TCE_64 3723:Architectures: powerpc 3724:Type: vm ioctl 3725:Parameters: struct kvm_create_spapr_tce_64 (in) 3726:Returns: file descriptor for manipulating the created TCE table 3727 3728This is an extension for KVM_CAP_SPAPR_TCE which only supports 32bit 3729windows, described in 4.62 KVM_CREATE_SPAPR_TCE 3730 3731This capability uses extended struct in ioctl interface:: 3732 3733 /* for KVM_CAP_SPAPR_TCE_64 */ 3734 struct kvm_create_spapr_tce_64 { 3735 __u64 liobn; 3736 __u32 page_shift; 3737 __u32 flags; 3738 __u64 offset; /* in pages */ 3739 __u64 size; /* in pages */ 3740 }; 3741 3742The aim of extension is to support an additional bigger DMA window with 3743a variable page size. 3744KVM_CREATE_SPAPR_TCE_64 receives a 64bit window size, an IOMMU page shift and 3745a bus offset of the corresponding DMA window, @size and @offset are numbers 3746of IOMMU pages. 3747 3748@flags are not used at the moment. 3749 3750The rest of functionality is identical to KVM_CREATE_SPAPR_TCE. 3751 37524.99 KVM_REINJECT_CONTROL 3753------------------------- 3754 3755:Capability: KVM_CAP_REINJECT_CONTROL 3756:Architectures: x86 3757:Type: vm ioctl 3758:Parameters: struct kvm_reinject_control (in) 3759:Returns: 0 on success, 3760 -EFAULT if struct kvm_reinject_control cannot be read, 3761 -ENXIO if KVM_CREATE_PIT or KVM_CREATE_PIT2 didn't succeed earlier. 3762 3763i8254 (PIT) has two modes, reinject and !reinject. The default is reinject, 3764where KVM queues elapsed i8254 ticks and monitors completion of interrupt from 3765vector(s) that i8254 injects. Reinject mode dequeues a tick and injects its 3766interrupt whenever there isn't a pending interrupt from i8254. 3767!reinject mode injects an interrupt as soon as a tick arrives. 3768 3769:: 3770 3771 struct kvm_reinject_control { 3772 __u8 pit_reinject; 3773 __u8 reserved[31]; 3774 }; 3775 3776pit_reinject = 0 (!reinject mode) is recommended, unless running an old 3777operating system that uses the PIT for timing (e.g. Linux 2.4.x). 3778 37794.100 KVM_PPC_CONFIGURE_V3_MMU 3780------------------------------ 3781 3782:Capability: KVM_CAP_PPC_RADIX_MMU or KVM_CAP_PPC_HASH_MMU_V3 3783:Architectures: ppc 3784:Type: vm ioctl 3785:Parameters: struct kvm_ppc_mmuv3_cfg (in) 3786:Returns: 0 on success, 3787 -EFAULT if struct kvm_ppc_mmuv3_cfg cannot be read, 3788 -EINVAL if the configuration is invalid 3789 3790This ioctl controls whether the guest will use radix or HPT (hashed 3791page table) translation, and sets the pointer to the process table for 3792the guest. 3793 3794:: 3795 3796 struct kvm_ppc_mmuv3_cfg { 3797 __u64 flags; 3798 __u64 process_table; 3799 }; 3800 3801There are two bits that can be set in flags; KVM_PPC_MMUV3_RADIX and 3802KVM_PPC_MMUV3_GTSE. KVM_PPC_MMUV3_RADIX, if set, configures the guest 3803to use radix tree translation, and if clear, to use HPT translation. 3804KVM_PPC_MMUV3_GTSE, if set and if KVM permits it, configures the guest 3805to be able to use the global TLB and SLB invalidation instructions; 3806if clear, the guest may not use these instructions. 3807 3808The process_table field specifies the address and size of the guest 3809process table, which is in the guest's space. This field is formatted 3810as the second doubleword of the partition table entry, as defined in 3811the Power ISA V3.00, Book III section 5.7.6.1. 3812 38134.101 KVM_PPC_GET_RMMU_INFO 3814--------------------------- 3815 3816:Capability: KVM_CAP_PPC_RADIX_MMU 3817:Architectures: ppc 3818:Type: vm ioctl 3819:Parameters: struct kvm_ppc_rmmu_info (out) 3820:Returns: 0 on success, 3821 -EFAULT if struct kvm_ppc_rmmu_info cannot be written, 3822 -EINVAL if no useful information can be returned 3823 3824This ioctl returns a structure containing two things: (a) a list 3825containing supported radix tree geometries, and (b) a list that maps 3826page sizes to put in the "AP" (actual page size) field for the tlbie 3827(TLB invalidate entry) instruction. 3828 3829:: 3830 3831 struct kvm_ppc_rmmu_info { 3832 struct kvm_ppc_radix_geom { 3833 __u8 page_shift; 3834 __u8 level_bits[4]; 3835 __u8 pad[3]; 3836 } geometries[8]; 3837 __u32 ap_encodings[8]; 3838 }; 3839 3840The geometries[] field gives up to 8 supported geometries for the 3841radix page table, in terms of the log base 2 of the smallest page 3842size, and the number of bits indexed at each level of the tree, from 3843the PTE level up to the PGD level in that order. Any unused entries 3844will have 0 in the page_shift field. 3845 3846The ap_encodings gives the supported page sizes and their AP field 3847encodings, encoded with the AP value in the top 3 bits and the log 3848base 2 of the page size in the bottom 6 bits. 3849 38504.102 KVM_PPC_RESIZE_HPT_PREPARE 3851-------------------------------- 3852 3853:Capability: KVM_CAP_SPAPR_RESIZE_HPT 3854:Architectures: powerpc 3855:Type: vm ioctl 3856:Parameters: struct kvm_ppc_resize_hpt (in) 3857:Returns: 0 on successful completion, 3858 >0 if a new HPT is being prepared, the value is an estimated 3859 number of milliseconds until preparation is complete, 3860 -EFAULT if struct kvm_reinject_control cannot be read, 3861 -EINVAL if the supplied shift or flags are invalid, 3862 -ENOMEM if unable to allocate the new HPT, 3863 3864Used to implement the PAPR extension for runtime resizing of a guest's 3865Hashed Page Table (HPT). Specifically this starts, stops or monitors 3866the preparation of a new potential HPT for the guest, essentially 3867implementing the H_RESIZE_HPT_PREPARE hypercall. 3868 3869:: 3870 3871 struct kvm_ppc_resize_hpt { 3872 __u64 flags; 3873 __u32 shift; 3874 __u32 pad; 3875 }; 3876 3877If called with shift > 0 when there is no pending HPT for the guest, 3878this begins preparation of a new pending HPT of size 2^(shift) bytes. 3879It then returns a positive integer with the estimated number of 3880milliseconds until preparation is complete. 3881 3882If called when there is a pending HPT whose size does not match that 3883requested in the parameters, discards the existing pending HPT and 3884creates a new one as above. 3885 3886If called when there is a pending HPT of the size requested, will: 3887 3888 * If preparation of the pending HPT is already complete, return 0 3889 * If preparation of the pending HPT has failed, return an error 3890 code, then discard the pending HPT. 3891 * If preparation of the pending HPT is still in progress, return an 3892 estimated number of milliseconds until preparation is complete. 3893 3894If called with shift == 0, discards any currently pending HPT and 3895returns 0 (i.e. cancels any in-progress preparation). 3896 3897flags is reserved for future expansion, currently setting any bits in 3898flags will result in an -EINVAL. 3899 3900Normally this will be called repeatedly with the same parameters until 3901it returns <= 0. The first call will initiate preparation, subsequent 3902ones will monitor preparation until it completes or fails. 3903 39044.103 KVM_PPC_RESIZE_HPT_COMMIT 3905------------------------------- 3906 3907:Capability: KVM_CAP_SPAPR_RESIZE_HPT 3908:Architectures: powerpc 3909:Type: vm ioctl 3910:Parameters: struct kvm_ppc_resize_hpt (in) 3911:Returns: 0 on successful completion, 3912 -EFAULT if struct kvm_reinject_control cannot be read, 3913 -EINVAL if the supplied shift or flags are invalid, 3914 -ENXIO is there is no pending HPT, or the pending HPT doesn't 3915 have the requested size, 3916 -EBUSY if the pending HPT is not fully prepared, 3917 -ENOSPC if there was a hash collision when moving existing 3918 HPT entries to the new HPT, 3919 -EIO on other error conditions 3920 3921Used to implement the PAPR extension for runtime resizing of a guest's 3922Hashed Page Table (HPT). Specifically this requests that the guest be 3923transferred to working with the new HPT, essentially implementing the 3924H_RESIZE_HPT_COMMIT hypercall. 3925 3926:: 3927 3928 struct kvm_ppc_resize_hpt { 3929 __u64 flags; 3930 __u32 shift; 3931 __u32 pad; 3932 }; 3933 3934This should only be called after KVM_PPC_RESIZE_HPT_PREPARE has 3935returned 0 with the same parameters. In other cases 3936KVM_PPC_RESIZE_HPT_COMMIT will return an error (usually -ENXIO or 3937-EBUSY, though others may be possible if the preparation was started, 3938but failed). 3939 3940This will have undefined effects on the guest if it has not already 3941placed itself in a quiescent state where no vcpu will make MMU enabled 3942memory accesses. 3943 3944On succsful completion, the pending HPT will become the guest's active 3945HPT and the previous HPT will be discarded. 3946 3947On failure, the guest will still be operating on its previous HPT. 3948 39494.104 KVM_X86_GET_MCE_CAP_SUPPORTED 3950----------------------------------- 3951 3952:Capability: KVM_CAP_MCE 3953:Architectures: x86 3954:Type: system ioctl 3955:Parameters: u64 mce_cap (out) 3956:Returns: 0 on success, -1 on error 3957 3958Returns supported MCE capabilities. The u64 mce_cap parameter 3959has the same format as the MSR_IA32_MCG_CAP register. Supported 3960capabilities will have the corresponding bits set. 3961 39624.105 KVM_X86_SETUP_MCE 3963----------------------- 3964 3965:Capability: KVM_CAP_MCE 3966:Architectures: x86 3967:Type: vcpu ioctl 3968:Parameters: u64 mcg_cap (in) 3969:Returns: 0 on success, 3970 -EFAULT if u64 mcg_cap cannot be read, 3971 -EINVAL if the requested number of banks is invalid, 3972 -EINVAL if requested MCE capability is not supported. 3973 3974Initializes MCE support for use. The u64 mcg_cap parameter 3975has the same format as the MSR_IA32_MCG_CAP register and 3976specifies which capabilities should be enabled. The maximum 3977supported number of error-reporting banks can be retrieved when 3978checking for KVM_CAP_MCE. The supported capabilities can be 3979retrieved with KVM_X86_GET_MCE_CAP_SUPPORTED. 3980 39814.106 KVM_X86_SET_MCE 3982--------------------- 3983 3984:Capability: KVM_CAP_MCE 3985:Architectures: x86 3986:Type: vcpu ioctl 3987:Parameters: struct kvm_x86_mce (in) 3988:Returns: 0 on success, 3989 -EFAULT if struct kvm_x86_mce cannot be read, 3990 -EINVAL if the bank number is invalid, 3991 -EINVAL if VAL bit is not set in status field. 3992 3993Inject a machine check error (MCE) into the guest. The input 3994parameter is:: 3995 3996 struct kvm_x86_mce { 3997 __u64 status; 3998 __u64 addr; 3999 __u64 misc; 4000 __u64 mcg_status; 4001 __u8 bank; 4002 __u8 pad1[7]; 4003 __u64 pad2[3]; 4004 }; 4005 4006If the MCE being reported is an uncorrected error, KVM will 4007inject it as an MCE exception into the guest. If the guest 4008MCG_STATUS register reports that an MCE is in progress, KVM 4009causes an KVM_EXIT_SHUTDOWN vmexit. 4010 4011Otherwise, if the MCE is a corrected error, KVM will just 4012store it in the corresponding bank (provided this bank is 4013not holding a previously reported uncorrected error). 4014 40154.107 KVM_S390_GET_CMMA_BITS 4016---------------------------- 4017 4018:Capability: KVM_CAP_S390_CMMA_MIGRATION 4019:Architectures: s390 4020:Type: vm ioctl 4021:Parameters: struct kvm_s390_cmma_log (in, out) 4022:Returns: 0 on success, a negative value on error 4023 4024This ioctl is used to get the values of the CMMA bits on the s390 4025architecture. It is meant to be used in two scenarios: 4026 4027- During live migration to save the CMMA values. Live migration needs 4028 to be enabled via the KVM_REQ_START_MIGRATION VM property. 4029- To non-destructively peek at the CMMA values, with the flag 4030 KVM_S390_CMMA_PEEK set. 4031 4032The ioctl takes parameters via the kvm_s390_cmma_log struct. The desired 4033values are written to a buffer whose location is indicated via the "values" 4034member in the kvm_s390_cmma_log struct. The values in the input struct are 4035also updated as needed. 4036 4037Each CMMA value takes up one byte. 4038 4039:: 4040 4041 struct kvm_s390_cmma_log { 4042 __u64 start_gfn; 4043 __u32 count; 4044 __u32 flags; 4045 union { 4046 __u64 remaining; 4047 __u64 mask; 4048 }; 4049 __u64 values; 4050 }; 4051 4052start_gfn is the number of the first guest frame whose CMMA values are 4053to be retrieved, 4054 4055count is the length of the buffer in bytes, 4056 4057values points to the buffer where the result will be written to. 4058 4059If count is greater than KVM_S390_SKEYS_MAX, then it is considered to be 4060KVM_S390_SKEYS_MAX. KVM_S390_SKEYS_MAX is re-used for consistency with 4061other ioctls. 4062 4063The result is written in the buffer pointed to by the field values, and 4064the values of the input parameter are updated as follows. 4065 4066Depending on the flags, different actions are performed. The only 4067supported flag so far is KVM_S390_CMMA_PEEK. 4068 4069The default behaviour if KVM_S390_CMMA_PEEK is not set is: 4070start_gfn will indicate the first page frame whose CMMA bits were dirty. 4071It is not necessarily the same as the one passed as input, as clean pages 4072are skipped. 4073 4074count will indicate the number of bytes actually written in the buffer. 4075It can (and very often will) be smaller than the input value, since the 4076buffer is only filled until 16 bytes of clean values are found (which 4077are then not copied in the buffer). Since a CMMA migration block needs 4078the base address and the length, for a total of 16 bytes, we will send 4079back some clean data if there is some dirty data afterwards, as long as 4080the size of the clean data does not exceed the size of the header. This 4081allows to minimize the amount of data to be saved or transferred over 4082the network at the expense of more roundtrips to userspace. The next 4083invocation of the ioctl will skip over all the clean values, saving 4084potentially more than just the 16 bytes we found. 4085 4086If KVM_S390_CMMA_PEEK is set: 4087the existing storage attributes are read even when not in migration 4088mode, and no other action is performed; 4089 4090the output start_gfn will be equal to the input start_gfn, 4091 4092the output count will be equal to the input count, except if the end of 4093memory has been reached. 4094 4095In both cases: 4096the field "remaining" will indicate the total number of dirty CMMA values 4097still remaining, or 0 if KVM_S390_CMMA_PEEK is set and migration mode is 4098not enabled. 4099 4100mask is unused. 4101 4102values points to the userspace buffer where the result will be stored. 4103 4104This ioctl can fail with -ENOMEM if not enough memory can be allocated to 4105complete the task, with -ENXIO if CMMA is not enabled, with -EINVAL if 4106KVM_S390_CMMA_PEEK is not set but migration mode was not enabled, with 4107-EFAULT if the userspace address is invalid or if no page table is 4108present for the addresses (e.g. when using hugepages). 4109 41104.108 KVM_S390_SET_CMMA_BITS 4111---------------------------- 4112 4113:Capability: KVM_CAP_S390_CMMA_MIGRATION 4114:Architectures: s390 4115:Type: vm ioctl 4116:Parameters: struct kvm_s390_cmma_log (in) 4117:Returns: 0 on success, a negative value on error 4118 4119This ioctl is used to set the values of the CMMA bits on the s390 4120architecture. It is meant to be used during live migration to restore 4121the CMMA values, but there are no restrictions on its use. 4122The ioctl takes parameters via the kvm_s390_cmma_values struct. 4123Each CMMA value takes up one byte. 4124 4125:: 4126 4127 struct kvm_s390_cmma_log { 4128 __u64 start_gfn; 4129 __u32 count; 4130 __u32 flags; 4131 union { 4132 __u64 remaining; 4133 __u64 mask; 4134 }; 4135 __u64 values; 4136 }; 4137 4138start_gfn indicates the starting guest frame number, 4139 4140count indicates how many values are to be considered in the buffer, 4141 4142flags is not used and must be 0. 4143 4144mask indicates which PGSTE bits are to be considered. 4145 4146remaining is not used. 4147 4148values points to the buffer in userspace where to store the values. 4149 4150This ioctl can fail with -ENOMEM if not enough memory can be allocated to 4151complete the task, with -ENXIO if CMMA is not enabled, with -EINVAL if 4152the count field is too large (e.g. more than KVM_S390_CMMA_SIZE_MAX) or 4153if the flags field was not 0, with -EFAULT if the userspace address is 4154invalid, if invalid pages are written to (e.g. after the end of memory) 4155or if no page table is present for the addresses (e.g. when using 4156hugepages). 4157 41584.109 KVM_PPC_GET_CPU_CHAR 4159-------------------------- 4160 4161:Capability: KVM_CAP_PPC_GET_CPU_CHAR 4162:Architectures: powerpc 4163:Type: vm ioctl 4164:Parameters: struct kvm_ppc_cpu_char (out) 4165:Returns: 0 on successful completion, 4166 -EFAULT if struct kvm_ppc_cpu_char cannot be written 4167 4168This ioctl gives userspace information about certain characteristics 4169of the CPU relating to speculative execution of instructions and 4170possible information leakage resulting from speculative execution (see 4171CVE-2017-5715, CVE-2017-5753 and CVE-2017-5754). The information is 4172returned in struct kvm_ppc_cpu_char, which looks like this:: 4173 4174 struct kvm_ppc_cpu_char { 4175 __u64 character; /* characteristics of the CPU */ 4176 __u64 behaviour; /* recommended software behaviour */ 4177 __u64 character_mask; /* valid bits in character */ 4178 __u64 behaviour_mask; /* valid bits in behaviour */ 4179 }; 4180 4181For extensibility, the character_mask and behaviour_mask fields 4182indicate which bits of character and behaviour have been filled in by 4183the kernel. If the set of defined bits is extended in future then 4184userspace will be able to tell whether it is running on a kernel that 4185knows about the new bits. 4186 4187The character field describes attributes of the CPU which can help 4188with preventing inadvertent information disclosure - specifically, 4189whether there is an instruction to flash-invalidate the L1 data cache 4190(ori 30,30,0 or mtspr SPRN_TRIG2,rN), whether the L1 data cache is set 4191to a mode where entries can only be used by the thread that created 4192them, whether the bcctr[l] instruction prevents speculation, and 4193whether a speculation barrier instruction (ori 31,31,0) is provided. 4194 4195The behaviour field describes actions that software should take to 4196prevent inadvertent information disclosure, and thus describes which 4197vulnerabilities the hardware is subject to; specifically whether the 4198L1 data cache should be flushed when returning to user mode from the 4199kernel, and whether a speculation barrier should be placed between an 4200array bounds check and the array access. 4201 4202These fields use the same bit definitions as the new 4203H_GET_CPU_CHARACTERISTICS hypercall. 4204 42054.110 KVM_MEMORY_ENCRYPT_OP 4206--------------------------- 4207 4208:Capability: basic 4209:Architectures: x86 4210:Type: vm 4211:Parameters: an opaque platform specific structure (in/out) 4212:Returns: 0 on success; -1 on error 4213 4214If the platform supports creating encrypted VMs then this ioctl can be used 4215for issuing platform-specific memory encryption commands to manage those 4216encrypted VMs. 4217 4218Currently, this ioctl is used for issuing Secure Encrypted Virtualization 4219(SEV) commands on AMD Processors. The SEV commands are defined in 4220Documentation/virt/kvm/amd-memory-encryption.rst. 4221 42224.111 KVM_MEMORY_ENCRYPT_REG_REGION 4223----------------------------------- 4224 4225:Capability: basic 4226:Architectures: x86 4227:Type: system 4228:Parameters: struct kvm_enc_region (in) 4229:Returns: 0 on success; -1 on error 4230 4231This ioctl can be used to register a guest memory region which may 4232contain encrypted data (e.g. guest RAM, SMRAM etc). 4233 4234It is used in the SEV-enabled guest. When encryption is enabled, a guest 4235memory region may contain encrypted data. The SEV memory encryption 4236engine uses a tweak such that two identical plaintext pages, each at 4237different locations will have differing ciphertexts. So swapping or 4238moving ciphertext of those pages will not result in plaintext being 4239swapped. So relocating (or migrating) physical backing pages for the SEV 4240guest will require some additional steps. 4241 4242Note: The current SEV key management spec does not provide commands to 4243swap or migrate (move) ciphertext pages. Hence, for now we pin the guest 4244memory region registered with the ioctl. 4245 42464.112 KVM_MEMORY_ENCRYPT_UNREG_REGION 4247------------------------------------- 4248 4249:Capability: basic 4250:Architectures: x86 4251:Type: system 4252:Parameters: struct kvm_enc_region (in) 4253:Returns: 0 on success; -1 on error 4254 4255This ioctl can be used to unregister the guest memory region registered 4256with KVM_MEMORY_ENCRYPT_REG_REGION ioctl above. 4257 42584.113 KVM_HYPERV_EVENTFD 4259------------------------ 4260 4261:Capability: KVM_CAP_HYPERV_EVENTFD 4262:Architectures: x86 4263:Type: vm ioctl 4264:Parameters: struct kvm_hyperv_eventfd (in) 4265 4266This ioctl (un)registers an eventfd to receive notifications from the guest on 4267the specified Hyper-V connection id through the SIGNAL_EVENT hypercall, without 4268causing a user exit. SIGNAL_EVENT hypercall with non-zero event flag number 4269(bits 24-31) still triggers a KVM_EXIT_HYPERV_HCALL user exit. 4270 4271:: 4272 4273 struct kvm_hyperv_eventfd { 4274 __u32 conn_id; 4275 __s32 fd; 4276 __u32 flags; 4277 __u32 padding[3]; 4278 }; 4279 4280The conn_id field should fit within 24 bits:: 4281 4282 #define KVM_HYPERV_CONN_ID_MASK 0x00ffffff 4283 4284The acceptable values for the flags field are:: 4285 4286 #define KVM_HYPERV_EVENTFD_DEASSIGN (1 << 0) 4287 4288:Returns: 0 on success, 4289 -EINVAL if conn_id or flags is outside the allowed range, 4290 -ENOENT on deassign if the conn_id isn't registered, 4291 -EEXIST on assign if the conn_id is already registered 4292 42934.114 KVM_GET_NESTED_STATE 4294-------------------------- 4295 4296:Capability: KVM_CAP_NESTED_STATE 4297:Architectures: x86 4298:Type: vcpu ioctl 4299:Parameters: struct kvm_nested_state (in/out) 4300:Returns: 0 on success, -1 on error 4301 4302Errors: 4303 4304 ===== ============================================================= 4305 E2BIG the total state size exceeds the value of 'size' specified by 4306 the user; the size required will be written into size. 4307 ===== ============================================================= 4308 4309:: 4310 4311 struct kvm_nested_state { 4312 __u16 flags; 4313 __u16 format; 4314 __u32 size; 4315 4316 union { 4317 struct kvm_vmx_nested_state_hdr vmx; 4318 struct kvm_svm_nested_state_hdr svm; 4319 4320 /* Pad the header to 128 bytes. */ 4321 __u8 pad[120]; 4322 } hdr; 4323 4324 union { 4325 struct kvm_vmx_nested_state_data vmx[0]; 4326 struct kvm_svm_nested_state_data svm[0]; 4327 } data; 4328 }; 4329 4330 #define KVM_STATE_NESTED_GUEST_MODE 0x00000001 4331 #define KVM_STATE_NESTED_RUN_PENDING 0x00000002 4332 #define KVM_STATE_NESTED_EVMCS 0x00000004 4333 4334 #define KVM_STATE_NESTED_FORMAT_VMX 0 4335 #define KVM_STATE_NESTED_FORMAT_SVM 1 4336 4337 #define KVM_STATE_NESTED_VMX_VMCS_SIZE 0x1000 4338 4339 #define KVM_STATE_NESTED_VMX_SMM_GUEST_MODE 0x00000001 4340 #define KVM_STATE_NESTED_VMX_SMM_VMXON 0x00000002 4341 4342 #define KVM_STATE_VMX_PREEMPTION_TIMER_DEADLINE 0x00000001 4343 4344 struct kvm_vmx_nested_state_hdr { 4345 __u64 vmxon_pa; 4346 __u64 vmcs12_pa; 4347 4348 struct { 4349 __u16 flags; 4350 } smm; 4351 4352 __u32 flags; 4353 __u64 preemption_timer_deadline; 4354 }; 4355 4356 struct kvm_vmx_nested_state_data { 4357 __u8 vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE]; 4358 __u8 shadow_vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE]; 4359 }; 4360 4361This ioctl copies the vcpu's nested virtualization state from the kernel to 4362userspace. 4363 4364The maximum size of the state can be retrieved by passing KVM_CAP_NESTED_STATE 4365to the KVM_CHECK_EXTENSION ioctl(). 4366 43674.115 KVM_SET_NESTED_STATE 4368-------------------------- 4369 4370:Capability: KVM_CAP_NESTED_STATE 4371:Architectures: x86 4372:Type: vcpu ioctl 4373:Parameters: struct kvm_nested_state (in) 4374:Returns: 0 on success, -1 on error 4375 4376This copies the vcpu's kvm_nested_state struct from userspace to the kernel. 4377For the definition of struct kvm_nested_state, see KVM_GET_NESTED_STATE. 4378 43794.116 KVM_(UN)REGISTER_COALESCED_MMIO 4380------------------------------------- 4381 4382:Capability: KVM_CAP_COALESCED_MMIO (for coalesced mmio) 4383 KVM_CAP_COALESCED_PIO (for coalesced pio) 4384:Architectures: all 4385:Type: vm ioctl 4386:Parameters: struct kvm_coalesced_mmio_zone 4387:Returns: 0 on success, < 0 on error 4388 4389Coalesced I/O is a performance optimization that defers hardware 4390register write emulation so that userspace exits are avoided. It is 4391typically used to reduce the overhead of emulating frequently accessed 4392hardware registers. 4393 4394When a hardware register is configured for coalesced I/O, write accesses 4395do not exit to userspace and their value is recorded in a ring buffer 4396that is shared between kernel and userspace. 4397 4398Coalesced I/O is used if one or more write accesses to a hardware 4399register can be deferred until a read or a write to another hardware 4400register on the same device. This last access will cause a vmexit and 4401userspace will process accesses from the ring buffer before emulating 4402it. That will avoid exiting to userspace on repeated writes. 4403 4404Coalesced pio is based on coalesced mmio. There is little difference 4405between coalesced mmio and pio except that coalesced pio records accesses 4406to I/O ports. 4407 44084.117 KVM_CLEAR_DIRTY_LOG (vm ioctl) 4409------------------------------------ 4410 4411:Capability: KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 4412:Architectures: x86, arm, arm64, mips 4413:Type: vm ioctl 4414:Parameters: struct kvm_clear_dirty_log (in) 4415:Returns: 0 on success, -1 on error 4416 4417:: 4418 4419 /* for KVM_CLEAR_DIRTY_LOG */ 4420 struct kvm_clear_dirty_log { 4421 __u32 slot; 4422 __u32 num_pages; 4423 __u64 first_page; 4424 union { 4425 void __user *dirty_bitmap; /* one bit per page */ 4426 __u64 padding; 4427 }; 4428 }; 4429 4430The ioctl clears the dirty status of pages in a memory slot, according to 4431the bitmap that is passed in struct kvm_clear_dirty_log's dirty_bitmap 4432field. Bit 0 of the bitmap corresponds to page "first_page" in the 4433memory slot, and num_pages is the size in bits of the input bitmap. 4434first_page must be a multiple of 64; num_pages must also be a multiple of 443564 unless first_page + num_pages is the size of the memory slot. For each 4436bit that is set in the input bitmap, the corresponding page is marked "clean" 4437in KVM's dirty bitmap, and dirty tracking is re-enabled for that page 4438(for example via write-protection, or by clearing the dirty bit in 4439a page table entry). 4440 4441If KVM_CAP_MULTI_ADDRESS_SPACE is available, bits 16-31 of slot field specifies 4442the address space for which you want to clear the dirty status. See 4443KVM_SET_USER_MEMORY_REGION for details on the usage of slot field. 4444 4445This ioctl is mostly useful when KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 4446is enabled; for more information, see the description of the capability. 4447However, it can always be used as long as KVM_CHECK_EXTENSION confirms 4448that KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 is present. 4449 44504.118 KVM_GET_SUPPORTED_HV_CPUID 4451-------------------------------- 4452 4453:Capability: KVM_CAP_HYPERV_CPUID (vcpu), KVM_CAP_SYS_HYPERV_CPUID (system) 4454:Architectures: x86 4455:Type: system ioctl, vcpu ioctl 4456:Parameters: struct kvm_cpuid2 (in/out) 4457:Returns: 0 on success, -1 on error 4458 4459:: 4460 4461 struct kvm_cpuid2 { 4462 __u32 nent; 4463 __u32 padding; 4464 struct kvm_cpuid_entry2 entries[0]; 4465 }; 4466 4467 struct kvm_cpuid_entry2 { 4468 __u32 function; 4469 __u32 index; 4470 __u32 flags; 4471 __u32 eax; 4472 __u32 ebx; 4473 __u32 ecx; 4474 __u32 edx; 4475 __u32 padding[3]; 4476 }; 4477 4478This ioctl returns x86 cpuid features leaves related to Hyper-V emulation in 4479KVM. Userspace can use the information returned by this ioctl to construct 4480cpuid information presented to guests consuming Hyper-V enlightenments (e.g. 4481Windows or Hyper-V guests). 4482 4483CPUID feature leaves returned by this ioctl are defined by Hyper-V Top Level 4484Functional Specification (TLFS). These leaves can't be obtained with 4485KVM_GET_SUPPORTED_CPUID ioctl because some of them intersect with KVM feature 4486leaves (0x40000000, 0x40000001). 4487 4488Currently, the following list of CPUID leaves are returned: 4489 4490 - HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS 4491 - HYPERV_CPUID_INTERFACE 4492 - HYPERV_CPUID_VERSION 4493 - HYPERV_CPUID_FEATURES 4494 - HYPERV_CPUID_ENLIGHTMENT_INFO 4495 - HYPERV_CPUID_IMPLEMENT_LIMITS 4496 - HYPERV_CPUID_NESTED_FEATURES 4497 - HYPERV_CPUID_SYNDBG_VENDOR_AND_MAX_FUNCTIONS 4498 - HYPERV_CPUID_SYNDBG_INTERFACE 4499 - HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES 4500 4501Userspace invokes KVM_GET_SUPPORTED_HV_CPUID by passing a kvm_cpuid2 structure 4502with the 'nent' field indicating the number of entries in the variable-size 4503array 'entries'. If the number of entries is too low to describe all Hyper-V 4504feature leaves, an error (E2BIG) is returned. If the number is more or equal 4505to the number of Hyper-V feature leaves, the 'nent' field is adjusted to the 4506number of valid entries in the 'entries' array, which is then filled. 4507 4508'index' and 'flags' fields in 'struct kvm_cpuid_entry2' are currently reserved, 4509userspace should not expect to get any particular value there. 4510 4511Note, vcpu version of KVM_GET_SUPPORTED_HV_CPUID is currently deprecated. Unlike 4512system ioctl which exposes all supported feature bits unconditionally, vcpu 4513version has the following quirks: 4514 4515- HYPERV_CPUID_NESTED_FEATURES leaf and HV_X64_ENLIGHTENED_VMCS_RECOMMENDED 4516 feature bit are only exposed when Enlightened VMCS was previously enabled 4517 on the corresponding vCPU (KVM_CAP_HYPERV_ENLIGHTENED_VMCS). 4518- HV_STIMER_DIRECT_MODE_AVAILABLE bit is only exposed with in-kernel LAPIC. 4519 (presumes KVM_CREATE_IRQCHIP has already been called). 4520 45214.119 KVM_ARM_VCPU_FINALIZE 4522--------------------------- 4523 4524:Architectures: arm, arm64 4525:Type: vcpu ioctl 4526:Parameters: int feature (in) 4527:Returns: 0 on success, -1 on error 4528 4529Errors: 4530 4531 ====== ============================================================== 4532 EPERM feature not enabled, needs configuration, or already finalized 4533 EINVAL feature unknown or not present 4534 ====== ============================================================== 4535 4536Recognised values for feature: 4537 4538 ===== =========================================== 4539 arm64 KVM_ARM_VCPU_SVE (requires KVM_CAP_ARM_SVE) 4540 ===== =========================================== 4541 4542Finalizes the configuration of the specified vcpu feature. 4543 4544The vcpu must already have been initialised, enabling the affected feature, by 4545means of a successful KVM_ARM_VCPU_INIT call with the appropriate flag set in 4546features[]. 4547 4548For affected vcpu features, this is a mandatory step that must be performed 4549before the vcpu is fully usable. 4550 4551Between KVM_ARM_VCPU_INIT and KVM_ARM_VCPU_FINALIZE, the feature may be 4552configured by use of ioctls such as KVM_SET_ONE_REG. The exact configuration 4553that should be performaned and how to do it are feature-dependent. 4554 4555Other calls that depend on a particular feature being finalized, such as 4556KVM_RUN, KVM_GET_REG_LIST, KVM_GET_ONE_REG and KVM_SET_ONE_REG, will fail with 4557-EPERM unless the feature has already been finalized by means of a 4558KVM_ARM_VCPU_FINALIZE call. 4559 4560See KVM_ARM_VCPU_INIT for details of vcpu features that require finalization 4561using this ioctl. 4562 45634.120 KVM_SET_PMU_EVENT_FILTER 4564------------------------------ 4565 4566:Capability: KVM_CAP_PMU_EVENT_FILTER 4567:Architectures: x86 4568:Type: vm ioctl 4569:Parameters: struct kvm_pmu_event_filter (in) 4570:Returns: 0 on success, -1 on error 4571 4572:: 4573 4574 struct kvm_pmu_event_filter { 4575 __u32 action; 4576 __u32 nevents; 4577 __u32 fixed_counter_bitmap; 4578 __u32 flags; 4579 __u32 pad[4]; 4580 __u64 events[0]; 4581 }; 4582 4583This ioctl restricts the set of PMU events that the guest can program. 4584The argument holds a list of events which will be allowed or denied. 4585The eventsel+umask of each event the guest attempts to program is compared 4586against the events field to determine whether the guest should have access. 4587The events field only controls general purpose counters; fixed purpose 4588counters are controlled by the fixed_counter_bitmap. 4589 4590No flags are defined yet, the field must be zero. 4591 4592Valid values for 'action':: 4593 4594 #define KVM_PMU_EVENT_ALLOW 0 4595 #define KVM_PMU_EVENT_DENY 1 4596 45974.121 KVM_PPC_SVM_OFF 4598--------------------- 4599 4600:Capability: basic 4601:Architectures: powerpc 4602:Type: vm ioctl 4603:Parameters: none 4604:Returns: 0 on successful completion, 4605 4606Errors: 4607 4608 ====== ================================================================ 4609 EINVAL if ultravisor failed to terminate the secure guest 4610 ENOMEM if hypervisor failed to allocate new radix page tables for guest 4611 ====== ================================================================ 4612 4613This ioctl is used to turn off the secure mode of the guest or transition 4614the guest from secure mode to normal mode. This is invoked when the guest 4615is reset. This has no effect if called for a normal guest. 4616 4617This ioctl issues an ultravisor call to terminate the secure guest, 4618unpins the VPA pages and releases all the device pages that are used to 4619track the secure pages by hypervisor. 4620 46214.122 KVM_S390_NORMAL_RESET 4622--------------------------- 4623 4624:Capability: KVM_CAP_S390_VCPU_RESETS 4625:Architectures: s390 4626:Type: vcpu ioctl 4627:Parameters: none 4628:Returns: 0 4629 4630This ioctl resets VCPU registers and control structures according to 4631the cpu reset definition in the POP (Principles Of Operation). 4632 46334.123 KVM_S390_INITIAL_RESET 4634---------------------------- 4635 4636:Capability: none 4637:Architectures: s390 4638:Type: vcpu ioctl 4639:Parameters: none 4640:Returns: 0 4641 4642This ioctl resets VCPU registers and control structures according to 4643the initial cpu reset definition in the POP. However, the cpu is not 4644put into ESA mode. This reset is a superset of the normal reset. 4645 46464.124 KVM_S390_CLEAR_RESET 4647-------------------------- 4648 4649:Capability: KVM_CAP_S390_VCPU_RESETS 4650:Architectures: s390 4651:Type: vcpu ioctl 4652:Parameters: none 4653:Returns: 0 4654 4655This ioctl resets VCPU registers and control structures according to 4656the clear cpu reset definition in the POP. However, the cpu is not put 4657into ESA mode. This reset is a superset of the initial reset. 4658 4659 46604.125 KVM_S390_PV_COMMAND 4661------------------------- 4662 4663:Capability: KVM_CAP_S390_PROTECTED 4664:Architectures: s390 4665:Type: vm ioctl 4666:Parameters: struct kvm_pv_cmd 4667:Returns: 0 on success, < 0 on error 4668 4669:: 4670 4671 struct kvm_pv_cmd { 4672 __u32 cmd; /* Command to be executed */ 4673 __u16 rc; /* Ultravisor return code */ 4674 __u16 rrc; /* Ultravisor return reason code */ 4675 __u64 data; /* Data or address */ 4676 __u32 flags; /* flags for future extensions. Must be 0 for now */ 4677 __u32 reserved[3]; 4678 }; 4679 4680cmd values: 4681 4682KVM_PV_ENABLE 4683 Allocate memory and register the VM with the Ultravisor, thereby 4684 donating memory to the Ultravisor that will become inaccessible to 4685 KVM. All existing CPUs are converted to protected ones. After this 4686 command has succeeded, any CPU added via hotplug will become 4687 protected during its creation as well. 4688 4689 Errors: 4690 4691 ===== ============================= 4692 EINTR an unmasked signal is pending 4693 ===== ============================= 4694 4695KVM_PV_DISABLE 4696 4697 Deregister the VM from the Ultravisor and reclaim the memory that 4698 had been donated to the Ultravisor, making it usable by the kernel 4699 again. All registered VCPUs are converted back to non-protected 4700 ones. 4701 4702KVM_PV_VM_SET_SEC_PARMS 4703 Pass the image header from VM memory to the Ultravisor in 4704 preparation of image unpacking and verification. 4705 4706KVM_PV_VM_UNPACK 4707 Unpack (protect and decrypt) a page of the encrypted boot image. 4708 4709KVM_PV_VM_VERIFY 4710 Verify the integrity of the unpacked image. Only if this succeeds, 4711 KVM is allowed to start protected VCPUs. 4712 47134.126 KVM_X86_SET_MSR_FILTER 4714---------------------------- 4715 4716:Capability: KVM_X86_SET_MSR_FILTER 4717:Architectures: x86 4718:Type: vm ioctl 4719:Parameters: struct kvm_msr_filter 4720:Returns: 0 on success, < 0 on error 4721 4722:: 4723 4724 struct kvm_msr_filter_range { 4725 #define KVM_MSR_FILTER_READ (1 << 0) 4726 #define KVM_MSR_FILTER_WRITE (1 << 1) 4727 __u32 flags; 4728 __u32 nmsrs; /* number of msrs in bitmap */ 4729 __u32 base; /* MSR index the bitmap starts at */ 4730 __u8 *bitmap; /* a 1 bit allows the operations in flags, 0 denies */ 4731 }; 4732 4733 #define KVM_MSR_FILTER_MAX_RANGES 16 4734 struct kvm_msr_filter { 4735 #define KVM_MSR_FILTER_DEFAULT_ALLOW (0 << 0) 4736 #define KVM_MSR_FILTER_DEFAULT_DENY (1 << 0) 4737 __u32 flags; 4738 struct kvm_msr_filter_range ranges[KVM_MSR_FILTER_MAX_RANGES]; 4739 }; 4740 4741flags values for ``struct kvm_msr_filter_range``: 4742 4743``KVM_MSR_FILTER_READ`` 4744 4745 Filter read accesses to MSRs using the given bitmap. A 0 in the bitmap 4746 indicates that a read should immediately fail, while a 1 indicates that 4747 a read for a particular MSR should be handled regardless of the default 4748 filter action. 4749 4750``KVM_MSR_FILTER_WRITE`` 4751 4752 Filter write accesses to MSRs using the given bitmap. A 0 in the bitmap 4753 indicates that a write should immediately fail, while a 1 indicates that 4754 a write for a particular MSR should be handled regardless of the default 4755 filter action. 4756 4757``KVM_MSR_FILTER_READ | KVM_MSR_FILTER_WRITE`` 4758 4759 Filter both read and write accesses to MSRs using the given bitmap. A 0 4760 in the bitmap indicates that both reads and writes should immediately fail, 4761 while a 1 indicates that reads and writes for a particular MSR are not 4762 filtered by this range. 4763 4764flags values for ``struct kvm_msr_filter``: 4765 4766``KVM_MSR_FILTER_DEFAULT_ALLOW`` 4767 4768 If no filter range matches an MSR index that is getting accessed, KVM will 4769 fall back to allowing access to the MSR. 4770 4771``KVM_MSR_FILTER_DEFAULT_DENY`` 4772 4773 If no filter range matches an MSR index that is getting accessed, KVM will 4774 fall back to rejecting access to the MSR. In this mode, all MSRs that should 4775 be processed by KVM need to explicitly be marked as allowed in the bitmaps. 4776 4777This ioctl allows user space to define up to 16 bitmaps of MSR ranges to 4778specify whether a certain MSR access should be explicitly filtered for or not. 4779 4780If this ioctl has never been invoked, MSR accesses are not guarded and the 4781default KVM in-kernel emulation behavior is fully preserved. 4782 4783Calling this ioctl with an empty set of ranges (all nmsrs == 0) disables MSR 4784filtering. In that mode, ``KVM_MSR_FILTER_DEFAULT_DENY`` is invalid and causes 4785an error. 4786 4787As soon as the filtering is in place, every MSR access is processed through 4788the filtering except for accesses to the x2APIC MSRs (from 0x800 to 0x8ff); 4789x2APIC MSRs are always allowed, independent of the ``default_allow`` setting, 4790and their behavior depends on the ``X2APIC_ENABLE`` bit of the APIC base 4791register. 4792 4793If a bit is within one of the defined ranges, read and write accesses are 4794guarded by the bitmap's value for the MSR index if the kind of access 4795is included in the ``struct kvm_msr_filter_range`` flags. If no range 4796cover this particular access, the behavior is determined by the flags 4797field in the kvm_msr_filter struct: ``KVM_MSR_FILTER_DEFAULT_ALLOW`` 4798and ``KVM_MSR_FILTER_DEFAULT_DENY``. 4799 4800Each bitmap range specifies a range of MSRs to potentially allow access on. 4801The range goes from MSR index [base .. base+nmsrs]. The flags field 4802indicates whether reads, writes or both reads and writes are filtered 4803by setting a 1 bit in the bitmap for the corresponding MSR index. 4804 4805If an MSR access is not permitted through the filtering, it generates a 4806#GP inside the guest. When combined with KVM_CAP_X86_USER_SPACE_MSR, that 4807allows user space to deflect and potentially handle various MSR accesses 4808into user space. 4809 4810Note, invoking this ioctl with a vCPU is running is inherently racy. However, 4811KVM does guarantee that vCPUs will see either the previous filter or the new 4812filter, e.g. MSRs with identical settings in both the old and new filter will 4813have deterministic behavior. 4814 48154.127 KVM_XEN_HVM_SET_ATTR 4816-------------------------- 4817 4818:Capability: KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_SHARED_INFO 4819:Architectures: x86 4820:Type: vm ioctl 4821:Parameters: struct kvm_xen_hvm_attr 4822:Returns: 0 on success, < 0 on error 4823 4824:: 4825 4826 struct kvm_xen_hvm_attr { 4827 __u16 type; 4828 __u16 pad[3]; 4829 union { 4830 __u8 long_mode; 4831 __u8 vector; 4832 struct { 4833 __u64 gfn; 4834 } shared_info; 4835 __u64 pad[4]; 4836 } u; 4837 }; 4838 4839type values: 4840 4841KVM_XEN_ATTR_TYPE_LONG_MODE 4842 Sets the ABI mode of the VM to 32-bit or 64-bit (long mode). This 4843 determines the layout of the shared info pages exposed to the VM. 4844 4845KVM_XEN_ATTR_TYPE_SHARED_INFO 4846 Sets the guest physical frame number at which the Xen "shared info" 4847 page resides. Note that although Xen places vcpu_info for the first 4848 32 vCPUs in the shared_info page, KVM does not automatically do so 4849 and instead requires that KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO be used 4850 explicitly even when the vcpu_info for a given vCPU resides at the 4851 "default" location in the shared_info page. This is because KVM is 4852 not aware of the Xen CPU id which is used as the index into the 4853 vcpu_info[] array, so cannot know the correct default location. 4854 4855KVM_XEN_ATTR_TYPE_UPCALL_VECTOR 4856 Sets the exception vector used to deliver Xen event channel upcalls. 4857 48584.128 KVM_XEN_HVM_GET_ATTR 4859-------------------------- 4860 4861:Capability: KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_SHARED_INFO 4862:Architectures: x86 4863:Type: vm ioctl 4864:Parameters: struct kvm_xen_hvm_attr 4865:Returns: 0 on success, < 0 on error 4866 4867Allows Xen VM attributes to be read. For the structure and types, 4868see KVM_XEN_HVM_SET_ATTR above. 4869 48704.129 KVM_XEN_VCPU_SET_ATTR 4871--------------------------- 4872 4873:Capability: KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_SHARED_INFO 4874:Architectures: x86 4875:Type: vcpu ioctl 4876:Parameters: struct kvm_xen_vcpu_attr 4877:Returns: 0 on success, < 0 on error 4878 4879:: 4880 4881 struct kvm_xen_vcpu_attr { 4882 __u16 type; 4883 __u16 pad[3]; 4884 union { 4885 __u64 gpa; 4886 __u64 pad[4]; 4887 struct { 4888 __u64 state; 4889 __u64 state_entry_time; 4890 __u64 time_running; 4891 __u64 time_runnable; 4892 __u64 time_blocked; 4893 __u64 time_offline; 4894 } runstate; 4895 } u; 4896 }; 4897 4898type values: 4899 4900KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO 4901 Sets the guest physical address of the vcpu_info for a given vCPU. 4902 4903KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO 4904 Sets the guest physical address of an additional pvclock structure 4905 for a given vCPU. This is typically used for guest vsyscall support. 4906 4907KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADDR 4908 Sets the guest physical address of the vcpu_runstate_info for a given 4909 vCPU. This is how a Xen guest tracks CPU state such as steal time. 4910 4911KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_CURRENT 4912 Sets the runstate (RUNSTATE_running/_runnable/_blocked/_offline) of 4913 the given vCPU from the .u.runstate.state member of the structure. 4914 KVM automatically accounts running and runnable time but blocked 4915 and offline states are only entered explicitly. 4916 4917KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_DATA 4918 Sets all fields of the vCPU runstate data from the .u.runstate member 4919 of the structure, including the current runstate. The state_entry_time 4920 must equal the sum of the other four times. 4921 4922KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADJUST 4923 This *adds* the contents of the .u.runstate members of the structure 4924 to the corresponding members of the given vCPU's runstate data, thus 4925 permitting atomic adjustments to the runstate times. The adjustment 4926 to the state_entry_time must equal the sum of the adjustments to the 4927 other four times. The state field must be set to -1, or to a valid 4928 runstate value (RUNSTATE_running, RUNSTATE_runnable, RUNSTATE_blocked 4929 or RUNSTATE_offline) to set the current accounted state as of the 4930 adjusted state_entry_time. 4931 49324.130 KVM_XEN_VCPU_GET_ATTR 4933--------------------------- 4934 4935:Capability: KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_SHARED_INFO 4936:Architectures: x86 4937:Type: vcpu ioctl 4938:Parameters: struct kvm_xen_vcpu_attr 4939:Returns: 0 on success, < 0 on error 4940 4941Allows Xen vCPU attributes to be read. For the structure and types, 4942see KVM_XEN_VCPU_SET_ATTR above. 4943 4944The KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADJUST type may not be used 4945with the KVM_XEN_VCPU_GET_ATTR ioctl. 4946 49475. The kvm_run structure 4948======================== 4949 4950Application code obtains a pointer to the kvm_run structure by 4951mmap()ing a vcpu fd. From that point, application code can control 4952execution by changing fields in kvm_run prior to calling the KVM_RUN 4953ioctl, and obtain information about the reason KVM_RUN returned by 4954looking up structure members. 4955 4956:: 4957 4958 struct kvm_run { 4959 /* in */ 4960 __u8 request_interrupt_window; 4961 4962Request that KVM_RUN return when it becomes possible to inject external 4963interrupts into the guest. Useful in conjunction with KVM_INTERRUPT. 4964 4965:: 4966 4967 __u8 immediate_exit; 4968 4969This field is polled once when KVM_RUN starts; if non-zero, KVM_RUN 4970exits immediately, returning -EINTR. In the common scenario where a 4971signal is used to "kick" a VCPU out of KVM_RUN, this field can be used 4972to avoid usage of KVM_SET_SIGNAL_MASK, which has worse scalability. 4973Rather than blocking the signal outside KVM_RUN, userspace can set up 4974a signal handler that sets run->immediate_exit to a non-zero value. 4975 4976This field is ignored if KVM_CAP_IMMEDIATE_EXIT is not available. 4977 4978:: 4979 4980 __u8 padding1[6]; 4981 4982 /* out */ 4983 __u32 exit_reason; 4984 4985When KVM_RUN has returned successfully (return value 0), this informs 4986application code why KVM_RUN has returned. Allowable values for this 4987field are detailed below. 4988 4989:: 4990 4991 __u8 ready_for_interrupt_injection; 4992 4993If request_interrupt_window has been specified, this field indicates 4994an interrupt can be injected now with KVM_INTERRUPT. 4995 4996:: 4997 4998 __u8 if_flag; 4999 5000The value of the current interrupt flag. Only valid if in-kernel 5001local APIC is not used. 5002 5003:: 5004 5005 __u16 flags; 5006 5007More architecture-specific flags detailing state of the VCPU that may 5008affect the device's behavior. Current defined flags:: 5009 5010 /* x86, set if the VCPU is in system management mode */ 5011 #define KVM_RUN_X86_SMM (1 << 0) 5012 /* x86, set if bus lock detected in VM */ 5013 #define KVM_RUN_BUS_LOCK (1 << 1) 5014 5015:: 5016 5017 /* in (pre_kvm_run), out (post_kvm_run) */ 5018 __u64 cr8; 5019 5020The value of the cr8 register. Only valid if in-kernel local APIC is 5021not used. Both input and output. 5022 5023:: 5024 5025 __u64 apic_base; 5026 5027The value of the APIC BASE msr. Only valid if in-kernel local 5028APIC is not used. Both input and output. 5029 5030:: 5031 5032 union { 5033 /* KVM_EXIT_UNKNOWN */ 5034 struct { 5035 __u64 hardware_exit_reason; 5036 } hw; 5037 5038If exit_reason is KVM_EXIT_UNKNOWN, the vcpu has exited due to unknown 5039reasons. Further architecture-specific information is available in 5040hardware_exit_reason. 5041 5042:: 5043 5044 /* KVM_EXIT_FAIL_ENTRY */ 5045 struct { 5046 __u64 hardware_entry_failure_reason; 5047 __u32 cpu; /* if KVM_LAST_CPU */ 5048 } fail_entry; 5049 5050If exit_reason is KVM_EXIT_FAIL_ENTRY, the vcpu could not be run due 5051to unknown reasons. Further architecture-specific information is 5052available in hardware_entry_failure_reason. 5053 5054:: 5055 5056 /* KVM_EXIT_EXCEPTION */ 5057 struct { 5058 __u32 exception; 5059 __u32 error_code; 5060 } ex; 5061 5062Unused. 5063 5064:: 5065 5066 /* KVM_EXIT_IO */ 5067 struct { 5068 #define KVM_EXIT_IO_IN 0 5069 #define KVM_EXIT_IO_OUT 1 5070 __u8 direction; 5071 __u8 size; /* bytes */ 5072 __u16 port; 5073 __u32 count; 5074 __u64 data_offset; /* relative to kvm_run start */ 5075 } io; 5076 5077If exit_reason is KVM_EXIT_IO, then the vcpu has 5078executed a port I/O instruction which could not be satisfied by kvm. 5079data_offset describes where the data is located (KVM_EXIT_IO_OUT) or 5080where kvm expects application code to place the data for the next 5081KVM_RUN invocation (KVM_EXIT_IO_IN). Data format is a packed array. 5082 5083:: 5084 5085 /* KVM_EXIT_DEBUG */ 5086 struct { 5087 struct kvm_debug_exit_arch arch; 5088 } debug; 5089 5090If the exit_reason is KVM_EXIT_DEBUG, then a vcpu is processing a debug event 5091for which architecture specific information is returned. 5092 5093:: 5094 5095 /* KVM_EXIT_MMIO */ 5096 struct { 5097 __u64 phys_addr; 5098 __u8 data[8]; 5099 __u32 len; 5100 __u8 is_write; 5101 } mmio; 5102 5103If exit_reason is KVM_EXIT_MMIO, then the vcpu has 5104executed a memory-mapped I/O instruction which could not be satisfied 5105by kvm. The 'data' member contains the written data if 'is_write' is 5106true, and should be filled by application code otherwise. 5107 5108The 'data' member contains, in its first 'len' bytes, the value as it would 5109appear if the VCPU performed a load or store of the appropriate width directly 5110to the byte array. 5111 5112.. note:: 5113 5114 For KVM_EXIT_IO, KVM_EXIT_MMIO, KVM_EXIT_OSI, KVM_EXIT_PAPR, KVM_EXIT_XEN, 5115 KVM_EXIT_EPR, KVM_EXIT_X86_RDMSR and KVM_EXIT_X86_WRMSR the corresponding 5116 operations are complete (and guest state is consistent) only after userspace 5117 has re-entered the kernel with KVM_RUN. The kernel side will first finish 5118 incomplete operations and then check for pending signals. 5119 5120 The pending state of the operation is not preserved in state which is 5121 visible to userspace, thus userspace should ensure that the operation is 5122 completed before performing a live migration. Userspace can re-enter the 5123 guest with an unmasked signal pending or with the immediate_exit field set 5124 to complete pending operations without allowing any further instructions 5125 to be executed. 5126 5127:: 5128 5129 /* KVM_EXIT_HYPERCALL */ 5130 struct { 5131 __u64 nr; 5132 __u64 args[6]; 5133 __u64 ret; 5134 __u32 longmode; 5135 __u32 pad; 5136 } hypercall; 5137 5138Unused. This was once used for 'hypercall to userspace'. To implement 5139such functionality, use KVM_EXIT_IO (x86) or KVM_EXIT_MMIO (all except s390). 5140 5141.. note:: KVM_EXIT_IO is significantly faster than KVM_EXIT_MMIO. 5142 5143:: 5144 5145 /* KVM_EXIT_TPR_ACCESS */ 5146 struct { 5147 __u64 rip; 5148 __u32 is_write; 5149 __u32 pad; 5150 } tpr_access; 5151 5152To be documented (KVM_TPR_ACCESS_REPORTING). 5153 5154:: 5155 5156 /* KVM_EXIT_S390_SIEIC */ 5157 struct { 5158 __u8 icptcode; 5159 __u64 mask; /* psw upper half */ 5160 __u64 addr; /* psw lower half */ 5161 __u16 ipa; 5162 __u32 ipb; 5163 } s390_sieic; 5164 5165s390 specific. 5166 5167:: 5168 5169 /* KVM_EXIT_S390_RESET */ 5170 #define KVM_S390_RESET_POR 1 5171 #define KVM_S390_RESET_CLEAR 2 5172 #define KVM_S390_RESET_SUBSYSTEM 4 5173 #define KVM_S390_RESET_CPU_INIT 8 5174 #define KVM_S390_RESET_IPL 16 5175 __u64 s390_reset_flags; 5176 5177s390 specific. 5178 5179:: 5180 5181 /* KVM_EXIT_S390_UCONTROL */ 5182 struct { 5183 __u64 trans_exc_code; 5184 __u32 pgm_code; 5185 } s390_ucontrol; 5186 5187s390 specific. A page fault has occurred for a user controlled virtual 5188machine (KVM_VM_S390_UNCONTROL) on it's host page table that cannot be 5189resolved by the kernel. 5190The program code and the translation exception code that were placed 5191in the cpu's lowcore are presented here as defined by the z Architecture 5192Principles of Operation Book in the Chapter for Dynamic Address Translation 5193(DAT) 5194 5195:: 5196 5197 /* KVM_EXIT_DCR */ 5198 struct { 5199 __u32 dcrn; 5200 __u32 data; 5201 __u8 is_write; 5202 } dcr; 5203 5204Deprecated - was used for 440 KVM. 5205 5206:: 5207 5208 /* KVM_EXIT_OSI */ 5209 struct { 5210 __u64 gprs[32]; 5211 } osi; 5212 5213MOL uses a special hypercall interface it calls 'OSI'. To enable it, we catch 5214hypercalls and exit with this exit struct that contains all the guest gprs. 5215 5216If exit_reason is KVM_EXIT_OSI, then the vcpu has triggered such a hypercall. 5217Userspace can now handle the hypercall and when it's done modify the gprs as 5218necessary. Upon guest entry all guest GPRs will then be replaced by the values 5219in this struct. 5220 5221:: 5222 5223 /* KVM_EXIT_PAPR_HCALL */ 5224 struct { 5225 __u64 nr; 5226 __u64 ret; 5227 __u64 args[9]; 5228 } papr_hcall; 5229 5230This is used on 64-bit PowerPC when emulating a pSeries partition, 5231e.g. with the 'pseries' machine type in qemu. It occurs when the 5232guest does a hypercall using the 'sc 1' instruction. The 'nr' field 5233contains the hypercall number (from the guest R3), and 'args' contains 5234the arguments (from the guest R4 - R12). Userspace should put the 5235return code in 'ret' and any extra returned values in args[]. 5236The possible hypercalls are defined in the Power Architecture Platform 5237Requirements (PAPR) document available from www.power.org (free 5238developer registration required to access it). 5239 5240:: 5241 5242 /* KVM_EXIT_S390_TSCH */ 5243 struct { 5244 __u16 subchannel_id; 5245 __u16 subchannel_nr; 5246 __u32 io_int_parm; 5247 __u32 io_int_word; 5248 __u32 ipb; 5249 __u8 dequeued; 5250 } s390_tsch; 5251 5252s390 specific. This exit occurs when KVM_CAP_S390_CSS_SUPPORT has been enabled 5253and TEST SUBCHANNEL was intercepted. If dequeued is set, a pending I/O 5254interrupt for the target subchannel has been dequeued and subchannel_id, 5255subchannel_nr, io_int_parm and io_int_word contain the parameters for that 5256interrupt. ipb is needed for instruction parameter decoding. 5257 5258:: 5259 5260 /* KVM_EXIT_EPR */ 5261 struct { 5262 __u32 epr; 5263 } epr; 5264 5265On FSL BookE PowerPC chips, the interrupt controller has a fast patch 5266interrupt acknowledge path to the core. When the core successfully 5267delivers an interrupt, it automatically populates the EPR register with 5268the interrupt vector number and acknowledges the interrupt inside 5269the interrupt controller. 5270 5271In case the interrupt controller lives in user space, we need to do 5272the interrupt acknowledge cycle through it to fetch the next to be 5273delivered interrupt vector using this exit. 5274 5275It gets triggered whenever both KVM_CAP_PPC_EPR are enabled and an 5276external interrupt has just been delivered into the guest. User space 5277should put the acknowledged interrupt vector into the 'epr' field. 5278 5279:: 5280 5281 /* KVM_EXIT_SYSTEM_EVENT */ 5282 struct { 5283 #define KVM_SYSTEM_EVENT_SHUTDOWN 1 5284 #define KVM_SYSTEM_EVENT_RESET 2 5285 #define KVM_SYSTEM_EVENT_CRASH 3 5286 __u32 type; 5287 __u64 flags; 5288 } system_event; 5289 5290If exit_reason is KVM_EXIT_SYSTEM_EVENT then the vcpu has triggered 5291a system-level event using some architecture specific mechanism (hypercall 5292or some special instruction). In case of ARM/ARM64, this is triggered using 5293HVC instruction based PSCI call from the vcpu. The 'type' field describes 5294the system-level event type. The 'flags' field describes architecture 5295specific flags for the system-level event. 5296 5297Valid values for 'type' are: 5298 5299 - KVM_SYSTEM_EVENT_SHUTDOWN -- the guest has requested a shutdown of the 5300 VM. Userspace is not obliged to honour this, and if it does honour 5301 this does not need to destroy the VM synchronously (ie it may call 5302 KVM_RUN again before shutdown finally occurs). 5303 - KVM_SYSTEM_EVENT_RESET -- the guest has requested a reset of the VM. 5304 As with SHUTDOWN, userspace can choose to ignore the request, or 5305 to schedule the reset to occur in the future and may call KVM_RUN again. 5306 - KVM_SYSTEM_EVENT_CRASH -- the guest crash occurred and the guest 5307 has requested a crash condition maintenance. Userspace can choose 5308 to ignore the request, or to gather VM memory core dump and/or 5309 reset/shutdown of the VM. 5310 5311:: 5312 5313 /* KVM_EXIT_IOAPIC_EOI */ 5314 struct { 5315 __u8 vector; 5316 } eoi; 5317 5318Indicates that the VCPU's in-kernel local APIC received an EOI for a 5319level-triggered IOAPIC interrupt. This exit only triggers when the 5320IOAPIC is implemented in userspace (i.e. KVM_CAP_SPLIT_IRQCHIP is enabled); 5321the userspace IOAPIC should process the EOI and retrigger the interrupt if 5322it is still asserted. Vector is the LAPIC interrupt vector for which the 5323EOI was received. 5324 5325:: 5326 5327 struct kvm_hyperv_exit { 5328 #define KVM_EXIT_HYPERV_SYNIC 1 5329 #define KVM_EXIT_HYPERV_HCALL 2 5330 #define KVM_EXIT_HYPERV_SYNDBG 3 5331 __u32 type; 5332 __u32 pad1; 5333 union { 5334 struct { 5335 __u32 msr; 5336 __u32 pad2; 5337 __u64 control; 5338 __u64 evt_page; 5339 __u64 msg_page; 5340 } synic; 5341 struct { 5342 __u64 input; 5343 __u64 result; 5344 __u64 params[2]; 5345 } hcall; 5346 struct { 5347 __u32 msr; 5348 __u32 pad2; 5349 __u64 control; 5350 __u64 status; 5351 __u64 send_page; 5352 __u64 recv_page; 5353 __u64 pending_page; 5354 } syndbg; 5355 } u; 5356 }; 5357 /* KVM_EXIT_HYPERV */ 5358 struct kvm_hyperv_exit hyperv; 5359 5360Indicates that the VCPU exits into userspace to process some tasks 5361related to Hyper-V emulation. 5362 5363Valid values for 'type' are: 5364 5365 - KVM_EXIT_HYPERV_SYNIC -- synchronously notify user-space about 5366 5367Hyper-V SynIC state change. Notification is used to remap SynIC 5368event/message pages and to enable/disable SynIC messages/events processing 5369in userspace. 5370 5371 - KVM_EXIT_HYPERV_SYNDBG -- synchronously notify user-space about 5372 5373Hyper-V Synthetic debugger state change. Notification is used to either update 5374the pending_page location or to send a control command (send the buffer located 5375in send_page or recv a buffer to recv_page). 5376 5377:: 5378 5379 /* KVM_EXIT_ARM_NISV */ 5380 struct { 5381 __u64 esr_iss; 5382 __u64 fault_ipa; 5383 } arm_nisv; 5384 5385Used on arm and arm64 systems. If a guest accesses memory not in a memslot, 5386KVM will typically return to userspace and ask it to do MMIO emulation on its 5387behalf. However, for certain classes of instructions, no instruction decode 5388(direction, length of memory access) is provided, and fetching and decoding 5389the instruction from the VM is overly complicated to live in the kernel. 5390 5391Historically, when this situation occurred, KVM would print a warning and kill 5392the VM. KVM assumed that if the guest accessed non-memslot memory, it was 5393trying to do I/O, which just couldn't be emulated, and the warning message was 5394phrased accordingly. However, what happened more often was that a guest bug 5395caused access outside the guest memory areas which should lead to a more 5396meaningful warning message and an external abort in the guest, if the access 5397did not fall within an I/O window. 5398 5399Userspace implementations can query for KVM_CAP_ARM_NISV_TO_USER, and enable 5400this capability at VM creation. Once this is done, these types of errors will 5401instead return to userspace with KVM_EXIT_ARM_NISV, with the valid bits from 5402the HSR (arm) and ESR_EL2 (arm64) in the esr_iss field, and the faulting IPA 5403in the fault_ipa field. Userspace can either fix up the access if it's 5404actually an I/O access by decoding the instruction from guest memory (if it's 5405very brave) and continue executing the guest, or it can decide to suspend, 5406dump, or restart the guest. 5407 5408Note that KVM does not skip the faulting instruction as it does for 5409KVM_EXIT_MMIO, but userspace has to emulate any change to the processing state 5410if it decides to decode and emulate the instruction. 5411 5412:: 5413 5414 /* KVM_EXIT_X86_RDMSR / KVM_EXIT_X86_WRMSR */ 5415 struct { 5416 __u8 error; /* user -> kernel */ 5417 __u8 pad[7]; 5418 __u32 reason; /* kernel -> user */ 5419 __u32 index; /* kernel -> user */ 5420 __u64 data; /* kernel <-> user */ 5421 } msr; 5422 5423Used on x86 systems. When the VM capability KVM_CAP_X86_USER_SPACE_MSR is 5424enabled, MSR accesses to registers that would invoke a #GP by KVM kernel code 5425will instead trigger a KVM_EXIT_X86_RDMSR exit for reads and KVM_EXIT_X86_WRMSR 5426exit for writes. 5427 5428The "reason" field specifies why the MSR trap occurred. User space will only 5429receive MSR exit traps when a particular reason was requested during through 5430ENABLE_CAP. Currently valid exit reasons are: 5431 5432 KVM_MSR_EXIT_REASON_UNKNOWN - access to MSR that is unknown to KVM 5433 KVM_MSR_EXIT_REASON_INVAL - access to invalid MSRs or reserved bits 5434 KVM_MSR_EXIT_REASON_FILTER - access blocked by KVM_X86_SET_MSR_FILTER 5435 5436For KVM_EXIT_X86_RDMSR, the "index" field tells user space which MSR the guest 5437wants to read. To respond to this request with a successful read, user space 5438writes the respective data into the "data" field and must continue guest 5439execution to ensure the read data is transferred into guest register state. 5440 5441If the RDMSR request was unsuccessful, user space indicates that with a "1" in 5442the "error" field. This will inject a #GP into the guest when the VCPU is 5443executed again. 5444 5445For KVM_EXIT_X86_WRMSR, the "index" field tells user space which MSR the guest 5446wants to write. Once finished processing the event, user space must continue 5447vCPU execution. If the MSR write was unsuccessful, user space also sets the 5448"error" field to "1". 5449 5450:: 5451 5452 5453 struct kvm_xen_exit { 5454 #define KVM_EXIT_XEN_HCALL 1 5455 __u32 type; 5456 union { 5457 struct { 5458 __u32 longmode; 5459 __u32 cpl; 5460 __u64 input; 5461 __u64 result; 5462 __u64 params[6]; 5463 } hcall; 5464 } u; 5465 }; 5466 /* KVM_EXIT_XEN */ 5467 struct kvm_hyperv_exit xen; 5468 5469Indicates that the VCPU exits into userspace to process some tasks 5470related to Xen emulation. 5471 5472Valid values for 'type' are: 5473 5474 - KVM_EXIT_XEN_HCALL -- synchronously notify user-space about Xen hypercall. 5475 Userspace is expected to place the hypercall result into the appropriate 5476 field before invoking KVM_RUN again. 5477 5478:: 5479 5480 /* Fix the size of the union. */ 5481 char padding[256]; 5482 }; 5483 5484 /* 5485 * shared registers between kvm and userspace. 5486 * kvm_valid_regs specifies the register classes set by the host 5487 * kvm_dirty_regs specified the register classes dirtied by userspace 5488 * struct kvm_sync_regs is architecture specific, as well as the 5489 * bits for kvm_valid_regs and kvm_dirty_regs 5490 */ 5491 __u64 kvm_valid_regs; 5492 __u64 kvm_dirty_regs; 5493 union { 5494 struct kvm_sync_regs regs; 5495 char padding[SYNC_REGS_SIZE_BYTES]; 5496 } s; 5497 5498If KVM_CAP_SYNC_REGS is defined, these fields allow userspace to access 5499certain guest registers without having to call SET/GET_*REGS. Thus we can 5500avoid some system call overhead if userspace has to handle the exit. 5501Userspace can query the validity of the structure by checking 5502kvm_valid_regs for specific bits. These bits are architecture specific 5503and usually define the validity of a groups of registers. (e.g. one bit 5504for general purpose registers) 5505 5506Please note that the kernel is allowed to use the kvm_run structure as the 5507primary storage for certain register types. Therefore, the kernel may use the 5508values in kvm_run even if the corresponding bit in kvm_dirty_regs is not set. 5509 5510:: 5511 5512 }; 5513 5514 5515 55166. Capabilities that can be enabled on vCPUs 5517============================================ 5518 5519There are certain capabilities that change the behavior of the virtual CPU or 5520the virtual machine when enabled. To enable them, please see section 4.37. 5521Below you can find a list of capabilities and what their effect on the vCPU or 5522the virtual machine is when enabling them. 5523 5524The following information is provided along with the description: 5525 5526 Architectures: 5527 which instruction set architectures provide this ioctl. 5528 x86 includes both i386 and x86_64. 5529 5530 Target: 5531 whether this is a per-vcpu or per-vm capability. 5532 5533 Parameters: 5534 what parameters are accepted by the capability. 5535 5536 Returns: 5537 the return value. General error numbers (EBADF, ENOMEM, EINVAL) 5538 are not detailed, but errors with specific meanings are. 5539 5540 55416.1 KVM_CAP_PPC_OSI 5542------------------- 5543 5544:Architectures: ppc 5545:Target: vcpu 5546:Parameters: none 5547:Returns: 0 on success; -1 on error 5548 5549This capability enables interception of OSI hypercalls that otherwise would 5550be treated as normal system calls to be injected into the guest. OSI hypercalls 5551were invented by Mac-on-Linux to have a standardized communication mechanism 5552between the guest and the host. 5553 5554When this capability is enabled, KVM_EXIT_OSI can occur. 5555 5556 55576.2 KVM_CAP_PPC_PAPR 5558-------------------- 5559 5560:Architectures: ppc 5561:Target: vcpu 5562:Parameters: none 5563:Returns: 0 on success; -1 on error 5564 5565This capability enables interception of PAPR hypercalls. PAPR hypercalls are 5566done using the hypercall instruction "sc 1". 5567 5568It also sets the guest privilege level to "supervisor" mode. Usually the guest 5569runs in "hypervisor" privilege mode with a few missing features. 5570 5571In addition to the above, it changes the semantics of SDR1. In this mode, the 5572HTAB address part of SDR1 contains an HVA instead of a GPA, as PAPR keeps the 5573HTAB invisible to the guest. 5574 5575When this capability is enabled, KVM_EXIT_PAPR_HCALL can occur. 5576 5577 55786.3 KVM_CAP_SW_TLB 5579------------------ 5580 5581:Architectures: ppc 5582:Target: vcpu 5583:Parameters: args[0] is the address of a struct kvm_config_tlb 5584:Returns: 0 on success; -1 on error 5585 5586:: 5587 5588 struct kvm_config_tlb { 5589 __u64 params; 5590 __u64 array; 5591 __u32 mmu_type; 5592 __u32 array_len; 5593 }; 5594 5595Configures the virtual CPU's TLB array, establishing a shared memory area 5596between userspace and KVM. The "params" and "array" fields are userspace 5597addresses of mmu-type-specific data structures. The "array_len" field is an 5598safety mechanism, and should be set to the size in bytes of the memory that 5599userspace has reserved for the array. It must be at least the size dictated 5600by "mmu_type" and "params". 5601 5602While KVM_RUN is active, the shared region is under control of KVM. Its 5603contents are undefined, and any modification by userspace results in 5604boundedly undefined behavior. 5605 5606On return from KVM_RUN, the shared region will reflect the current state of 5607the guest's TLB. If userspace makes any changes, it must call KVM_DIRTY_TLB 5608to tell KVM which entries have been changed, prior to calling KVM_RUN again 5609on this vcpu. 5610 5611For mmu types KVM_MMU_FSL_BOOKE_NOHV and KVM_MMU_FSL_BOOKE_HV: 5612 5613 - The "params" field is of type "struct kvm_book3e_206_tlb_params". 5614 - The "array" field points to an array of type "struct 5615 kvm_book3e_206_tlb_entry". 5616 - The array consists of all entries in the first TLB, followed by all 5617 entries in the second TLB. 5618 - Within a TLB, entries are ordered first by increasing set number. Within a 5619 set, entries are ordered by way (increasing ESEL). 5620 - The hash for determining set number in TLB0 is: (MAS2 >> 12) & (num_sets - 1) 5621 where "num_sets" is the tlb_sizes[] value divided by the tlb_ways[] value. 5622 - The tsize field of mas1 shall be set to 4K on TLB0, even though the 5623 hardware ignores this value for TLB0. 5624 56256.4 KVM_CAP_S390_CSS_SUPPORT 5626---------------------------- 5627 5628:Architectures: s390 5629:Target: vcpu 5630:Parameters: none 5631:Returns: 0 on success; -1 on error 5632 5633This capability enables support for handling of channel I/O instructions. 5634 5635TEST PENDING INTERRUPTION and the interrupt portion of TEST SUBCHANNEL are 5636handled in-kernel, while the other I/O instructions are passed to userspace. 5637 5638When this capability is enabled, KVM_EXIT_S390_TSCH will occur on TEST 5639SUBCHANNEL intercepts. 5640 5641Note that even though this capability is enabled per-vcpu, the complete 5642virtual machine is affected. 5643 56446.5 KVM_CAP_PPC_EPR 5645------------------- 5646 5647:Architectures: ppc 5648:Target: vcpu 5649:Parameters: args[0] defines whether the proxy facility is active 5650:Returns: 0 on success; -1 on error 5651 5652This capability enables or disables the delivery of interrupts through the 5653external proxy facility. 5654 5655When enabled (args[0] != 0), every time the guest gets an external interrupt 5656delivered, it automatically exits into user space with a KVM_EXIT_EPR exit 5657to receive the topmost interrupt vector. 5658 5659When disabled (args[0] == 0), behavior is as if this facility is unsupported. 5660 5661When this capability is enabled, KVM_EXIT_EPR can occur. 5662 56636.6 KVM_CAP_IRQ_MPIC 5664-------------------- 5665 5666:Architectures: ppc 5667:Parameters: args[0] is the MPIC device fd; 5668 args[1] is the MPIC CPU number for this vcpu 5669 5670This capability connects the vcpu to an in-kernel MPIC device. 5671 56726.7 KVM_CAP_IRQ_XICS 5673-------------------- 5674 5675:Architectures: ppc 5676:Target: vcpu 5677:Parameters: args[0] is the XICS device fd; 5678 args[1] is the XICS CPU number (server ID) for this vcpu 5679 5680This capability connects the vcpu to an in-kernel XICS device. 5681 56826.8 KVM_CAP_S390_IRQCHIP 5683------------------------ 5684 5685:Architectures: s390 5686:Target: vm 5687:Parameters: none 5688 5689This capability enables the in-kernel irqchip for s390. Please refer to 5690"4.24 KVM_CREATE_IRQCHIP" for details. 5691 56926.9 KVM_CAP_MIPS_FPU 5693-------------------- 5694 5695:Architectures: mips 5696:Target: vcpu 5697:Parameters: args[0] is reserved for future use (should be 0). 5698 5699This capability allows the use of the host Floating Point Unit by the guest. It 5700allows the Config1.FP bit to be set to enable the FPU in the guest. Once this is 5701done the ``KVM_REG_MIPS_FPR_*`` and ``KVM_REG_MIPS_FCR_*`` registers can be 5702accessed (depending on the current guest FPU register mode), and the Status.FR, 5703Config5.FRE bits are accessible via the KVM API and also from the guest, 5704depending on them being supported by the FPU. 5705 57066.10 KVM_CAP_MIPS_MSA 5707--------------------- 5708 5709:Architectures: mips 5710:Target: vcpu 5711:Parameters: args[0] is reserved for future use (should be 0). 5712 5713This capability allows the use of the MIPS SIMD Architecture (MSA) by the guest. 5714It allows the Config3.MSAP bit to be set to enable the use of MSA by the guest. 5715Once this is done the ``KVM_REG_MIPS_VEC_*`` and ``KVM_REG_MIPS_MSA_*`` 5716registers can be accessed, and the Config5.MSAEn bit is accessible via the 5717KVM API and also from the guest. 5718 57196.74 KVM_CAP_SYNC_REGS 5720---------------------- 5721 5722:Architectures: s390, x86 5723:Target: s390: always enabled, x86: vcpu 5724:Parameters: none 5725:Returns: x86: KVM_CHECK_EXTENSION returns a bit-array indicating which register 5726 sets are supported 5727 (bitfields defined in arch/x86/include/uapi/asm/kvm.h). 5728 5729As described above in the kvm_sync_regs struct info in section 5 (kvm_run): 5730KVM_CAP_SYNC_REGS "allow[s] userspace to access certain guest registers 5731without having to call SET/GET_*REGS". This reduces overhead by eliminating 5732repeated ioctl calls for setting and/or getting register values. This is 5733particularly important when userspace is making synchronous guest state 5734modifications, e.g. when emulating and/or intercepting instructions in 5735userspace. 5736 5737For s390 specifics, please refer to the source code. 5738 5739For x86: 5740 5741- the register sets to be copied out to kvm_run are selectable 5742 by userspace (rather that all sets being copied out for every exit). 5743- vcpu_events are available in addition to regs and sregs. 5744 5745For x86, the 'kvm_valid_regs' field of struct kvm_run is overloaded to 5746function as an input bit-array field set by userspace to indicate the 5747specific register sets to be copied out on the next exit. 5748 5749To indicate when userspace has modified values that should be copied into 5750the vCPU, the all architecture bitarray field, 'kvm_dirty_regs' must be set. 5751This is done using the same bitflags as for the 'kvm_valid_regs' field. 5752If the dirty bit is not set, then the register set values will not be copied 5753into the vCPU even if they've been modified. 5754 5755Unused bitfields in the bitarrays must be set to zero. 5756 5757:: 5758 5759 struct kvm_sync_regs { 5760 struct kvm_regs regs; 5761 struct kvm_sregs sregs; 5762 struct kvm_vcpu_events events; 5763 }; 5764 57656.75 KVM_CAP_PPC_IRQ_XIVE 5766------------------------- 5767 5768:Architectures: ppc 5769:Target: vcpu 5770:Parameters: args[0] is the XIVE device fd; 5771 args[1] is the XIVE CPU number (server ID) for this vcpu 5772 5773This capability connects the vcpu to an in-kernel XIVE device. 5774 57757. Capabilities that can be enabled on VMs 5776========================================== 5777 5778There are certain capabilities that change the behavior of the virtual 5779machine when enabled. To enable them, please see section 4.37. Below 5780you can find a list of capabilities and what their effect on the VM 5781is when enabling them. 5782 5783The following information is provided along with the description: 5784 5785 Architectures: 5786 which instruction set architectures provide this ioctl. 5787 x86 includes both i386 and x86_64. 5788 5789 Parameters: 5790 what parameters are accepted by the capability. 5791 5792 Returns: 5793 the return value. General error numbers (EBADF, ENOMEM, EINVAL) 5794 are not detailed, but errors with specific meanings are. 5795 5796 57977.1 KVM_CAP_PPC_ENABLE_HCALL 5798---------------------------- 5799 5800:Architectures: ppc 5801:Parameters: args[0] is the sPAPR hcall number; 5802 args[1] is 0 to disable, 1 to enable in-kernel handling 5803 5804This capability controls whether individual sPAPR hypercalls (hcalls) 5805get handled by the kernel or not. Enabling or disabling in-kernel 5806handling of an hcall is effective across the VM. On creation, an 5807initial set of hcalls are enabled for in-kernel handling, which 5808consists of those hcalls for which in-kernel handlers were implemented 5809before this capability was implemented. If disabled, the kernel will 5810not to attempt to handle the hcall, but will always exit to userspace 5811to handle it. Note that it may not make sense to enable some and 5812disable others of a group of related hcalls, but KVM does not prevent 5813userspace from doing that. 5814 5815If the hcall number specified is not one that has an in-kernel 5816implementation, the KVM_ENABLE_CAP ioctl will fail with an EINVAL 5817error. 5818 58197.2 KVM_CAP_S390_USER_SIGP 5820-------------------------- 5821 5822:Architectures: s390 5823:Parameters: none 5824 5825This capability controls which SIGP orders will be handled completely in user 5826space. With this capability enabled, all fast orders will be handled completely 5827in the kernel: 5828 5829- SENSE 5830- SENSE RUNNING 5831- EXTERNAL CALL 5832- EMERGENCY SIGNAL 5833- CONDITIONAL EMERGENCY SIGNAL 5834 5835All other orders will be handled completely in user space. 5836 5837Only privileged operation exceptions will be checked for in the kernel (or even 5838in the hardware prior to interception). If this capability is not enabled, the 5839old way of handling SIGP orders is used (partially in kernel and user space). 5840 58417.3 KVM_CAP_S390_VECTOR_REGISTERS 5842--------------------------------- 5843 5844:Architectures: s390 5845:Parameters: none 5846:Returns: 0 on success, negative value on error 5847 5848Allows use of the vector registers introduced with z13 processor, and 5849provides for the synchronization between host and user space. Will 5850return -EINVAL if the machine does not support vectors. 5851 58527.4 KVM_CAP_S390_USER_STSI 5853-------------------------- 5854 5855:Architectures: s390 5856:Parameters: none 5857 5858This capability allows post-handlers for the STSI instruction. After 5859initial handling in the kernel, KVM exits to user space with 5860KVM_EXIT_S390_STSI to allow user space to insert further data. 5861 5862Before exiting to userspace, kvm handlers should fill in s390_stsi field of 5863vcpu->run:: 5864 5865 struct { 5866 __u64 addr; 5867 __u8 ar; 5868 __u8 reserved; 5869 __u8 fc; 5870 __u8 sel1; 5871 __u16 sel2; 5872 } s390_stsi; 5873 5874 @addr - guest address of STSI SYSIB 5875 @fc - function code 5876 @sel1 - selector 1 5877 @sel2 - selector 2 5878 @ar - access register number 5879 5880KVM handlers should exit to userspace with rc = -EREMOTE. 5881 58827.5 KVM_CAP_SPLIT_IRQCHIP 5883------------------------- 5884 5885:Architectures: x86 5886:Parameters: args[0] - number of routes reserved for userspace IOAPICs 5887:Returns: 0 on success, -1 on error 5888 5889Create a local apic for each processor in the kernel. This can be used 5890instead of KVM_CREATE_IRQCHIP if the userspace VMM wishes to emulate the 5891IOAPIC and PIC (and also the PIT, even though this has to be enabled 5892separately). 5893 5894This capability also enables in kernel routing of interrupt requests; 5895when KVM_CAP_SPLIT_IRQCHIP only routes of KVM_IRQ_ROUTING_MSI type are 5896used in the IRQ routing table. The first args[0] MSI routes are reserved 5897for the IOAPIC pins. Whenever the LAPIC receives an EOI for these routes, 5898a KVM_EXIT_IOAPIC_EOI vmexit will be reported to userspace. 5899 5900Fails if VCPU has already been created, or if the irqchip is already in the 5901kernel (i.e. KVM_CREATE_IRQCHIP has already been called). 5902 59037.6 KVM_CAP_S390_RI 5904------------------- 5905 5906:Architectures: s390 5907:Parameters: none 5908 5909Allows use of runtime-instrumentation introduced with zEC12 processor. 5910Will return -EINVAL if the machine does not support runtime-instrumentation. 5911Will return -EBUSY if a VCPU has already been created. 5912 59137.7 KVM_CAP_X2APIC_API 5914---------------------- 5915 5916:Architectures: x86 5917:Parameters: args[0] - features that should be enabled 5918:Returns: 0 on success, -EINVAL when args[0] contains invalid features 5919 5920Valid feature flags in args[0] are:: 5921 5922 #define KVM_X2APIC_API_USE_32BIT_IDS (1ULL << 0) 5923 #define KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK (1ULL << 1) 5924 5925Enabling KVM_X2APIC_API_USE_32BIT_IDS changes the behavior of 5926KVM_SET_GSI_ROUTING, KVM_SIGNAL_MSI, KVM_SET_LAPIC, and KVM_GET_LAPIC, 5927allowing the use of 32-bit APIC IDs. See KVM_CAP_X2APIC_API in their 5928respective sections. 5929 5930KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK must be enabled for x2APIC to work 5931in logical mode or with more than 255 VCPUs. Otherwise, KVM treats 0xff 5932as a broadcast even in x2APIC mode in order to support physical x2APIC 5933without interrupt remapping. This is undesirable in logical mode, 5934where 0xff represents CPUs 0-7 in cluster 0. 5935 59367.8 KVM_CAP_S390_USER_INSTR0 5937---------------------------- 5938 5939:Architectures: s390 5940:Parameters: none 5941 5942With this capability enabled, all illegal instructions 0x0000 (2 bytes) will 5943be intercepted and forwarded to user space. User space can use this 5944mechanism e.g. to realize 2-byte software breakpoints. The kernel will 5945not inject an operating exception for these instructions, user space has 5946to take care of that. 5947 5948This capability can be enabled dynamically even if VCPUs were already 5949created and are running. 5950 59517.9 KVM_CAP_S390_GS 5952------------------- 5953 5954:Architectures: s390 5955:Parameters: none 5956:Returns: 0 on success; -EINVAL if the machine does not support 5957 guarded storage; -EBUSY if a VCPU has already been created. 5958 5959Allows use of guarded storage for the KVM guest. 5960 59617.10 KVM_CAP_S390_AIS 5962--------------------- 5963 5964:Architectures: s390 5965:Parameters: none 5966 5967Allow use of adapter-interruption suppression. 5968:Returns: 0 on success; -EBUSY if a VCPU has already been created. 5969 59707.11 KVM_CAP_PPC_SMT 5971-------------------- 5972 5973:Architectures: ppc 5974:Parameters: vsmt_mode, flags 5975 5976Enabling this capability on a VM provides userspace with a way to set 5977the desired virtual SMT mode (i.e. the number of virtual CPUs per 5978virtual core). The virtual SMT mode, vsmt_mode, must be a power of 2 5979between 1 and 8. On POWER8, vsmt_mode must also be no greater than 5980the number of threads per subcore for the host. Currently flags must 5981be 0. A successful call to enable this capability will result in 5982vsmt_mode being returned when the KVM_CAP_PPC_SMT capability is 5983subsequently queried for the VM. This capability is only supported by 5984HV KVM, and can only be set before any VCPUs have been created. 5985The KVM_CAP_PPC_SMT_POSSIBLE capability indicates which virtual SMT 5986modes are available. 5987 59887.12 KVM_CAP_PPC_FWNMI 5989---------------------- 5990 5991:Architectures: ppc 5992:Parameters: none 5993 5994With this capability a machine check exception in the guest address 5995space will cause KVM to exit the guest with NMI exit reason. This 5996enables QEMU to build error log and branch to guest kernel registered 5997machine check handling routine. Without this capability KVM will 5998branch to guests' 0x200 interrupt vector. 5999 60007.13 KVM_CAP_X86_DISABLE_EXITS 6001------------------------------ 6002 6003:Architectures: x86 6004:Parameters: args[0] defines which exits are disabled 6005:Returns: 0 on success, -EINVAL when args[0] contains invalid exits 6006 6007Valid bits in args[0] are:: 6008 6009 #define KVM_X86_DISABLE_EXITS_MWAIT (1 << 0) 6010 #define KVM_X86_DISABLE_EXITS_HLT (1 << 1) 6011 #define KVM_X86_DISABLE_EXITS_PAUSE (1 << 2) 6012 #define KVM_X86_DISABLE_EXITS_CSTATE (1 << 3) 6013 6014Enabling this capability on a VM provides userspace with a way to no 6015longer intercept some instructions for improved latency in some 6016workloads, and is suggested when vCPUs are associated to dedicated 6017physical CPUs. More bits can be added in the future; userspace can 6018just pass the KVM_CHECK_EXTENSION result to KVM_ENABLE_CAP to disable 6019all such vmexits. 6020 6021Do not enable KVM_FEATURE_PV_UNHALT if you disable HLT exits. 6022 60237.14 KVM_CAP_S390_HPAGE_1M 6024-------------------------- 6025 6026:Architectures: s390 6027:Parameters: none 6028:Returns: 0 on success, -EINVAL if hpage module parameter was not set 6029 or cmma is enabled, or the VM has the KVM_VM_S390_UCONTROL 6030 flag set 6031 6032With this capability the KVM support for memory backing with 1m pages 6033through hugetlbfs can be enabled for a VM. After the capability is 6034enabled, cmma can't be enabled anymore and pfmfi and the storage key 6035interpretation are disabled. If cmma has already been enabled or the 6036hpage module parameter is not set to 1, -EINVAL is returned. 6037 6038While it is generally possible to create a huge page backed VM without 6039this capability, the VM will not be able to run. 6040 60417.15 KVM_CAP_MSR_PLATFORM_INFO 6042------------------------------ 6043 6044:Architectures: x86 6045:Parameters: args[0] whether feature should be enabled or not 6046 6047With this capability, a guest may read the MSR_PLATFORM_INFO MSR. Otherwise, 6048a #GP would be raised when the guest tries to access. Currently, this 6049capability does not enable write permissions of this MSR for the guest. 6050 60517.16 KVM_CAP_PPC_NESTED_HV 6052-------------------------- 6053 6054:Architectures: ppc 6055:Parameters: none 6056:Returns: 0 on success, -EINVAL when the implementation doesn't support 6057 nested-HV virtualization. 6058 6059HV-KVM on POWER9 and later systems allows for "nested-HV" 6060virtualization, which provides a way for a guest VM to run guests that 6061can run using the CPU's supervisor mode (privileged non-hypervisor 6062state). Enabling this capability on a VM depends on the CPU having 6063the necessary functionality and on the facility being enabled with a 6064kvm-hv module parameter. 6065 60667.17 KVM_CAP_EXCEPTION_PAYLOAD 6067------------------------------ 6068 6069:Architectures: x86 6070:Parameters: args[0] whether feature should be enabled or not 6071 6072With this capability enabled, CR2 will not be modified prior to the 6073emulated VM-exit when L1 intercepts a #PF exception that occurs in 6074L2. Similarly, for kvm-intel only, DR6 will not be modified prior to 6075the emulated VM-exit when L1 intercepts a #DB exception that occurs in 6076L2. As a result, when KVM_GET_VCPU_EVENTS reports a pending #PF (or 6077#DB) exception for L2, exception.has_payload will be set and the 6078faulting address (or the new DR6 bits*) will be reported in the 6079exception_payload field. Similarly, when userspace injects a #PF (or 6080#DB) into L2 using KVM_SET_VCPU_EVENTS, it is expected to set 6081exception.has_payload and to put the faulting address - or the new DR6 6082bits\ [#]_ - in the exception_payload field. 6083 6084This capability also enables exception.pending in struct 6085kvm_vcpu_events, which allows userspace to distinguish between pending 6086and injected exceptions. 6087 6088 6089.. [#] For the new DR6 bits, note that bit 16 is set iff the #DB exception 6090 will clear DR6.RTM. 6091 60927.18 KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 6093 6094:Architectures: x86, arm, arm64, mips 6095:Parameters: args[0] whether feature should be enabled or not 6096 6097Valid flags are:: 6098 6099 #define KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE (1 << 0) 6100 #define KVM_DIRTY_LOG_INITIALLY_SET (1 << 1) 6101 6102With KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE is set, KVM_GET_DIRTY_LOG will not 6103automatically clear and write-protect all pages that are returned as dirty. 6104Rather, userspace will have to do this operation separately using 6105KVM_CLEAR_DIRTY_LOG. 6106 6107At the cost of a slightly more complicated operation, this provides better 6108scalability and responsiveness for two reasons. First, 6109KVM_CLEAR_DIRTY_LOG ioctl can operate on a 64-page granularity rather 6110than requiring to sync a full memslot; this ensures that KVM does not 6111take spinlocks for an extended period of time. Second, in some cases a 6112large amount of time can pass between a call to KVM_GET_DIRTY_LOG and 6113userspace actually using the data in the page. Pages can be modified 6114during this time, which is inefficient for both the guest and userspace: 6115the guest will incur a higher penalty due to write protection faults, 6116while userspace can see false reports of dirty pages. Manual reprotection 6117helps reducing this time, improving guest performance and reducing the 6118number of dirty log false positives. 6119 6120With KVM_DIRTY_LOG_INITIALLY_SET set, all the bits of the dirty bitmap 6121will be initialized to 1 when created. This also improves performance because 6122dirty logging can be enabled gradually in small chunks on the first call 6123to KVM_CLEAR_DIRTY_LOG. KVM_DIRTY_LOG_INITIALLY_SET depends on 6124KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE (it is also only available on 6125x86 and arm64 for now). 6126 6127KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 was previously available under the name 6128KVM_CAP_MANUAL_DIRTY_LOG_PROTECT, but the implementation had bugs that make 6129it hard or impossible to use it correctly. The availability of 6130KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 signals that those bugs are fixed. 6131Userspace should not try to use KVM_CAP_MANUAL_DIRTY_LOG_PROTECT. 6132 61337.19 KVM_CAP_PPC_SECURE_GUEST 6134------------------------------ 6135 6136:Architectures: ppc 6137 6138This capability indicates that KVM is running on a host that has 6139ultravisor firmware and thus can support a secure guest. On such a 6140system, a guest can ask the ultravisor to make it a secure guest, 6141one whose memory is inaccessible to the host except for pages which 6142are explicitly requested to be shared with the host. The ultravisor 6143notifies KVM when a guest requests to become a secure guest, and KVM 6144has the opportunity to veto the transition. 6145 6146If present, this capability can be enabled for a VM, meaning that KVM 6147will allow the transition to secure guest mode. Otherwise KVM will 6148veto the transition. 6149 61507.20 KVM_CAP_HALT_POLL 6151---------------------- 6152 6153:Architectures: all 6154:Target: VM 6155:Parameters: args[0] is the maximum poll time in nanoseconds 6156:Returns: 0 on success; -1 on error 6157 6158This capability overrides the kvm module parameter halt_poll_ns for the 6159target VM. 6160 6161VCPU polling allows a VCPU to poll for wakeup events instead of immediately 6162scheduling during guest halts. The maximum time a VCPU can spend polling is 6163controlled by the kvm module parameter halt_poll_ns. This capability allows 6164the maximum halt time to specified on a per-VM basis, effectively overriding 6165the module parameter for the target VM. 6166 61677.21 KVM_CAP_X86_USER_SPACE_MSR 6168------------------------------- 6169 6170:Architectures: x86 6171:Target: VM 6172:Parameters: args[0] contains the mask of KVM_MSR_EXIT_REASON_* events to report 6173:Returns: 0 on success; -1 on error 6174 6175This capability enables trapping of #GP invoking RDMSR and WRMSR instructions 6176into user space. 6177 6178When a guest requests to read or write an MSR, KVM may not implement all MSRs 6179that are relevant to a respective system. It also does not differentiate by 6180CPU type. 6181 6182To allow more fine grained control over MSR handling, user space may enable 6183this capability. With it enabled, MSR accesses that match the mask specified in 6184args[0] and trigger a #GP event inside the guest by KVM will instead trigger 6185KVM_EXIT_X86_RDMSR and KVM_EXIT_X86_WRMSR exit notifications which user space 6186can then handle to implement model specific MSR handling and/or user notifications 6187to inform a user that an MSR was not handled. 6188 61897.22 KVM_CAP_X86_BUS_LOCK_EXIT 6190------------------------------- 6191 6192:Architectures: x86 6193:Target: VM 6194:Parameters: args[0] defines the policy used when bus locks detected in guest 6195:Returns: 0 on success, -EINVAL when args[0] contains invalid bits 6196 6197Valid bits in args[0] are:: 6198 6199 #define KVM_BUS_LOCK_DETECTION_OFF (1 << 0) 6200 #define KVM_BUS_LOCK_DETECTION_EXIT (1 << 1) 6201 6202Enabling this capability on a VM provides userspace with a way to select 6203a policy to handle the bus locks detected in guest. Userspace can obtain 6204the supported modes from the result of KVM_CHECK_EXTENSION and define it 6205through the KVM_ENABLE_CAP. 6206 6207KVM_BUS_LOCK_DETECTION_OFF and KVM_BUS_LOCK_DETECTION_EXIT are supported 6208currently and mutually exclusive with each other. More bits can be added in 6209the future. 6210 6211With KVM_BUS_LOCK_DETECTION_OFF set, bus locks in guest will not cause vm exits 6212so that no additional actions are needed. This is the default mode. 6213 6214With KVM_BUS_LOCK_DETECTION_EXIT set, vm exits happen when bus lock detected 6215in VM. KVM just exits to userspace when handling them. Userspace can enforce 6216its own throttling or other policy based mitigations. 6217 6218This capability is aimed to address the thread that VM can exploit bus locks to 6219degree the performance of the whole system. Once the userspace enable this 6220capability and select the KVM_BUS_LOCK_DETECTION_EXIT mode, KVM will set the 6221KVM_RUN_BUS_LOCK flag in vcpu-run->flags field and exit to userspace. Concerning 6222the bus lock vm exit can be preempted by a higher priority VM exit, the exit 6223notifications to userspace can be KVM_EXIT_BUS_LOCK or other reasons. 6224KVM_RUN_BUS_LOCK flag is used to distinguish between them. 6225 62267.23 KVM_CAP_PPC_DAWR1 6227---------------------- 6228 6229:Architectures: ppc 6230:Parameters: none 6231:Returns: 0 on success, -EINVAL when CPU doesn't support 2nd DAWR 6232 6233This capability can be used to check / enable 2nd DAWR feature provided 6234by POWER10 processor. 6235 62368. Other capabilities. 6237====================== 6238 6239This section lists capabilities that give information about other 6240features of the KVM implementation. 6241 62428.1 KVM_CAP_PPC_HWRNG 6243--------------------- 6244 6245:Architectures: ppc 6246 6247This capability, if KVM_CHECK_EXTENSION indicates that it is 6248available, means that the kernel has an implementation of the 6249H_RANDOM hypercall backed by a hardware random-number generator. 6250If present, the kernel H_RANDOM handler can be enabled for guest use 6251with the KVM_CAP_PPC_ENABLE_HCALL capability. 6252 62538.2 KVM_CAP_HYPERV_SYNIC 6254------------------------ 6255 6256:Architectures: x86 6257 6258This capability, if KVM_CHECK_EXTENSION indicates that it is 6259available, means that the kernel has an implementation of the 6260Hyper-V Synthetic interrupt controller(SynIC). Hyper-V SynIC is 6261used to support Windows Hyper-V based guest paravirt drivers(VMBus). 6262 6263In order to use SynIC, it has to be activated by setting this 6264capability via KVM_ENABLE_CAP ioctl on the vcpu fd. Note that this 6265will disable the use of APIC hardware virtualization even if supported 6266by the CPU, as it's incompatible with SynIC auto-EOI behavior. 6267 62688.3 KVM_CAP_PPC_RADIX_MMU 6269------------------------- 6270 6271:Architectures: ppc 6272 6273This capability, if KVM_CHECK_EXTENSION indicates that it is 6274available, means that the kernel can support guests using the 6275radix MMU defined in Power ISA V3.00 (as implemented in the POWER9 6276processor). 6277 62788.4 KVM_CAP_PPC_HASH_MMU_V3 6279--------------------------- 6280 6281:Architectures: ppc 6282 6283This capability, if KVM_CHECK_EXTENSION indicates that it is 6284available, means that the kernel can support guests using the 6285hashed page table MMU defined in Power ISA V3.00 (as implemented in 6286the POWER9 processor), including in-memory segment tables. 6287 62888.5 KVM_CAP_MIPS_VZ 6289------------------- 6290 6291:Architectures: mips 6292 6293This capability, if KVM_CHECK_EXTENSION on the main kvm handle indicates that 6294it is available, means that full hardware assisted virtualization capabilities 6295of the hardware are available for use through KVM. An appropriate 6296KVM_VM_MIPS_* type must be passed to KVM_CREATE_VM to create a VM which 6297utilises it. 6298 6299If KVM_CHECK_EXTENSION on a kvm VM handle indicates that this capability is 6300available, it means that the VM is using full hardware assisted virtualization 6301capabilities of the hardware. This is useful to check after creating a VM with 6302KVM_VM_MIPS_DEFAULT. 6303 6304The value returned by KVM_CHECK_EXTENSION should be compared against known 6305values (see below). All other values are reserved. This is to allow for the 6306possibility of other hardware assisted virtualization implementations which 6307may be incompatible with the MIPS VZ ASE. 6308 6309== ========================================================================== 6310 0 The trap & emulate implementation is in use to run guest code in user 6311 mode. Guest virtual memory segments are rearranged to fit the guest in the 6312 user mode address space. 6313 6314 1 The MIPS VZ ASE is in use, providing full hardware assisted 6315 virtualization, including standard guest virtual memory segments. 6316== ========================================================================== 6317 63188.6 KVM_CAP_MIPS_TE 6319------------------- 6320 6321:Architectures: mips 6322 6323This capability, if KVM_CHECK_EXTENSION on the main kvm handle indicates that 6324it is available, means that the trap & emulate implementation is available to 6325run guest code in user mode, even if KVM_CAP_MIPS_VZ indicates that hardware 6326assisted virtualisation is also available. KVM_VM_MIPS_TE (0) must be passed 6327to KVM_CREATE_VM to create a VM which utilises it. 6328 6329If KVM_CHECK_EXTENSION on a kvm VM handle indicates that this capability is 6330available, it means that the VM is using trap & emulate. 6331 63328.7 KVM_CAP_MIPS_64BIT 6333---------------------- 6334 6335:Architectures: mips 6336 6337This capability indicates the supported architecture type of the guest, i.e. the 6338supported register and address width. 6339 6340The values returned when this capability is checked by KVM_CHECK_EXTENSION on a 6341kvm VM handle correspond roughly to the CP0_Config.AT register field, and should 6342be checked specifically against known values (see below). All other values are 6343reserved. 6344 6345== ======================================================================== 6346 0 MIPS32 or microMIPS32. 6347 Both registers and addresses are 32-bits wide. 6348 It will only be possible to run 32-bit guest code. 6349 6350 1 MIPS64 or microMIPS64 with access only to 32-bit compatibility segments. 6351 Registers are 64-bits wide, but addresses are 32-bits wide. 6352 64-bit guest code may run but cannot access MIPS64 memory segments. 6353 It will also be possible to run 32-bit guest code. 6354 6355 2 MIPS64 or microMIPS64 with access to all address segments. 6356 Both registers and addresses are 64-bits wide. 6357 It will be possible to run 64-bit or 32-bit guest code. 6358== ======================================================================== 6359 63608.9 KVM_CAP_ARM_USER_IRQ 6361------------------------ 6362 6363:Architectures: arm, arm64 6364 6365This capability, if KVM_CHECK_EXTENSION indicates that it is available, means 6366that if userspace creates a VM without an in-kernel interrupt controller, it 6367will be notified of changes to the output level of in-kernel emulated devices, 6368which can generate virtual interrupts, presented to the VM. 6369For such VMs, on every return to userspace, the kernel 6370updates the vcpu's run->s.regs.device_irq_level field to represent the actual 6371output level of the device. 6372 6373Whenever kvm detects a change in the device output level, kvm guarantees at 6374least one return to userspace before running the VM. This exit could either 6375be a KVM_EXIT_INTR or any other exit event, like KVM_EXIT_MMIO. This way, 6376userspace can always sample the device output level and re-compute the state of 6377the userspace interrupt controller. Userspace should always check the state 6378of run->s.regs.device_irq_level on every kvm exit. 6379The value in run->s.regs.device_irq_level can represent both level and edge 6380triggered interrupt signals, depending on the device. Edge triggered interrupt 6381signals will exit to userspace with the bit in run->s.regs.device_irq_level 6382set exactly once per edge signal. 6383 6384The field run->s.regs.device_irq_level is available independent of 6385run->kvm_valid_regs or run->kvm_dirty_regs bits. 6386 6387If KVM_CAP_ARM_USER_IRQ is supported, the KVM_CHECK_EXTENSION ioctl returns a 6388number larger than 0 indicating the version of this capability is implemented 6389and thereby which bits in run->s.regs.device_irq_level can signal values. 6390 6391Currently the following bits are defined for the device_irq_level bitmap:: 6392 6393 KVM_CAP_ARM_USER_IRQ >= 1: 6394 6395 KVM_ARM_DEV_EL1_VTIMER - EL1 virtual timer 6396 KVM_ARM_DEV_EL1_PTIMER - EL1 physical timer 6397 KVM_ARM_DEV_PMU - ARM PMU overflow interrupt signal 6398 6399Future versions of kvm may implement additional events. These will get 6400indicated by returning a higher number from KVM_CHECK_EXTENSION and will be 6401listed above. 6402 64038.10 KVM_CAP_PPC_SMT_POSSIBLE 6404----------------------------- 6405 6406:Architectures: ppc 6407 6408Querying this capability returns a bitmap indicating the possible 6409virtual SMT modes that can be set using KVM_CAP_PPC_SMT. If bit N 6410(counting from the right) is set, then a virtual SMT mode of 2^N is 6411available. 6412 64138.11 KVM_CAP_HYPERV_SYNIC2 6414-------------------------- 6415 6416:Architectures: x86 6417 6418This capability enables a newer version of Hyper-V Synthetic interrupt 6419controller (SynIC). The only difference with KVM_CAP_HYPERV_SYNIC is that KVM 6420doesn't clear SynIC message and event flags pages when they are enabled by 6421writing to the respective MSRs. 6422 64238.12 KVM_CAP_HYPERV_VP_INDEX 6424---------------------------- 6425 6426:Architectures: x86 6427 6428This capability indicates that userspace can load HV_X64_MSR_VP_INDEX msr. Its 6429value is used to denote the target vcpu for a SynIC interrupt. For 6430compatibilty, KVM initializes this msr to KVM's internal vcpu index. When this 6431capability is absent, userspace can still query this msr's value. 6432 64338.13 KVM_CAP_S390_AIS_MIGRATION 6434------------------------------- 6435 6436:Architectures: s390 6437:Parameters: none 6438 6439This capability indicates if the flic device will be able to get/set the 6440AIS states for migration via the KVM_DEV_FLIC_AISM_ALL attribute and allows 6441to discover this without having to create a flic device. 6442 64438.14 KVM_CAP_S390_PSW 6444--------------------- 6445 6446:Architectures: s390 6447 6448This capability indicates that the PSW is exposed via the kvm_run structure. 6449 64508.15 KVM_CAP_S390_GMAP 6451---------------------- 6452 6453:Architectures: s390 6454 6455This capability indicates that the user space memory used as guest mapping can 6456be anywhere in the user memory address space, as long as the memory slots are 6457aligned and sized to a segment (1MB) boundary. 6458 64598.16 KVM_CAP_S390_COW 6460--------------------- 6461 6462:Architectures: s390 6463 6464This capability indicates that the user space memory used as guest mapping can 6465use copy-on-write semantics as well as dirty pages tracking via read-only page 6466tables. 6467 64688.17 KVM_CAP_S390_BPB 6469--------------------- 6470 6471:Architectures: s390 6472 6473This capability indicates that kvm will implement the interfaces to handle 6474reset, migration and nested KVM for branch prediction blocking. The stfle 6475facility 82 should not be provided to the guest without this capability. 6476 64778.18 KVM_CAP_HYPERV_TLBFLUSH 6478---------------------------- 6479 6480:Architectures: x86 6481 6482This capability indicates that KVM supports paravirtualized Hyper-V TLB Flush 6483hypercalls: 6484HvFlushVirtualAddressSpace, HvFlushVirtualAddressSpaceEx, 6485HvFlushVirtualAddressList, HvFlushVirtualAddressListEx. 6486 64878.19 KVM_CAP_ARM_INJECT_SERROR_ESR 6488---------------------------------- 6489 6490:Architectures: arm, arm64 6491 6492This capability indicates that userspace can specify (via the 6493KVM_SET_VCPU_EVENTS ioctl) the syndrome value reported to the guest when it 6494takes a virtual SError interrupt exception. 6495If KVM advertises this capability, userspace can only specify the ISS field for 6496the ESR syndrome. Other parts of the ESR, such as the EC are generated by the 6497CPU when the exception is taken. If this virtual SError is taken to EL1 using 6498AArch64, this value will be reported in the ISS field of ESR_ELx. 6499 6500See KVM_CAP_VCPU_EVENTS for more details. 6501 65028.20 KVM_CAP_HYPERV_SEND_IPI 6503---------------------------- 6504 6505:Architectures: x86 6506 6507This capability indicates that KVM supports paravirtualized Hyper-V IPI send 6508hypercalls: 6509HvCallSendSyntheticClusterIpi, HvCallSendSyntheticClusterIpiEx. 6510 65118.21 KVM_CAP_HYPERV_DIRECT_TLBFLUSH 6512----------------------------------- 6513 6514:Architectures: x86 6515 6516This capability indicates that KVM running on top of Hyper-V hypervisor 6517enables Direct TLB flush for its guests meaning that TLB flush 6518hypercalls are handled by Level 0 hypervisor (Hyper-V) bypassing KVM. 6519Due to the different ABI for hypercall parameters between Hyper-V and 6520KVM, enabling this capability effectively disables all hypercall 6521handling by KVM (as some KVM hypercall may be mistakenly treated as TLB 6522flush hypercalls by Hyper-V) so userspace should disable KVM identification 6523in CPUID and only exposes Hyper-V identification. In this case, guest 6524thinks it's running on Hyper-V and only use Hyper-V hypercalls. 6525 65268.22 KVM_CAP_S390_VCPU_RESETS 6527----------------------------- 6528 6529:Architectures: s390 6530 6531This capability indicates that the KVM_S390_NORMAL_RESET and 6532KVM_S390_CLEAR_RESET ioctls are available. 6533 65348.23 KVM_CAP_S390_PROTECTED 6535--------------------------- 6536 6537:Architectures: s390 6538 6539This capability indicates that the Ultravisor has been initialized and 6540KVM can therefore start protected VMs. 6541This capability governs the KVM_S390_PV_COMMAND ioctl and the 6542KVM_MP_STATE_LOAD MP_STATE. KVM_SET_MP_STATE can fail for protected 6543guests when the state change is invalid. 6544 65458.24 KVM_CAP_STEAL_TIME 6546----------------------- 6547 6548:Architectures: arm64, x86 6549 6550This capability indicates that KVM supports steal time accounting. 6551When steal time accounting is supported it may be enabled with 6552architecture-specific interfaces. This capability and the architecture- 6553specific interfaces must be consistent, i.e. if one says the feature 6554is supported, than the other should as well and vice versa. For arm64 6555see Documentation/virt/kvm/devices/vcpu.rst "KVM_ARM_VCPU_PVTIME_CTRL". 6556For x86 see Documentation/virt/kvm/msr.rst "MSR_KVM_STEAL_TIME". 6557 65588.25 KVM_CAP_S390_DIAG318 6559------------------------- 6560 6561:Architectures: s390 6562 6563This capability enables a guest to set information about its control program 6564(i.e. guest kernel type and version). The information is helpful during 6565system/firmware service events, providing additional data about the guest 6566environments running on the machine. 6567 6568The information is associated with the DIAGNOSE 0x318 instruction, which sets 6569an 8-byte value consisting of a one-byte Control Program Name Code (CPNC) and 6570a 7-byte Control Program Version Code (CPVC). The CPNC determines what 6571environment the control program is running in (e.g. Linux, z/VM...), and the 6572CPVC is used for information specific to OS (e.g. Linux version, Linux 6573distribution...) 6574 6575If this capability is available, then the CPNC and CPVC can be synchronized 6576between KVM and userspace via the sync regs mechanism (KVM_SYNC_DIAG318). 6577 65788.26 KVM_CAP_X86_USER_SPACE_MSR 6579------------------------------- 6580 6581:Architectures: x86 6582 6583This capability indicates that KVM supports deflection of MSR reads and 6584writes to user space. It can be enabled on a VM level. If enabled, MSR 6585accesses that would usually trigger a #GP by KVM into the guest will 6586instead get bounced to user space through the KVM_EXIT_X86_RDMSR and 6587KVM_EXIT_X86_WRMSR exit notifications. 6588 65898.27 KVM_X86_SET_MSR_FILTER 6590--------------------------- 6591 6592:Architectures: x86 6593 6594This capability indicates that KVM supports that accesses to user defined MSRs 6595may be rejected. With this capability exposed, KVM exports new VM ioctl 6596KVM_X86_SET_MSR_FILTER which user space can call to specify bitmaps of MSR 6597ranges that KVM should reject access to. 6598 6599In combination with KVM_CAP_X86_USER_SPACE_MSR, this allows user space to 6600trap and emulate MSRs that are outside of the scope of KVM as well as 6601limit the attack surface on KVM's MSR emulation code. 6602 66038.28 KVM_CAP_ENFORCE_PV_CPUID 6604----------------------------- 6605 6606Architectures: x86 6607 6608When enabled, KVM will disable paravirtual features provided to the 6609guest according to the bits in the KVM_CPUID_FEATURES CPUID leaf 6610(0x40000001). Otherwise, a guest may use the paravirtual features 6611regardless of what has actually been exposed through the CPUID leaf. 6612 66138.29 KVM_CAP_DIRTY_LOG_RING 6614--------------------------- 6615 6616:Architectures: x86 6617:Parameters: args[0] - size of the dirty log ring 6618 6619KVM is capable of tracking dirty memory using ring buffers that are 6620mmaped into userspace; there is one dirty ring per vcpu. 6621 6622The dirty ring is available to userspace as an array of 6623``struct kvm_dirty_gfn``. Each dirty entry it's defined as:: 6624 6625 struct kvm_dirty_gfn { 6626 __u32 flags; 6627 __u32 slot; /* as_id | slot_id */ 6628 __u64 offset; 6629 }; 6630 6631The following values are defined for the flags field to define the 6632current state of the entry:: 6633 6634 #define KVM_DIRTY_GFN_F_DIRTY BIT(0) 6635 #define KVM_DIRTY_GFN_F_RESET BIT(1) 6636 #define KVM_DIRTY_GFN_F_MASK 0x3 6637 6638Userspace should call KVM_ENABLE_CAP ioctl right after KVM_CREATE_VM 6639ioctl to enable this capability for the new guest and set the size of 6640the rings. Enabling the capability is only allowed before creating any 6641vCPU, and the size of the ring must be a power of two. The larger the 6642ring buffer, the less likely the ring is full and the VM is forced to 6643exit to userspace. The optimal size depends on the workload, but it is 6644recommended that it be at least 64 KiB (4096 entries). 6645 6646Just like for dirty page bitmaps, the buffer tracks writes to 6647all user memory regions for which the KVM_MEM_LOG_DIRTY_PAGES flag was 6648set in KVM_SET_USER_MEMORY_REGION. Once a memory region is registered 6649with the flag set, userspace can start harvesting dirty pages from the 6650ring buffer. 6651 6652An entry in the ring buffer can be unused (flag bits ``00``), 6653dirty (flag bits ``01``) or harvested (flag bits ``1X``). The 6654state machine for the entry is as follows:: 6655 6656 dirtied harvested reset 6657 00 -----------> 01 -------------> 1X -------+ 6658 ^ | 6659 | | 6660 +------------------------------------------+ 6661 6662To harvest the dirty pages, userspace accesses the mmaped ring buffer 6663to read the dirty GFNs. If the flags has the DIRTY bit set (at this stage 6664the RESET bit must be cleared), then it means this GFN is a dirty GFN. 6665The userspace should harvest this GFN and mark the flags from state 6666``01b`` to ``1Xb`` (bit 0 will be ignored by KVM, but bit 1 must be set 6667to show that this GFN is harvested and waiting for a reset), and move 6668on to the next GFN. The userspace should continue to do this until the 6669flags of a GFN have the DIRTY bit cleared, meaning that it has harvested 6670all the dirty GFNs that were available. 6671 6672It's not necessary for userspace to harvest the all dirty GFNs at once. 6673However it must collect the dirty GFNs in sequence, i.e., the userspace 6674program cannot skip one dirty GFN to collect the one next to it. 6675 6676After processing one or more entries in the ring buffer, userspace 6677calls the VM ioctl KVM_RESET_DIRTY_RINGS to notify the kernel about 6678it, so that the kernel will reprotect those collected GFNs. 6679Therefore, the ioctl must be called *before* reading the content of 6680the dirty pages. 6681 6682The dirty ring can get full. When it happens, the KVM_RUN of the 6683vcpu will return with exit reason KVM_EXIT_DIRTY_LOG_FULL. 6684 6685The dirty ring interface has a major difference comparing to the 6686KVM_GET_DIRTY_LOG interface in that, when reading the dirty ring from 6687userspace, it's still possible that the kernel has not yet flushed the 6688processor's dirty page buffers into the kernel buffer (with dirty bitmaps, the 6689flushing is done by the KVM_GET_DIRTY_LOG ioctl). To achieve that, one 6690needs to kick the vcpu out of KVM_RUN using a signal. The resulting 6691vmexit ensures that all dirty GFNs are flushed to the dirty rings. 6692 6693NOTE: the capability KVM_CAP_DIRTY_LOG_RING and the corresponding 6694ioctl KVM_RESET_DIRTY_RINGS are mutual exclusive to the existing ioctls 6695KVM_GET_DIRTY_LOG and KVM_CLEAR_DIRTY_LOG. After enabling 6696KVM_CAP_DIRTY_LOG_RING with an acceptable dirty ring size, the virtual 6697machine will switch to ring-buffer dirty page tracking and further 6698KVM_GET_DIRTY_LOG or KVM_CLEAR_DIRTY_LOG ioctls will fail. 6699 67008.30 KVM_CAP_XEN_HVM 6701-------------------- 6702 6703:Architectures: x86 6704 6705This capability indicates the features that Xen supports for hosting Xen 6706PVHVM guests. Valid flags are:: 6707 6708 #define KVM_XEN_HVM_CONFIG_HYPERCALL_MSR (1 << 0) 6709 #define KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL (1 << 1) 6710 #define KVM_XEN_HVM_CONFIG_SHARED_INFO (1 << 2) 6711 #define KVM_XEN_HVM_CONFIG_RUNSTATE (1 << 2) 6712 6713The KVM_XEN_HVM_CONFIG_HYPERCALL_MSR flag indicates that the KVM_XEN_HVM_CONFIG 6714ioctl is available, for the guest to set its hypercall page. 6715 6716If KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL is also set, the same flag may also be 6717provided in the flags to KVM_XEN_HVM_CONFIG, without providing hypercall page 6718contents, to request that KVM generate hypercall page content automatically 6719and also enable interception of guest hypercalls with KVM_EXIT_XEN. 6720 6721The KVM_XEN_HVM_CONFIG_SHARED_INFO flag indicates the availability of the 6722KVM_XEN_HVM_SET_ATTR, KVM_XEN_HVM_GET_ATTR, KVM_XEN_VCPU_SET_ATTR and 6723KVM_XEN_VCPU_GET_ATTR ioctls, as well as the delivery of exception vectors 6724for event channel upcalls when the evtchn_upcall_pending field of a vcpu's 6725vcpu_info is set. 6726 6727The KVM_XEN_HVM_CONFIG_RUNSTATE flag indicates that the runstate-related 6728features KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADDR/_CURRENT/_DATA/_ADJUST are 6729supported by the KVM_XEN_VCPU_SET_ATTR/KVM_XEN_VCPU_GET_ATTR ioctls. 6730