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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
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+.. SPDX-License-Identifier: GPL-2.0
+
+===================================================================
+The Definitive KVM (Kernel-based Virtual Machine) API Documentation
+===================================================================
+
+1. General description
+======================
+
+The kvm API is a set of ioctls that are issued to control various aspects
+of a virtual machine. The ioctls belong to the following classes:
+
+ - System ioctls: These query and set global attributes which affect the
+ whole kvm subsystem. In addition a system ioctl is used to create
+ virtual machines.
+
+ - VM ioctls: These query and set attributes that affect an entire virtual
+ machine, for example memory layout. In addition a VM ioctl is used to
+ create virtual cpus (vcpus) and devices.
+
+ VM ioctls must be issued from the same process (address space) that was
+ used to create the VM.
+
+ - vcpu ioctls: These query and set attributes that control the operation
+ of a single virtual cpu.
+
+ vcpu ioctls should be issued from the same thread that was used to create
+ the vcpu, except for asynchronous vcpu ioctl that are marked as such in
+ the documentation. Otherwise, the first ioctl after switching threads
+ could see a performance impact.
+
+ - device ioctls: These query and set attributes that control the operation
+ of a single device.
+
+ device ioctls must be issued from the same process (address space) that
+ was used to create the VM.
+
+2. File descriptors
+===================
+
+The kvm API is centered around file descriptors. An initial
+open("/dev/kvm") obtains a handle to the kvm subsystem; this handle
+can be used to issue system ioctls. A KVM_CREATE_VM ioctl on this
+handle will create a VM file descriptor which can be used to issue VM
+ioctls. A KVM_CREATE_VCPU or KVM_CREATE_DEVICE ioctl on a VM fd will
+create a virtual cpu or device and return a file descriptor pointing to
+the new resource. Finally, ioctls on a vcpu or device fd can be used
+to control the vcpu or device. For vcpus, this includes the important
+task of actually running guest code.
+
+In general file descriptors can be migrated among processes by means
+of fork() and the SCM_RIGHTS facility of unix domain socket. These
+kinds of tricks are explicitly not supported by kvm. While they will
+not cause harm to the host, their actual behavior is not guaranteed by
+the API. See "General description" for details on the ioctl usage
+model that is supported by KVM.
+
+It is important to note that althought VM ioctls may only be issued from
+the process that created the VM, a VM's lifecycle is associated with its
+file descriptor, not its creator (process). In other words, the VM and
+its resources, *including the associated address space*, are not freed
+until the last reference to the VM's file descriptor has been released.
+For example, if fork() is issued after ioctl(KVM_CREATE_VM), the VM will
+not be freed until both the parent (original) process and its child have
+put their references to the VM's file descriptor.
+
+Because a VM's resources are not freed until the last reference to its
+file descriptor is released, creating additional references to a VM
+via fork(), dup(), etc... without careful consideration is strongly
+discouraged and may have unwanted side effects, e.g. memory allocated
+by and on behalf of the VM's process may not be freed/unaccounted when
+the VM is shut down.
+
+
+3. Extensions
+=============
+
+As of Linux 2.6.22, the KVM ABI has been stabilized: no backward
+incompatible change are allowed. However, there is an extension
+facility that allows backward-compatible extensions to the API to be
+queried and used.
+
+The extension mechanism is not based on the Linux version number.
+Instead, kvm defines extension identifiers and a facility to query
+whether a particular extension identifier is available. If it is, a
+set of ioctls is available for application use.
+
+
+4. API description
+==================
+
+This section describes ioctls that can be used to control kvm guests.
+For each ioctl, the following information is provided along with a
+description:
+
+ Capability:
+ which KVM extension provides this ioctl. Can be 'basic',
+ which means that is will be provided by any kernel that supports
+ API version 12 (see section 4.1), a KVM_CAP_xyz constant, which
+ means availability needs to be checked with KVM_CHECK_EXTENSION
+ (see section 4.4), or 'none' which means that while not all kernels
+ support this ioctl, there's no capability bit to check its
+ availability: for kernels that don't support the ioctl,
+ the ioctl returns -ENOTTY.
+
+ Architectures:
+ which instruction set architectures provide this ioctl.
+ x86 includes both i386 and x86_64.
+
+ Type:
+ system, vm, or vcpu.
+
+ Parameters:
+ what parameters are accepted by the ioctl.
+
+ Returns:
+ the return value. General error numbers (EBADF, ENOMEM, EINVAL)
+ are not detailed, but errors with specific meanings are.
+
+
+4.1 KVM_GET_API_VERSION
+-----------------------
+
+:Capability: basic
+:Architectures: all
+:Type: system ioctl
+:Parameters: none
+:Returns: the constant KVM_API_VERSION (=12)
+
+This identifies the API version as the stable kvm API. It is not
+expected that this number will change. However, Linux 2.6.20 and
+2.6.21 report earlier versions; these are not documented and not
+supported. Applications should refuse to run if KVM_GET_API_VERSION
+returns a value other than 12. If this check passes, all ioctls
+described as 'basic' will be available.
+
+
+4.2 KVM_CREATE_VM
+-----------------
+
+:Capability: basic
+:Architectures: all
+:Type: system ioctl
+:Parameters: machine type identifier (KVM_VM_*)
+:Returns: a VM fd that can be used to control the new virtual machine.
+
+The new VM has no virtual cpus and no memory.
+You probably want to use 0 as machine type.
+
+In order to create user controlled virtual machines on S390, check
+KVM_CAP_S390_UCONTROL and use the flag KVM_VM_S390_UCONTROL as
+privileged user (CAP_SYS_ADMIN).
+
+To use hardware assisted virtualization on MIPS (VZ ASE) rather than
+the default trap & emulate implementation (which changes the virtual
+memory layout to fit in user mode), check KVM_CAP_MIPS_VZ and use the
+flag KVM_VM_MIPS_VZ.
+
+
+On arm64, the physical address size for a VM (IPA Size limit) is limited
+to 40bits by default. The limit can be configured if the host supports the
+extension KVM_CAP_ARM_VM_IPA_SIZE. When supported, use
+KVM_VM_TYPE_ARM_IPA_SIZE(IPA_Bits) to set the size in the machine type
+identifier, where IPA_Bits is the maximum width of any physical
+address used by the VM. The IPA_Bits is encoded in bits[7-0] of the
+machine type identifier.
+
+e.g, to configure a guest to use 48bit physical address size::
+
+ vm_fd = ioctl(dev_fd, KVM_CREATE_VM, KVM_VM_TYPE_ARM_IPA_SIZE(48));
+
+The requested size (IPA_Bits) must be:
+
+ == =========================================================
+ 0 Implies default size, 40bits (for backward compatibility)
+ N Implies N bits, where N is a positive integer such that,
+ 32 <= N <= Host_IPA_Limit
+ == =========================================================
+
+Host_IPA_Limit is the maximum possible value for IPA_Bits on the host and
+is dependent on the CPU capability and the kernel configuration. The limit can
+be retrieved using KVM_CAP_ARM_VM_IPA_SIZE of the KVM_CHECK_EXTENSION
+ioctl() at run-time.
+
+Creation of the VM will fail if the requested IPA size (whether it is
+implicit or explicit) is unsupported on the host.
+
+Please note that configuring the IPA size does not affect the capability
+exposed by the guest CPUs in ID_AA64MMFR0_EL1[PARange]. It only affects
+size of the address translated by the stage2 level (guest physical to
+host physical address translations).
+
+
+4.3 KVM_GET_MSR_INDEX_LIST, KVM_GET_MSR_FEATURE_INDEX_LIST
+----------------------------------------------------------
+
+:Capability: basic, KVM_CAP_GET_MSR_FEATURES for KVM_GET_MSR_FEATURE_INDEX_LIST
+:Architectures: x86
+:Type: system ioctl
+:Parameters: struct kvm_msr_list (in/out)
+:Returns: 0 on success; -1 on error
+
+Errors:
+
+ ====== ============================================================
+ EFAULT the msr index list cannot be read from or written to
+ E2BIG the msr index list is to be to fit in the array specified by
+ the user.
+ ====== ============================================================
+
+::
+
+ struct kvm_msr_list {
+ __u32 nmsrs; /* number of msrs in entries */
+ __u32 indices[0];
+ };
+
+The user fills in the size of the indices array in nmsrs, and in return
+kvm adjusts nmsrs to reflect the actual number of msrs and fills in the
+indices array with their numbers.
+
+KVM_GET_MSR_INDEX_LIST returns the guest msrs that are supported. The list
+varies by kvm version and host processor, but does not change otherwise.
+
+Note: if kvm indicates supports MCE (KVM_CAP_MCE), then the MCE bank MSRs are
+not returned in the MSR list, as different vcpus can have a different number
+of banks, as set via the KVM_X86_SETUP_MCE ioctl.
+
+KVM_GET_MSR_FEATURE_INDEX_LIST returns the list of MSRs that can be passed
+to the KVM_GET_MSRS system ioctl. This lets userspace probe host capabilities
+and processor features that are exposed via MSRs (e.g., VMX capabilities).
+This list also varies by kvm version and host processor, but does not change
+otherwise.
+
+
+4.4 KVM_CHECK_EXTENSION
+-----------------------
+
+:Capability: basic, KVM_CAP_CHECK_EXTENSION_VM for vm ioctl
+:Architectures: all
+:Type: system ioctl, vm ioctl
+:Parameters: extension identifier (KVM_CAP_*)
+:Returns: 0 if unsupported; 1 (or some other positive integer) if supported
+
+The API allows the application to query about extensions to the core
+kvm API. Userspace passes an extension identifier (an integer) and
+receives an integer that describes the extension availability.
+Generally 0 means no and 1 means yes, but some extensions may report
+additional information in the integer return value.
+
+Based on their initialization different VMs may have different capabilities.
+It is thus encouraged to use the vm ioctl to query for capabilities (available
+with KVM_CAP_CHECK_EXTENSION_VM on the vm fd)
+
+4.5 KVM_GET_VCPU_MMAP_SIZE
+--------------------------
+
+:Capability: basic
+:Architectures: all
+:Type: system ioctl
+:Parameters: none
+:Returns: size of vcpu mmap area, in bytes
+
+The KVM_RUN ioctl (cf.) communicates with userspace via a shared
+memory region. This ioctl returns the size of that region. See the
+KVM_RUN documentation for details.
+
+
+4.6 KVM_SET_MEMORY_REGION
+-------------------------
+
+:Capability: basic
+:Architectures: all
+:Type: vm ioctl
+:Parameters: struct kvm_memory_region (in)
+:Returns: 0 on success, -1 on error
+
+This ioctl is obsolete and has been removed.
+
+
+4.7 KVM_CREATE_VCPU
+-------------------
+
+:Capability: basic
+:Architectures: all
+:Type: vm ioctl
+:Parameters: vcpu id (apic id on x86)
+:Returns: vcpu fd on success, -1 on error
+
+This API adds a vcpu to a virtual machine. No more than max_vcpus may be added.
+The vcpu id is an integer in the range [0, max_vcpu_id).
+
+The recommended max_vcpus value can be retrieved using the KVM_CAP_NR_VCPUS of
+the KVM_CHECK_EXTENSION ioctl() at run-time.
+The maximum possible value for max_vcpus can be retrieved using the
+KVM_CAP_MAX_VCPUS of the KVM_CHECK_EXTENSION ioctl() at run-time.
+
+If the KVM_CAP_NR_VCPUS does not exist, you should assume that max_vcpus is 4
+cpus max.
+If the KVM_CAP_MAX_VCPUS does not exist, you should assume that max_vcpus is
+same as the value returned from KVM_CAP_NR_VCPUS.
+
+The maximum possible value for max_vcpu_id can be retrieved using the
+KVM_CAP_MAX_VCPU_ID of the KVM_CHECK_EXTENSION ioctl() at run-time.
+
+If the KVM_CAP_MAX_VCPU_ID does not exist, you should assume that max_vcpu_id
+is the same as the value returned from KVM_CAP_MAX_VCPUS.
+
+On powerpc using book3s_hv mode, the vcpus are mapped onto virtual
+threads in one or more virtual CPU cores. (This is because the
+hardware requires all the hardware threads in a CPU core to be in the
+same partition.) The KVM_CAP_PPC_SMT capability indicates the number
+of vcpus per virtual core (vcore). The vcore id is obtained by
+dividing the vcpu id by the number of vcpus per vcore. The vcpus in a
+given vcore will always be in the same physical core as each other
+(though that might be a different physical core from time to time).
+Userspace can control the threading (SMT) mode of the guest by its
+allocation of vcpu ids. For example, if userspace wants
+single-threaded guest vcpus, it should make all vcpu ids be a multiple
+of the number of vcpus per vcore.
+
+For virtual cpus that have been created with S390 user controlled virtual
+machines, the resulting vcpu fd can be memory mapped at page offset
+KVM_S390_SIE_PAGE_OFFSET in order to obtain a memory map of the virtual
+cpu's hardware control block.
+
+
+4.8 KVM_GET_DIRTY_LOG (vm ioctl)
+--------------------------------
+
+:Capability: basic
+:Architectures: all
+:Type: vm ioctl
+:Parameters: struct kvm_dirty_log (in/out)
+:Returns: 0 on success, -1 on error
+
+::
+
+ /* for KVM_GET_DIRTY_LOG */
+ struct kvm_dirty_log {
+ __u32 slot;
+ __u32 padding;
+ union {
+ void __user *dirty_bitmap; /* one bit per page */
+ __u64 padding;
+ };
+ };
+
+Given a memory slot, return a bitmap containing any pages dirtied
+since the last call to this ioctl. Bit 0 is the first page in the
+memory slot. Ensure the entire structure is cleared to avoid padding
+issues.
+
+If KVM_CAP_MULTI_ADDRESS_SPACE is available, bits 16-31 specifies
+the address space for which you want to return the dirty bitmap.
+They must be less than the value that KVM_CHECK_EXTENSION returns for
+the KVM_CAP_MULTI_ADDRESS_SPACE capability.
+
+The bits in the dirty bitmap are cleared before the ioctl returns, unless
+KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 is enabled. For more information,
+see the description of the capability.
+
+4.9 KVM_SET_MEMORY_ALIAS
+------------------------
+
+:Capability: basic
+:Architectures: x86
+:Type: vm ioctl
+:Parameters: struct kvm_memory_alias (in)
+:Returns: 0 (success), -1 (error)
+
+This ioctl is obsolete and has been removed.
+
+
+4.10 KVM_RUN
+------------
+
+:Capability: basic
+:Architectures: all
+:Type: vcpu ioctl
+:Parameters: none
+:Returns: 0 on success, -1 on error
+
+Errors:
+
+ ===== =============================
+ EINTR an unmasked signal is pending
+ ===== =============================
+
+This ioctl is used to run a guest virtual cpu. While there are no
+explicit parameters, there is an implicit parameter block that can be
+obtained by mmap()ing the vcpu fd at offset 0, with the size given by
+KVM_GET_VCPU_MMAP_SIZE. The parameter block is formatted as a 'struct
+kvm_run' (see below).
+
+
+4.11 KVM_GET_REGS
+-----------------
+
+:Capability: basic
+:Architectures: all except ARM, arm64
+:Type: vcpu ioctl
+:Parameters: struct kvm_regs (out)
+:Returns: 0 on success, -1 on error
+
+Reads the general purpose registers from the vcpu.
+
+::
+
+ /* x86 */
+ struct kvm_regs {
+ /* out (KVM_GET_REGS) / in (KVM_SET_REGS) */
+ __u64 rax, rbx, rcx, rdx;
+ __u64 rsi, rdi, rsp, rbp;
+ __u64 r8, r9, r10, r11;
+ __u64 r12, r13, r14, r15;
+ __u64 rip, rflags;
+ };
+
+ /* mips */
+ struct kvm_regs {
+ /* out (KVM_GET_REGS) / in (KVM_SET_REGS) */
+ __u64 gpr[32];
+ __u64 hi;
+ __u64 lo;
+ __u64 pc;
+ };
+
+
+4.12 KVM_SET_REGS
+-----------------
+
+:Capability: basic
+:Architectures: all except ARM, arm64
+:Type: vcpu ioctl
+:Parameters: struct kvm_regs (in)
+:Returns: 0 on success, -1 on error
+
+Writes the general purpose registers into the vcpu.
+
+See KVM_GET_REGS for the data structure.
+
+
+4.13 KVM_GET_SREGS
+------------------
+
+:Capability: basic
+:Architectures: x86, ppc
+:Type: vcpu ioctl
+:Parameters: struct kvm_sregs (out)
+:Returns: 0 on success, -1 on error
+
+Reads special registers from the vcpu.
+
+::
+
+ /* x86 */
+ struct kvm_sregs {
+ struct kvm_segment cs, ds, es, fs, gs, ss;
+ struct kvm_segment tr, ldt;
+ struct kvm_dtable gdt, idt;
+ __u64 cr0, cr2, cr3, cr4, cr8;
+ __u64 efer;
+ __u64 apic_base;
+ __u64 interrupt_bitmap[(KVM_NR_INTERRUPTS + 63) / 64];
+ };
+
+ /* ppc -- see arch/powerpc/include/uapi/asm/kvm.h */
+
+interrupt_bitmap is a bitmap of pending external interrupts. At most
+one bit may be set. This interrupt has been acknowledged by the APIC
+but not yet injected into the cpu core.
+
+
+4.14 KVM_SET_SREGS
+------------------
+
+:Capability: basic
+:Architectures: x86, ppc
+:Type: vcpu ioctl
+:Parameters: struct kvm_sregs (in)
+:Returns: 0 on success, -1 on error
+
+Writes special registers into the vcpu. See KVM_GET_SREGS for the
+data structures.
+
+
+4.15 KVM_TRANSLATE
+------------------
+
+:Capability: basic
+:Architectures: x86
+:Type: vcpu ioctl
+:Parameters: struct kvm_translation (in/out)
+:Returns: 0 on success, -1 on error
+
+Translates a virtual address according to the vcpu's current address
+translation mode.
+
+::
+
+ struct kvm_translation {
+ /* in */
+ __u64 linear_address;
+
+ /* out */
+ __u64 physical_address;
+ __u8 valid;
+ __u8 writeable;
+ __u8 usermode;
+ __u8 pad[5];
+ };
+
+
+4.16 KVM_INTERRUPT
+------------------
+
+:Capability: basic
+:Architectures: x86, ppc, mips
+:Type: vcpu ioctl
+:Parameters: struct kvm_interrupt (in)
+:Returns: 0 on success, negative on failure.
+
+Queues a hardware interrupt vector to be injected.
+
+::
+
+ /* for KVM_INTERRUPT */
+ struct kvm_interrupt {
+ /* in */
+ __u32 irq;
+ };
+
+X86:
+^^^^
+
+:Returns:
+
+ ========= ===================================
+ 0 on success,
+ -EEXIST if an interrupt is already enqueued
+ -EINVAL the irq number is invalid
+ -ENXIO if the PIC is in the kernel
+ -EFAULT if the pointer is invalid
+ ========= ===================================
+
+Note 'irq' is an interrupt vector, not an interrupt pin or line. This
+ioctl is useful if the in-kernel PIC is not used.
+
+PPC:
+^^^^
+
+Queues an external interrupt to be injected. This ioctl is overleaded
+with 3 different irq values:
+
+a) KVM_INTERRUPT_SET
+
+ This injects an edge type external interrupt into the guest once it's ready
+ to receive interrupts. When injected, the interrupt is done.
+
+b) KVM_INTERRUPT_UNSET
+
+ This unsets any pending interrupt.
+
+ Only available with KVM_CAP_PPC_UNSET_IRQ.
+
+c) KVM_INTERRUPT_SET_LEVEL
+
+ This injects a level type external interrupt into the guest context. The
+ interrupt stays pending until a specific ioctl with KVM_INTERRUPT_UNSET
+ is triggered.
+
+ Only available with KVM_CAP_PPC_IRQ_LEVEL.
+
+Note that any value for 'irq' other than the ones stated above is invalid
+and incurs unexpected behavior.
+
+This is an asynchronous vcpu ioctl and can be invoked from any thread.
+
+MIPS:
+^^^^^
+
+Queues an external interrupt to be injected into the virtual CPU. A negative
+interrupt number dequeues the interrupt.
+
+This is an asynchronous vcpu ioctl and can be invoked from any thread.
+
+
+4.17 KVM_DEBUG_GUEST
+--------------------
+
+:Capability: basic
+:Architectures: none
+:Type: vcpu ioctl
+:Parameters: none)
+:Returns: -1 on error
+
+Support for this has been removed. Use KVM_SET_GUEST_DEBUG instead.
+
+
+4.18 KVM_GET_MSRS
+-----------------
+
+:Capability: basic (vcpu), KVM_CAP_GET_MSR_FEATURES (system)
+:Architectures: x86
+:Type: system ioctl, vcpu ioctl
+:Parameters: struct kvm_msrs (in/out)
+:Returns: number of msrs successfully returned;
+ -1 on error
+
+When used as a system ioctl:
+Reads the values of MSR-based features that are available for the VM. This
+is similar to KVM_GET_SUPPORTED_CPUID, but it returns MSR indices and values.
+The list of msr-based features can be obtained using KVM_GET_MSR_FEATURE_INDEX_LIST
+in a system ioctl.
+
+When used as a vcpu ioctl:
+Reads model-specific registers from the vcpu. Supported msr indices can
+be obtained using KVM_GET_MSR_INDEX_LIST in a system ioctl.
+
+::
+
+ struct kvm_msrs {
+ __u32 nmsrs; /* number of msrs in entries */
+ __u32 pad;
+
+ struct kvm_msr_entry entries[0];
+ };
+
+ struct kvm_msr_entry {
+ __u32 index;
+ __u32 reserved;
+ __u64 data;
+ };
+
+Application code should set the 'nmsrs' member (which indicates the
+size of the entries array) and the 'index' member of each array entry.
+kvm will fill in the 'data' member.
+
+
+4.19 KVM_SET_MSRS
+-----------------
+
+:Capability: basic
+:Architectures: x86
+:Type: vcpu ioctl
+:Parameters: struct kvm_msrs (in)
+:Returns: number of msrs successfully set (see below), -1 on error
+
+Writes model-specific registers to the vcpu. See KVM_GET_MSRS for the
+data structures.
+
+Application code should set the 'nmsrs' member (which indicates the
+size of the entries array), and the 'index' and 'data' members of each
+array entry.
+
+It tries to set the MSRs in array entries[] one by one. If setting an MSR
+fails, e.g., due to setting reserved bits, the MSR isn't supported/emulated
+by KVM, etc..., it stops processing the MSR list and returns the number of
+MSRs that have been set successfully.
+
+
+4.20 KVM_SET_CPUID
+------------------
+
+:Capability: basic
+:Architectures: x86
+:Type: vcpu ioctl
+:Parameters: struct kvm_cpuid (in)
+:Returns: 0 on success, -1 on error
+
+Defines the vcpu responses to the cpuid instruction. Applications
+should use the KVM_SET_CPUID2 ioctl if available.
+
+Note, when this IOCTL fails, KVM gives no guarantees that previous valid CPUID
+configuration (if there is) is not corrupted. Userspace can get a copy of the
+resulting CPUID configuration through KVM_GET_CPUID2 in case.
+
+::
+
+ struct kvm_cpuid_entry {
+ __u32 function;
+ __u32 eax;
+ __u32 ebx;
+ __u32 ecx;
+ __u32 edx;
+ __u32 padding;
+ };
+
+ /* for KVM_SET_CPUID */
+ struct kvm_cpuid {
+ __u32 nent;
+ __u32 padding;
+ struct kvm_cpuid_entry entries[0];
+ };
+
+
+4.21 KVM_SET_SIGNAL_MASK
+------------------------
+
+:Capability: basic
+:Architectures: all
+:Type: vcpu ioctl
+:Parameters: struct kvm_signal_mask (in)
+:Returns: 0 on success, -1 on error
+
+Defines which signals are blocked during execution of KVM_RUN. This
+signal mask temporarily overrides the threads signal mask. Any
+unblocked signal received (except SIGKILL and SIGSTOP, which retain
+their traditional behaviour) will cause KVM_RUN to return with -EINTR.
+
+Note the signal will only be delivered if not blocked by the original
+signal mask.
+
+::
+
+ /* for KVM_SET_SIGNAL_MASK */
+ struct kvm_signal_mask {
+ __u32 len;
+ __u8 sigset[0];
+ };
+
+
+4.22 KVM_GET_FPU
+----------------
+
+:Capability: basic
+:Architectures: x86
+:Type: vcpu ioctl
+:Parameters: struct kvm_fpu (out)
+:Returns: 0 on success, -1 on error
+
+Reads the floating point state from the vcpu.
+
+::
+
+ /* for KVM_GET_FPU and KVM_SET_FPU */
+ struct kvm_fpu {
+ __u8 fpr[8][16];
+ __u16 fcw;
+ __u16 fsw;
+ __u8 ftwx; /* in fxsave format */
+ __u8 pad1;
+ __u16 last_opcode;
+ __u64 last_ip;
+ __u64 last_dp;
+ __u8 xmm[16][16];
+ __u32 mxcsr;
+ __u32 pad2;
+ };
+
+
+4.23 KVM_SET_FPU
+----------------
+
+:Capability: basic
+:Architectures: x86
+:Type: vcpu ioctl
+:Parameters: struct kvm_fpu (in)
+:Returns: 0 on success, -1 on error
+
+Writes the floating point state to the vcpu.
+
+::
+
+ /* for KVM_GET_FPU and KVM_SET_FPU */
+ struct kvm_fpu {
+ __u8 fpr[8][16];
+ __u16 fcw;
+ __u16 fsw;
+ __u8 ftwx; /* in fxsave format */
+ __u8 pad1;
+ __u16 last_opcode;
+ __u64 last_ip;
+ __u64 last_dp;
+ __u8 xmm[16][16];
+ __u32 mxcsr;
+ __u32 pad2;
+ };
+
+
+4.24 KVM_CREATE_IRQCHIP
+-----------------------
+
+:Capability: KVM_CAP_IRQCHIP, KVM_CAP_S390_IRQCHIP (s390)
+:Architectures: x86, ARM, arm64, s390
+:Type: vm ioctl
+:Parameters: none
+:Returns: 0 on success, -1 on error
+
+Creates an interrupt controller model in the kernel.
+On x86, creates a virtual ioapic, a virtual PIC (two PICs, nested), and sets up
+future vcpus to have a local APIC. IRQ routing for GSIs 0-15 is set to both
+PIC and IOAPIC; GSI 16-23 only go to the IOAPIC.
+On ARM/arm64, a GICv2 is created. Any other GIC versions require the usage of
+KVM_CREATE_DEVICE, which also supports creating a GICv2. Using
+KVM_CREATE_DEVICE is preferred over KVM_CREATE_IRQCHIP for GICv2.
+On s390, a dummy irq routing table is created.
+
+Note that on s390 the KVM_CAP_S390_IRQCHIP vm capability needs to be enabled
+before KVM_CREATE_IRQCHIP can be used.
+
+
+4.25 KVM_IRQ_LINE
+-----------------
+
+:Capability: KVM_CAP_IRQCHIP
+:Architectures: x86, arm, arm64
+:Type: vm ioctl
+:Parameters: struct kvm_irq_level
+:Returns: 0 on success, -1 on error
+
+Sets the level of a GSI input to the interrupt controller model in the kernel.
+On some architectures it is required that an interrupt controller model has
+been previously created with KVM_CREATE_IRQCHIP. Note that edge-triggered
+interrupts require the level to be set to 1 and then back to 0.
+
+On real hardware, interrupt pins can be active-low or active-high. This
+does not matter for the level field of struct kvm_irq_level: 1 always
+means active (asserted), 0 means inactive (deasserted).
+
+x86 allows the operating system to program the interrupt polarity
+(active-low/active-high) for level-triggered interrupts, and KVM used
+to consider the polarity. However, due to bitrot in the handling of
+active-low interrupts, the above convention is now valid on x86 too.
+This is signaled by KVM_CAP_X86_IOAPIC_POLARITY_IGNORED. Userspace
+should not present interrupts to the guest as active-low unless this
+capability is present (or unless it is not using the in-kernel irqchip,
+of course).
+
+
+ARM/arm64 can signal an interrupt either at the CPU level, or at the
+in-kernel irqchip (GIC), and for in-kernel irqchip can tell the GIC to
+use PPIs designated for specific cpus. The irq field is interpreted
+like this::
+
+  bits: | 31 ... 28 | 27 ... 24 | 23 ... 16 | 15 ... 0 |
+ field: | vcpu2_index | irq_type | vcpu_index | irq_id |
+
+The irq_type field has the following values:
+
+- irq_type[0]:
+ out-of-kernel GIC: irq_id 0 is IRQ, irq_id 1 is FIQ
+- irq_type[1]:
+ in-kernel GIC: SPI, irq_id between 32 and 1019 (incl.)
+ (the vcpu_index field is ignored)
+- irq_type[2]:
+ in-kernel GIC: PPI, irq_id between 16 and 31 (incl.)
+
+(The irq_id field thus corresponds nicely to the IRQ ID in the ARM GIC specs)
+
+In both cases, level is used to assert/deassert the line.
+
+When KVM_CAP_ARM_IRQ_LINE_LAYOUT_2 is supported, the target vcpu is
+identified as (256 * vcpu2_index + vcpu_index). Otherwise, vcpu2_index
+must be zero.
+
+Note that on arm/arm64, the KVM_CAP_IRQCHIP capability only conditions
+injection of interrupts for the in-kernel irqchip. KVM_IRQ_LINE can always
+be used for a userspace interrupt controller.
+
+::
+
+ struct kvm_irq_level {
+ union {
+ __u32 irq; /* GSI */
+ __s32 status; /* not used for KVM_IRQ_LEVEL */
+ };
+ __u32 level; /* 0 or 1 */
+ };
+
+
+4.26 KVM_GET_IRQCHIP
+--------------------
+
+:Capability: KVM_CAP_IRQCHIP
+:Architectures: x86
+:Type: vm ioctl
+:Parameters: struct kvm_irqchip (in/out)
+:Returns: 0 on success, -1 on error
+
+Reads the state of a kernel interrupt controller created with
+KVM_CREATE_IRQCHIP into a buffer provided by the caller.
+
+::
+
+ struct kvm_irqchip {
+ __u32 chip_id; /* 0 = PIC1, 1 = PIC2, 2 = IOAPIC */
+ __u32 pad;
+ union {
+ char dummy[512]; /* reserving space */
+ struct kvm_pic_state pic;
+ struct kvm_ioapic_state ioapic;
+ } chip;
+ };
+
+
+4.27 KVM_SET_IRQCHIP
+--------------------
+
+:Capability: KVM_CAP_IRQCHIP
+:Architectures: x86
+:Type: vm ioctl
+:Parameters: struct kvm_irqchip (in)
+:Returns: 0 on success, -1 on error
+
+Sets the state of a kernel interrupt controller created with
+KVM_CREATE_IRQCHIP from a buffer provided by the caller.
+
+::
+
+ struct kvm_irqchip {
+ __u32 chip_id; /* 0 = PIC1, 1 = PIC2, 2 = IOAPIC */
+ __u32 pad;
+ union {
+ char dummy[512]; /* reserving space */
+ struct kvm_pic_state pic;
+ struct kvm_ioapic_state ioapic;
+ } chip;
+ };
+
+
+4.28 KVM_XEN_HVM_CONFIG
+-----------------------
+
+:Capability: KVM_CAP_XEN_HVM
+:Architectures: x86
+:Type: vm ioctl
+:Parameters: struct kvm_xen_hvm_config (in)
+:Returns: 0 on success, -1 on error
+
+Sets the MSR that the Xen HVM guest uses to initialize its hypercall
+page, and provides the starting address and size of the hypercall
+blobs in userspace. When the guest writes the MSR, kvm copies one
+page of a blob (32- or 64-bit, depending on the vcpu mode) to guest
+memory.
+
+::
+
+ struct kvm_xen_hvm_config {
+ __u32 flags;
+ __u32 msr;
+ __u64 blob_addr_32;
+ __u64 blob_addr_64;
+ __u8 blob_size_32;
+ __u8 blob_size_64;
+ __u8 pad2[30];
+ };
+
+
+4.29 KVM_GET_CLOCK
+------------------
+
+:Capability: KVM_CAP_ADJUST_CLOCK
+:Architectures: x86
+:Type: vm ioctl
+:Parameters: struct kvm_clock_data (out)
+:Returns: 0 on success, -1 on error
+
+Gets the current timestamp of kvmclock as seen by the current guest. In
+conjunction with KVM_SET_CLOCK, it is used to ensure monotonicity on scenarios
+such as migration.
+
+When KVM_CAP_ADJUST_CLOCK is passed to KVM_CHECK_EXTENSION, it returns the
+set of bits that KVM can return in struct kvm_clock_data's flag member.
+
+The only flag defined now is KVM_CLOCK_TSC_STABLE. If set, the returned
+value is the exact kvmclock value seen by all VCPUs at the instant
+when KVM_GET_CLOCK was called. If clear, the returned value is simply
+CLOCK_MONOTONIC plus a constant offset; the offset can be modified
+with KVM_SET_CLOCK. KVM will try to make all VCPUs follow this clock,
+but the exact value read by each VCPU could differ, because the host
+TSC is not stable.
+
+::
+
+ struct kvm_clock_data {
+ __u64 clock; /* kvmclock current value */
+ __u32 flags;
+ __u32 pad[9];
+ };
+
+
+4.30 KVM_SET_CLOCK
+------------------
+
+:Capability: KVM_CAP_ADJUST_CLOCK
+:Architectures: x86
+:Type: vm ioctl
+:Parameters: struct kvm_clock_data (in)
+:Returns: 0 on success, -1 on error
+
+Sets the current timestamp of kvmclock to the value specified in its parameter.
+In conjunction with KVM_GET_CLOCK, it is used to ensure monotonicity on scenarios
+such as migration.
+
+::
+
+ struct kvm_clock_data {
+ __u64 clock; /* kvmclock current value */
+ __u32 flags;
+ __u32 pad[9];
+ };
+
+
+4.31 KVM_GET_VCPU_EVENTS
+------------------------
+
+:Capability: KVM_CAP_VCPU_EVENTS
+:Extended by: KVM_CAP_INTR_SHADOW
+:Architectures: x86, arm, arm64
+:Type: vcpu ioctl
+:Parameters: struct kvm_vcpu_event (out)
+:Returns: 0 on success, -1 on error
+
+X86:
+^^^^
+
+Gets currently pending exceptions, interrupts, and NMIs as well as related
+states of the vcpu.
+
+::
+
+ struct kvm_vcpu_events {
+ struct {
+ __u8 injected;
+ __u8 nr;
+ __u8 has_error_code;
+ __u8 pending;
+ __u32 error_code;
+ } exception;
+ struct {
+ __u8 injected;
+ __u8 nr;
+ __u8 soft;
+ __u8 shadow;
+ } interrupt;
+ struct {
+ __u8 injected;
+ __u8 pending;
+ __u8 masked;
+ __u8 pad;
+ } nmi;
+ __u32 sipi_vector;
+ __u32 flags;
+ struct {
+ __u8 smm;
+ __u8 pending;
+ __u8 smm_inside_nmi;
+ __u8 latched_init;
+ } smi;
+ __u8 reserved[27];
+ __u8 exception_has_payload;
+ __u64 exception_payload;
+ };
+
+The following bits are defined in the flags field:
+
+- KVM_VCPUEVENT_VALID_SHADOW may be set to signal that
+ interrupt.shadow contains a valid state.
+
+- KVM_VCPUEVENT_VALID_SMM may be set to signal that smi contains a
+ valid state.
+
+- KVM_VCPUEVENT_VALID_PAYLOAD may be set to signal that the
+ exception_has_payload, exception_payload, and exception.pending
+ fields contain a valid state. This bit will be set whenever
+ KVM_CAP_EXCEPTION_PAYLOAD is enabled.
+
+ARM/ARM64:
+^^^^^^^^^^
+
+If the guest accesses a device that is being emulated by the host kernel in
+such a way that a real device would generate a physical SError, KVM may make
+a virtual SError pending for that VCPU. This system error interrupt remains
+pending until the guest takes the exception by unmasking PSTATE.A.
+
+Running the VCPU may cause it to take a pending SError, or make an access that
+causes an SError to become pending. The event's description is only valid while
+the VPCU is not running.
+
+This API provides a way to read and write the pending 'event' state that is not
+visible to the guest. To save, restore or migrate a VCPU the struct representing
+the state can be read then written using this GET/SET API, along with the other
+guest-visible registers. It is not possible to 'cancel' an SError that has been
+made pending.
+
+A device being emulated in user-space may also wish to generate an SError. To do
+this the events structure can be populated by user-space. The current state
+should be read first, to ensure no existing SError is pending. If an existing
+SError is pending, the architecture's 'Multiple SError interrupts' rules should
+be followed. (2.5.3 of DDI0587.a "ARM Reliability, Availability, and
+Serviceability (RAS) Specification").
+
+SError exceptions always have an ESR value. Some CPUs have the ability to
+specify what the virtual SError's ESR value should be. These systems will
+advertise KVM_CAP_ARM_INJECT_SERROR_ESR. In this case exception.has_esr will
+always have a non-zero value when read, and the agent making an SError pending
+should specify the ISS field in the lower 24 bits of exception.serror_esr. If
+the system supports KVM_CAP_ARM_INJECT_SERROR_ESR, but user-space sets the events
+with exception.has_esr as zero, KVM will choose an ESR.
+
+Specifying exception.has_esr on a system that does not support it will return
+-EINVAL. Setting anything other than the lower 24bits of exception.serror_esr
+will return -EINVAL.
+
+It is not possible to read back a pending external abort (injected via
+KVM_SET_VCPU_EVENTS or otherwise) because such an exception is always delivered
+directly to the virtual CPU).
+
+::
+
+ struct kvm_vcpu_events {
+ struct {
+ __u8 serror_pending;
+ __u8 serror_has_esr;
+ __u8 ext_dabt_pending;
+ /* Align it to 8 bytes */
+ __u8 pad[5];
+ __u64 serror_esr;
+ } exception;
+ __u32 reserved[12];
+ };
+
+4.32 KVM_SET_VCPU_EVENTS
+------------------------
+
+:Capability: KVM_CAP_VCPU_EVENTS
+:Extended by: KVM_CAP_INTR_SHADOW
+:Architectures: x86, arm, arm64
+:Type: vcpu ioctl
+:Parameters: struct kvm_vcpu_event (in)
+:Returns: 0 on success, -1 on error
+
+X86:
+^^^^
+
+Set pending exceptions, interrupts, and NMIs as well as related states of the
+vcpu.
+
+See KVM_GET_VCPU_EVENTS for the data structure.
+
+Fields that may be modified asynchronously by running VCPUs can be excluded
+from the update. These fields are nmi.pending, sipi_vector, smi.smm,
+smi.pending. Keep the corresponding bits in the flags field cleared to
+suppress overwriting the current in-kernel state. The bits are:
+
+=============================== ==================================
+KVM_VCPUEVENT_VALID_NMI_PENDING transfer nmi.pending to the kernel
+KVM_VCPUEVENT_VALID_SIPI_VECTOR transfer sipi_vector
+KVM_VCPUEVENT_VALID_SMM transfer the smi sub-struct.
+=============================== ==================================
+
+If KVM_CAP_INTR_SHADOW is available, KVM_VCPUEVENT_VALID_SHADOW can be set in
+the flags field to signal that interrupt.shadow contains a valid state and
+shall be written into the VCPU.
+
+KVM_VCPUEVENT_VALID_SMM can only be set if KVM_CAP_X86_SMM is available.
+
+If KVM_CAP_EXCEPTION_PAYLOAD is enabled, KVM_VCPUEVENT_VALID_PAYLOAD
+can be set in the flags field to signal that the
+exception_has_payload, exception_payload, and exception.pending fields
+contain a valid state and shall be written into the VCPU.
+
+ARM/ARM64:
+^^^^^^^^^^
+
+User space may need to inject several types of events to the guest.
+
+Set the pending SError exception state for this VCPU. It is not possible to
+'cancel' an Serror that has been made pending.
+
+If the guest performed an access to I/O memory which could not be handled by
+userspace, for example because of missing instruction syndrome decode
+information or because there is no device mapped at the accessed IPA, then
+userspace can ask the kernel to inject an external abort using the address
+from the exiting fault on the VCPU. It is a programming error to set
+ext_dabt_pending after an exit which was not either KVM_EXIT_MMIO or
+KVM_EXIT_ARM_NISV. This feature is only available if the system supports
+KVM_CAP_ARM_INJECT_EXT_DABT. This is a helper which provides commonality in
+how userspace reports accesses for the above cases to guests, across different
+userspace implementations. Nevertheless, userspace can still emulate all Arm
+exceptions by manipulating individual registers using the KVM_SET_ONE_REG API.
+
+See KVM_GET_VCPU_EVENTS for the data structure.
+
+
+4.33 KVM_GET_DEBUGREGS
+----------------------
+
+:Capability: KVM_CAP_DEBUGREGS
+:Architectures: x86
+:Type: vm ioctl
+:Parameters: struct kvm_debugregs (out)
+:Returns: 0 on success, -1 on error
+
+Reads debug registers from the vcpu.
+
+::
+
+ struct kvm_debugregs {
+ __u64 db[4];
+ __u64 dr6;
+ __u64 dr7;
+ __u64 flags;
+ __u64 reserved[9];
+ };
+
+
+4.34 KVM_SET_DEBUGREGS
+----------------------
+
+:Capability: KVM_CAP_DEBUGREGS
+:Architectures: x86
+:Type: vm ioctl
+:Parameters: struct kvm_debugregs (in)
+:Returns: 0 on success, -1 on error
+
+Writes debug registers into the vcpu.
+
+See KVM_GET_DEBUGREGS for the data structure. The flags field is unused
+yet and must be cleared on entry.
+
+
+4.35 KVM_SET_USER_MEMORY_REGION
+-------------------------------
+
+:Capability: KVM_CAP_USER_MEMORY
+:Architectures: all
+:Type: vm ioctl
+:Parameters: struct kvm_userspace_memory_region (in)
+:Returns: 0 on success, -1 on error
+
+::
+
+ struct kvm_userspace_memory_region {
+ __u32 slot;
+ __u32 flags;
+ __u64 guest_phys_addr;
+ __u64 memory_size; /* bytes */
+ __u64 userspace_addr; /* start of the userspace allocated memory */
+ };
+
+ /* for kvm_memory_region::flags */
+ #define KVM_MEM_LOG_DIRTY_PAGES (1UL << 0)
+ #define KVM_MEM_READONLY (1UL << 1)
+
+This ioctl allows the user to create, modify or delete a guest physical
+memory slot. Bits 0-15 of "slot" specify the slot id and this value
+should be less than the maximum number of user memory slots supported per
+VM. The maximum allowed slots can be queried using KVM_CAP_NR_MEMSLOTS.
+Slots may not overlap in guest physical address space.
+
+If KVM_CAP_MULTI_ADDRESS_SPACE is available, bits 16-31 of "slot"
+specifies the address space which is being modified. They must be
+less than the value that KVM_CHECK_EXTENSION returns for the
+KVM_CAP_MULTI_ADDRESS_SPACE capability. Slots in separate address spaces
+are unrelated; the restriction on overlapping slots only applies within
+each address space.
+
+Deleting a slot is done by passing zero for memory_size. When changing
+an existing slot, it may be moved in the guest physical memory space,
+or its flags may be modified, but it may not be resized.
+
+Memory for the region is taken starting at the address denoted by the
+field userspace_addr, which must point at user addressable memory for
+the entire memory slot size. Any object may back this memory, including
+anonymous memory, ordinary files, and hugetlbfs.
+
+On architectures that support a form of address tagging, userspace_addr must
+be an untagged address.
+
+It is recommended that the lower 21 bits of guest_phys_addr and userspace_addr
+be identical. This allows large pages in the guest to be backed by large
+pages in the host.
+
+The flags field supports two flags: KVM_MEM_LOG_DIRTY_PAGES and
+KVM_MEM_READONLY. The former can be set to instruct KVM to keep track of
+writes to memory within the slot. See KVM_GET_DIRTY_LOG ioctl to know how to
+use it. The latter can be set, if KVM_CAP_READONLY_MEM capability allows it,
+to make a new slot read-only. In this case, writes to this memory will be
+posted to userspace as KVM_EXIT_MMIO exits.
+
+When the KVM_CAP_SYNC_MMU capability is available, changes in the backing of
+the memory region are automatically reflected into the guest. For example, an
+mmap() that affects the region will be made visible immediately. Another
+example is madvise(MADV_DROP).
+
+It is recommended to use this API instead of the KVM_SET_MEMORY_REGION ioctl.
+The KVM_SET_MEMORY_REGION does not allow fine grained control over memory
+allocation and is deprecated.
+
+
+4.36 KVM_SET_TSS_ADDR
+---------------------
+
+:Capability: KVM_CAP_SET_TSS_ADDR
+:Architectures: x86
+:Type: vm ioctl
+:Parameters: unsigned long tss_address (in)
+:Returns: 0 on success, -1 on error
+
+This ioctl defines the physical address of a three-page region in the guest
+physical address space. The region must be within the first 4GB of the
+guest physical address space and must not conflict with any memory slot
+or any mmio address. The guest may malfunction if it accesses this memory
+region.
+
+This ioctl is required on Intel-based hosts. This is needed on Intel hardware
+because of a quirk in the virtualization implementation (see the internals
+documentation when it pops into existence).
+
+
+4.37 KVM_ENABLE_CAP
+-------------------
+
+:Capability: KVM_CAP_ENABLE_CAP
+:Architectures: mips, ppc, s390
+:Type: vcpu ioctl
+:Parameters: struct kvm_enable_cap (in)
+:Returns: 0 on success; -1 on error
+
+:Capability: KVM_CAP_ENABLE_CAP_VM
+:Architectures: all
+:Type: vm ioctl
+:Parameters: struct kvm_enable_cap (in)
+:Returns: 0 on success; -1 on error
+
+.. note::
+
+ Not all extensions are enabled by default. Using this ioctl the application
+ can enable an extension, making it available to the guest.
+
+On systems that do not support this ioctl, it always fails. On systems that
+do support it, it only works for extensions that are supported for enablement.
+
+To check if a capability can be enabled, the KVM_CHECK_EXTENSION ioctl should
+be used.
+
+::
+
+ struct kvm_enable_cap {
+ /* in */
+ __u32 cap;
+
+The capability that is supposed to get enabled.
+
+::
+
+ __u32 flags;
+
+A bitfield indicating future enhancements. Has to be 0 for now.
+
+::
+
+ __u64 args[4];
+
+Arguments for enabling a feature. If a feature needs initial values to
+function properly, this is the place to put them.
+
+::
+
+ __u8 pad[64];
+ };
+
+The vcpu ioctl should be used for vcpu-specific capabilities, the vm ioctl
+for vm-wide capabilities.
+
+4.38 KVM_GET_MP_STATE
+---------------------
+
+:Capability: KVM_CAP_MP_STATE
+:Architectures: x86, s390, arm, arm64
+:Type: vcpu ioctl
+:Parameters: struct kvm_mp_state (out)
+:Returns: 0 on success; -1 on error
+
+::
+
+ struct kvm_mp_state {
+ __u32 mp_state;
+ };
+
+Returns the vcpu's current "multiprocessing state" (though also valid on
+uniprocessor guests).
+
+Possible values are:
+
+ ========================== ===============================================
+ KVM_MP_STATE_RUNNABLE the vcpu is currently running [x86,arm/arm64]
+ KVM_MP_STATE_UNINITIALIZED the vcpu is an application processor (AP)
+ which has not yet received an INIT signal [x86]
+ KVM_MP_STATE_INIT_RECEIVED the vcpu has received an INIT signal, and is
+ now ready for a SIPI [x86]
+ KVM_MP_STATE_HALTED the vcpu has executed a HLT instruction and
+ is waiting for an interrupt [x86]
+ KVM_MP_STATE_SIPI_RECEIVED the vcpu has just received a SIPI (vector
+ accessible via KVM_GET_VCPU_EVENTS) [x86]
+ KVM_MP_STATE_STOPPED the vcpu is stopped [s390,arm/arm64]
+ KVM_MP_STATE_CHECK_STOP the vcpu is in a special error state [s390]
+ KVM_MP_STATE_OPERATING the vcpu is operating (running or halted)
+ [s390]
+ KVM_MP_STATE_LOAD the vcpu is in a special load/startup state
+ [s390]
+ ========================== ===============================================
+
+On x86, this ioctl is only useful after KVM_CREATE_IRQCHIP. Without an
+in-kernel irqchip, the multiprocessing state must be maintained by userspace on
+these architectures.
+
+For arm/arm64:
+^^^^^^^^^^^^^^
+
+The only states that are valid are KVM_MP_STATE_STOPPED and
+KVM_MP_STATE_RUNNABLE which reflect if the vcpu is paused or not.
+
+4.39 KVM_SET_MP_STATE
+---------------------
+
+:Capability: KVM_CAP_MP_STATE
+:Architectures: x86, s390, arm, arm64
+:Type: vcpu ioctl
+:Parameters: struct kvm_mp_state (in)
+:Returns: 0 on success; -1 on error
+
+Sets the vcpu's current "multiprocessing state"; see KVM_GET_MP_STATE for
+arguments.
+
+On x86, this ioctl is only useful after KVM_CREATE_IRQCHIP. Without an
+in-kernel irqchip, the multiprocessing state must be maintained by userspace on
+these architectures.
+
+For arm/arm64:
+^^^^^^^^^^^^^^
+
+The only states that are valid are KVM_MP_STATE_STOPPED and
+KVM_MP_STATE_RUNNABLE which reflect if the vcpu should be paused or not.
+
+4.40 KVM_SET_IDENTITY_MAP_ADDR
+------------------------------
+
+:Capability: KVM_CAP_SET_IDENTITY_MAP_ADDR
+:Architectures: x86
+:Type: vm ioctl
+:Parameters: unsigned long identity (in)
+:Returns: 0 on success, -1 on error
+
+This ioctl defines the physical address of a one-page region in the guest
+physical address space. The region must be within the first 4GB of the
+guest physical address space and must not conflict with any memory slot
+or any mmio address. The guest may malfunction if it accesses this memory
+region.
+
+Setting the address to 0 will result in resetting the address to its default
+(0xfffbc000).
+
+This ioctl is required on Intel-based hosts. This is needed on Intel hardware
+because of a quirk in the virtualization implementation (see the internals
+documentation when it pops into existence).
+
+Fails if any VCPU has already been created.
+
+4.41 KVM_SET_BOOT_CPU_ID
+------------------------
+
+:Capability: KVM_CAP_SET_BOOT_CPU_ID
+:Architectures: x86
+:Type: vm ioctl
+:Parameters: unsigned long vcpu_id
+:Returns: 0 on success, -1 on error
+
+Define which vcpu is the Bootstrap Processor (BSP). Values are the same
+as the vcpu id in KVM_CREATE_VCPU. If this ioctl is not called, the default
+is vcpu 0.
+
+
+4.42 KVM_GET_XSAVE
+------------------
+
+:Capability: KVM_CAP_XSAVE
+:Architectures: x86
+:Type: vcpu ioctl
+:Parameters: struct kvm_xsave (out)
+:Returns: 0 on success, -1 on error
+
+
+::
+
+ struct kvm_xsave {
+ __u32 region[1024];
+ };
+
+This ioctl would copy current vcpu's xsave struct to the userspace.
+
+
+4.43 KVM_SET_XSAVE
+------------------
+
+:Capability: KVM_CAP_XSAVE
+:Architectures: x86
+:Type: vcpu ioctl
+:Parameters: struct kvm_xsave (in)
+:Returns: 0 on success, -1 on error
+
+::
+
+
+ struct kvm_xsave {
+ __u32 region[1024];
+ };
+
+This ioctl would copy userspace's xsave struct to the kernel.
+
+
+4.44 KVM_GET_XCRS
+-----------------
+
+:Capability: KVM_CAP_XCRS
+:Architectures: x86
+:Type: vcpu ioctl
+:Parameters: struct kvm_xcrs (out)
+:Returns: 0 on success, -1 on error
+
+::
+
+ struct kvm_xcr {
+ __u32 xcr;
+ __u32 reserved;
+ __u64 value;
+ };
+
+ struct kvm_xcrs {
+ __u32 nr_xcrs;
+ __u32 flags;
+ struct kvm_xcr xcrs[KVM_MAX_XCRS];
+ __u64 padding[16];
+ };
+
+This ioctl would copy current vcpu's xcrs to the userspace.
+
+
+4.45 KVM_SET_XCRS
+-----------------
+
+:Capability: KVM_CAP_XCRS
+:Architectures: x86
+:Type: vcpu ioctl
+:Parameters: struct kvm_xcrs (in)
+:Returns: 0 on success, -1 on error
+
+::
+
+ struct kvm_xcr {
+ __u32 xcr;
+ __u32 reserved;
+ __u64 value;
+ };
+
+ struct kvm_xcrs {
+ __u32 nr_xcrs;
+ __u32 flags;
+ struct kvm_xcr xcrs[KVM_MAX_XCRS];
+ __u64 padding[16];
+ };
+
+This ioctl would set vcpu's xcr to the value userspace specified.
+
+
+4.46 KVM_GET_SUPPORTED_CPUID
+----------------------------
+
+:Capability: KVM_CAP_EXT_CPUID
+:Architectures: x86
+:Type: system ioctl
+:Parameters: struct kvm_cpuid2 (in/out)
+:Returns: 0 on success, -1 on error
+
+::
+
+ struct kvm_cpuid2 {
+ __u32 nent;
+ __u32 padding;
+ struct kvm_cpuid_entry2 entries[0];
+ };
+
+ #define KVM_CPUID_FLAG_SIGNIFCANT_INDEX BIT(0)
+ #define KVM_CPUID_FLAG_STATEFUL_FUNC BIT(1) /* deprecated */
+ #define KVM_CPUID_FLAG_STATE_READ_NEXT BIT(2) /* deprecated */
+
+ struct kvm_cpuid_entry2 {
+ __u32 function;
+ __u32 index;
+ __u32 flags;
+ __u32 eax;
+ __u32 ebx;
+ __u32 ecx;
+ __u32 edx;
+ __u32 padding[3];
+ };
+
+This ioctl returns x86 cpuid features which are supported by both the
+hardware and kvm in its default configuration. Userspace can use the
+information returned by this ioctl to construct cpuid information (for
+KVM_SET_CPUID2) that is consistent with hardware, kernel, and
+userspace capabilities, and with user requirements (for example, the
+user may wish to constrain cpuid to emulate older hardware, or for
+feature consistency across a cluster).
+
+Note that certain capabilities, such as KVM_CAP_X86_DISABLE_EXITS, may
+expose cpuid features (e.g. MONITOR) which are not supported by kvm in
+its default configuration. If userspace enables such capabilities, it
+is responsible for modifying the results of this ioctl appropriately.
+
+Userspace invokes KVM_GET_SUPPORTED_CPUID by passing a kvm_cpuid2 structure
+with the 'nent' field indicating the number of entries in the variable-size
+array 'entries'. If the number of entries is too low to describe the cpu
+capabilities, an error (E2BIG) is returned. If the number is too high,
+the 'nent' field is adjusted and an error (ENOMEM) is returned. If the
+number is just right, the 'nent' field is adjusted to the number of valid
+entries in the 'entries' array, which is then filled.
+
+The entries returned are the host cpuid as returned by the cpuid instruction,
+with unknown or unsupported features masked out. Some features (for example,
+x2apic), may not be present in the host cpu, but are exposed by kvm if it can
+emulate them efficiently. The fields in each entry are defined as follows:
+
+ function:
+ the eax value used to obtain the entry
+
+ index:
+ the ecx value used to obtain the entry (for entries that are
+ affected by ecx)
+
+ flags:
+ an OR of zero or more of the following:
+
+ KVM_CPUID_FLAG_SIGNIFCANT_INDEX:
+ if the index field is valid
+
+ eax, ebx, ecx, edx:
+ the values returned by the cpuid instruction for
+ this function/index combination
+
+The TSC deadline timer feature (CPUID leaf 1, ecx[24]) is always returned
+as false, since the feature depends on KVM_CREATE_IRQCHIP for local APIC
+support. Instead it is reported via::
+
+ ioctl(KVM_CHECK_EXTENSION, KVM_CAP_TSC_DEADLINE_TIMER)
+
+if that returns true and you use KVM_CREATE_IRQCHIP, or if you emulate the
+feature in userspace, then you can enable the feature for KVM_SET_CPUID2.
+
+
+4.47 KVM_PPC_GET_PVINFO
+-----------------------
+
+:Capability: KVM_CAP_PPC_GET_PVINFO
+:Architectures: ppc
+:Type: vm ioctl
+:Parameters: struct kvm_ppc_pvinfo (out)
+:Returns: 0 on success, !0 on error
+
+::
+
+ struct kvm_ppc_pvinfo {
+ __u32 flags;
+ __u32 hcall[4];
+ __u8 pad[108];
+ };
+
+This ioctl fetches PV specific information that need to be passed to the guest
+using the device tree or other means from vm context.
+
+The hcall array defines 4 instructions that make up a hypercall.
+
+If any additional field gets added to this structure later on, a bit for that
+additional piece of information will be set in the flags bitmap.
+
+The flags bitmap is defined as::
+
+ /* the host supports the ePAPR idle hcall
+ #define KVM_PPC_PVINFO_FLAGS_EV_IDLE (1<<0)
+
+4.52 KVM_SET_GSI_ROUTING
+------------------------
+
+:Capability: KVM_CAP_IRQ_ROUTING
+:Architectures: x86 s390 arm arm64
+:Type: vm ioctl
+:Parameters: struct kvm_irq_routing (in)
+:Returns: 0 on success, -1 on error
+
+Sets the GSI routing table entries, overwriting any previously set entries.
+
+On arm/arm64, GSI routing has the following limitation:
+
+- GSI routing does not apply to KVM_IRQ_LINE but only to KVM_IRQFD.
+
+::
+
+ struct kvm_irq_routing {
+ __u32 nr;
+ __u32 flags;
+ struct kvm_irq_routing_entry entries[0];
+ };
+
+No flags are specified so far, the corresponding field must be set to zero.
+
+::
+
+ struct kvm_irq_routing_entry {
+ __u32 gsi;
+ __u32 type;
+ __u32 flags;
+ __u32 pad;
+ union {
+ struct kvm_irq_routing_irqchip irqchip;
+ struct kvm_irq_routing_msi msi;
+ struct kvm_irq_routing_s390_adapter adapter;
+ struct kvm_irq_routing_hv_sint hv_sint;
+ __u32 pad[8];
+ } u;
+ };
+
+ /* gsi routing entry types */
+ #define KVM_IRQ_ROUTING_IRQCHIP 1
+ #define KVM_IRQ_ROUTING_MSI 2
+ #define KVM_IRQ_ROUTING_S390_ADAPTER 3
+ #define KVM_IRQ_ROUTING_HV_SINT 4
+
+flags:
+
+- KVM_MSI_VALID_DEVID: used along with KVM_IRQ_ROUTING_MSI routing entry
+ type, specifies that the devid field contains a valid value. The per-VM
+ KVM_CAP_MSI_DEVID capability advertises the requirement to provide
+ the device ID. If this capability is not available, userspace should
+ never set the KVM_MSI_VALID_DEVID flag as the ioctl might fail.
+- zero otherwise
+
+::
+
+ struct kvm_irq_routing_irqchip {
+ __u32 irqchip;
+ __u32 pin;
+ };
+
+ struct kvm_irq_routing_msi {
+ __u32 address_lo;
+ __u32 address_hi;
+ __u32 data;
+ union {
+ __u32 pad;
+ __u32 devid;
+ };
+ };
+
+If KVM_MSI_VALID_DEVID is set, devid contains a unique device identifier
+for the device that wrote the MSI message. For PCI, this is usually a
+BFD identifier in the lower 16 bits.
+
+On x86, address_hi is ignored unless the KVM_X2APIC_API_USE_32BIT_IDS
+feature of KVM_CAP_X2APIC_API capability is enabled. If it is enabled,
+address_hi bits 31-8 provide bits 31-8 of the destination id. Bits 7-0 of
+address_hi must be zero.
+
+::
+
+ struct kvm_irq_routing_s390_adapter {
+ __u64 ind_addr;
+ __u64 summary_addr;
+ __u64 ind_offset;
+ __u32 summary_offset;
+ __u32 adapter_id;
+ };
+
+ struct kvm_irq_routing_hv_sint {
+ __u32 vcpu;
+ __u32 sint;
+ };
+
+
+4.55 KVM_SET_TSC_KHZ
+--------------------
+
+:Capability: KVM_CAP_TSC_CONTROL
+:Architectures: x86
+:Type: vcpu ioctl
+:Parameters: virtual tsc_khz
+:Returns: 0 on success, -1 on error
+
+Specifies the tsc frequency for the virtual machine. The unit of the
+frequency is KHz.
+
+
+4.56 KVM_GET_TSC_KHZ
+--------------------
+
+:Capability: KVM_CAP_GET_TSC_KHZ
+:Architectures: x86
+:Type: vcpu ioctl
+:Parameters: none
+:Returns: virtual tsc-khz on success, negative value on error
+
+Returns the tsc frequency of the guest. The unit of the return value is
+KHz. If the host has unstable tsc this ioctl returns -EIO instead as an
+error.
+
+
+4.57 KVM_GET_LAPIC
+------------------
+
+:Capability: KVM_CAP_IRQCHIP
+:Architectures: x86
+:Type: vcpu ioctl
+:Parameters: struct kvm_lapic_state (out)
+:Returns: 0 on success, -1 on error
+
+::
+
+ #define KVM_APIC_REG_SIZE 0x400
+ struct kvm_lapic_state {
+ char regs[KVM_APIC_REG_SIZE];
+ };
+
+Reads the Local APIC registers and copies them into the input argument. The
+data format and layout are the same as documented in the architecture manual.
+
+If KVM_X2APIC_API_USE_32BIT_IDS feature of KVM_CAP_X2APIC_API is
+enabled, then the format of APIC_ID register depends on the APIC mode
+(reported by MSR_IA32_APICBASE) of its VCPU. x2APIC stores APIC ID in
+the APIC_ID register (bytes 32-35). xAPIC only allows an 8-bit APIC ID
+which is stored in bits 31-24 of the APIC register, or equivalently in
+byte 35 of struct kvm_lapic_state's regs field. KVM_GET_LAPIC must then
+be called after MSR_IA32_APICBASE has been set with KVM_SET_MSR.
+
+If KVM_X2APIC_API_USE_32BIT_IDS feature is disabled, struct kvm_lapic_state
+always uses xAPIC format.
+
+
+4.58 KVM_SET_LAPIC
+------------------
+
+:Capability: KVM_CAP_IRQCHIP
+:Architectures: x86
+:Type: vcpu ioctl
+:Parameters: struct kvm_lapic_state (in)
+:Returns: 0 on success, -1 on error
+
+::
+
+ #define KVM_APIC_REG_SIZE 0x400
+ struct kvm_lapic_state {
+ char regs[KVM_APIC_REG_SIZE];
+ };
+
+Copies the input argument into the Local APIC registers. The data format
+and layout are the same as documented in the architecture manual.
+
+The format of the APIC ID register (bytes 32-35 of struct kvm_lapic_state's
+regs field) depends on the state of the KVM_CAP_X2APIC_API capability.
+See the note in KVM_GET_LAPIC.
+
+
+4.59 KVM_IOEVENTFD
+------------------
+
+:Capability: KVM_CAP_IOEVENTFD
+:Architectures: all
+:Type: vm ioctl
+:Parameters: struct kvm_ioeventfd (in)
+:Returns: 0 on success, !0 on error
+
+This ioctl attaches or detaches an ioeventfd to a legal pio/mmio address
+within the guest. A guest write in the registered address will signal the
+provided event instead of triggering an exit.
+
+::
+
+ struct kvm_ioeventfd {
+ __u64 datamatch;
+ __u64 addr; /* legal pio/mmio address */
+ __u32 len; /* 0, 1, 2, 4, or 8 bytes */
+ __s32 fd;
+ __u32 flags;
+ __u8 pad[36];
+ };
+
+For the special case of virtio-ccw devices on s390, the ioevent is matched
+to a subchannel/virtqueue tuple instead.
+
+The following flags are defined::
+
+ #define KVM_IOEVENTFD_FLAG_DATAMATCH (1 << kvm_ioeventfd_flag_nr_datamatch)
+ #define KVM_IOEVENTFD_FLAG_PIO (1 << kvm_ioeventfd_flag_nr_pio)
+ #define KVM_IOEVENTFD_FLAG_DEASSIGN (1 << kvm_ioeventfd_flag_nr_deassign)
+ #define KVM_IOEVENTFD_FLAG_VIRTIO_CCW_NOTIFY \
+ (1 << kvm_ioeventfd_flag_nr_virtio_ccw_notify)
+
+If datamatch flag is set, the event will be signaled only if the written value
+to the registered address is equal to datamatch in struct kvm_ioeventfd.
+
+For virtio-ccw devices, addr contains the subchannel id and datamatch the
+virtqueue index.
+
+With KVM_CAP_IOEVENTFD_ANY_LENGTH, a zero length ioeventfd is allowed, and
+the kernel will ignore the length of guest write and may get a faster vmexit.
+The speedup may only apply to specific architectures, but the ioeventfd will
+work anyway.
+
+4.60 KVM_DIRTY_TLB
+------------------
+
+:Capability: KVM_CAP_SW_TLB
+:Architectures: ppc
+:Type: vcpu ioctl
+:Parameters: struct kvm_dirty_tlb (in)
+:Returns: 0 on success, -1 on error
+
+::
+
+ struct kvm_dirty_tlb {
+ __u64 bitmap;
+ __u32 num_dirty;
+ };
+
+This must be called whenever userspace has changed an entry in the shared
+TLB, prior to calling KVM_RUN on the associated vcpu.
+
+The "bitmap" field is the userspace address of an array. This array
+consists of a number of bits, equal to the total number of TLB entries as
+determined by the last successful call to KVM_CONFIG_TLB, rounded up to the
+nearest multiple of 64.
+
+Each bit corresponds to one TLB entry, ordered the same as in the shared TLB
+array.
+
+The array is little-endian: the bit 0 is the least significant bit of the
+first byte, bit 8 is the least significant bit of the second byte, etc.
+This avoids any complications with differing word sizes.
+
+The "num_dirty" field is a performance hint for KVM to determine whether it
+should skip processing the bitmap and just invalidate everything. It must
+be set to the number of set bits in the bitmap.
+
+
+4.62 KVM_CREATE_SPAPR_TCE
+-------------------------
+
+:Capability: KVM_CAP_SPAPR_TCE
+:Architectures: powerpc
+:Type: vm ioctl
+:Parameters: struct kvm_create_spapr_tce (in)
+:Returns: file descriptor for manipulating the created TCE table
+
+This creates a virtual TCE (translation control entry) table, which
+is an IOMMU for PAPR-style virtual I/O. It is used to translate
+logical addresses used in virtual I/O into guest physical addresses,
+and provides a scatter/gather capability for PAPR virtual I/O.
+
+::
+
+ /* for KVM_CAP_SPAPR_TCE */
+ struct kvm_create_spapr_tce {
+ __u64 liobn;
+ __u32 window_size;
+ };
+
+The liobn field gives the logical IO bus number for which to create a
+TCE table. The window_size field specifies the size of the DMA window
+which this TCE table will translate - the table will contain one 64
+bit TCE entry for every 4kiB of the DMA window.
+
+When the guest issues an H_PUT_TCE hcall on a liobn for which a TCE
+table has been created using this ioctl(), the kernel will handle it
+in real mode, updating the TCE table. H_PUT_TCE calls for other
+liobns will cause a vm exit and must be handled by userspace.
+
+The return value is a file descriptor which can be passed to mmap(2)
+to map the created TCE table into userspace. This lets userspace read
+the entries written by kernel-handled H_PUT_TCE calls, and also lets
+userspace update the TCE table directly which is useful in some
+circumstances.
+
+
+4.63 KVM_ALLOCATE_RMA
+---------------------
+
+:Capability: KVM_CAP_PPC_RMA
+:Architectures: powerpc
+:Type: vm ioctl
+:Parameters: struct kvm_allocate_rma (out)
+:Returns: file descriptor for mapping the allocated RMA
+
+This allocates a Real Mode Area (RMA) from the pool allocated at boot
+time by the kernel. An RMA is a physically-contiguous, aligned region
+of memory used on older POWER processors to provide the memory which
+will be accessed by real-mode (MMU off) accesses in a KVM guest.
+POWER processors support a set of sizes for the RMA that usually
+includes 64MB, 128MB, 256MB and some larger powers of two.
+
+::
+
+ /* for KVM_ALLOCATE_RMA */
+ struct kvm_allocate_rma {
+ __u64 rma_size;
+ };
+
+The return value is a file descriptor which can be passed to mmap(2)
+to map the allocated RMA into userspace. The mapped area can then be
+passed to the KVM_SET_USER_MEMORY_REGION ioctl to establish it as the
+RMA for a virtual machine. The size of the RMA in bytes (which is
+fixed at host kernel boot time) is returned in the rma_size field of
+the argument structure.
+
+The KVM_CAP_PPC_RMA capability is 1 or 2 if the KVM_ALLOCATE_RMA ioctl
+is supported; 2 if the processor requires all virtual machines to have
+an RMA, or 1 if the processor can use an RMA but doesn't require it,
+because it supports the Virtual RMA (VRMA) facility.
+
+
+4.64 KVM_NMI
+------------
+
+:Capability: KVM_CAP_USER_NMI
+:Architectures: x86
+:Type: vcpu ioctl
+:Parameters: none
+:Returns: 0 on success, -1 on error
+
+Queues an NMI on the thread's vcpu. Note this is well defined only
+when KVM_CREATE_IRQCHIP has not been called, since this is an interface
+between the virtual cpu core and virtual local APIC. After KVM_CREATE_IRQCHIP
+has been called, this interface is completely emulated within the kernel.
+
+To use this to emulate the LINT1 input with KVM_CREATE_IRQCHIP, use the
+following algorithm:
+
+ - pause the vcpu
+ - read the local APIC's state (KVM_GET_LAPIC)
+ - check whether changing LINT1 will queue an NMI (see the LVT entry for LINT1)
+ - if so, issue KVM_NMI
+ - resume the vcpu
+
+Some guests configure the LINT1 NMI input to cause a panic, aiding in
+debugging.
+
+
+4.65 KVM_S390_UCAS_MAP
+----------------------
+
+:Capability: KVM_CAP_S390_UCONTROL
+:Architectures: s390
+:Type: vcpu ioctl
+:Parameters: struct kvm_s390_ucas_mapping (in)
+:Returns: 0 in case of success
+
+The parameter is defined like this::
+
+ struct kvm_s390_ucas_mapping {
+ __u64 user_addr;
+ __u64 vcpu_addr;
+ __u64 length;
+ };
+
+This ioctl maps the memory at "user_addr" with the length "length" to
+the vcpu's address space starting at "vcpu_addr". All parameters need to
+be aligned by 1 megabyte.
+
+
+4.66 KVM_S390_UCAS_UNMAP
+------------------------
+
+:Capability: KVM_CAP_S390_UCONTROL
+:Architectures: s390
+:Type: vcpu ioctl
+:Parameters: struct kvm_s390_ucas_mapping (in)
+:Returns: 0 in case of success
+
+The parameter is defined like this::
+
+ struct kvm_s390_ucas_mapping {
+ __u64 user_addr;
+ __u64 vcpu_addr;
+ __u64 length;
+ };
+
+This ioctl unmaps the memory in the vcpu's address space starting at
+"vcpu_addr" with the length "length". The field "user_addr" is ignored.
+All parameters need to be aligned by 1 megabyte.
+
+
+4.67 KVM_S390_VCPU_FAULT
+------------------------
+
+:Capability: KVM_CAP_S390_UCONTROL
+:Architectures: s390
+:Type: vcpu ioctl
+:Parameters: vcpu absolute address (in)
+:Returns: 0 in case of success
+
+This call creates a page table entry on the virtual cpu's address space
+(for user controlled virtual machines) or the virtual machine's address
+space (for regular virtual machines). This only works for minor faults,
+thus it's recommended to access subject memory page via the user page
+table upfront. This is useful to handle validity intercepts for user
+controlled virtual machines to fault in the virtual cpu's lowcore pages
+prior to calling the KVM_RUN ioctl.
+
+
+4.68 KVM_SET_ONE_REG
+--------------------
+
+:Capability: KVM_CAP_ONE_REG
+:Architectures: all
+:Type: vcpu ioctl
+:Parameters: struct kvm_one_reg (in)
+:Returns: 0 on success, negative value on failure
+
+Errors:
+
+ ====== ============================================================
+  ENOENT   no such register
+  EINVAL   invalid register ID, or no such register or used with VMs in
+ protected virtualization mode on s390
+  EPERM    (arm64) register access not allowed before vcpu finalization
+ ====== ============================================================
+
+(These error codes are indicative only: do not rely on a specific error
+code being returned in a specific situation.)
+
+::
+
+ struct kvm_one_reg {
+ __u64 id;
+ __u64 addr;
+ };
+
+Using this ioctl, a single vcpu register can be set to a specific value
+defined by user space with the passed in struct kvm_one_reg, where id
+refers to the register identifier as described below and addr is a pointer
+to a variable with the respective size. There can be architecture agnostic
+and architecture specific registers. Each have their own range of operation
+and their own constants and width. To keep track of the implemented
+registers, find a list below:
+
+ ======= =============================== ============
+ Arch Register Width (bits)
+ ======= =============================== ============
+ PPC KVM_REG_PPC_HIOR 64
+ PPC KVM_REG_PPC_IAC1 64
+ PPC KVM_REG_PPC_IAC2 64
+ PPC KVM_REG_PPC_IAC3 64
+ PPC KVM_REG_PPC_IAC4 64
+ PPC KVM_REG_PPC_DAC1 64
+ PPC KVM_REG_PPC_DAC2 64
+ PPC KVM_REG_PPC_DABR 64
+ PPC KVM_REG_PPC_DSCR 64
+ PPC KVM_REG_PPC_PURR 64
+ PPC KVM_REG_PPC_SPURR 64
+ PPC KVM_REG_PPC_DAR 64
+ PPC KVM_REG_PPC_DSISR 32
+ PPC KVM_REG_PPC_AMR 64
+ PPC KVM_REG_PPC_UAMOR 64
+ PPC KVM_REG_PPC_MMCR0 64
+ PPC KVM_REG_PPC_MMCR1 64
+ PPC KVM_REG_PPC_MMCRA 64
+ PPC KVM_REG_PPC_MMCR2 64
+ PPC KVM_REG_PPC_MMCRS 64
+ PPC KVM_REG_PPC_MMCR3 64
+ PPC KVM_REG_PPC_SIAR 64
+ PPC KVM_REG_PPC_SDAR 64
+ PPC KVM_REG_PPC_SIER 64
+ PPC KVM_REG_PPC_SIER2 64
+ PPC KVM_REG_PPC_SIER3 64
+ PPC KVM_REG_PPC_PMC1 32
+ PPC KVM_REG_PPC_PMC2 32
+ PPC KVM_REG_PPC_PMC3 32
+ PPC KVM_REG_PPC_PMC4 32
+ PPC KVM_REG_PPC_PMC5 32
+ PPC KVM_REG_PPC_PMC6 32
+ PPC KVM_REG_PPC_PMC7 32
+ PPC KVM_REG_PPC_PMC8 32
+ PPC KVM_REG_PPC_FPR0 64
+ ...
+ PPC KVM_REG_PPC_FPR31 64
+ PPC KVM_REG_PPC_VR0 128
+ ...
+ PPC KVM_REG_PPC_VR31 128
+ PPC KVM_REG_PPC_VSR0 128
+ ...
+ PPC KVM_REG_PPC_VSR31 128
+ PPC KVM_REG_PPC_FPSCR 64
+ PPC KVM_REG_PPC_VSCR 32
+ PPC KVM_REG_PPC_VPA_ADDR 64
+ PPC KVM_REG_PPC_VPA_SLB 128
+ PPC KVM_REG_PPC_VPA_DTL 128
+ PPC KVM_REG_PPC_EPCR 32
+ PPC KVM_REG_PPC_EPR 32
+ PPC KVM_REG_PPC_TCR 32
+ PPC KVM_REG_PPC_TSR 32
+ PPC KVM_REG_PPC_OR_TSR 32
+ PPC KVM_REG_PPC_CLEAR_TSR 32
+ PPC KVM_REG_PPC_MAS0 32
+ PPC KVM_REG_PPC_MAS1 32
+ PPC KVM_REG_PPC_MAS2 64
+ PPC KVM_REG_PPC_MAS7_3 64
+ PPC KVM_REG_PPC_MAS4 32
+ PPC KVM_REG_PPC_MAS6 32
+ PPC KVM_REG_PPC_MMUCFG 32
+ PPC KVM_REG_PPC_TLB0CFG 32
+ PPC KVM_REG_PPC_TLB1CFG 32
+ PPC KVM_REG_PPC_TLB2CFG 32
+ PPC KVM_REG_PPC_TLB3CFG 32
+ PPC KVM_REG_PPC_TLB0PS 32
+ PPC KVM_REG_PPC_TLB1PS 32
+ PPC KVM_REG_PPC_TLB2PS 32
+ PPC KVM_REG_PPC_TLB3PS 32
+ PPC KVM_REG_PPC_EPTCFG 32
+ PPC KVM_REG_PPC_ICP_STATE 64
+ PPC KVM_REG_PPC_VP_STATE 128
+ PPC KVM_REG_PPC_TB_OFFSET 64
+ PPC KVM_REG_PPC_SPMC1 32
+ PPC KVM_REG_PPC_SPMC2 32
+ PPC KVM_REG_PPC_IAMR 64
+ PPC KVM_REG_PPC_TFHAR 64
+ PPC KVM_REG_PPC_TFIAR 64
+ PPC KVM_REG_PPC_TEXASR 64
+ PPC KVM_REG_PPC_FSCR 64
+ PPC KVM_REG_PPC_PSPB 32
+ PPC KVM_REG_PPC_EBBHR 64
+ PPC KVM_REG_PPC_EBBRR 64
+ PPC KVM_REG_PPC_BESCR 64
+ PPC KVM_REG_PPC_TAR 64
+ PPC KVM_REG_PPC_DPDES 64
+ PPC KVM_REG_PPC_DAWR 64
+ PPC KVM_REG_PPC_DAWRX 64
+ PPC KVM_REG_PPC_CIABR 64
+ PPC KVM_REG_PPC_IC 64
+ PPC KVM_REG_PPC_VTB 64
+ PPC KVM_REG_PPC_CSIGR 64
+ PPC KVM_REG_PPC_TACR 64
+ PPC KVM_REG_PPC_TCSCR 64
+ PPC KVM_REG_PPC_PID 64
+ PPC KVM_REG_PPC_ACOP 64
+ PPC KVM_REG_PPC_VRSAVE 32
+ PPC KVM_REG_PPC_LPCR 32
+ PPC KVM_REG_PPC_LPCR_64 64
+ PPC KVM_REG_PPC_PPR 64
+ PPC KVM_REG_PPC_ARCH_COMPAT 32
+ PPC KVM_REG_PPC_DABRX 32
+ PPC KVM_REG_PPC_WORT 64
+ PPC KVM_REG_PPC_SPRG9 64
+ PPC KVM_REG_PPC_DBSR 32
+ PPC KVM_REG_PPC_TIDR 64
+ PPC KVM_REG_PPC_PSSCR 64
+ PPC KVM_REG_PPC_DEC_EXPIRY 64
+ PPC KVM_REG_PPC_PTCR 64
+ PPC KVM_REG_PPC_TM_GPR0 64
+ ...
+ PPC KVM_REG_PPC_TM_GPR31 64
+ PPC KVM_REG_PPC_TM_VSR0 128
+ ...
+ PPC KVM_REG_PPC_TM_VSR63 128
+ PPC KVM_REG_PPC_TM_CR 64
+ PPC KVM_REG_PPC_TM_LR 64
+ PPC KVM_REG_PPC_TM_CTR 64
+ PPC KVM_REG_PPC_TM_FPSCR 64
+ PPC KVM_REG_PPC_TM_AMR 64
+ PPC KVM_REG_PPC_TM_PPR 64
+ PPC KVM_REG_PPC_TM_VRSAVE 64
+ PPC KVM_REG_PPC_TM_VSCR 32
+ PPC KVM_REG_PPC_TM_DSCR 64
+ PPC KVM_REG_PPC_TM_TAR 64
+ PPC KVM_REG_PPC_TM_XER 64
+
+ MIPS KVM_REG_MIPS_R0 64
+ ...
+ MIPS KVM_REG_MIPS_R31 64
+ MIPS KVM_REG_MIPS_HI 64
+ MIPS KVM_REG_MIPS_LO 64
+ MIPS KVM_REG_MIPS_PC 64
+ MIPS KVM_REG_MIPS_CP0_INDEX 32
+ MIPS KVM_REG_MIPS_CP0_ENTRYLO0 64
+ MIPS KVM_REG_MIPS_CP0_ENTRYLO1 64
+ MIPS KVM_REG_MIPS_CP0_CONTEXT 64
+ MIPS KVM_REG_MIPS_CP0_CONTEXTCONFIG 32
+ MIPS KVM_REG_MIPS_CP0_USERLOCAL 64
+ MIPS KVM_REG_MIPS_CP0_XCONTEXTCONFIG 64
+ MIPS KVM_REG_MIPS_CP0_PAGEMASK 32
+ MIPS KVM_REG_MIPS_CP0_PAGEGRAIN 32
+ MIPS KVM_REG_MIPS_CP0_SEGCTL0 64
+ MIPS KVM_REG_MIPS_CP0_SEGCTL1 64
+ MIPS KVM_REG_MIPS_CP0_SEGCTL2 64
+ MIPS KVM_REG_MIPS_CP0_PWBASE 64
+ MIPS KVM_REG_MIPS_CP0_PWFIELD 64
+ MIPS KVM_REG_MIPS_CP0_PWSIZE 64
+ MIPS KVM_REG_MIPS_CP0_WIRED 32
+ MIPS KVM_REG_MIPS_CP0_PWCTL 32
+ MIPS KVM_REG_MIPS_CP0_HWRENA 32
+ MIPS KVM_REG_MIPS_CP0_BADVADDR 64
+ MIPS KVM_REG_MIPS_CP0_BADINSTR 32
+ MIPS KVM_REG_MIPS_CP0_BADINSTRP 32
+ MIPS KVM_REG_MIPS_CP0_COUNT 32
+ MIPS KVM_REG_MIPS_CP0_ENTRYHI 64
+ MIPS KVM_REG_MIPS_CP0_COMPARE 32
+ MIPS KVM_REG_MIPS_CP0_STATUS 32
+ MIPS KVM_REG_MIPS_CP0_INTCTL 32
+ MIPS KVM_REG_MIPS_CP0_CAUSE 32
+ MIPS KVM_REG_MIPS_CP0_EPC 64
+ MIPS KVM_REG_MIPS_CP0_PRID 32
+ MIPS KVM_REG_MIPS_CP0_EBASE 64
+ MIPS KVM_REG_MIPS_CP0_CONFIG 32
+ MIPS KVM_REG_MIPS_CP0_CONFIG1 32
+ MIPS KVM_REG_MIPS_CP0_CONFIG2 32
+ MIPS KVM_REG_MIPS_CP0_CONFIG3 32
+ MIPS KVM_REG_MIPS_CP0_CONFIG4 32
+ MIPS KVM_REG_MIPS_CP0_CONFIG5 32
+ MIPS KVM_REG_MIPS_CP0_CONFIG7 32
+ MIPS KVM_REG_MIPS_CP0_XCONTEXT 64
+ MIPS KVM_REG_MIPS_CP0_ERROREPC 64
+ MIPS KVM_REG_MIPS_CP0_KSCRATCH1 64
+ MIPS KVM_REG_MIPS_CP0_KSCRATCH2 64
+ MIPS KVM_REG_MIPS_CP0_KSCRATCH3 64
+ MIPS KVM_REG_MIPS_CP0_KSCRATCH4 64
+ MIPS KVM_REG_MIPS_CP0_KSCRATCH5 64
+ MIPS KVM_REG_MIPS_CP0_KSCRATCH6 64
+ MIPS KVM_REG_MIPS_CP0_MAAR(0..63) 64
+ MIPS KVM_REG_MIPS_COUNT_CTL 64
+ MIPS KVM_REG_MIPS_COUNT_RESUME 64
+ MIPS KVM_REG_MIPS_COUNT_HZ 64
+ MIPS KVM_REG_MIPS_FPR_32(0..31) 32
+ MIPS KVM_REG_MIPS_FPR_64(0..31) 64
+ MIPS KVM_REG_MIPS_VEC_128(0..31) 128
+ MIPS KVM_REG_MIPS_FCR_IR 32
+ MIPS KVM_REG_MIPS_FCR_CSR 32
+ MIPS KVM_REG_MIPS_MSA_IR 32
+ MIPS KVM_REG_MIPS_MSA_CSR 32
+ ======= =============================== ============
+
+ARM registers are mapped using the lower 32 bits. The upper 16 of that
+is the register group type, or coprocessor number:
+
+ARM core registers have the following id bit patterns::
+
+ 0x4020 0000 0010 <index into the kvm_regs struct:16>
+
+ARM 32-bit CP15 registers have the following id bit patterns::
+
+ 0x4020 0000 000F <zero:1> <crn:4> <crm:4> <opc1:4> <opc2:3>
+
+ARM 64-bit CP15 registers have the following id bit patterns::
+
+ 0x4030 0000 000F <zero:1> <zero:4> <crm:4> <opc1:4> <zero:3>
+
+ARM CCSIDR registers are demultiplexed by CSSELR value::
+
+ 0x4020 0000 0011 00 <csselr:8>
+
+ARM 32-bit VFP control registers have the following id bit patterns::
+
+ 0x4020 0000 0012 1 <regno:12>
+
+ARM 64-bit FP registers have the following id bit patterns::
+
+ 0x4030 0000 0012 0 <regno:12>
+
+ARM firmware pseudo-registers have the following bit pattern::
+
+ 0x4030 0000 0014 <regno:16>
+
+
+arm64 registers are mapped using the lower 32 bits. The upper 16 of
+that is the register group type, or coprocessor number:
+
+arm64 core/FP-SIMD registers have the following id bit patterns. Note
+that the size of the access is variable, as the kvm_regs structure
+contains elements ranging from 32 to 128 bits. The index is a 32bit
+value in the kvm_regs structure seen as a 32bit array::
+
+ 0x60x0 0000 0010 <index into the kvm_regs struct:16>
+
+Specifically:
+
+======================= ========= ===== =======================================
+ Encoding Register Bits kvm_regs member
+======================= ========= ===== =======================================
+ 0x6030 0000 0010 0000 X0 64 regs.regs[0]
+ 0x6030 0000 0010 0002 X1 64 regs.regs[1]
+ ...
+ 0x6030 0000 0010 003c X30 64 regs.regs[30]
+ 0x6030 0000 0010 003e SP 64 regs.sp
+ 0x6030 0000 0010 0040 PC 64 regs.pc
+ 0x6030 0000 0010 0042 PSTATE 64 regs.pstate
+ 0x6030 0000 0010 0044 SP_EL1 64 sp_el1
+ 0x6030 0000 0010 0046 ELR_EL1 64 elr_el1
+ 0x6030 0000 0010 0048 SPSR_EL1 64 spsr[KVM_SPSR_EL1] (alias SPSR_SVC)
+ 0x6030 0000 0010 004a SPSR_ABT 64 spsr[KVM_SPSR_ABT]
+ 0x6030 0000 0010 004c SPSR_UND 64 spsr[KVM_SPSR_UND]
+ 0x6030 0000 0010 004e SPSR_IRQ 64 spsr[KVM_SPSR_IRQ]
+ 0x6060 0000 0010 0050 SPSR_FIQ 64 spsr[KVM_SPSR_FIQ]
+ 0x6040 0000 0010 0054 V0 128 fp_regs.vregs[0] [1]_
+ 0x6040 0000 0010 0058 V1 128 fp_regs.vregs[1] [1]_
+ ...
+ 0x6040 0000 0010 00d0 V31 128 fp_regs.vregs[31] [1]_
+ 0x6020 0000 0010 00d4 FPSR 32 fp_regs.fpsr
+ 0x6020 0000 0010 00d5 FPCR 32 fp_regs.fpcr
+======================= ========= ===== =======================================
+
+.. [1] These encodings are not accepted for SVE-enabled vcpus. See
+ KVM_ARM_VCPU_INIT.
+
+ The equivalent register content can be accessed via bits [127:0] of
+ the corresponding SVE Zn registers instead for vcpus that have SVE
+ enabled (see below).
+
+arm64 CCSIDR registers are demultiplexed by CSSELR value::
+
+ 0x6020 0000 0011 00 <csselr:8>
+
+arm64 system registers have the following id bit patterns::
+
+ 0x6030 0000 0013 <op0:2> <op1:3> <crn:4> <crm:4> <op2:3>
+
+.. warning::
+
+ Two system register IDs do not follow the specified pattern. These
+ are KVM_REG_ARM_TIMER_CVAL and KVM_REG_ARM_TIMER_CNT, which map to
+ system registers CNTV_CVAL_EL0 and CNTVCT_EL0 respectively. These
+ two had their values accidentally swapped, which means TIMER_CVAL is
+ derived from the register encoding for CNTVCT_EL0 and TIMER_CNT is
+ derived from the register encoding for CNTV_CVAL_EL0. As this is
+ API, it must remain this way.
+
+arm64 firmware pseudo-registers have the following bit pattern::
+
+ 0x6030 0000 0014 <regno:16>
+
+arm64 SVE registers have the following bit patterns::
+
+ 0x6080 0000 0015 00 <n:5> <slice:5> Zn bits[2048*slice + 2047 : 2048*slice]
+ 0x6050 0000 0015 04 <n:4> <slice:5> Pn bits[256*slice + 255 : 256*slice]
+ 0x6050 0000 0015 060 <slice:5> FFR bits[256*slice + 255 : 256*slice]
+ 0x6060 0000 0015 ffff KVM_REG_ARM64_SVE_VLS pseudo-register
+
+Access to register IDs where 2048 * slice >= 128 * max_vq will fail with
+ENOENT. max_vq is the vcpu's maximum supported vector length in 128-bit
+quadwords: see [2]_ below.
+
+These registers are only accessible on vcpus for which SVE is enabled.
+See KVM_ARM_VCPU_INIT for details.
+
+In addition, except for KVM_REG_ARM64_SVE_VLS, these registers are not
+accessible until the vcpu's SVE configuration has been finalized
+using KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE). See KVM_ARM_VCPU_INIT
+and KVM_ARM_VCPU_FINALIZE for more information about this procedure.
+
+KVM_REG_ARM64_SVE_VLS is a pseudo-register that allows the set of vector
+lengths supported by the vcpu to be discovered and configured by
+userspace. When transferred to or from user memory via KVM_GET_ONE_REG
+or KVM_SET_ONE_REG, the value of this register is of type
+__u64[KVM_ARM64_SVE_VLS_WORDS], and encodes the set of vector lengths as
+follows::
+
+ __u64 vector_lengths[KVM_ARM64_SVE_VLS_WORDS];
+
+ if (vq >= SVE_VQ_MIN && vq <= SVE_VQ_MAX &&
+ ((vector_lengths[(vq - KVM_ARM64_SVE_VQ_MIN) / 64] >>
+ ((vq - KVM_ARM64_SVE_VQ_MIN) % 64)) & 1))
+ /* Vector length vq * 16 bytes supported */
+ else
+ /* Vector length vq * 16 bytes not supported */
+
+.. [2] The maximum value vq for which the above condition is true is
+ max_vq. This is the maximum vector length available to the guest on
+ this vcpu, and determines which register slices are visible through
+ this ioctl interface.
+
+(See Documentation/arm64/sve.rst for an explanation of the "vq"
+nomenclature.)
+
+KVM_REG_ARM64_SVE_VLS is only accessible after KVM_ARM_VCPU_INIT.
+KVM_ARM_VCPU_INIT initialises it to the best set of vector lengths that
+the host supports.
+
+Userspace may subsequently modify it if desired until the vcpu's SVE
+configuration is finalized using KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE).
+
+Apart from simply removing all vector lengths from the host set that
+exceed some value, support for arbitrarily chosen sets of vector lengths
+is hardware-dependent and may not be available. Attempting to configure
+an invalid set of vector lengths via KVM_SET_ONE_REG will fail with
+EINVAL.
+
+After the vcpu's SVE configuration is finalized, further attempts to
+write this register will fail with EPERM.
+
+
+MIPS registers are mapped using the lower 32 bits. The upper 16 of that is
+the register group type:
+
+MIPS core registers (see above) have the following id bit patterns::
+
+ 0x7030 0000 0000 <reg:16>
+
+MIPS CP0 registers (see KVM_REG_MIPS_CP0_* above) have the following id bit
+patterns depending on whether they're 32-bit or 64-bit registers::
+
+ 0x7020 0000 0001 00 <reg:5> <sel:3> (32-bit)
+ 0x7030 0000 0001 00 <reg:5> <sel:3> (64-bit)
+
+Note: KVM_REG_MIPS_CP0_ENTRYLO0 and KVM_REG_MIPS_CP0_ENTRYLO1 are the MIPS64
+versions of the EntryLo registers regardless of the word size of the host
+hardware, host kernel, guest, and whether XPA is present in the guest, i.e.
+with the RI and XI bits (if they exist) in bits 63 and 62 respectively, and
+the PFNX field starting at bit 30.
+
+MIPS MAARs (see KVM_REG_MIPS_CP0_MAAR(*) above) have the following id bit
+patterns::
+
+ 0x7030 0000 0001 01 <reg:8>
+
+MIPS KVM control registers (see above) have the following id bit patterns::
+
+ 0x7030 0000 0002 <reg:16>
+
+MIPS FPU registers (see KVM_REG_MIPS_FPR_{32,64}() above) have the following
+id bit patterns depending on the size of the register being accessed. They are
+always accessed according to the current guest FPU mode (Status.FR and
+Config5.FRE), i.e. as the guest would see them, and they become unpredictable
+if the guest FPU mode is changed. MIPS SIMD Architecture (MSA) vector
+registers (see KVM_REG_MIPS_VEC_128() above) have similar patterns as they
+overlap the FPU registers::
+
+ 0x7020 0000 0003 00 <0:3> <reg:5> (32-bit FPU registers)
+ 0x7030 0000 0003 00 <0:3> <reg:5> (64-bit FPU registers)
+ 0x7040 0000 0003 00 <0:3> <reg:5> (128-bit MSA vector registers)
+
+MIPS FPU control registers (see KVM_REG_MIPS_FCR_{IR,CSR} above) have the
+following id bit patterns::
+
+ 0x7020 0000 0003 01 <0:3> <reg:5>
+
+MIPS MSA control registers (see KVM_REG_MIPS_MSA_{IR,CSR} above) have the
+following id bit patterns::
+
+ 0x7020 0000 0003 02 <0:3> <reg:5>
+
+
+4.69 KVM_GET_ONE_REG
+--------------------
+
+:Capability: KVM_CAP_ONE_REG
+:Architectures: all
+:Type: vcpu ioctl
+:Parameters: struct kvm_one_reg (in and out)
+:Returns: 0 on success, negative value on failure
+
+Errors include:
+
+ ======== ============================================================
+  ENOENT   no such register
+  EINVAL   invalid register ID, or no such register or used with VMs in
+ protected virtualization mode on s390
+  EPERM    (arm64) register access not allowed before vcpu finalization
+ ======== ============================================================
+
+(These error codes are indicative only: do not rely on a specific error
+code being returned in a specific situation.)
+
+This ioctl allows to receive the value of a single register implemented
+in a vcpu. The register to read is indicated by the "id" field of the
+kvm_one_reg struct passed in. On success, the register value can be found
+at the memory location pointed to by "addr".
+
+The list of registers accessible using this interface is identical to the
+list in 4.68.
+
+
+4.70 KVM_KVMCLOCK_CTRL
+----------------------
+
+:Capability: KVM_CAP_KVMCLOCK_CTRL
+:Architectures: Any that implement pvclocks (currently x86 only)
+:Type: vcpu ioctl
+:Parameters: None
+:Returns: 0 on success, -1 on error
+
+This ioctl sets a flag accessible to the guest indicating that the specified
+vCPU has been paused by the host userspace.
+
+The host will set a flag in the pvclock structure that is checked from the
+soft lockup watchdog. The flag is part of the pvclock structure that is
+shared between guest and host, specifically the second bit of the flags
+field of the pvclock_vcpu_time_info structure. It will be set exclusively by
+the host and read/cleared exclusively by the guest. The guest operation of
+checking and clearing the flag must be an atomic operation so
+load-link/store-conditional, or equivalent must be used. There are two cases
+where the guest will clear the flag: when the soft lockup watchdog timer resets
+itself or when a soft lockup is detected. This ioctl can be called any time
+after pausing the vcpu, but before it is resumed.
+
+
+4.71 KVM_SIGNAL_MSI
+-------------------
+
+:Capability: KVM_CAP_SIGNAL_MSI
+:Architectures: x86 arm arm64
+:Type: vm ioctl
+:Parameters: struct kvm_msi (in)
+:Returns: >0 on delivery, 0 if guest blocked the MSI, and -1 on error
+
+Directly inject a MSI message. Only valid with in-kernel irqchip that handles
+MSI messages.
+
+::
+
+ struct kvm_msi {
+ __u32 address_lo;
+ __u32 address_hi;
+ __u32 data;
+ __u32 flags;
+ __u32 devid;
+ __u8 pad[12];
+ };
+
+flags:
+ KVM_MSI_VALID_DEVID: devid contains a valid value. The per-VM
+ KVM_CAP_MSI_DEVID capability advertises the requirement to provide
+ the device ID. If this capability is not available, userspace
+ should never set the KVM_MSI_VALID_DEVID flag as the ioctl might fail.
+
+If KVM_MSI_VALID_DEVID is set, devid contains a unique device identifier
+for the device that wrote the MSI message. For PCI, this is usually a
+BFD identifier in the lower 16 bits.
+
+On x86, address_hi is ignored unless the KVM_X2APIC_API_USE_32BIT_IDS
+feature of KVM_CAP_X2APIC_API capability is enabled. If it is enabled,
+address_hi bits 31-8 provide bits 31-8 of the destination id. Bits 7-0 of
+address_hi must be zero.
+
+
+4.71 KVM_CREATE_PIT2
+--------------------
+
+:Capability: KVM_CAP_PIT2
+:Architectures: x86
+:Type: vm ioctl
+:Parameters: struct kvm_pit_config (in)
+:Returns: 0 on success, -1 on error
+
+Creates an in-kernel device model for the i8254 PIT. This call is only valid
+after enabling in-kernel irqchip support via KVM_CREATE_IRQCHIP. The following
+parameters have to be passed::
+
+ struct kvm_pit_config {
+ __u32 flags;
+ __u32 pad[15];
+ };
+
+Valid flags are::
+
+ #define KVM_PIT_SPEAKER_DUMMY 1 /* emulate speaker port stub */
+
+PIT timer interrupts may use a per-VM kernel thread for injection. If it
+exists, this thread will have a name of the following pattern::
+
+ kvm-pit/<owner-process-pid>
+
+When running a guest with elevated priorities, the scheduling parameters of
+this thread may have to be adjusted accordingly.
+
+This IOCTL replaces the obsolete KVM_CREATE_PIT.
+
+
+4.72 KVM_GET_PIT2
+-----------------
+
+:Capability: KVM_CAP_PIT_STATE2
+:Architectures: x86
+:Type: vm ioctl
+:Parameters: struct kvm_pit_state2 (out)
+:Returns: 0 on success, -1 on error
+
+Retrieves the state of the in-kernel PIT model. Only valid after
+KVM_CREATE_PIT2. The state is returned in the following structure::
+
+ struct kvm_pit_state2 {
+ struct kvm_pit_channel_state channels[3];
+ __u32 flags;
+ __u32 reserved[9];
+ };
+
+Valid flags are::
+
+ /* disable PIT in HPET legacy mode */
+ #define KVM_PIT_FLAGS_HPET_LEGACY 0x00000001
+
+This IOCTL replaces the obsolete KVM_GET_PIT.
+
+
+4.73 KVM_SET_PIT2
+-----------------
+
+:Capability: KVM_CAP_PIT_STATE2
+:Architectures: x86
+:Type: vm ioctl
+:Parameters: struct kvm_pit_state2 (in)
+:Returns: 0 on success, -1 on error
+
+Sets the state of the in-kernel PIT model. Only valid after KVM_CREATE_PIT2.
+See KVM_GET_PIT2 for details on struct kvm_pit_state2.
+
+This IOCTL replaces the obsolete KVM_SET_PIT.
+
+
+4.74 KVM_PPC_GET_SMMU_INFO
+--------------------------
+
+:Capability: KVM_CAP_PPC_GET_SMMU_INFO
+:Architectures: powerpc
+:Type: vm ioctl
+:Parameters: None
+:Returns: 0 on success, -1 on error
+
+This populates and returns a structure describing the features of
+the "Server" class MMU emulation supported by KVM.
+This can in turn be used by userspace to generate the appropriate
+device-tree properties for the guest operating system.
+
+The structure contains some global information, followed by an
+array of supported segment page sizes::
+
+ struct kvm_ppc_smmu_info {
+ __u64 flags;
+ __u32 slb_size;
+ __u32 pad;
+ struct kvm_ppc_one_seg_page_size sps[KVM_PPC_PAGE_SIZES_MAX_SZ];
+ };
+
+The supported flags are:
+
+ - KVM_PPC_PAGE_SIZES_REAL:
+ When that flag is set, guest page sizes must "fit" the backing
+ store page sizes. When not set, any page size in the list can
+ be used regardless of how they are backed by userspace.
+
+ - KVM_PPC_1T_SEGMENTS
+ The emulated MMU supports 1T segments in addition to the
+ standard 256M ones.
+
+ - KVM_PPC_NO_HASH
+ This flag indicates that HPT guests are not supported by KVM,
+ thus all guests must use radix MMU mode.
+
+The "slb_size" field indicates how many SLB entries are supported
+
+The "sps" array contains 8 entries indicating the supported base
+page sizes for a segment in increasing order. Each entry is defined
+as follow::
+
+ struct kvm_ppc_one_seg_page_size {
+ __u32 page_shift; /* Base page shift of segment (or 0) */
+ __u32 slb_enc; /* SLB encoding for BookS */
+ struct kvm_ppc_one_page_size enc[KVM_PPC_PAGE_SIZES_MAX_SZ];
+ };
+
+An entry with a "page_shift" of 0 is unused. Because the array is
+organized in increasing order, a lookup can stop when encoutering
+such an entry.
+
+The "slb_enc" field provides the encoding to use in the SLB for the
+page size. The bits are in positions such as the value can directly
+be OR'ed into the "vsid" argument of the slbmte instruction.
+
+The "enc" array is a list which for each of those segment base page
+size provides the list of supported actual page sizes (which can be
+only larger or equal to the base page size), along with the
+corresponding encoding in the hash PTE. Similarly, the array is
+8 entries sorted by increasing sizes and an entry with a "0" shift
+is an empty entry and a terminator::
+
+ struct kvm_ppc_one_page_size {
+ __u32 page_shift; /* Page shift (or 0) */
+ __u32 pte_enc; /* Encoding in the HPTE (>>12) */
+ };
+
+The "pte_enc" field provides a value that can OR'ed into the hash
+PTE's RPN field (ie, it needs to be shifted left by 12 to OR it
+into the hash PTE second double word).
+
+4.75 KVM_IRQFD
+--------------
+
+:Capability: KVM_CAP_IRQFD
+:Architectures: x86 s390 arm arm64
+:Type: vm ioctl
+:Parameters: struct kvm_irqfd (in)
+:Returns: 0 on success, -1 on error
+
+Allows setting an eventfd to directly trigger a guest interrupt.
+kvm_irqfd.fd specifies the file descriptor to use as the eventfd and
+kvm_irqfd.gsi specifies the irqchip pin toggled by this event. When
+an event is triggered on the eventfd, an interrupt is injected into
+the guest using the specified gsi pin. The irqfd is removed using
+the KVM_IRQFD_FLAG_DEASSIGN flag, specifying both kvm_irqfd.fd
+and kvm_irqfd.gsi.
+
+With KVM_CAP_IRQFD_RESAMPLE, KVM_IRQFD supports a de-assert and notify
+mechanism allowing emulation of level-triggered, irqfd-based
+interrupts. When KVM_IRQFD_FLAG_RESAMPLE is set the user must pass an
+additional eventfd in the kvm_irqfd.resamplefd field. When operating
+in resample mode, posting of an interrupt through kvm_irq.fd asserts
+the specified gsi in the irqchip. When the irqchip is resampled, such
+as from an EOI, the gsi is de-asserted and the user is notified via
+kvm_irqfd.resamplefd. It is the user's responsibility to re-queue
+the interrupt if the device making use of it still requires service.
+Note that closing the resamplefd is not sufficient to disable the
+irqfd. The KVM_IRQFD_FLAG_RESAMPLE is only necessary on assignment
+and need not be specified with KVM_IRQFD_FLAG_DEASSIGN.
+
+On arm/arm64, gsi routing being supported, the following can happen:
+
+- in case no routing entry is associated to this gsi, injection fails
+- in case the gsi is associated to an irqchip routing entry,
+ irqchip.pin + 32 corresponds to the injected SPI ID.
+- in case the gsi is associated to an MSI routing entry, the MSI
+ message and device ID are translated into an LPI (support restricted
+ to GICv3 ITS in-kernel emulation).
+
+4.76 KVM_PPC_ALLOCATE_HTAB
+--------------------------
+
+:Capability: KVM_CAP_PPC_ALLOC_HTAB
+:Architectures: powerpc
+:Type: vm ioctl
+:Parameters: Pointer to u32 containing hash table order (in/out)
+:Returns: 0 on success, -1 on error
+
+This requests the host kernel to allocate an MMU hash table for a
+guest using the PAPR paravirtualization interface. This only does
+anything if the kernel is configured to use the Book 3S HV style of
+virtualization. Otherwise the capability doesn't exist and the ioctl
+returns an ENOTTY error. The rest of this description assumes Book 3S
+HV.
+
+There must be no vcpus running when this ioctl is called; if there
+are, it will do nothing and return an EBUSY error.
+
+The parameter is a pointer to a 32-bit unsigned integer variable
+containing the order (log base 2) of the desired size of the hash
+table, which must be between 18 and 46. On successful return from the
+ioctl, the value will not be changed by the kernel.
+
+If no hash table has been allocated when any vcpu is asked to run
+(with the KVM_RUN ioctl), the host kernel will allocate a
+default-sized hash table (16 MB).
+
+If this ioctl is called when a hash table has already been allocated,
+with a different order from the existing hash table, the existing hash
+table will be freed and a new one allocated. If this is ioctl is
+called when a hash table has already been allocated of the same order
+as specified, the kernel will clear out the existing hash table (zero
+all HPTEs). In either case, if the guest is using the virtualized
+real-mode area (VRMA) facility, the kernel will re-create the VMRA
+HPTEs on the next KVM_RUN of any vcpu.
+
+4.77 KVM_S390_INTERRUPT
+-----------------------
+
+:Capability: basic
+:Architectures: s390
+:Type: vm ioctl, vcpu ioctl
+:Parameters: struct kvm_s390_interrupt (in)
+:Returns: 0 on success, -1 on error
+
+Allows to inject an interrupt to the guest. Interrupts can be floating
+(vm ioctl) or per cpu (vcpu ioctl), depending on the interrupt type.
+
+Interrupt parameters are passed via kvm_s390_interrupt::
+
+ struct kvm_s390_interrupt {
+ __u32 type;
+ __u32 parm;
+ __u64 parm64;
+ };
+
+type can be one of the following:
+
+KVM_S390_SIGP_STOP (vcpu)
+ - sigp stop; optional flags in parm
+KVM_S390_PROGRAM_INT (vcpu)
+ - program check; code in parm
+KVM_S390_SIGP_SET_PREFIX (vcpu)
+ - sigp set prefix; prefix address in parm
+KVM_S390_RESTART (vcpu)
+ - restart
+KVM_S390_INT_CLOCK_COMP (vcpu)
+ - clock comparator interrupt
+KVM_S390_INT_CPU_TIMER (vcpu)
+ - CPU timer interrupt
+KVM_S390_INT_VIRTIO (vm)
+ - virtio external interrupt; external interrupt
+ parameters in parm and parm64
+KVM_S390_INT_SERVICE (vm)
+ - sclp external interrupt; sclp parameter in parm
+KVM_S390_INT_EMERGENCY (vcpu)
+ - sigp emergency; source cpu in parm
+KVM_S390_INT_EXTERNAL_CALL (vcpu)
+ - sigp external call; source cpu in parm
+KVM_S390_INT_IO(ai,cssid,ssid,schid) (vm)
+ - compound value to indicate an
+ I/O interrupt (ai - adapter interrupt; cssid,ssid,schid - subchannel);
+ I/O interruption parameters in parm (subchannel) and parm64 (intparm,
+ interruption subclass)
+KVM_S390_MCHK (vm, vcpu)
+ - machine check interrupt; cr 14 bits in parm, machine check interrupt
+ code in parm64 (note that machine checks needing further payload are not
+ supported by this ioctl)
+
+This is an asynchronous vcpu ioctl and can be invoked from any thread.
+
+4.78 KVM_PPC_GET_HTAB_FD
+------------------------
+
+:Capability: KVM_CAP_PPC_HTAB_FD
+:Architectures: powerpc
+:Type: vm ioctl
+:Parameters: Pointer to struct kvm_get_htab_fd (in)
+:Returns: file descriptor number (>= 0) on success, -1 on error
+
+This returns a file descriptor that can be used either to read out the
+entries in the guest's hashed page table (HPT), or to write entries to
+initialize the HPT. The returned fd can only be written to if the
+KVM_GET_HTAB_WRITE bit is set in the flags field of the argument, and
+can only be read if that bit is clear. The argument struct looks like
+this::
+
+ /* For KVM_PPC_GET_HTAB_FD */
+ struct kvm_get_htab_fd {
+ __u64 flags;
+ __u64 start_index;
+ __u64 reserved[2];
+ };
+
+ /* Values for kvm_get_htab_fd.flags */
+ #define KVM_GET_HTAB_BOLTED_ONLY ((__u64)0x1)
+ #define KVM_GET_HTAB_WRITE ((__u64)0x2)
+
+The 'start_index' field gives the index in the HPT of the entry at
+which to start reading. It is ignored when writing.
+
+Reads on the fd will initially supply information about all
+"interesting" HPT entries. Interesting entries are those with the
+bolted bit set, if the KVM_GET_HTAB_BOLTED_ONLY bit is set, otherwise
+all entries. When the end of the HPT is reached, the read() will
+return. If read() is called again on the fd, it will start again from
+the beginning of the HPT, but will only return HPT entries that have
+changed since they were last read.
+
+Data read or written is structured as a header (8 bytes) followed by a
+series of valid HPT entries (16 bytes) each. The header indicates how
+many valid HPT entries there are and how many invalid entries follow
+the valid entries. The invalid entries are not represented explicitly
+in the stream. The header format is::
+
+ struct kvm_get_htab_header {
+ __u32 index;
+ __u16 n_valid;
+ __u16 n_invalid;
+ };
+
+Writes to the fd create HPT entries starting at the index given in the
+header; first 'n_valid' valid entries with contents from the data
+written, then 'n_invalid' invalid entries, invalidating any previously
+valid entries found.
+
+4.79 KVM_CREATE_DEVICE
+----------------------
+
+:Capability: KVM_CAP_DEVICE_CTRL
+:Type: vm ioctl
+:Parameters: struct kvm_create_device (in/out)
+:Returns: 0 on success, -1 on error
+
+Errors:
+
+ ====== =======================================================
+ ENODEV The device type is unknown or unsupported
+ EEXIST Device already created, and this type of device may not
+ be instantiated multiple times
+ ====== =======================================================
+
+ Other error conditions may be defined by individual device types or
+ have their standard meanings.
+
+Creates an emulated device in the kernel. The file descriptor returned
+in fd can be used with KVM_SET/GET/HAS_DEVICE_ATTR.
+
+If the KVM_CREATE_DEVICE_TEST flag is set, only test whether the
+device type is supported (not necessarily whether it can be created
+in the current vm).
+
+Individual devices should not define flags. Attributes should be used
+for specifying any behavior that is not implied by the device type
+number.
+
+::
+
+ struct kvm_create_device {
+ __u32 type; /* in: KVM_DEV_TYPE_xxx */
+ __u32 fd; /* out: device handle */
+ __u32 flags; /* in: KVM_CREATE_DEVICE_xxx */
+ };
+
+4.80 KVM_SET_DEVICE_ATTR/KVM_GET_DEVICE_ATTR
+--------------------------------------------
+
+:Capability: KVM_CAP_DEVICE_CTRL, KVM_CAP_VM_ATTRIBUTES for vm device,
+ KVM_CAP_VCPU_ATTRIBUTES for vcpu device
+:Type: device ioctl, vm ioctl, vcpu ioctl
+:Parameters: struct kvm_device_attr
+:Returns: 0 on success, -1 on error
+
+Errors:
+
+ ===== =============================================================
+ ENXIO The group or attribute is unknown/unsupported for this device
+ or hardware support is missing.
+ EPERM The attribute cannot (currently) be accessed this way
+ (e.g. read-only attribute, or attribute that only makes
+ sense when the device is in a different state)
+ ===== =============================================================
+
+ Other error conditions may be defined by individual device types.
+
+Gets/sets a specified piece of device configuration and/or state. The
+semantics are device-specific. See individual device documentation in
+the "devices" directory. As with ONE_REG, the size of the data
+transferred is defined by the particular attribute.
+
+::
+
+ struct kvm_device_attr {
+ __u32 flags; /* no flags currently defined */
+ __u32 group; /* device-defined */
+ __u64 attr; /* group-defined */
+ __u64 addr; /* userspace address of attr data */
+ };
+
+4.81 KVM_HAS_DEVICE_ATTR
+------------------------
+
+:Capability: KVM_CAP_DEVICE_CTRL, KVM_CAP_VM_ATTRIBUTES for vm device,
+ KVM_CAP_VCPU_ATTRIBUTES for vcpu device
+:Type: device ioctl, vm ioctl, vcpu ioctl
+:Parameters: struct kvm_device_attr
+:Returns: 0 on success, -1 on error
+
+Errors:
+
+ ===== =============================================================
+ ENXIO The group or attribute is unknown/unsupported for this device
+ or hardware support is missing.
+ ===== =============================================================
+
+Tests whether a device supports a particular attribute. A successful
+return indicates the attribute is implemented. It does not necessarily
+indicate that the attribute can be read or written in the device's
+current state. "addr" is ignored.
+
+4.82 KVM_ARM_VCPU_INIT
+----------------------
+
+:Capability: basic
+:Architectures: arm, arm64
+:Type: vcpu ioctl
+:Parameters: struct kvm_vcpu_init (in)
+:Returns: 0 on success; -1 on error
+
+Errors:
+
+ ====== =================================================================
+  EINVAL    the target is unknown, or the combination of features is invalid.
+  ENOENT    a features bit specified is unknown.
+ ====== =================================================================
+
+This tells KVM what type of CPU to present to the guest, and what
+optional features it should have.  This will cause a reset of the cpu
+registers to their initial values.  If this is not called, KVM_RUN will
+return ENOEXEC for that vcpu.
+
+Note that because some registers reflect machine topology, all vcpus
+should be created before this ioctl is invoked.
+
+Userspace can call this function multiple times for a given vcpu, including
+after the vcpu has been run. This will reset the vcpu to its initial
+state. All calls to this function after the initial call must use the same
+target and same set of feature flags, otherwise EINVAL will be returned.
+
+Possible features:
+
+ - KVM_ARM_VCPU_POWER_OFF: Starts the CPU in a power-off state.
+ Depends on KVM_CAP_ARM_PSCI. If not set, the CPU will be powered on
+ and execute guest code when KVM_RUN is called.
+ - KVM_ARM_VCPU_EL1_32BIT: Starts the CPU in a 32bit mode.
+ Depends on KVM_CAP_ARM_EL1_32BIT (arm64 only).
+ - KVM_ARM_VCPU_PSCI_0_2: Emulate PSCI v0.2 (or a future revision
+ backward compatible with v0.2) for the CPU.
+ Depends on KVM_CAP_ARM_PSCI_0_2.
+ - KVM_ARM_VCPU_PMU_V3: Emulate PMUv3 for the CPU.
+ Depends on KVM_CAP_ARM_PMU_V3.
+
+ - KVM_ARM_VCPU_PTRAUTH_ADDRESS: Enables Address Pointer authentication
+ for arm64 only.
+ Depends on KVM_CAP_ARM_PTRAUTH_ADDRESS.
+ If KVM_CAP_ARM_PTRAUTH_ADDRESS and KVM_CAP_ARM_PTRAUTH_GENERIC are
+ both present, then both KVM_ARM_VCPU_PTRAUTH_ADDRESS and
+ KVM_ARM_VCPU_PTRAUTH_GENERIC must be requested or neither must be
+ requested.
+
+ - KVM_ARM_VCPU_PTRAUTH_GENERIC: Enables Generic Pointer authentication
+ for arm64 only.
+ Depends on KVM_CAP_ARM_PTRAUTH_GENERIC.
+ If KVM_CAP_ARM_PTRAUTH_ADDRESS and KVM_CAP_ARM_PTRAUTH_GENERIC are
+ both present, then both KVM_ARM_VCPU_PTRAUTH_ADDRESS and
+ KVM_ARM_VCPU_PTRAUTH_GENERIC must be requested or neither must be
+ requested.
+
+ - KVM_ARM_VCPU_SVE: Enables SVE for the CPU (arm64 only).
+ Depends on KVM_CAP_ARM_SVE.
+ Requires KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE):
+
+ * After KVM_ARM_VCPU_INIT:
+
+ - KVM_REG_ARM64_SVE_VLS may be read using KVM_GET_ONE_REG: the
+ initial value of this pseudo-register indicates the best set of
+ vector lengths possible for a vcpu on this host.
+
+ * Before KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE):
+
+ - KVM_RUN and KVM_GET_REG_LIST are not available;
+
+ - KVM_GET_ONE_REG and KVM_SET_ONE_REG cannot be used to access
+ the scalable archietctural SVE registers
+ KVM_REG_ARM64_SVE_ZREG(), KVM_REG_ARM64_SVE_PREG() or
+ KVM_REG_ARM64_SVE_FFR;
+
+ - KVM_REG_ARM64_SVE_VLS may optionally be written using
+ KVM_SET_ONE_REG, to modify the set of vector lengths available
+ for the vcpu.
+
+ * After KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE):
+
+ - the KVM_REG_ARM64_SVE_VLS pseudo-register is immutable, and can
+ no longer be written using KVM_SET_ONE_REG.
+
+4.83 KVM_ARM_PREFERRED_TARGET
+-----------------------------
+
+:Capability: basic
+:Architectures: arm, arm64
+:Type: vm ioctl
+:Parameters: struct kvm_vcpu_init (out)
+:Returns: 0 on success; -1 on error
+
+Errors:
+
+ ====== ==========================================
+ ENODEV no preferred target available for the host
+ ====== ==========================================
+
+This queries KVM for preferred CPU target type which can be emulated
+by KVM on underlying host.
+
+The ioctl returns struct kvm_vcpu_init instance containing information
+about preferred CPU target type and recommended features for it. The
+kvm_vcpu_init->features bitmap returned will have feature bits set if
+the preferred target recommends setting these features, but this is
+not mandatory.
+
+The information returned by this ioctl can be used to prepare an instance
+of struct kvm_vcpu_init for KVM_ARM_VCPU_INIT ioctl which will result in
+VCPU matching underlying host.
+
+
+4.84 KVM_GET_REG_LIST
+---------------------
+
+:Capability: basic
+:Architectures: arm, arm64, mips
+:Type: vcpu ioctl
+:Parameters: struct kvm_reg_list (in/out)
+:Returns: 0 on success; -1 on error
+
+Errors:
+
+ ===== ==============================================================
+  E2BIG     the reg index list is too big to fit in the array specified by
+             the user (the number required will be written into n).
+ ===== ==============================================================
+
+::
+
+ struct kvm_reg_list {
+ __u64 n; /* number of registers in reg[] */
+ __u64 reg[0];
+ };
+
+This ioctl returns the guest registers that are supported for the
+KVM_GET_ONE_REG/KVM_SET_ONE_REG calls.
+
+
+4.85 KVM_ARM_SET_DEVICE_ADDR (deprecated)
+-----------------------------------------
+
+:Capability: KVM_CAP_ARM_SET_DEVICE_ADDR
+:Architectures: arm, arm64
+:Type: vm ioctl
+:Parameters: struct kvm_arm_device_address (in)
+:Returns: 0 on success, -1 on error
+
+Errors:
+
+ ====== ============================================
+ ENODEV The device id is unknown
+ ENXIO Device not supported on current system
+ EEXIST Address already set
+ E2BIG Address outside guest physical address space
+ EBUSY Address overlaps with other device range
+ ====== ============================================
+
+::
+
+ struct kvm_arm_device_addr {
+ __u64 id;
+ __u64 addr;
+ };
+
+Specify a device address in the guest's physical address space where guests
+can access emulated or directly exposed devices, which the host kernel needs
+to know about. The id field is an architecture specific identifier for a
+specific device.
+
+ARM/arm64 divides the id field into two parts, a device id and an
+address type id specific to the individual device::
+
+  bits: | 63 ... 32 | 31 ... 16 | 15 ... 0 |
+ field: | 0x00000000 | device id | addr type id |
+
+ARM/arm64 currently only require this when using the in-kernel GIC
+support for the hardware VGIC features, using KVM_ARM_DEVICE_VGIC_V2
+as the device id. When setting the base address for the guest's
+mapping of the VGIC virtual CPU and distributor interface, the ioctl
+must be called after calling KVM_CREATE_IRQCHIP, but before calling
+KVM_RUN on any of the VCPUs. Calling this ioctl twice for any of the
+base addresses will return -EEXIST.
+
+Note, this IOCTL is deprecated and the more flexible SET/GET_DEVICE_ATTR API
+should be used instead.
+
+
+4.86 KVM_PPC_RTAS_DEFINE_TOKEN
+------------------------------
+
+:Capability: KVM_CAP_PPC_RTAS
+:Architectures: ppc
+:Type: vm ioctl
+:Parameters: struct kvm_rtas_token_args
+:Returns: 0 on success, -1 on error
+
+Defines a token value for a RTAS (Run Time Abstraction Services)
+service in order to allow it to be handled in the kernel. The
+argument struct gives the name of the service, which must be the name
+of a service that has a kernel-side implementation. If the token
+value is non-zero, it will be associated with that service, and
+subsequent RTAS calls by the guest specifying that token will be
+handled by the kernel. If the token value is 0, then any token
+associated with the service will be forgotten, and subsequent RTAS
+calls by the guest for that service will be passed to userspace to be
+handled.
+
+4.87 KVM_SET_GUEST_DEBUG
+------------------------
+
+:Capability: KVM_CAP_SET_GUEST_DEBUG
+:Architectures: x86, s390, ppc, arm64
+:Type: vcpu ioctl
+:Parameters: struct kvm_guest_debug (in)
+:Returns: 0 on success; -1 on error
+
+::
+
+ struct kvm_guest_debug {
+ __u32 control;
+ __u32 pad;
+ struct kvm_guest_debug_arch arch;
+ };
+
+Set up the processor specific debug registers and configure vcpu for
+handling guest debug events. There are two parts to the structure, the
+first a control bitfield indicates the type of debug events to handle
+when running. Common control bits are:
+
+ - KVM_GUESTDBG_ENABLE: guest debugging is enabled
+ - KVM_GUESTDBG_SINGLESTEP: the next run should single-step
+
+The top 16 bits of the control field are architecture specific control
+flags which can include the following:
+
+ - KVM_GUESTDBG_USE_SW_BP: using software breakpoints [x86, arm64]
+ - KVM_GUESTDBG_USE_HW_BP: using hardware breakpoints [x86, s390, arm64]
+ - KVM_GUESTDBG_INJECT_DB: inject DB type exception [x86]
+ - KVM_GUESTDBG_INJECT_BP: inject BP type exception [x86]
+ - KVM_GUESTDBG_EXIT_PENDING: trigger an immediate guest exit [s390]
+
+For example KVM_GUESTDBG_USE_SW_BP indicates that software breakpoints
+are enabled in memory so we need to ensure breakpoint exceptions are
+correctly trapped and the KVM run loop exits at the breakpoint and not
+running off into the normal guest vector. For KVM_GUESTDBG_USE_HW_BP
+we need to ensure the guest vCPUs architecture specific registers are
+updated to the correct (supplied) values.
+
+The second part of the structure is architecture specific and
+typically contains a set of debug registers.
+
+For arm64 the number of debug registers is implementation defined and
+can be determined by querying the KVM_CAP_GUEST_DEBUG_HW_BPS and
+KVM_CAP_GUEST_DEBUG_HW_WPS capabilities which return a positive number
+indicating the number of supported registers.
+
+For ppc, the KVM_CAP_PPC_GUEST_DEBUG_SSTEP capability indicates whether
+the single-step debug event (KVM_GUESTDBG_SINGLESTEP) is supported.
+
+When debug events exit the main run loop with the reason
+KVM_EXIT_DEBUG with the kvm_debug_exit_arch part of the kvm_run
+structure containing architecture specific debug information.
+
+4.88 KVM_GET_EMULATED_CPUID
+---------------------------
+
+:Capability: KVM_CAP_EXT_EMUL_CPUID
+:Architectures: x86
+:Type: system ioctl
+:Parameters: struct kvm_cpuid2 (in/out)
+:Returns: 0 on success, -1 on error
+
+::
+
+ struct kvm_cpuid2 {
+ __u32 nent;
+ __u32 flags;
+ struct kvm_cpuid_entry2 entries[0];
+ };
+
+The member 'flags' is used for passing flags from userspace.
+
+::
+
+ #define KVM_CPUID_FLAG_SIGNIFCANT_INDEX BIT(0)
+ #define KVM_CPUID_FLAG_STATEFUL_FUNC BIT(1) /* deprecated */
+ #define KVM_CPUID_FLAG_STATE_READ_NEXT BIT(2) /* deprecated */
+
+ struct kvm_cpuid_entry2 {
+ __u32 function;
+ __u32 index;
+ __u32 flags;
+ __u32 eax;
+ __u32 ebx;
+ __u32 ecx;
+ __u32 edx;
+ __u32 padding[3];
+ };
+
+This ioctl returns x86 cpuid features which are emulated by
+kvm.Userspace can use the information returned by this ioctl to query
+which features are emulated by kvm instead of being present natively.
+
+Userspace invokes KVM_GET_EMULATED_CPUID by passing a kvm_cpuid2
+structure with the 'nent' field indicating the number of entries in
+the variable-size array 'entries'. If the number of entries is too low
+to describe the cpu capabilities, an error (E2BIG) is returned. If the
+number is too high, the 'nent' field is adjusted and an error (ENOMEM)
+is returned. If the number is just right, the 'nent' field is adjusted
+to the number of valid entries in the 'entries' array, which is then
+filled.
+
+The entries returned are the set CPUID bits of the respective features
+which kvm emulates, as returned by the CPUID instruction, with unknown
+or unsupported feature bits cleared.
+
+Features like x2apic, for example, may not be present in the host cpu
+but are exposed by kvm in KVM_GET_SUPPORTED_CPUID because they can be
+emulated efficiently and thus not included here.
+
+The fields in each entry are defined as follows:
+
+ function:
+ the eax value used to obtain the entry
+ index:
+ the ecx value used to obtain the entry (for entries that are
+ affected by ecx)
+ flags:
+ an OR of zero or more of the following:
+
+ KVM_CPUID_FLAG_SIGNIFCANT_INDEX:
+ if the index field is valid
+
+ eax, ebx, ecx, edx:
+
+ the values returned by the cpuid instruction for
+ this function/index combination
+
+4.89 KVM_S390_MEM_OP
+--------------------
+
+:Capability: KVM_CAP_S390_MEM_OP
+:Architectures: s390
+:Type: vcpu ioctl
+:Parameters: struct kvm_s390_mem_op (in)
+:Returns: = 0 on success,
+ < 0 on generic error (e.g. -EFAULT or -ENOMEM),
+ > 0 if an exception occurred while walking the page tables
+
+Read or write data from/to the logical (virtual) memory of a VCPU.
+
+Parameters are specified via the following structure::
+
+ struct kvm_s390_mem_op {
+ __u64 gaddr; /* the guest address */
+ __u64 flags; /* flags */
+ __u32 size; /* amount of bytes */
+ __u32 op; /* type of operation */
+ __u64 buf; /* buffer in userspace */
+ __u8 ar; /* the access register number */
+ __u8 reserved[31]; /* should be set to 0 */
+ };
+
+The type of operation is specified in the "op" field. It is either
+KVM_S390_MEMOP_LOGICAL_READ for reading from logical memory space or
+KVM_S390_MEMOP_LOGICAL_WRITE for writing to logical memory space. The
+KVM_S390_MEMOP_F_CHECK_ONLY flag can be set in the "flags" field to check
+whether the corresponding memory access would create an access exception
+(without touching the data in the memory at the destination). In case an
+access exception occurred while walking the MMU tables of the guest, the
+ioctl returns a positive error number to indicate the type of exception.
+This exception is also raised directly at the corresponding VCPU if the
+flag KVM_S390_MEMOP_F_INJECT_EXCEPTION is set in the "flags" field.
+
+The start address of the memory region has to be specified in the "gaddr"
+field, and the length of the region in the "size" field (which must not
+be 0). The maximum value for "size" can be obtained by checking the
+KVM_CAP_S390_MEM_OP capability. "buf" is the buffer supplied by the
+userspace application where the read data should be written to for
+KVM_S390_MEMOP_LOGICAL_READ, or where the data that should be written is
+stored for a KVM_S390_MEMOP_LOGICAL_WRITE. When KVM_S390_MEMOP_F_CHECK_ONLY
+is specified, "buf" is unused and can be NULL. "ar" designates the access
+register number to be used; the valid range is 0..15.
+
+The "reserved" field is meant for future extensions. It is not used by
+KVM with the currently defined set of flags.
+
+4.90 KVM_S390_GET_SKEYS
+-----------------------
+
+:Capability: KVM_CAP_S390_SKEYS
+:Architectures: s390
+:Type: vm ioctl
+:Parameters: struct kvm_s390_skeys
+:Returns: 0 on success, KVM_S390_GET_KEYS_NONE if guest is not using storage
+ keys, negative value on error
+
+This ioctl is used to get guest storage key values on the s390
+architecture. The ioctl takes parameters via the kvm_s390_skeys struct::
+
+ struct kvm_s390_skeys {
+ __u64 start_gfn;
+ __u64 count;
+ __u64 skeydata_addr;
+ __u32 flags;
+ __u32 reserved[9];
+ };
+
+The start_gfn field is the number of the first guest frame whose storage keys
+you want to get.
+
+The count field is the number of consecutive frames (starting from start_gfn)
+whose storage keys to get. The count field must be at least 1 and the maximum
+allowed value is defined as KVM_S390_SKEYS_ALLOC_MAX. Values outside this range
+will cause the ioctl to return -EINVAL.
+
+The skeydata_addr field is the address to a buffer large enough to hold count
+bytes. This buffer will be filled with storage key data by the ioctl.
+
+4.91 KVM_S390_SET_SKEYS
+-----------------------
+
+:Capability: KVM_CAP_S390_SKEYS
+:Architectures: s390
+:Type: vm ioctl
+:Parameters: struct kvm_s390_skeys
+:Returns: 0 on success, negative value on error
+
+This ioctl is used to set guest storage key values on the s390
+architecture. The ioctl takes parameters via the kvm_s390_skeys struct.
+See section on KVM_S390_GET_SKEYS for struct definition.
+
+The start_gfn field is the number of the first guest frame whose storage keys
+you want to set.
+
+The count field is the number of consecutive frames (starting from start_gfn)
+whose storage keys to get. The count field must be at least 1 and the maximum
+allowed value is defined as KVM_S390_SKEYS_ALLOC_MAX. Values outside this range
+will cause the ioctl to return -EINVAL.
+
+The skeydata_addr field is the address to a buffer containing count bytes of
+storage keys. Each byte in the buffer will be set as the storage key for a
+single frame starting at start_gfn for count frames.
+
+Note: If any architecturally invalid key value is found in the given data then
+the ioctl will return -EINVAL.
+
+4.92 KVM_S390_IRQ
+-----------------
+
+:Capability: KVM_CAP_S390_INJECT_IRQ
+:Architectures: s390
+:Type: vcpu ioctl
+:Parameters: struct kvm_s390_irq (in)
+:Returns: 0 on success, -1 on error
+
+Errors:
+
+
+ ====== =================================================================
+ EINVAL interrupt type is invalid
+ type is KVM_S390_SIGP_STOP and flag parameter is invalid value,
+ type is KVM_S390_INT_EXTERNAL_CALL and code is bigger
+ than the maximum of VCPUs
+ EBUSY type is KVM_S390_SIGP_SET_PREFIX and vcpu is not stopped,
+ type is KVM_S390_SIGP_STOP and a stop irq is already pending,
+ type is KVM_S390_INT_EXTERNAL_CALL and an external call interrupt
+ is already pending
+ ====== =================================================================
+
+Allows to inject an interrupt to the guest.
+
+Using struct kvm_s390_irq as a parameter allows
+to inject additional payload which is not
+possible via KVM_S390_INTERRUPT.
+
+Interrupt parameters are passed via kvm_s390_irq::
+
+ struct kvm_s390_irq {
+ __u64 type;
+ union {
+ struct kvm_s390_io_info io;
+ struct kvm_s390_ext_info ext;
+ struct kvm_s390_pgm_info pgm;
+ struct kvm_s390_emerg_info emerg;
+ struct kvm_s390_extcall_info extcall;
+ struct kvm_s390_prefix_info prefix;
+ struct kvm_s390_stop_info stop;
+ struct kvm_s390_mchk_info mchk;
+ char reserved[64];
+ } u;
+ };
+
+type can be one of the following:
+
+- KVM_S390_SIGP_STOP - sigp stop; parameter in .stop
+- KVM_S390_PROGRAM_INT - program check; parameters in .pgm
+- KVM_S390_SIGP_SET_PREFIX - sigp set prefix; parameters in .prefix
+- KVM_S390_RESTART - restart; no parameters
+- KVM_S390_INT_CLOCK_COMP - clock comparator interrupt; no parameters
+- KVM_S390_INT_CPU_TIMER - CPU timer interrupt; no parameters
+- KVM_S390_INT_EMERGENCY - sigp emergency; parameters in .emerg
+- KVM_S390_INT_EXTERNAL_CALL - sigp external call; parameters in .extcall
+- KVM_S390_MCHK - machine check interrupt; parameters in .mchk
+
+This is an asynchronous vcpu ioctl and can be invoked from any thread.
+
+4.94 KVM_S390_GET_IRQ_STATE
+---------------------------
+
+:Capability: KVM_CAP_S390_IRQ_STATE
+:Architectures: s390
+:Type: vcpu ioctl
+:Parameters: struct kvm_s390_irq_state (out)
+:Returns: >= number of bytes copied into buffer,
+ -EINVAL if buffer size is 0,
+ -ENOBUFS if buffer size is too small to fit all pending interrupts,
+ -EFAULT if the buffer address was invalid
+
+This ioctl allows userspace to retrieve the complete state of all currently
+pending interrupts in a single buffer. Use cases include migration
+and introspection. The parameter structure contains the address of a
+userspace buffer and its length::
+
+ struct kvm_s390_irq_state {
+ __u64 buf;
+ __u32 flags; /* will stay unused for compatibility reasons */
+ __u32 len;
+ __u32 reserved[4]; /* will stay unused for compatibility reasons */
+ };
+
+Userspace passes in the above struct and for each pending interrupt a
+struct kvm_s390_irq is copied to the provided buffer.
+
+The structure contains a flags and a reserved field for future extensions. As
+the kernel never checked for flags == 0 and QEMU never pre-zeroed flags and
+reserved, these fields can not be used in the future without breaking
+compatibility.
+
+If -ENOBUFS is returned the buffer provided was too small and userspace
+may retry with a bigger buffer.
+
+4.95 KVM_S390_SET_IRQ_STATE
+---------------------------
+
+:Capability: KVM_CAP_S390_IRQ_STATE
+:Architectures: s390
+:Type: vcpu ioctl
+:Parameters: struct kvm_s390_irq_state (in)
+:Returns: 0 on success,
+ -EFAULT if the buffer address was invalid,
+ -EINVAL for an invalid buffer length (see below),
+ -EBUSY if there were already interrupts pending,
+ errors occurring when actually injecting the
+ interrupt. See KVM_S390_IRQ.
+
+This ioctl allows userspace to set the complete state of all cpu-local
+interrupts currently pending for the vcpu. It is intended for restoring
+interrupt state after a migration. The input parameter is a userspace buffer
+containing a struct kvm_s390_irq_state::
+
+ struct kvm_s390_irq_state {
+ __u64 buf;
+ __u32 flags; /* will stay unused for compatibility reasons */
+ __u32 len;
+ __u32 reserved[4]; /* will stay unused for compatibility reasons */
+ };
+
+The restrictions for flags and reserved apply as well.
+(see KVM_S390_GET_IRQ_STATE)
+
+The userspace memory referenced by buf contains a struct kvm_s390_irq
+for each interrupt to be injected into the guest.
+If one of the interrupts could not be injected for some reason the
+ioctl aborts.
+
+len must be a multiple of sizeof(struct kvm_s390_irq). It must be > 0
+and it must not exceed (max_vcpus + 32) * sizeof(struct kvm_s390_irq),
+which is the maximum number of possibly pending cpu-local interrupts.
+
+4.96 KVM_SMI
+------------
+
+:Capability: KVM_CAP_X86_SMM
+:Architectures: x86
+:Type: vcpu ioctl
+:Parameters: none
+:Returns: 0 on success, -1 on error
+
+Queues an SMI on the thread's vcpu.
+
+4.97 KVM_CAP_PPC_MULTITCE
+-------------------------
+
+:Capability: KVM_CAP_PPC_MULTITCE
+:Architectures: ppc
+:Type: vm
+
+This capability means the kernel is capable of handling hypercalls
+H_PUT_TCE_INDIRECT and H_STUFF_TCE without passing those into the user
+space. This significantly accelerates DMA operations for PPC KVM guests.
+User space should expect that its handlers for these hypercalls
+are not going to be called if user space previously registered LIOBN
+in KVM (via KVM_CREATE_SPAPR_TCE or similar calls).
+
+In order to enable H_PUT_TCE_INDIRECT and H_STUFF_TCE use in the guest,
+user space might have to advertise it for the guest. For example,
+IBM pSeries (sPAPR) guest starts using them if "hcall-multi-tce" is
+present in the "ibm,hypertas-functions" device-tree property.
+
+The hypercalls mentioned above may or may not be processed successfully
+in the kernel based fast path. If they can not be handled by the kernel,
+they will get passed on to user space. So user space still has to have
+an implementation for these despite the in kernel acceleration.
+
+This capability is always enabled.
+
+4.98 KVM_CREATE_SPAPR_TCE_64
+----------------------------
+
+:Capability: KVM_CAP_SPAPR_TCE_64
+:Architectures: powerpc
+:Type: vm ioctl
+:Parameters: struct kvm_create_spapr_tce_64 (in)
+:Returns: file descriptor for manipulating the created TCE table
+
+This is an extension for KVM_CAP_SPAPR_TCE which only supports 32bit
+windows, described in 4.62 KVM_CREATE_SPAPR_TCE
+
+This capability uses extended struct in ioctl interface::
+
+ /* for KVM_CAP_SPAPR_TCE_64 */
+ struct kvm_create_spapr_tce_64 {
+ __u64 liobn;
+ __u32 page_shift;
+ __u32 flags;
+ __u64 offset; /* in pages */
+ __u64 size; /* in pages */
+ };
+
+The aim of extension is to support an additional bigger DMA window with
+a variable page size.
+KVM_CREATE_SPAPR_TCE_64 receives a 64bit window size, an IOMMU page shift and
+a bus offset of the corresponding DMA window, @size and @offset are numbers
+of IOMMU pages.
+
+@flags are not used at the moment.
+
+The rest of functionality is identical to KVM_CREATE_SPAPR_TCE.
+
+4.99 KVM_REINJECT_CONTROL
+-------------------------
+
+:Capability: KVM_CAP_REINJECT_CONTROL
+:Architectures: x86
+:Type: vm ioctl
+:Parameters: struct kvm_reinject_control (in)
+:Returns: 0 on success,
+ -EFAULT if struct kvm_reinject_control cannot be read,
+ -ENXIO if KVM_CREATE_PIT or KVM_CREATE_PIT2 didn't succeed earlier.
+
+i8254 (PIT) has two modes, reinject and !reinject. The default is reinject,
+where KVM queues elapsed i8254 ticks and monitors completion of interrupt from
+vector(s) that i8254 injects. Reinject mode dequeues a tick and injects its
+interrupt whenever there isn't a pending interrupt from i8254.
+!reinject mode injects an interrupt as soon as a tick arrives.
+
+::
+
+ struct kvm_reinject_control {
+ __u8 pit_reinject;
+ __u8 reserved[31];
+ };
+
+pit_reinject = 0 (!reinject mode) is recommended, unless running an old
+operating system that uses the PIT for timing (e.g. Linux 2.4.x).
+
+4.100 KVM_PPC_CONFIGURE_V3_MMU
+------------------------------
+
+:Capability: KVM_CAP_PPC_RADIX_MMU or KVM_CAP_PPC_HASH_MMU_V3
+:Architectures: ppc
+:Type: vm ioctl
+:Parameters: struct kvm_ppc_mmuv3_cfg (in)
+:Returns: 0 on success,
+ -EFAULT if struct kvm_ppc_mmuv3_cfg cannot be read,
+ -EINVAL if the configuration is invalid
+
+This ioctl controls whether the guest will use radix or HPT (hashed
+page table) translation, and sets the pointer to the process table for
+the guest.
+
+::
+
+ struct kvm_ppc_mmuv3_cfg {
+ __u64 flags;
+ __u64 process_table;
+ };
+
+There are two bits that can be set in flags; KVM_PPC_MMUV3_RADIX and
+KVM_PPC_MMUV3_GTSE. KVM_PPC_MMUV3_RADIX, if set, configures the guest
+to use radix tree translation, and if clear, to use HPT translation.
+KVM_PPC_MMUV3_GTSE, if set and if KVM permits it, configures the guest
+to be able to use the global TLB and SLB invalidation instructions;
+if clear, the guest may not use these instructions.
+
+The process_table field specifies the address and size of the guest
+process table, which is in the guest's space. This field is formatted
+as the second doubleword of the partition table entry, as defined in
+the Power ISA V3.00, Book III section 5.7.6.1.
+
+4.101 KVM_PPC_GET_RMMU_INFO
+---------------------------
+
+:Capability: KVM_CAP_PPC_RADIX_MMU
+:Architectures: ppc
+:Type: vm ioctl
+:Parameters: struct kvm_ppc_rmmu_info (out)
+:Returns: 0 on success,
+ -EFAULT if struct kvm_ppc_rmmu_info cannot be written,
+ -EINVAL if no useful information can be returned
+
+This ioctl returns a structure containing two things: (a) a list
+containing supported radix tree geometries, and (b) a list that maps
+page sizes to put in the "AP" (actual page size) field for the tlbie
+(TLB invalidate entry) instruction.
+
+::
+
+ struct kvm_ppc_rmmu_info {
+ struct kvm_ppc_radix_geom {
+ __u8 page_shift;
+ __u8 level_bits[4];
+ __u8 pad[3];
+ } geometries[8];
+ __u32 ap_encodings[8];
+ };
+
+The geometries[] field gives up to 8 supported geometries for the
+radix page table, in terms of the log base 2 of the smallest page
+size, and the number of bits indexed at each level of the tree, from
+the PTE level up to the PGD level in that order. Any unused entries
+will have 0 in the page_shift field.
+
+The ap_encodings gives the supported page sizes and their AP field
+encodings, encoded with the AP value in the top 3 bits and the log
+base 2 of the page size in the bottom 6 bits.
+
+4.102 KVM_PPC_RESIZE_HPT_PREPARE
+--------------------------------
+
+:Capability: KVM_CAP_SPAPR_RESIZE_HPT
+:Architectures: powerpc
+:Type: vm ioctl
+:Parameters: struct kvm_ppc_resize_hpt (in)
+:Returns: 0 on successful completion,
+ >0 if a new HPT is being prepared, the value is an estimated
+ number of milliseconds until preparation is complete,
+ -EFAULT if struct kvm_reinject_control cannot be read,
+ -EINVAL if the supplied shift or flags are invalid,
+ -ENOMEM if unable to allocate the new HPT,
+ -ENOSPC if there was a hash collision
+
+::
+
+ struct kvm_ppc_rmmu_info {
+ struct kvm_ppc_radix_geom {
+ __u8 page_shift;
+ __u8 level_bits[4];
+ __u8 pad[3];
+ } geometries[8];
+ __u32 ap_encodings[8];
+ };
+
+The geometries[] field gives up to 8 supported geometries for the
+radix page table, in terms of the log base 2 of the smallest page
+size, and the number of bits indexed at each level of the tree, from
+the PTE level up to the PGD level in that order. Any unused entries
+will have 0 in the page_shift field.
+
+The ap_encodings gives the supported page sizes and their AP field
+encodings, encoded with the AP value in the top 3 bits and the log
+base 2 of the page size in the bottom 6 bits.
+
+4.102 KVM_PPC_RESIZE_HPT_PREPARE
+--------------------------------
+
+:Capability: KVM_CAP_SPAPR_RESIZE_HPT
+:Architectures: powerpc
+:Type: vm ioctl
+:Parameters: struct kvm_ppc_resize_hpt (in)
+:Returns: 0 on successful completion,
+ >0 if a new HPT is being prepared, the value is an estimated
+ number of milliseconds until preparation is complete,
+ -EFAULT if struct kvm_reinject_control cannot be read,
+ -EINVAL if the supplied shift or flags are invalid,when moving existing
+ HPT entries to the new HPT,
+ -EIO on other error conditions
+
+Used to implement the PAPR extension for runtime resizing of a guest's
+Hashed Page Table (HPT). Specifically this starts, stops or monitors
+the preparation of a new potential HPT for the guest, essentially
+implementing the H_RESIZE_HPT_PREPARE hypercall.
+
+If called with shift > 0 when there is no pending HPT for the guest,
+this begins preparation of a new pending HPT of size 2^(shift) bytes.
+It then returns a positive integer with the estimated number of
+milliseconds until preparation is complete.
+
+If called when there is a pending HPT whose size does not match that
+requested in the parameters, discards the existing pending HPT and
+creates a new one as above.
+
+If called when there is a pending HPT of the size requested, will:
+
+ * If preparation of the pending HPT is already complete, return 0
+ * If preparation of the pending HPT has failed, return an error
+ code, then discard the pending HPT.
+ * If preparation of the pending HPT is still in progress, return an
+ estimated number of milliseconds until preparation is complete.
+
+If called with shift == 0, discards any currently pending HPT and
+returns 0 (i.e. cancels any in-progress preparation).
+
+flags is reserved for future expansion, currently setting any bits in
+flags will result in an -EINVAL.
+
+Normally this will be called repeatedly with the same parameters until
+it returns <= 0. The first call will initiate preparation, subsequent
+ones will monitor preparation until it completes or fails.
+
+::
+
+ struct kvm_ppc_resize_hpt {
+ __u64 flags;
+ __u32 shift;
+ __u32 pad;
+ };
+
+4.103 KVM_PPC_RESIZE_HPT_COMMIT
+-------------------------------
+
+:Capability: KVM_CAP_SPAPR_RESIZE_HPT
+:Architectures: powerpc
+:Type: vm ioctl
+:Parameters: struct kvm_ppc_resize_hpt (in)
+:Returns: 0 on successful completion,
+ -EFAULT if struct kvm_reinject_control cannot be read,
+ -EINVAL if the supplied shift or flags are invalid,
+ -ENXIO is there is no pending HPT, or the pending HPT doesn't
+ have the requested size,
+ -EBUSY if the pending HPT is not fully prepared,
+ -ENOSPC if there was a hash collision when moving existing
+ HPT entries to the new HPT,
+ -EIO on other error conditions
+
+Used to implement the PAPR extension for runtime resizing of a guest's
+Hashed Page Table (HPT). Specifically this requests that the guest be
+transferred to working with the new HPT, essentially implementing the
+H_RESIZE_HPT_COMMIT hypercall.
+
+This should only be called after KVM_PPC_RESIZE_HPT_PREPARE has
+returned 0 with the same parameters. In other cases
+KVM_PPC_RESIZE_HPT_COMMIT will return an error (usually -ENXIO or
+-EBUSY, though others may be possible if the preparation was started,
+but failed).
+
+This will have undefined effects on the guest if it has not already
+placed itself in a quiescent state where no vcpu will make MMU enabled
+memory accesses.
+
+On succsful completion, the pending HPT will become the guest's active
+HPT and the previous HPT will be discarded.
+
+On failure, the guest will still be operating on its previous HPT.
+
+::
+
+ struct kvm_ppc_resize_hpt {
+ __u64 flags;
+ __u32 shift;
+ __u32 pad;
+ };
+
+4.104 KVM_X86_GET_MCE_CAP_SUPPORTED
+-----------------------------------
+
+:Capability: KVM_CAP_MCE
+:Architectures: x86
+:Type: system ioctl
+:Parameters: u64 mce_cap (out)
+:Returns: 0 on success, -1 on error
+
+Returns supported MCE capabilities. The u64 mce_cap parameter
+has the same format as the MSR_IA32_MCG_CAP register. Supported
+capabilities will have the corresponding bits set.
+
+4.105 KVM_X86_SETUP_MCE
+-----------------------
+
+:Capability: KVM_CAP_MCE
+:Architectures: x86
+:Type: vcpu ioctl
+:Parameters: u64 mcg_cap (in)
+:Returns: 0 on success,
+ -EFAULT if u64 mcg_cap cannot be read,
+ -EINVAL if the requested number of banks is invalid,
+ -EINVAL if requested MCE capability is not supported.
+
+Initializes MCE support for use. The u64 mcg_cap parameter
+has the same format as the MSR_IA32_MCG_CAP register and
+specifies which capabilities should be enabled. The maximum
+supported number of error-reporting banks can be retrieved when
+checking for KVM_CAP_MCE. The supported capabilities can be
+retrieved with KVM_X86_GET_MCE_CAP_SUPPORTED.
+
+4.106 KVM_X86_SET_MCE
+---------------------
+
+:Capability: KVM_CAP_MCE
+:Architectures: x86
+:Type: vcpu ioctl
+:Parameters: struct kvm_x86_mce (in)
+:Returns: 0 on success,
+ -EFAULT if struct kvm_x86_mce cannot be read,
+ -EINVAL if the bank number is invalid,
+ -EINVAL if VAL bit is not set in status field.
+
+Inject a machine check error (MCE) into the guest. The input
+parameter is::
+
+ struct kvm_x86_mce {
+ __u64 status;
+ __u64 addr;
+ __u64 misc;
+ __u64 mcg_status;
+ __u8 bank;
+ __u8 pad1[7];
+ __u64 pad2[3];
+ };
+
+If the MCE being reported is an uncorrected error, KVM will
+inject it as an MCE exception into the guest. If the guest
+MCG_STATUS register reports that an MCE is in progress, KVM
+causes an KVM_EXIT_SHUTDOWN vmexit.
+
+Otherwise, if the MCE is a corrected error, KVM will just
+store it in the corresponding bank (provided this bank is
+not holding a previously reported uncorrected error).
+
+4.107 KVM_S390_GET_CMMA_BITS
+----------------------------
+
+:Capability: KVM_CAP_S390_CMMA_MIGRATION
+:Architectures: s390
+:Type: vm ioctl
+:Parameters: struct kvm_s390_cmma_log (in, out)
+:Returns: 0 on success, a negative value on error
+
+Errors:
+
+ ====== =============================================================
+ ENOMEM not enough memory can be allocated to complete the task
+ ENXIO if CMMA is not enabled
+ EINVAL if KVM_S390_CMMA_PEEK is not set but migration mode was not enabled
+ EINVAL if KVM_S390_CMMA_PEEK is not set but dirty tracking has been
+ disabled (and thus migration mode was automatically disabled)
+ EFAULT if the userspace address is invalid or if no page table is
+ present for the addresses (e.g. when using hugepages).
+ ====== =============================================================
+
+This ioctl is used to get the values of the CMMA bits on the s390
+architecture. It is meant to be used in two scenarios:
+
+- During live migration to save the CMMA values. Live migration needs
+ to be enabled via the KVM_REQ_START_MIGRATION VM property.
+- To non-destructively peek at the CMMA values, with the flag
+ KVM_S390_CMMA_PEEK set.
+
+The ioctl takes parameters via the kvm_s390_cmma_log struct. The desired
+values are written to a buffer whose location is indicated via the "values"
+member in the kvm_s390_cmma_log struct. The values in the input struct are
+also updated as needed.
+
+Each CMMA value takes up one byte.
+
+::
+
+ struct kvm_s390_cmma_log {
+ __u64 start_gfn;
+ __u32 count;
+ __u32 flags;
+ union {
+ __u64 remaining;
+ __u64 mask;
+ };
+ __u64 values;
+ };
+
+start_gfn is the number of the first guest frame whose CMMA values are
+to be retrieved,
+
+count is the length of the buffer in bytes,
+
+values points to the buffer where the result will be written to.
+
+If count is greater than KVM_S390_SKEYS_MAX, then it is considered to be
+KVM_S390_SKEYS_MAX. KVM_S390_SKEYS_MAX is re-used for consistency with
+other ioctls.
+
+The result is written in the buffer pointed to by the field values, and
+the values of the input parameter are updated as follows.
+
+Depending on the flags, different actions are performed. The only
+supported flag so far is KVM_S390_CMMA_PEEK.
+
+The default behaviour if KVM_S390_CMMA_PEEK is not set is:
+start_gfn will indicate the first page frame whose CMMA bits were dirty.
+It is not necessarily the same as the one passed as input, as clean pages
+are skipped.
+
+count will indicate the number of bytes actually written in the buffer.
+It can (and very often will) be smaller than the input value, since the
+buffer is only filled until 16 bytes of clean values are found (which
+are then not copied in the buffer). Since a CMMA migration block needs
+the base address and the length, for a total of 16 bytes, we will send
+back some clean data if there is some dirty data afterwards, as long as
+the size of the clean data does not exceed the size of the header. This
+allows to minimize the amount of data to be saved or transferred over
+the network at the expense of more roundtrips to userspace. The next
+invocation of the ioctl will skip over all the clean values, saving
+potentially more than just the 16 bytes we found.
+
+If KVM_S390_CMMA_PEEK is set:
+the existing storage attributes are read even when not in migration
+mode, and no other action is performed;
+
+the output start_gfn will be equal to the input start_gfn,
+
+the output count will be equal to the input count, except if the end of
+memory has been reached.
+
+In both cases:
+the field "remaining" will indicate the total number of dirty CMMA values
+still remaining, or 0 if KVM_S390_CMMA_PEEK is set and migration mode is
+not enabled.
+
+mask is unused.
+
+values points to the userspace buffer where the result will be stored.
+
+4.108 KVM_S390_SET_CMMA_BITS
+----------------------------
+
+:Capability: KVM_CAP_S390_CMMA_MIGRATION
+:Architectures: s390
+:Type: vm ioctl
+:Parameters: struct kvm_s390_cmma_log (in)
+:Returns: 0 on success, a negative value on error
+
+This ioctl is used to set the values of the CMMA bits on the s390
+architecture. It is meant to be used during live migration to restore
+the CMMA values, but there are no restrictions on its use.
+The ioctl takes parameters via the kvm_s390_cmma_values struct.
+Each CMMA value takes up one byte.
+
+::
+
+ struct kvm_s390_cmma_log {
+ __u64 start_gfn;
+ __u32 count;
+ __u32 flags;
+ union {
+ __u64 remaining;
+ __u64 mask;
+ };
+ __u64 values;
+ };
+
+start_gfn indicates the starting guest frame number,
+
+count indicates how many values are to be considered in the buffer,
+
+flags is not used and must be 0.
+
+mask indicates which PGSTE bits are to be considered.
+
+remaining is not used.
+
+values points to the buffer in userspace where to store the values.
+
+This ioctl can fail with -ENOMEM if not enough memory can be allocated to
+complete the task, with -ENXIO if CMMA is not enabled, with -EINVAL if
+the count field is too large (e.g. more than KVM_S390_CMMA_SIZE_MAX) or
+if the flags field was not 0, with -EFAULT if the userspace address is
+invalid, if invalid pages are written to (e.g. after the end of memory)
+or if no page table is present for the addresses (e.g. when using
+hugepages).
+
+4.109 KVM_PPC_GET_CPU_CHAR
+--------------------------
+
+:Capability: KVM_CAP_PPC_GET_CPU_CHAR
+:Architectures: powerpc
+:Type: vm ioctl
+:Parameters: struct kvm_ppc_cpu_char (out)
+:Returns: 0 on successful completion,
+ -EFAULT if struct kvm_ppc_cpu_char cannot be written
+
+This ioctl gives userspace information about certain characteristics
+of the CPU relating to speculative execution of instructions and
+possible information leakage resulting from speculative execution (see
+CVE-2017-5715, CVE-2017-5753 and CVE-2017-5754). The information is
+returned in struct kvm_ppc_cpu_char, which looks like this::
+
+ struct kvm_ppc_cpu_char {
+ __u64 character; /* characteristics of the CPU */
+ __u64 behaviour; /* recommended software behaviour */
+ __u64 character_mask; /* valid bits in character */
+ __u64 behaviour_mask; /* valid bits in behaviour */
+ };
+
+For extensibility, the character_mask and behaviour_mask fields
+indicate which bits of character and behaviour have been filled in by
+the kernel. If the set of defined bits is extended in future then
+userspace will be able to tell whether it is running on a kernel that
+knows about the new bits.
+
+The character field describes attributes of the CPU which can help
+with preventing inadvertent information disclosure - specifically,
+whether there is an instruction to flash-invalidate the L1 data cache
+(ori 30,30,0 or mtspr SPRN_TRIG2,rN), whether the L1 data cache is set
+to a mode where entries can only be used by the thread that created
+them, whether the bcctr[l] instruction prevents speculation, and
+whether a speculation barrier instruction (ori 31,31,0) is provided.
+
+The behaviour field describes actions that software should take to
+prevent inadvertent information disclosure, and thus describes which
+vulnerabilities the hardware is subject to; specifically whether the
+L1 data cache should be flushed when returning to user mode from the
+kernel, and whether a speculation barrier should be placed between an
+array bounds check and the array access.
+
+These fields use the same bit definitions as the new
+H_GET_CPU_CHARACTERISTICS hypercall.
+
+4.110 KVM_MEMORY_ENCRYPT_OP
+---------------------------
+
+:Capability: basic
+:Architectures: x86
+:Type: vm
+:Parameters: an opaque platform specific structure (in/out)
+:Returns: 0 on success; -1 on error
+
+If the platform supports creating encrypted VMs then this ioctl can be used
+for issuing platform-specific memory encryption commands to manage those
+encrypted VMs.
+
+Currently, this ioctl is used for issuing Secure Encrypted Virtualization
+(SEV) commands on AMD Processors. The SEV commands are defined in
+Documentation/virt/kvm/amd-memory-encryption.rst.
+
+4.111 KVM_MEMORY_ENCRYPT_REG_REGION
+-----------------------------------
+
+:Capability: basic
+:Architectures: x86
+:Type: system
+:Parameters: struct kvm_enc_region (in)
+:Returns: 0 on success; -1 on error
+
+This ioctl can be used to register a guest memory region which may
+contain encrypted data (e.g. guest RAM, SMRAM etc).
+
+It is used in the SEV-enabled guest. When encryption is enabled, a guest
+memory region may contain encrypted data. The SEV memory encryption
+engine uses a tweak such that two identical plaintext pages, each at
+different locations will have differing ciphertexts. So swapping or
+moving ciphertext of those pages will not result in plaintext being
+swapped. So relocating (or migrating) physical backing pages for the SEV
+guest will require some additional steps.
+
+Note: The current SEV key management spec does not provide commands to
+swap or migrate (move) ciphertext pages. Hence, for now we pin the guest
+memory region registered with the ioctl.
+
+4.112 KVM_MEMORY_ENCRYPT_UNREG_REGION
+-------------------------------------
+
+:Capability: basic
+:Architectures: x86
+:Type: system
+:Parameters: struct kvm_enc_region (in)
+:Returns: 0 on success; -1 on error
+
+This ioctl can be used to unregister the guest memory region registered
+with KVM_MEMORY_ENCRYPT_REG_REGION ioctl above.
+
+4.113 KVM_HYPERV_EVENTFD
+------------------------
+
+:Capability: KVM_CAP_HYPERV_EVENTFD
+:Architectures: x86
+:Type: vm ioctl
+:Parameters: struct kvm_hyperv_eventfd (in)
+
+This ioctl (un)registers an eventfd to receive notifications from the guest on
+the specified Hyper-V connection id through the SIGNAL_EVENT hypercall, without
+causing a user exit. SIGNAL_EVENT hypercall with non-zero event flag number
+(bits 24-31) still triggers a KVM_EXIT_HYPERV_HCALL user exit.
+
+::
+
+ struct kvm_hyperv_eventfd {
+ __u32 conn_id;
+ __s32 fd;
+ __u32 flags;
+ __u32 padding[3];
+ };
+
+The conn_id field should fit within 24 bits::
+
+ #define KVM_HYPERV_CONN_ID_MASK 0x00ffffff
+
+The acceptable values for the flags field are::
+
+ #define KVM_HYPERV_EVENTFD_DEASSIGN (1 << 0)
+
+:Returns: 0 on success,
+ -EINVAL if conn_id or flags is outside the allowed range,
+ -ENOENT on deassign if the conn_id isn't registered,
+ -EEXIST on assign if the conn_id is already registered
+
+4.114 KVM_GET_NESTED_STATE
+--------------------------
+
+:Capability: KVM_CAP_NESTED_STATE
+:Architectures: x86
+:Type: vcpu ioctl
+:Parameters: struct kvm_nested_state (in/out)
+:Returns: 0 on success, -1 on error
+
+Errors:
+
+ ===== =============================================================
+ E2BIG the total state size exceeds the value of 'size' specified by
+ the user; the size required will be written into size.
+ ===== =============================================================
+
+::
+
+ struct kvm_nested_state {
+ __u16 flags;
+ __u16 format;
+ __u32 size;
+
+ union {
+ struct kvm_vmx_nested_state_hdr vmx;
+ struct kvm_svm_nested_state_hdr svm;
+
+ /* Pad the header to 128 bytes. */
+ __u8 pad[120];
+ } hdr;
+
+ union {
+ struct kvm_vmx_nested_state_data vmx[0];
+ struct kvm_svm_nested_state_data svm[0];
+ } data;
+ };
+
+ #define KVM_STATE_NESTED_GUEST_MODE 0x00000001
+ #define KVM_STATE_NESTED_RUN_PENDING 0x00000002
+ #define KVM_STATE_NESTED_EVMCS 0x00000004
+
+ #define KVM_STATE_NESTED_FORMAT_VMX 0
+ #define KVM_STATE_NESTED_FORMAT_SVM 1
+
+ #define KVM_STATE_NESTED_VMX_VMCS_SIZE 0x1000
+
+ #define KVM_STATE_NESTED_VMX_SMM_GUEST_MODE 0x00000001
+ #define KVM_STATE_NESTED_VMX_SMM_VMXON 0x00000002
+
+ #define KVM_STATE_VMX_PREEMPTION_TIMER_DEADLINE 0x00000001
+
+ struct kvm_vmx_nested_state_hdr {
+ __u64 vmxon_pa;
+ __u64 vmcs12_pa;
+
+ struct {
+ __u16 flags;
+ } smm;
+
+ __u32 flags;
+ __u64 preemption_timer_deadline;
+ };
+
+ struct kvm_vmx_nested_state_data {
+ __u8 vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE];
+ __u8 shadow_vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE];
+ };
+
+This ioctl copies the vcpu's nested virtualization state from the kernel to
+userspace.
+
+The maximum size of the state can be retrieved by passing KVM_CAP_NESTED_STATE
+to the KVM_CHECK_EXTENSION ioctl().
+
+4.115 KVM_SET_NESTED_STATE
+--------------------------
+
+:Capability: KVM_CAP_NESTED_STATE
+:Architectures: x86
+:Type: vcpu ioctl
+:Parameters: struct kvm_nested_state (in)
+:Returns: 0 on success, -1 on error
+
+This copies the vcpu's kvm_nested_state struct from userspace to the kernel.
+For the definition of struct kvm_nested_state, see KVM_GET_NESTED_STATE.
+
+4.116 KVM_(UN)REGISTER_COALESCED_MMIO
+-------------------------------------
+
+:Capability: KVM_CAP_COALESCED_MMIO (for coalesced mmio)
+ KVM_CAP_COALESCED_PIO (for coalesced pio)
+:Architectures: all
+:Type: vm ioctl
+:Parameters: struct kvm_coalesced_mmio_zone
+:Returns: 0 on success, < 0 on error
+
+Coalesced I/O is a performance optimization that defers hardware
+register write emulation so that userspace exits are avoided. It is
+typically used to reduce the overhead of emulating frequently accessed
+hardware registers.
+
+When a hardware register is configured for coalesced I/O, write accesses
+do not exit to userspace and their value is recorded in a ring buffer
+that is shared between kernel and userspace.
+
+Coalesced I/O is used if one or more write accesses to a hardware
+register can be deferred until a read or a write to another hardware
+register on the same device. This last access will cause a vmexit and
+userspace will process accesses from the ring buffer before emulating
+it. That will avoid exiting to userspace on repeated writes.
+
+Coalesced pio is based on coalesced mmio. There is little difference
+between coalesced mmio and pio except that coalesced pio records accesses
+to I/O ports.
+
+4.117 KVM_CLEAR_DIRTY_LOG (vm ioctl)
+------------------------------------
+
+:Capability: KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2
+:Architectures: x86, arm, arm64, mips
+:Type: vm ioctl
+:Parameters: struct kvm_dirty_log (in)
+:Returns: 0 on success, -1 on error
+
+::
+
+ /* for KVM_CLEAR_DIRTY_LOG */
+ struct kvm_clear_dirty_log {
+ __u32 slot;
+ __u32 num_pages;
+ __u64 first_page;
+ union {
+ void __user *dirty_bitmap; /* one bit per page */
+ __u64 padding;
+ };
+ };
+
+The ioctl clears the dirty status of pages in a memory slot, according to
+the bitmap that is passed in struct kvm_clear_dirty_log's dirty_bitmap
+field. Bit 0 of the bitmap corresponds to page "first_page" in the
+memory slot, and num_pages is the size in bits of the input bitmap.
+first_page must be a multiple of 64; num_pages must also be a multiple of
+64 unless first_page + num_pages is the size of the memory slot. For each
+bit that is set in the input bitmap, the corresponding page is marked "clean"
+in KVM's dirty bitmap, and dirty tracking is re-enabled for that page
+(for example via write-protection, or by clearing the dirty bit in
+a page table entry).
+
+If KVM_CAP_MULTI_ADDRESS_SPACE is available, bits 16-31 specifies
+the address space for which you want to return the dirty bitmap.
+They must be less than the value that KVM_CHECK_EXTENSION returns for
+the KVM_CAP_MULTI_ADDRESS_SPACE capability.
+
+This ioctl is mostly useful when KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2
+is enabled; for more information, see the description of the capability.
+However, it can always be used as long as KVM_CHECK_EXTENSION confirms
+that KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 is present.
+
+4.118 KVM_GET_SUPPORTED_HV_CPUID
+--------------------------------
+
+:Capability: KVM_CAP_HYPERV_CPUID
+:Architectures: x86
+:Type: vcpu ioctl
+:Parameters: struct kvm_cpuid2 (in/out)
+:Returns: 0 on success, -1 on error
+
+::
+
+ struct kvm_cpuid2 {
+ __u32 nent;
+ __u32 padding;
+ struct kvm_cpuid_entry2 entries[0];
+ };
+
+ struct kvm_cpuid_entry2 {
+ __u32 function;
+ __u32 index;
+ __u32 flags;
+ __u32 eax;
+ __u32 ebx;
+ __u32 ecx;
+ __u32 edx;
+ __u32 padding[3];
+ };
+
+This ioctl returns x86 cpuid features leaves related to Hyper-V emulation in
+KVM. Userspace can use the information returned by this ioctl to construct
+cpuid information presented to guests consuming Hyper-V enlightenments (e.g.
+Windows or Hyper-V guests).
+
+CPUID feature leaves returned by this ioctl are defined by Hyper-V Top Level
+Functional Specification (TLFS). These leaves can't be obtained with
+KVM_GET_SUPPORTED_CPUID ioctl because some of them intersect with KVM feature
+leaves (0x40000000, 0x40000001).
+
+Currently, the following list of CPUID leaves are returned:
+ - HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS
+ - HYPERV_CPUID_INTERFACE
+ - HYPERV_CPUID_VERSION
+ - HYPERV_CPUID_FEATURES
+ - HYPERV_CPUID_ENLIGHTMENT_INFO
+ - HYPERV_CPUID_IMPLEMENT_LIMITS
+ - HYPERV_CPUID_NESTED_FEATURES
+ - HYPERV_CPUID_SYNDBG_VENDOR_AND_MAX_FUNCTIONS
+ - HYPERV_CPUID_SYNDBG_INTERFACE
+ - HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES
+
+HYPERV_CPUID_NESTED_FEATURES leaf is only exposed when Enlightened VMCS was
+enabled on the corresponding vCPU (KVM_CAP_HYPERV_ENLIGHTENED_VMCS).
+
+Userspace invokes KVM_GET_SUPPORTED_HV_CPUID by passing a kvm_cpuid2 structure
+with the 'nent' field indicating the number of entries in the variable-size
+array 'entries'. If the number of entries is too low to describe all Hyper-V
+feature leaves, an error (E2BIG) is returned. If the number is more or equal
+to the number of Hyper-V feature leaves, the 'nent' field is adjusted to the
+number of valid entries in the 'entries' array, which is then filled.
+
+'index' and 'flags' fields in 'struct kvm_cpuid_entry2' are currently reserved,
+userspace should not expect to get any particular value there.
+
+4.119 KVM_ARM_VCPU_FINALIZE
+---------------------------
+
+:Architectures: arm, arm64
+:Type: vcpu ioctl
+:Parameters: int feature (in)
+:Returns: 0 on success, -1 on error
+
+Errors:
+
+ ====== ==============================================================
+ EPERM feature not enabled, needs configuration, or already finalized
+ EINVAL feature unknown or not present
+ ====== ==============================================================
+
+Recognised values for feature:
+
+ ===== ===========================================
+ arm64 KVM_ARM_VCPU_SVE (requires KVM_CAP_ARM_SVE)
+ ===== ===========================================
+
+Finalizes the configuration of the specified vcpu feature.
+
+The vcpu must already have been initialised, enabling the affected feature, by
+means of a successful KVM_ARM_VCPU_INIT call with the appropriate flag set in
+features[].
+
+For affected vcpu features, this is a mandatory step that must be performed
+before the vcpu is fully usable.
+
+Between KVM_ARM_VCPU_INIT and KVM_ARM_VCPU_FINALIZE, the feature may be
+configured by use of ioctls such as KVM_SET_ONE_REG. The exact configuration
+that should be performaned and how to do it are feature-dependent.
+
+Other calls that depend on a particular feature being finalized, such as
+KVM_RUN, KVM_GET_REG_LIST, KVM_GET_ONE_REG and KVM_SET_ONE_REG, will fail with
+-EPERM unless the feature has already been finalized by means of a
+KVM_ARM_VCPU_FINALIZE call.
+
+See KVM_ARM_VCPU_INIT for details of vcpu features that require finalization
+using this ioctl.
+
+4.120 KVM_SET_PMU_EVENT_FILTER
+------------------------------
+
+:Capability: KVM_CAP_PMU_EVENT_FILTER
+:Architectures: x86
+:Type: vm ioctl
+:Parameters: struct kvm_pmu_event_filter (in)
+:Returns: 0 on success, -1 on error
+
+::
+
+ struct kvm_pmu_event_filter {
+ __u32 action;
+ __u32 nevents;
+ __u32 fixed_counter_bitmap;
+ __u32 flags;
+ __u32 pad[4];
+ __u64 events[0];
+ };
+
+This ioctl restricts the set of PMU events that the guest can program.
+The argument holds a list of events which will be allowed or denied.
+The eventsel+umask of each event the guest attempts to program is compared
+against the events field to determine whether the guest should have access.
+The events field only controls general purpose counters; fixed purpose
+counters are controlled by the fixed_counter_bitmap.
+
+No flags are defined yet, the field must be zero.
+
+Valid values for 'action'::
+
+ #define KVM_PMU_EVENT_ALLOW 0
+ #define KVM_PMU_EVENT_DENY 1
+
+4.121 KVM_PPC_SVM_OFF
+---------------------
+
+:Capability: basic
+:Architectures: powerpc
+:Type: vm ioctl
+:Parameters: none
+:Returns: 0 on successful completion,
+
+Errors:
+
+ ====== ================================================================
+ EINVAL if ultravisor failed to terminate the secure guest
+ ENOMEM if hypervisor failed to allocate new radix page tables for guest
+ ====== ================================================================
+
+This ioctl is used to turn off the secure mode of the guest or transition
+the guest from secure mode to normal mode. This is invoked when the guest
+is reset. This has no effect if called for a normal guest.
+
+This ioctl issues an ultravisor call to terminate the secure guest,
+unpins the VPA pages and releases all the device pages that are used to
+track the secure pages by hypervisor.
+
+4.122 KVM_S390_NORMAL_RESET
+---------------------------
+
+:Capability: KVM_CAP_S390_VCPU_RESETS
+:Architectures: s390
+:Type: vcpu ioctl
+:Parameters: none
+:Returns: 0
+
+This ioctl resets VCPU registers and control structures according to
+the cpu reset definition in the POP (Principles Of Operation).
+
+4.123 KVM_S390_INITIAL_RESET
+----------------------------
+
+:Capability: none
+:Architectures: s390
+:Type: vcpu ioctl
+:Parameters: none
+:Returns: 0
+
+This ioctl resets VCPU registers and control structures according to
+the initial cpu reset definition in the POP. However, the cpu is not
+put into ESA mode. This reset is a superset of the normal reset.
+
+4.124 KVM_S390_CLEAR_RESET
+--------------------------
+
+:Capability: KVM_CAP_S390_VCPU_RESETS
+:Architectures: s390
+:Type: vcpu ioctl
+:Parameters: none
+:Returns: 0
+
+This ioctl resets VCPU registers and control structures according to
+the clear cpu reset definition in the POP. However, the cpu is not put
+into ESA mode. This reset is a superset of the initial reset.
+
+
+4.125 KVM_S390_PV_COMMAND
+-------------------------
+
+:Capability: KVM_CAP_S390_PROTECTED
+:Architectures: s390
+:Type: vm ioctl
+:Parameters: struct kvm_pv_cmd
+:Returns: 0 on success, < 0 on error
+
+::
+
+ struct kvm_pv_cmd {
+ __u32 cmd; /* Command to be executed */
+ __u16 rc; /* Ultravisor return code */
+ __u16 rrc; /* Ultravisor return reason code */
+ __u64 data; /* Data or address */
+ __u32 flags; /* flags for future extensions. Must be 0 for now */
+ __u32 reserved[3];
+ };
+
+cmd values:
+
+KVM_PV_ENABLE
+ Allocate memory and register the VM with the Ultravisor, thereby
+ donating memory to the Ultravisor that will become inaccessible to
+ KVM. All existing CPUs are converted to protected ones. After this
+ command has succeeded, any CPU added via hotplug will become
+ protected during its creation as well.
+
+ Errors:
+
+ ===== =============================
+ EINTR an unmasked signal is pending
+ ===== =============================
+
+KVM_PV_DISABLE
+
+ Deregister the VM from the Ultravisor and reclaim the memory that
+ had been donated to the Ultravisor, making it usable by the kernel
+ again. All registered VCPUs are converted back to non-protected
+ ones.
+
+KVM_PV_VM_SET_SEC_PARMS
+ Pass the image header from VM memory to the Ultravisor in
+ preparation of image unpacking and verification.
+
+KVM_PV_VM_UNPACK
+ Unpack (protect and decrypt) a page of the encrypted boot image.
+
+KVM_PV_VM_VERIFY
+ Verify the integrity of the unpacked image. Only if this succeeds,
+ KVM is allowed to start protected VCPUs.
+
+4.126 KVM_X86_SET_MSR_FILTER
+----------------------------
+
+:Capability: KVM_X86_SET_MSR_FILTER
+:Architectures: x86
+:Type: vm ioctl
+:Parameters: struct kvm_msr_filter
+:Returns: 0 on success, < 0 on error
+
+::
+
+ struct kvm_msr_filter_range {
+ #define KVM_MSR_FILTER_READ (1 << 0)
+ #define KVM_MSR_FILTER_WRITE (1 << 1)
+ __u32 flags;
+ __u32 nmsrs; /* number of msrs in bitmap */
+ __u32 base; /* MSR index the bitmap starts at */
+ __u8 *bitmap; /* a 1 bit allows the operations in flags, 0 denies */
+ };
+
+ #define KVM_MSR_FILTER_MAX_RANGES 16
+ struct kvm_msr_filter {
+ #define KVM_MSR_FILTER_DEFAULT_ALLOW (0 << 0)
+ #define KVM_MSR_FILTER_DEFAULT_DENY (1 << 0)
+ __u32 flags;
+ struct kvm_msr_filter_range ranges[KVM_MSR_FILTER_MAX_RANGES];
+ };
+
+flags values for ``struct kvm_msr_filter_range``:
+
+``KVM_MSR_FILTER_READ``
+
+ Filter read accesses to MSRs using the given bitmap. A 0 in the bitmap
+ indicates that a read should immediately fail, while a 1 indicates that
+ a read for a particular MSR should be handled regardless of the default
+ filter action.
+
+``KVM_MSR_FILTER_WRITE``
+
+ Filter write accesses to MSRs using the given bitmap. A 0 in the bitmap
+ indicates that a write should immediately fail, while a 1 indicates that
+ a write for a particular MSR should be handled regardless of the default
+ filter action.
+
+``KVM_MSR_FILTER_READ | KVM_MSR_FILTER_WRITE``
+
+ Filter both read and write accesses to MSRs using the given bitmap. A 0
+ in the bitmap indicates that both reads and writes should immediately fail,
+ while a 1 indicates that reads and writes for a particular MSR are not
+ filtered by this range.
+
+flags values for ``struct kvm_msr_filter``:
+
+``KVM_MSR_FILTER_DEFAULT_ALLOW``
+
+ If no filter range matches an MSR index that is getting accessed, KVM will
+ fall back to allowing access to the MSR.
+
+``KVM_MSR_FILTER_DEFAULT_DENY``
+
+ If no filter range matches an MSR index that is getting accessed, KVM will
+ fall back to rejecting access to the MSR. In this mode, all MSRs that should
+ be processed by KVM need to explicitly be marked as allowed in the bitmaps.
+
+This ioctl allows user space to define up to 16 bitmaps of MSR ranges to
+specify whether a certain MSR access should be explicitly filtered for or not.
+
+If this ioctl has never been invoked, MSR accesses are not guarded and the
+default KVM in-kernel emulation behavior is fully preserved.
+
+Calling this ioctl with an empty set of ranges (all nmsrs == 0) disables MSR
+filtering. In that mode, ``KVM_MSR_FILTER_DEFAULT_DENY`` is invalid and causes
+an error.
+
+As soon as the filtering is in place, every MSR access is processed through
+the filtering except for accesses to the x2APIC MSRs (from 0x800 to 0x8ff);
+x2APIC MSRs are always allowed, independent of the ``default_allow`` setting,
+and their behavior depends on the ``X2APIC_ENABLE`` bit of the APIC base
+register.
+
+If a bit is within one of the defined ranges, read and write accesses are
+guarded by the bitmap's value for the MSR index if the kind of access
+is included in the ``struct kvm_msr_filter_range`` flags. If no range
+cover this particular access, the behavior is determined by the flags
+field in the kvm_msr_filter struct: ``KVM_MSR_FILTER_DEFAULT_ALLOW``
+and ``KVM_MSR_FILTER_DEFAULT_DENY``.
+
+Each bitmap range specifies a range of MSRs to potentially allow access on.
+The range goes from MSR index [base .. base+nmsrs]. The flags field
+indicates whether reads, writes or both reads and writes are filtered
+by setting a 1 bit in the bitmap for the corresponding MSR index.
+
+If an MSR access is not permitted through the filtering, it generates a
+#GP inside the guest. When combined with KVM_CAP_X86_USER_SPACE_MSR, that
+allows user space to deflect and potentially handle various MSR accesses
+into user space.
+
+Note, invoking this ioctl with a vCPU is running is inherently racy. However,
+KVM does guarantee that vCPUs will see either the previous filter or the new
+filter, e.g. MSRs with identical settings in both the old and new filter will
+have deterministic behavior.
+
+
+5. The kvm_run structure
+========================
+
+Application code obtains a pointer to the kvm_run structure by
+mmap()ing a vcpu fd. From that point, application code can control
+execution by changing fields in kvm_run prior to calling the KVM_RUN
+ioctl, and obtain information about the reason KVM_RUN returned by
+looking up structure members.
+
+::
+
+ struct kvm_run {
+ /* in */
+ __u8 request_interrupt_window;
+
+Request that KVM_RUN return when it becomes possible to inject external
+interrupts into the guest. Useful in conjunction with KVM_INTERRUPT.
+
+::
+
+ __u8 immediate_exit;
+
+This field is polled once when KVM_RUN starts; if non-zero, KVM_RUN
+exits immediately, returning -EINTR. In the common scenario where a
+signal is used to "kick" a VCPU out of KVM_RUN, this field can be used
+to avoid usage of KVM_SET_SIGNAL_MASK, which has worse scalability.
+Rather than blocking the signal outside KVM_RUN, userspace can set up
+a signal handler that sets run->immediate_exit to a non-zero value.
+
+This field is ignored if KVM_CAP_IMMEDIATE_EXIT is not available.
+
+::
+
+ __u8 padding1[6];
+
+ /* out */
+ __u32 exit_reason;
+
+When KVM_RUN has returned successfully (return value 0), this informs
+application code why KVM_RUN has returned. Allowable values for this
+field are detailed below.
+
+::
+
+ __u8 ready_for_interrupt_injection;
+
+If request_interrupt_window has been specified, this field indicates
+an interrupt can be injected now with KVM_INTERRUPT.
+
+::
+
+ __u8 if_flag;
+
+The value of the current interrupt flag. Only valid if in-kernel
+local APIC is not used.
+
+::
+
+ __u16 flags;
+
+More architecture-specific flags detailing state of the VCPU that may
+affect the device's behavior. The only currently defined flag is
+KVM_RUN_X86_SMM, which is valid on x86 machines and is set if the
+VCPU is in system management mode.
+
+::
+
+ /* in (pre_kvm_run), out (post_kvm_run) */
+ __u64 cr8;
+
+The value of the cr8 register. Only valid if in-kernel local APIC is
+not used. Both input and output.
+
+::
+
+ __u64 apic_base;
+
+The value of the APIC BASE msr. Only valid if in-kernel local
+APIC is not used. Both input and output.
+
+::
+
+ union {
+ /* KVM_EXIT_UNKNOWN */
+ struct {
+ __u64 hardware_exit_reason;
+ } hw;
+
+If exit_reason is KVM_EXIT_UNKNOWN, the vcpu has exited due to unknown
+reasons. Further architecture-specific information is available in
+hardware_exit_reason.
+
+::
+
+ /* KVM_EXIT_FAIL_ENTRY */
+ struct {
+ __u64 hardware_entry_failure_reason;
+ __u32 cpu; /* if KVM_LAST_CPU */
+ } fail_entry;
+
+If exit_reason is KVM_EXIT_FAIL_ENTRY, the vcpu could not be run due
+to unknown reasons. Further architecture-specific information is
+available in hardware_entry_failure_reason.
+
+::
+
+ /* KVM_EXIT_EXCEPTION */
+ struct {
+ __u32 exception;
+ __u32 error_code;
+ } ex;
+
+Unused.
+
+::
+
+ /* KVM_EXIT_IO */
+ struct {
+ #define KVM_EXIT_IO_IN 0
+ #define KVM_EXIT_IO_OUT 1
+ __u8 direction;
+ __u8 size; /* bytes */
+ __u16 port;
+ __u32 count;
+ __u64 data_offset; /* relative to kvm_run start */
+ } io;
+
+If exit_reason is KVM_EXIT_IO, then the vcpu has
+executed a port I/O instruction which could not be satisfied by kvm.
+data_offset describes where the data is located (KVM_EXIT_IO_OUT) or
+where kvm expects application code to place the data for the next
+KVM_RUN invocation (KVM_EXIT_IO_IN). Data format is a packed array.
+
+::
+
+ /* KVM_EXIT_DEBUG */
+ struct {
+ struct kvm_debug_exit_arch arch;
+ } debug;
+
+If the exit_reason is KVM_EXIT_DEBUG, then a vcpu is processing a debug event
+for which architecture specific information is returned.
+
+::
+
+ /* KVM_EXIT_MMIO */
+ struct {
+ __u64 phys_addr;
+ __u8 data[8];
+ __u32 len;
+ __u8 is_write;
+ } mmio;
+
+If exit_reason is KVM_EXIT_MMIO, then the vcpu has
+executed a memory-mapped I/O instruction which could not be satisfied
+by kvm. The 'data' member contains the written data if 'is_write' is
+true, and should be filled by application code otherwise.
+
+The 'data' member contains, in its first 'len' bytes, the value as it would
+appear if the VCPU performed a load or store of the appropriate width directly
+to the byte array.
+
+.. note::
+
+ For KVM_EXIT_IO, KVM_EXIT_MMIO, KVM_EXIT_OSI, KVM_EXIT_PAPR,
+ KVM_EXIT_EPR, KVM_EXIT_X86_RDMSR and KVM_EXIT_X86_WRMSR the corresponding
+ operations are complete (and guest state is consistent) only after userspace
+ has re-entered the kernel with KVM_RUN. The kernel side will first finish
+ incomplete operations and then check for pending signals. Userspace
+ can re-enter the guest with an unmasked signal pending to complete
+ pending operations.
+
+::
+
+ /* KVM_EXIT_HYPERCALL */
+ struct {
+ __u64 nr;
+ __u64 args[6];
+ __u64 ret;
+ __u32 longmode;
+ __u32 pad;
+ } hypercall;
+
+Unused. This was once used for 'hypercall to userspace'. To implement
+such functionality, use KVM_EXIT_IO (x86) or KVM_EXIT_MMIO (all except s390).
+
+.. note:: KVM_EXIT_IO is significantly faster than KVM_EXIT_MMIO.
+
+::
+
+ /* KVM_EXIT_TPR_ACCESS */
+ struct {
+ __u64 rip;
+ __u32 is_write;
+ __u32 pad;
+ } tpr_access;
+
+To be documented (KVM_TPR_ACCESS_REPORTING).
+
+::
+
+ /* KVM_EXIT_S390_SIEIC */
+ struct {
+ __u8 icptcode;
+ __u64 mask; /* psw upper half */
+ __u64 addr; /* psw lower half */
+ __u16 ipa;
+ __u32 ipb;
+ } s390_sieic;
+
+s390 specific.
+
+::
+
+ /* KVM_EXIT_S390_RESET */
+ #define KVM_S390_RESET_POR 1
+ #define KVM_S390_RESET_CLEAR 2
+ #define KVM_S390_RESET_SUBSYSTEM 4
+ #define KVM_S390_RESET_CPU_INIT 8
+ #define KVM_S390_RESET_IPL 16
+ __u64 s390_reset_flags;
+
+s390 specific.
+
+::
+
+ /* KVM_EXIT_S390_UCONTROL */
+ struct {
+ __u64 trans_exc_code;
+ __u32 pgm_code;
+ } s390_ucontrol;
+
+s390 specific. A page fault has occurred for a user controlled virtual
+machine (KVM_VM_S390_UNCONTROL) on it's host page table that cannot be
+resolved by the kernel.
+The program code and the translation exception code that were placed
+in the cpu's lowcore are presented here as defined by the z Architecture
+Principles of Operation Book in the Chapter for Dynamic Address Translation
+(DAT)
+
+::
+
+ /* KVM_EXIT_DCR */
+ struct {
+ __u32 dcrn;
+ __u32 data;
+ __u8 is_write;
+ } dcr;
+
+Deprecated - was used for 440 KVM.
+
+::
+
+ /* KVM_EXIT_OSI */
+ struct {
+ __u64 gprs[32];
+ } osi;
+
+MOL uses a special hypercall interface it calls 'OSI'. To enable it, we catch
+hypercalls and exit with this exit struct that contains all the guest gprs.
+
+If exit_reason is KVM_EXIT_OSI, then the vcpu has triggered such a hypercall.
+Userspace can now handle the hypercall and when it's done modify the gprs as
+necessary. Upon guest entry all guest GPRs will then be replaced by the values
+in this struct.
+
+::
+
+ /* KVM_EXIT_PAPR_HCALL */
+ struct {
+ __u64 nr;
+ __u64 ret;
+ __u64 args[9];
+ } papr_hcall;
+
+This is used on 64-bit PowerPC when emulating a pSeries partition,
+e.g. with the 'pseries' machine type in qemu. It occurs when the
+guest does a hypercall using the 'sc 1' instruction. The 'nr' field
+contains the hypercall number (from the guest R3), and 'args' contains
+the arguments (from the guest R4 - R12). Userspace should put the
+return code in 'ret' and any extra returned values in args[].
+The possible hypercalls are defined in the Power Architecture Platform
+Requirements (PAPR) document available from www.power.org (free
+developer registration required to access it).
+
+::
+
+ /* KVM_EXIT_S390_TSCH */
+ struct {
+ __u16 subchannel_id;
+ __u16 subchannel_nr;
+ __u32 io_int_parm;
+ __u32 io_int_word;
+ __u32 ipb;
+ __u8 dequeued;
+ } s390_tsch;
+
+s390 specific. This exit occurs when KVM_CAP_S390_CSS_SUPPORT has been enabled
+and TEST SUBCHANNEL was intercepted. If dequeued is set, a pending I/O
+interrupt for the target subchannel has been dequeued and subchannel_id,
+subchannel_nr, io_int_parm and io_int_word contain the parameters for that
+interrupt. ipb is needed for instruction parameter decoding.
+
+::
+
+ /* KVM_EXIT_EPR */
+ struct {
+ __u32 epr;
+ } epr;
+
+On FSL BookE PowerPC chips, the interrupt controller has a fast patch
+interrupt acknowledge path to the core. When the core successfully
+delivers an interrupt, it automatically populates the EPR register with
+the interrupt vector number and acknowledges the interrupt inside
+the interrupt controller.
+
+In case the interrupt controller lives in user space, we need to do
+the interrupt acknowledge cycle through it to fetch the next to be
+delivered interrupt vector using this exit.
+
+It gets triggered whenever both KVM_CAP_PPC_EPR are enabled and an
+external interrupt has just been delivered into the guest. User space
+should put the acknowledged interrupt vector into the 'epr' field.
+
+::
+
+ /* KVM_EXIT_SYSTEM_EVENT */
+ struct {
+ #define KVM_SYSTEM_EVENT_SHUTDOWN 1
+ #define KVM_SYSTEM_EVENT_RESET 2
+ #define KVM_SYSTEM_EVENT_CRASH 3
+ __u32 type;
+ __u64 flags;
+ } system_event;
+
+If exit_reason is KVM_EXIT_SYSTEM_EVENT then the vcpu has triggered
+a system-level event using some architecture specific mechanism (hypercall
+or some special instruction). In case of ARM/ARM64, this is triggered using
+HVC instruction based PSCI call from the vcpu. The 'type' field describes
+the system-level event type. The 'flags' field describes architecture
+specific flags for the system-level event.
+
+Valid values for 'type' are:
+
+ - KVM_SYSTEM_EVENT_SHUTDOWN -- the guest has requested a shutdown of the
+ VM. Userspace is not obliged to honour this, and if it does honour
+ this does not need to destroy the VM synchronously (ie it may call
+ KVM_RUN again before shutdown finally occurs).
+ - KVM_SYSTEM_EVENT_RESET -- the guest has requested a reset of the VM.
+ As with SHUTDOWN, userspace can choose to ignore the request, or
+ to schedule the reset to occur in the future and may call KVM_RUN again.
+ - KVM_SYSTEM_EVENT_CRASH -- the guest crash occurred and the guest
+ has requested a crash condition maintenance. Userspace can choose
+ to ignore the request, or to gather VM memory core dump and/or
+ reset/shutdown of the VM.
+
+::
+
+ /* KVM_EXIT_IOAPIC_EOI */
+ struct {
+ __u8 vector;
+ } eoi;
+
+Indicates that the VCPU's in-kernel local APIC received an EOI for a
+level-triggered IOAPIC interrupt. This exit only triggers when the
+IOAPIC is implemented in userspace (i.e. KVM_CAP_SPLIT_IRQCHIP is enabled);
+the userspace IOAPIC should process the EOI and retrigger the interrupt if
+it is still asserted. Vector is the LAPIC interrupt vector for which the
+EOI was received.
+
+::
+
+ struct kvm_hyperv_exit {
+ #define KVM_EXIT_HYPERV_SYNIC 1
+ #define KVM_EXIT_HYPERV_HCALL 2
+ #define KVM_EXIT_HYPERV_SYNDBG 3
+ __u32 type;
+ __u32 pad1;
+ union {
+ struct {
+ __u32 msr;
+ __u32 pad2;
+ __u64 control;
+ __u64 evt_page;
+ __u64 msg_page;
+ } synic;
+ struct {
+ __u64 input;
+ __u64 result;
+ __u64 params[2];
+ } hcall;
+ struct {
+ __u32 msr;
+ __u32 pad2;
+ __u64 control;
+ __u64 status;
+ __u64 send_page;
+ __u64 recv_page;
+ __u64 pending_page;
+ } syndbg;
+ } u;
+ };
+ /* KVM_EXIT_HYPERV */
+ struct kvm_hyperv_exit hyperv;
+
+Indicates that the VCPU exits into userspace to process some tasks
+related to Hyper-V emulation.
+
+Valid values for 'type' are:
+
+ - KVM_EXIT_HYPERV_SYNIC -- synchronously notify user-space about
+
+Hyper-V SynIC state change. Notification is used to remap SynIC
+event/message pages and to enable/disable SynIC messages/events processing
+in userspace.
+
+ - KVM_EXIT_HYPERV_SYNDBG -- synchronously notify user-space about
+
+Hyper-V Synthetic debugger state change. Notification is used to either update
+the pending_page location or to send a control command (send the buffer located
+in send_page or recv a buffer to recv_page).
+
+::
+
+ /* KVM_EXIT_ARM_NISV */
+ struct {
+ __u64 esr_iss;
+ __u64 fault_ipa;
+ } arm_nisv;
+
+Used on arm and arm64 systems. If a guest accesses memory not in a memslot,
+KVM will typically return to userspace and ask it to do MMIO emulation on its
+behalf. However, for certain classes of instructions, no instruction decode
+(direction, length of memory access) is provided, and fetching and decoding
+the instruction from the VM is overly complicated to live in the kernel.
+
+Historically, when this situation occurred, KVM would print a warning and kill
+the VM. KVM assumed that if the guest accessed non-memslot memory, it was
+trying to do I/O, which just couldn't be emulated, and the warning message was
+phrased accordingly. However, what happened more often was that a guest bug
+caused access outside the guest memory areas which should lead to a more
+meaningful warning message and an external abort in the guest, if the access
+did not fall within an I/O window.
+
+Userspace implementations can query for KVM_CAP_ARM_NISV_TO_USER, and enable
+this capability at VM creation. Once this is done, these types of errors will
+instead return to userspace with KVM_EXIT_ARM_NISV, with the valid bits from
+the HSR (arm) and ESR_EL2 (arm64) in the esr_iss field, and the faulting IPA
+in the fault_ipa field. Userspace can either fix up the access if it's
+actually an I/O access by decoding the instruction from guest memory (if it's
+very brave) and continue executing the guest, or it can decide to suspend,
+dump, or restart the guest.
+
+Note that KVM does not skip the faulting instruction as it does for
+KVM_EXIT_MMIO, but userspace has to emulate any change to the processing state
+if it decides to decode and emulate the instruction.
+
+::
+
+ /* KVM_EXIT_X86_RDMSR / KVM_EXIT_X86_WRMSR */
+ struct {
+ __u8 error; /* user -> kernel */
+ __u8 pad[7];
+ __u32 reason; /* kernel -> user */
+ __u32 index; /* kernel -> user */
+ __u64 data; /* kernel <-> user */
+ } msr;
+
+Used on x86 systems. When the VM capability KVM_CAP_X86_USER_SPACE_MSR is
+enabled, MSR accesses to registers that would invoke a #GP by KVM kernel code
+will instead trigger a KVM_EXIT_X86_RDMSR exit for reads and KVM_EXIT_X86_WRMSR
+exit for writes.
+
+The "reason" field specifies why the MSR trap occurred. User space will only
+receive MSR exit traps when a particular reason was requested during through
+ENABLE_CAP. Currently valid exit reasons are:
+
+ KVM_MSR_EXIT_REASON_UNKNOWN - access to MSR that is unknown to KVM
+ KVM_MSR_EXIT_REASON_INVAL - access to invalid MSRs or reserved bits
+ KVM_MSR_EXIT_REASON_FILTER - access blocked by KVM_X86_SET_MSR_FILTER
+
+For KVM_EXIT_X86_RDMSR, the "index" field tells user space which MSR the guest
+wants to read. To respond to this request with a successful read, user space
+writes the respective data into the "data" field and must continue guest
+execution to ensure the read data is transferred into guest register state.
+
+If the RDMSR request was unsuccessful, user space indicates that with a "1" in
+the "error" field. This will inject a #GP into the guest when the VCPU is
+executed again.
+
+For KVM_EXIT_X86_WRMSR, the "index" field tells user space which MSR the guest
+wants to write. Once finished processing the event, user space must continue
+vCPU execution. If the MSR write was unsuccessful, user space also sets the
+"error" field to "1".
+
+::
+
+ /* Fix the size of the union. */
+ char padding[256];
+ };
+
+ /*
+ * shared registers between kvm and userspace.
+ * kvm_valid_regs specifies the register classes set by the host
+ * kvm_dirty_regs specified the register classes dirtied by userspace
+ * struct kvm_sync_regs is architecture specific, as well as the
+ * bits for kvm_valid_regs and kvm_dirty_regs
+ */
+ __u64 kvm_valid_regs;
+ __u64 kvm_dirty_regs;
+ union {
+ struct kvm_sync_regs regs;
+ char padding[SYNC_REGS_SIZE_BYTES];
+ } s;
+
+If KVM_CAP_SYNC_REGS is defined, these fields allow userspace to access
+certain guest registers without having to call SET/GET_*REGS. Thus we can
+avoid some system call overhead if userspace has to handle the exit.
+Userspace can query the validity of the structure by checking
+kvm_valid_regs for specific bits. These bits are architecture specific
+and usually define the validity of a groups of registers. (e.g. one bit
+for general purpose registers)
+
+Please note that the kernel is allowed to use the kvm_run structure as the
+primary storage for certain register types. Therefore, the kernel may use the
+values in kvm_run even if the corresponding bit in kvm_dirty_regs is not set.
+
+::
+
+ };
+
+
+
+6. Capabilities that can be enabled on vCPUs
+============================================
+
+There are certain capabilities that change the behavior of the virtual CPU or
+the virtual machine when enabled. To enable them, please see section 4.37.
+Below you can find a list of capabilities and what their effect on the vCPU or
+the virtual machine is when enabling them.
+
+The following information is provided along with the description:
+
+ Architectures:
+ which instruction set architectures provide this ioctl.
+ x86 includes both i386 and x86_64.
+
+ Target:
+ whether this is a per-vcpu or per-vm capability.
+
+ Parameters:
+ what parameters are accepted by the capability.
+
+ Returns:
+ the return value. General error numbers (EBADF, ENOMEM, EINVAL)
+ are not detailed, but errors with specific meanings are.
+
+
+6.1 KVM_CAP_PPC_OSI
+-------------------
+
+:Architectures: ppc
+:Target: vcpu
+:Parameters: none
+:Returns: 0 on success; -1 on error
+
+This capability enables interception of OSI hypercalls that otherwise would
+be treated as normal system calls to be injected into the guest. OSI hypercalls
+were invented by Mac-on-Linux to have a standardized communication mechanism
+between the guest and the host.
+
+When this capability is enabled, KVM_EXIT_OSI can occur.
+
+
+6.2 KVM_CAP_PPC_PAPR
+--------------------
+
+:Architectures: ppc
+:Target: vcpu
+:Parameters: none
+:Returns: 0 on success; -1 on error
+
+This capability enables interception of PAPR hypercalls. PAPR hypercalls are
+done using the hypercall instruction "sc 1".
+
+It also sets the guest privilege level to "supervisor" mode. Usually the guest
+runs in "hypervisor" privilege mode with a few missing features.
+
+In addition to the above, it changes the semantics of SDR1. In this mode, the
+HTAB address part of SDR1 contains an HVA instead of a GPA, as PAPR keeps the
+HTAB invisible to the guest.
+
+When this capability is enabled, KVM_EXIT_PAPR_HCALL can occur.
+
+
+6.3 KVM_CAP_SW_TLB
+------------------
+
+:Architectures: ppc
+:Target: vcpu
+:Parameters: args[0] is the address of a struct kvm_config_tlb
+:Returns: 0 on success; -1 on error
+
+::
+
+ struct kvm_config_tlb {
+ __u64 params;
+ __u64 array;
+ __u32 mmu_type;
+ __u32 array_len;
+ };
+
+Configures the virtual CPU's TLB array, establishing a shared memory area
+between userspace and KVM. The "params" and "array" fields are userspace
+addresses of mmu-type-specific data structures. The "array_len" field is an
+safety mechanism, and should be set to the size in bytes of the memory that
+userspace has reserved for the array. It must be at least the size dictated
+by "mmu_type" and "params".
+
+While KVM_RUN is active, the shared region is under control of KVM. Its
+contents are undefined, and any modification by userspace results in
+boundedly undefined behavior.
+
+On return from KVM_RUN, the shared region will reflect the current state of
+the guest's TLB. If userspace makes any changes, it must call KVM_DIRTY_TLB
+to tell KVM which entries have been changed, prior to calling KVM_RUN again
+on this vcpu.
+
+For mmu types KVM_MMU_FSL_BOOKE_NOHV and KVM_MMU_FSL_BOOKE_HV:
+
+ - The "params" field is of type "struct kvm_book3e_206_tlb_params".
+ - The "array" field points to an array of type "struct
+ kvm_book3e_206_tlb_entry".
+ - The array consists of all entries in the first TLB, followed by all
+ entries in the second TLB.
+ - Within a TLB, entries are ordered first by increasing set number. Within a
+ set, entries are ordered by way (increasing ESEL).
+ - The hash for determining set number in TLB0 is: (MAS2 >> 12) & (num_sets - 1)
+ where "num_sets" is the tlb_sizes[] value divided by the tlb_ways[] value.
+ - The tsize field of mas1 shall be set to 4K on TLB0, even though the
+ hardware ignores this value for TLB0.
+
+6.4 KVM_CAP_S390_CSS_SUPPORT
+----------------------------
+
+:Architectures: s390
+:Target: vcpu
+:Parameters: none
+:Returns: 0 on success; -1 on error
+
+This capability enables support for handling of channel I/O instructions.
+
+TEST PENDING INTERRUPTION and the interrupt portion of TEST SUBCHANNEL are
+handled in-kernel, while the other I/O instructions are passed to userspace.
+
+When this capability is enabled, KVM_EXIT_S390_TSCH will occur on TEST
+SUBCHANNEL intercepts.
+
+Note that even though this capability is enabled per-vcpu, the complete
+virtual machine is affected.
+
+6.5 KVM_CAP_PPC_EPR
+-------------------
+
+:Architectures: ppc
+:Target: vcpu
+:Parameters: args[0] defines whether the proxy facility is active
+:Returns: 0 on success; -1 on error
+
+This capability enables or disables the delivery of interrupts through the
+external proxy facility.
+
+When enabled (args[0] != 0), every time the guest gets an external interrupt
+delivered, it automatically exits into user space with a KVM_EXIT_EPR exit
+to receive the topmost interrupt vector.
+
+When disabled (args[0] == 0), behavior is as if this facility is unsupported.
+
+When this capability is enabled, KVM_EXIT_EPR can occur.
+
+6.6 KVM_CAP_IRQ_MPIC
+--------------------
+
+:Architectures: ppc
+:Parameters: args[0] is the MPIC device fd;
+ args[1] is the MPIC CPU number for this vcpu
+
+This capability connects the vcpu to an in-kernel MPIC device.
+
+6.7 KVM_CAP_IRQ_XICS
+--------------------
+
+:Architectures: ppc
+:Target: vcpu
+:Parameters: args[0] is the XICS device fd;
+ args[1] is the XICS CPU number (server ID) for this vcpu
+
+This capability connects the vcpu to an in-kernel XICS device.
+
+6.8 KVM_CAP_S390_IRQCHIP
+------------------------
+
+:Architectures: s390
+:Target: vm
+:Parameters: none
+
+This capability enables the in-kernel irqchip for s390. Please refer to
+"4.24 KVM_CREATE_IRQCHIP" for details.
+
+6.9 KVM_CAP_MIPS_FPU
+--------------------
+
+:Architectures: mips
+:Target: vcpu
+:Parameters: args[0] is reserved for future use (should be 0).
+
+This capability allows the use of the host Floating Point Unit by the guest. It
+allows the Config1.FP bit to be set to enable the FPU in the guest. Once this is
+done the ``KVM_REG_MIPS_FPR_*`` and ``KVM_REG_MIPS_FCR_*`` registers can be
+accessed (depending on the current guest FPU register mode), and the Status.FR,
+Config5.FRE bits are accessible via the KVM API and also from the guest,
+depending on them being supported by the FPU.
+
+6.10 KVM_CAP_MIPS_MSA
+---------------------
+
+:Architectures: mips
+:Target: vcpu
+:Parameters: args[0] is reserved for future use (should be 0).
+
+This capability allows the use of the MIPS SIMD Architecture (MSA) by the guest.
+It allows the Config3.MSAP bit to be set to enable the use of MSA by the guest.
+Once this is done the ``KVM_REG_MIPS_VEC_*`` and ``KVM_REG_MIPS_MSA_*``
+registers can be accessed, and the Config5.MSAEn bit is accessible via the
+KVM API and also from the guest.
+
+6.74 KVM_CAP_SYNC_REGS
+----------------------
+
+:Architectures: s390, x86
+:Target: s390: always enabled, x86: vcpu
+:Parameters: none
+:Returns: x86: KVM_CHECK_EXTENSION returns a bit-array indicating which register
+ sets are supported
+ (bitfields defined in arch/x86/include/uapi/asm/kvm.h).
+
+As described above in the kvm_sync_regs struct info in section 5 (kvm_run):
+KVM_CAP_SYNC_REGS "allow[s] userspace to access certain guest registers
+without having to call SET/GET_*REGS". This reduces overhead by eliminating
+repeated ioctl calls for setting and/or getting register values. This is
+particularly important when userspace is making synchronous guest state
+modifications, e.g. when emulating and/or intercepting instructions in
+userspace.
+
+For s390 specifics, please refer to the source code.
+
+For x86:
+
+- the register sets to be copied out to kvm_run are selectable
+ by userspace (rather that all sets being copied out for every exit).
+- vcpu_events are available in addition to regs and sregs.
+
+For x86, the 'kvm_valid_regs' field of struct kvm_run is overloaded to
+function as an input bit-array field set by userspace to indicate the
+specific register sets to be copied out on the next exit.
+
+To indicate when userspace has modified values that should be copied into
+the vCPU, the all architecture bitarray field, 'kvm_dirty_regs' must be set.
+This is done using the same bitflags as for the 'kvm_valid_regs' field.
+If the dirty bit is not set, then the register set values will not be copied
+into the vCPU even if they've been modified.
+
+Unused bitfields in the bitarrays must be set to zero.
+
+::
+
+ struct kvm_sync_regs {
+ struct kvm_regs regs;
+ struct kvm_sregs sregs;
+ struct kvm_vcpu_events events;
+ };
+
+6.75 KVM_CAP_PPC_IRQ_XIVE
+-------------------------
+
+:Architectures: ppc
+:Target: vcpu
+:Parameters: args[0] is the XIVE device fd;
+ args[1] is the XIVE CPU number (server ID) for this vcpu
+
+This capability connects the vcpu to an in-kernel XIVE device.
+
+7. Capabilities that can be enabled on VMs
+==========================================
+
+There are certain capabilities that change the behavior of the virtual
+machine when enabled. To enable them, please see section 4.37. Below
+you can find a list of capabilities and what their effect on the VM
+is when enabling them.
+
+The following information is provided along with the description:
+
+ Architectures:
+ which instruction set architectures provide this ioctl.
+ x86 includes both i386 and x86_64.
+
+ Parameters:
+ what parameters are accepted by the capability.
+
+ Returns:
+ the return value. General error numbers (EBADF, ENOMEM, EINVAL)
+ are not detailed, but errors with specific meanings are.
+
+
+7.1 KVM_CAP_PPC_ENABLE_HCALL
+----------------------------
+
+:Architectures: ppc
+:Parameters: args[0] is the sPAPR hcall number;
+ args[1] is 0 to disable, 1 to enable in-kernel handling
+
+This capability controls whether individual sPAPR hypercalls (hcalls)
+get handled by the kernel or not. Enabling or disabling in-kernel
+handling of an hcall is effective across the VM. On creation, an
+initial set of hcalls are enabled for in-kernel handling, which
+consists of those hcalls for which in-kernel handlers were implemented
+before this capability was implemented. If disabled, the kernel will
+not to attempt to handle the hcall, but will always exit to userspace
+to handle it. Note that it may not make sense to enable some and
+disable others of a group of related hcalls, but KVM does not prevent
+userspace from doing that.
+
+If the hcall number specified is not one that has an in-kernel
+implementation, the KVM_ENABLE_CAP ioctl will fail with an EINVAL
+error.
+
+7.2 KVM_CAP_S390_USER_SIGP
+--------------------------
+
+:Architectures: s390
+:Parameters: none
+
+This capability controls which SIGP orders will be handled completely in user
+space. With this capability enabled, all fast orders will be handled completely
+in the kernel:
+
+- SENSE
+- SENSE RUNNING
+- EXTERNAL CALL
+- EMERGENCY SIGNAL
+- CONDITIONAL EMERGENCY SIGNAL
+
+All other orders will be handled completely in user space.
+
+Only privileged operation exceptions will be checked for in the kernel (or even
+in the hardware prior to interception). If this capability is not enabled, the
+old way of handling SIGP orders is used (partially in kernel and user space).
+
+7.3 KVM_CAP_S390_VECTOR_REGISTERS
+---------------------------------
+
+:Architectures: s390
+:Parameters: none
+:Returns: 0 on success, negative value on error
+
+Allows use of the vector registers introduced with z13 processor, and
+provides for the synchronization between host and user space. Will
+return -EINVAL if the machine does not support vectors.
+
+7.4 KVM_CAP_S390_USER_STSI
+--------------------------
+
+:Architectures: s390
+:Parameters: none
+
+This capability allows post-handlers for the STSI instruction. After
+initial handling in the kernel, KVM exits to user space with
+KVM_EXIT_S390_STSI to allow user space to insert further data.
+
+Before exiting to userspace, kvm handlers should fill in s390_stsi field of
+vcpu->run::
+
+ struct {
+ __u64 addr;
+ __u8 ar;
+ __u8 reserved;
+ __u8 fc;
+ __u8 sel1;
+ __u16 sel2;
+ } s390_stsi;
+
+ @addr - guest address of STSI SYSIB
+ @fc - function code
+ @sel1 - selector 1
+ @sel2 - selector 2
+ @ar - access register number
+
+KVM handlers should exit to userspace with rc = -EREMOTE.
+
+7.5 KVM_CAP_SPLIT_IRQCHIP
+-------------------------
+
+:Architectures: x86
+:Parameters: args[0] - number of routes reserved for userspace IOAPICs
+:Returns: 0 on success, -1 on error
+
+Create a local apic for each processor in the kernel. This can be used
+instead of KVM_CREATE_IRQCHIP if the userspace VMM wishes to emulate the
+IOAPIC and PIC (and also the PIT, even though this has to be enabled
+separately).
+
+This capability also enables in kernel routing of interrupt requests;
+when KVM_CAP_SPLIT_IRQCHIP only routes of KVM_IRQ_ROUTING_MSI type are
+used in the IRQ routing table. The first args[0] MSI routes are reserved
+for the IOAPIC pins. Whenever the LAPIC receives an EOI for these routes,
+a KVM_EXIT_IOAPIC_EOI vmexit will be reported to userspace.
+
+Fails if VCPU has already been created, or if the irqchip is already in the
+kernel (i.e. KVM_CREATE_IRQCHIP has already been called).
+
+7.6 KVM_CAP_S390_RI
+-------------------
+
+:Architectures: s390
+:Parameters: none
+
+Allows use of runtime-instrumentation introduced with zEC12 processor.
+Will return -EINVAL if the machine does not support runtime-instrumentation.
+Will return -EBUSY if a VCPU has already been created.
+
+7.7 KVM_CAP_X2APIC_API
+----------------------
+
+:Architectures: x86
+:Parameters: args[0] - features that should be enabled
+:Returns: 0 on success, -EINVAL when args[0] contains invalid features
+
+Valid feature flags in args[0] are::
+
+ #define KVM_X2APIC_API_USE_32BIT_IDS (1ULL << 0)
+ #define KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK (1ULL << 1)
+
+Enabling KVM_X2APIC_API_USE_32BIT_IDS changes the behavior of
+KVM_SET_GSI_ROUTING, KVM_SIGNAL_MSI, KVM_SET_LAPIC, and KVM_GET_LAPIC,
+allowing the use of 32-bit APIC IDs. See KVM_CAP_X2APIC_API in their
+respective sections.
+
+KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK must be enabled for x2APIC to work
+in logical mode or with more than 255 VCPUs. Otherwise, KVM treats 0xff
+as a broadcast even in x2APIC mode in order to support physical x2APIC
+without interrupt remapping. This is undesirable in logical mode,
+where 0xff represents CPUs 0-7 in cluster 0.
+
+7.8 KVM_CAP_S390_USER_INSTR0
+----------------------------
+
+:Architectures: s390
+:Parameters: none
+
+With this capability enabled, all illegal instructions 0x0000 (2 bytes) will
+be intercepted and forwarded to user space. User space can use this
+mechanism e.g. to realize 2-byte software breakpoints. The kernel will
+not inject an operating exception for these instructions, user space has
+to take care of that.
+
+This capability can be enabled dynamically even if VCPUs were already
+created and are running.
+
+7.9 KVM_CAP_S390_GS
+-------------------
+
+:Architectures: s390
+:Parameters: none
+:Returns: 0 on success; -EINVAL if the machine does not support
+ guarded storage; -EBUSY if a VCPU has already been created.
+
+Allows use of guarded storage for the KVM guest.
+
+7.10 KVM_CAP_S390_AIS
+---------------------
+
+:Architectures: s390
+:Parameters: none
+
+Allow use of adapter-interruption suppression.
+:Returns: 0 on success; -EBUSY if a VCPU has already been created.
+
+7.11 KVM_CAP_PPC_SMT
+--------------------
+
+:Architectures: ppc
+:Parameters: vsmt_mode, flags
+
+Enabling this capability on a VM provides userspace with a way to set
+the desired virtual SMT mode (i.e. the number of virtual CPUs per
+virtual core). The virtual SMT mode, vsmt_mode, must be a power of 2
+between 1 and 8. On POWER8, vsmt_mode must also be no greater than
+the number of threads per subcore for the host. Currently flags must
+be 0. A successful call to enable this capability will result in
+vsmt_mode being returned when the KVM_CAP_PPC_SMT capability is
+subsequently queried for the VM. This capability is only supported by
+HV KVM, and can only be set before any VCPUs have been created.
+The KVM_CAP_PPC_SMT_POSSIBLE capability indicates which virtual SMT
+modes are available.
+
+7.12 KVM_CAP_PPC_FWNMI
+----------------------
+
+:Architectures: ppc
+:Parameters: none
+
+With this capability a machine check exception in the guest address
+space will cause KVM to exit the guest with NMI exit reason. This
+enables QEMU to build error log and branch to guest kernel registered
+machine check handling routine. Without this capability KVM will
+branch to guests' 0x200 interrupt vector.
+
+7.13 KVM_CAP_X86_DISABLE_EXITS
+------------------------------
+
+:Architectures: x86
+:Parameters: args[0] defines which exits are disabled
+:Returns: 0 on success, -EINVAL when args[0] contains invalid exits
+
+Valid bits in args[0] are::
+
+ #define KVM_X86_DISABLE_EXITS_MWAIT (1 << 0)
+ #define KVM_X86_DISABLE_EXITS_HLT (1 << 1)
+ #define KVM_X86_DISABLE_EXITS_PAUSE (1 << 2)
+ #define KVM_X86_DISABLE_EXITS_CSTATE (1 << 3)
+
+Enabling this capability on a VM provides userspace with a way to no
+longer intercept some instructions for improved latency in some
+workloads, and is suggested when vCPUs are associated to dedicated
+physical CPUs. More bits can be added in the future; userspace can
+just pass the KVM_CHECK_EXTENSION result to KVM_ENABLE_CAP to disable
+all such vmexits.
+
+Do not enable KVM_FEATURE_PV_UNHALT if you disable HLT exits.
+
+7.14 KVM_CAP_S390_HPAGE_1M
+--------------------------
+
+:Architectures: s390
+:Parameters: none
+:Returns: 0 on success, -EINVAL if hpage module parameter was not set
+ or cmma is enabled, or the VM has the KVM_VM_S390_UCONTROL
+ flag set
+
+With this capability the KVM support for memory backing with 1m pages
+through hugetlbfs can be enabled for a VM. After the capability is
+enabled, cmma can't be enabled anymore and pfmfi and the storage key
+interpretation are disabled. If cmma has already been enabled or the
+hpage module parameter is not set to 1, -EINVAL is returned.
+
+While it is generally possible to create a huge page backed VM without
+this capability, the VM will not be able to run.
+
+7.15 KVM_CAP_MSR_PLATFORM_INFO
+------------------------------
+
+:Architectures: x86
+:Parameters: args[0] whether feature should be enabled or not
+
+With this capability, a guest may read the MSR_PLATFORM_INFO MSR. Otherwise,
+a #GP would be raised when the guest tries to access. Currently, this
+capability does not enable write permissions of this MSR for the guest.
+
+7.16 KVM_CAP_PPC_NESTED_HV
+--------------------------
+
+:Architectures: ppc
+:Parameters: none
+:Returns: 0 on success, -EINVAL when the implementation doesn't support
+ nested-HV virtualization.
+
+HV-KVM on POWER9 and later systems allows for "nested-HV"
+virtualization, which provides a way for a guest VM to run guests that
+can run using the CPU's supervisor mode (privileged non-hypervisor
+state). Enabling this capability on a VM depends on the CPU having
+the necessary functionality and on the facility being enabled with a
+kvm-hv module parameter.
+
+7.17 KVM_CAP_EXCEPTION_PAYLOAD
+------------------------------
+
+:Architectures: x86
+:Parameters: args[0] whether feature should be enabled or not
+
+With this capability enabled, CR2 will not be modified prior to the
+emulated VM-exit when L1 intercepts a #PF exception that occurs in
+L2. Similarly, for kvm-intel only, DR6 will not be modified prior to
+the emulated VM-exit when L1 intercepts a #DB exception that occurs in
+L2. As a result, when KVM_GET_VCPU_EVENTS reports a pending #PF (or
+#DB) exception for L2, exception.has_payload will be set and the
+faulting address (or the new DR6 bits*) will be reported in the
+exception_payload field. Similarly, when userspace injects a #PF (or
+#DB) into L2 using KVM_SET_VCPU_EVENTS, it is expected to set
+exception.has_payload and to put the faulting address - or the new DR6
+bits\ [#]_ - in the exception_payload field.
+
+This capability also enables exception.pending in struct
+kvm_vcpu_events, which allows userspace to distinguish between pending
+and injected exceptions.
+
+
+.. [#] For the new DR6 bits, note that bit 16 is set iff the #DB exception
+ will clear DR6.RTM.
+
+7.18 KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2
+
+:Architectures: x86, arm, arm64, mips
+:Parameters: args[0] whether feature should be enabled or not
+
+Valid flags are::
+
+ #define KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE (1 << 0)
+ #define KVM_DIRTY_LOG_INITIALLY_SET (1 << 1)
+
+With KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE is set, KVM_GET_DIRTY_LOG will not
+automatically clear and write-protect all pages that are returned as dirty.
+Rather, userspace will have to do this operation separately using
+KVM_CLEAR_DIRTY_LOG.
+
+At the cost of a slightly more complicated operation, this provides better
+scalability and responsiveness for two reasons. First,
+KVM_CLEAR_DIRTY_LOG ioctl can operate on a 64-page granularity rather
+than requiring to sync a full memslot; this ensures that KVM does not
+take spinlocks for an extended period of time. Second, in some cases a
+large amount of time can pass between a call to KVM_GET_DIRTY_LOG and
+userspace actually using the data in the page. Pages can be modified
+during this time, which is inefficient for both the guest and userspace:
+the guest will incur a higher penalty due to write protection faults,
+while userspace can see false reports of dirty pages. Manual reprotection
+helps reducing this time, improving guest performance and reducing the
+number of dirty log false positives.
+
+With KVM_DIRTY_LOG_INITIALLY_SET set, all the bits of the dirty bitmap
+will be initialized to 1 when created. This also improves performance because
+dirty logging can be enabled gradually in small chunks on the first call
+to KVM_CLEAR_DIRTY_LOG. KVM_DIRTY_LOG_INITIALLY_SET depends on
+KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE (it is also only available on
+x86 and arm64 for now).
+
+KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 was previously available under the name
+KVM_CAP_MANUAL_DIRTY_LOG_PROTECT, but the implementation had bugs that make
+it hard or impossible to use it correctly. The availability of
+KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 signals that those bugs are fixed.
+Userspace should not try to use KVM_CAP_MANUAL_DIRTY_LOG_PROTECT.
+
+7.19 KVM_CAP_PPC_SECURE_GUEST
+------------------------------
+
+:Architectures: ppc
+
+This capability indicates that KVM is running on a host that has
+ultravisor firmware and thus can support a secure guest. On such a
+system, a guest can ask the ultravisor to make it a secure guest,
+one whose memory is inaccessible to the host except for pages which
+are explicitly requested to be shared with the host. The ultravisor
+notifies KVM when a guest requests to become a secure guest, and KVM
+has the opportunity to veto the transition.
+
+If present, this capability can be enabled for a VM, meaning that KVM
+will allow the transition to secure guest mode. Otherwise KVM will
+veto the transition.
+
+7.20 KVM_CAP_HALT_POLL
+----------------------
+
+:Architectures: all
+:Target: VM
+:Parameters: args[0] is the maximum poll time in nanoseconds
+:Returns: 0 on success; -1 on error
+
+This capability overrides the kvm module parameter halt_poll_ns for the
+target VM.
+
+VCPU polling allows a VCPU to poll for wakeup events instead of immediately
+scheduling during guest halts. The maximum time a VCPU can spend polling is
+controlled by the kvm module parameter halt_poll_ns. This capability allows
+the maximum halt time to specified on a per-VM basis, effectively overriding
+the module parameter for the target VM.
+
+7.21 KVM_CAP_X86_USER_SPACE_MSR
+-------------------------------
+
+:Architectures: x86
+:Target: VM
+:Parameters: args[0] contains the mask of KVM_MSR_EXIT_REASON_* events to report
+:Returns: 0 on success; -1 on error
+
+This capability enables trapping of #GP invoking RDMSR and WRMSR instructions
+into user space.
+
+When a guest requests to read or write an MSR, KVM may not implement all MSRs
+that are relevant to a respective system. It also does not differentiate by
+CPU type.
+
+To allow more fine grained control over MSR handling, user space may enable
+this capability. With it enabled, MSR accesses that match the mask specified in
+args[0] and trigger a #GP event inside the guest by KVM will instead trigger
+KVM_EXIT_X86_RDMSR and KVM_EXIT_X86_WRMSR exit notifications which user space
+can then handle to implement model specific MSR handling and/or user notifications
+to inform a user that an MSR was not handled.
+
+8. Other capabilities.
+======================
+
+This section lists capabilities that give information about other
+features of the KVM implementation.
+
+8.1 KVM_CAP_PPC_HWRNG
+---------------------
+
+:Architectures: ppc
+
+This capability, if KVM_CHECK_EXTENSION indicates that it is
+available, means that the kernel has an implementation of the
+H_RANDOM hypercall backed by a hardware random-number generator.
+If present, the kernel H_RANDOM handler can be enabled for guest use
+with the KVM_CAP_PPC_ENABLE_HCALL capability.
+
+8.2 KVM_CAP_HYPERV_SYNIC
+------------------------
+
+:Architectures: x86
+
+This capability, if KVM_CHECK_EXTENSION indicates that it is
+available, means that the kernel has an implementation of the
+Hyper-V Synthetic interrupt controller(SynIC). Hyper-V SynIC is
+used to support Windows Hyper-V based guest paravirt drivers(VMBus).
+
+In order to use SynIC, it has to be activated by setting this
+capability via KVM_ENABLE_CAP ioctl on the vcpu fd. Note that this
+will disable the use of APIC hardware virtualization even if supported
+by the CPU, as it's incompatible with SynIC auto-EOI behavior.
+
+8.3 KVM_CAP_PPC_RADIX_MMU
+-------------------------
+
+:Architectures: ppc
+
+This capability, if KVM_CHECK_EXTENSION indicates that it is
+available, means that the kernel can support guests using the
+radix MMU defined in Power ISA V3.00 (as implemented in the POWER9
+processor).
+
+8.4 KVM_CAP_PPC_HASH_MMU_V3
+---------------------------
+
+:Architectures: ppc
+
+This capability, if KVM_CHECK_EXTENSION indicates that it is
+available, means that the kernel can support guests using the
+hashed page table MMU defined in Power ISA V3.00 (as implemented in
+the POWER9 processor), including in-memory segment tables.
+
+8.5 KVM_CAP_MIPS_VZ
+-------------------
+
+:Architectures: mips
+
+This capability, if KVM_CHECK_EXTENSION on the main kvm handle indicates that
+it is available, means that full hardware assisted virtualization capabilities
+of the hardware are available for use through KVM. An appropriate
+KVM_VM_MIPS_* type must be passed to KVM_CREATE_VM to create a VM which
+utilises it.
+
+If KVM_CHECK_EXTENSION on a kvm VM handle indicates that this capability is
+available, it means that the VM is using full hardware assisted virtualization
+capabilities of the hardware. This is useful to check after creating a VM with
+KVM_VM_MIPS_DEFAULT.
+
+The value returned by KVM_CHECK_EXTENSION should be compared against known
+values (see below). All other values are reserved. This is to allow for the
+possibility of other hardware assisted virtualization implementations which
+may be incompatible with the MIPS VZ ASE.
+
+== ==========================================================================
+ 0 The trap & emulate implementation is in use to run guest code in user
+ mode. Guest virtual memory segments are rearranged to fit the guest in the
+ user mode address space.
+
+ 1 The MIPS VZ ASE is in use, providing full hardware assisted
+ virtualization, including standard guest virtual memory segments.
+== ==========================================================================
+
+8.6 KVM_CAP_MIPS_TE
+-------------------
+
+:Architectures: mips
+
+This capability, if KVM_CHECK_EXTENSION on the main kvm handle indicates that
+it is available, means that the trap & emulate implementation is available to
+run guest code in user mode, even if KVM_CAP_MIPS_VZ indicates that hardware
+assisted virtualisation is also available. KVM_VM_MIPS_TE (0) must be passed
+to KVM_CREATE_VM to create a VM which utilises it.
+
+If KVM_CHECK_EXTENSION on a kvm VM handle indicates that this capability is
+available, it means that the VM is using trap & emulate.
+
+8.7 KVM_CAP_MIPS_64BIT
+----------------------
+
+:Architectures: mips
+
+This capability indicates the supported architecture type of the guest, i.e. the
+supported register and address width.
+
+The values returned when this capability is checked by KVM_CHECK_EXTENSION on a
+kvm VM handle correspond roughly to the CP0_Config.AT register field, and should
+be checked specifically against known values (see below). All other values are
+reserved.
+
+== ========================================================================
+ 0 MIPS32 or microMIPS32.
+ Both registers and addresses are 32-bits wide.
+ It will only be possible to run 32-bit guest code.
+
+ 1 MIPS64 or microMIPS64 with access only to 32-bit compatibility segments.
+ Registers are 64-bits wide, but addresses are 32-bits wide.
+ 64-bit guest code may run but cannot access MIPS64 memory segments.
+ It will also be possible to run 32-bit guest code.
+
+ 2 MIPS64 or microMIPS64 with access to all address segments.
+ Both registers and addresses are 64-bits wide.
+ It will be possible to run 64-bit or 32-bit guest code.
+== ========================================================================
+
+8.9 KVM_CAP_ARM_USER_IRQ
+------------------------
+
+:Architectures: arm, arm64
+
+This capability, if KVM_CHECK_EXTENSION indicates that it is available, means
+that if userspace creates a VM without an in-kernel interrupt controller, it
+will be notified of changes to the output level of in-kernel emulated devices,
+which can generate virtual interrupts, presented to the VM.
+For such VMs, on every return to userspace, the kernel
+updates the vcpu's run->s.regs.device_irq_level field to represent the actual
+output level of the device.
+
+Whenever kvm detects a change in the device output level, kvm guarantees at
+least one return to userspace before running the VM. This exit could either
+be a KVM_EXIT_INTR or any other exit event, like KVM_EXIT_MMIO. This way,
+userspace can always sample the device output level and re-compute the state of
+the userspace interrupt controller. Userspace should always check the state
+of run->s.regs.device_irq_level on every kvm exit.
+The value in run->s.regs.device_irq_level can represent both level and edge
+triggered interrupt signals, depending on the device. Edge triggered interrupt
+signals will exit to userspace with the bit in run->s.regs.device_irq_level
+set exactly once per edge signal.
+
+The field run->s.regs.device_irq_level is available independent of
+run->kvm_valid_regs or run->kvm_dirty_regs bits.
+
+If KVM_CAP_ARM_USER_IRQ is supported, the KVM_CHECK_EXTENSION ioctl returns a
+number larger than 0 indicating the version of this capability is implemented
+and thereby which bits in run->s.regs.device_irq_level can signal values.
+
+Currently the following bits are defined for the device_irq_level bitmap::
+
+ KVM_CAP_ARM_USER_IRQ >= 1:
+
+ KVM_ARM_DEV_EL1_VTIMER - EL1 virtual timer
+ KVM_ARM_DEV_EL1_PTIMER - EL1 physical timer
+ KVM_ARM_DEV_PMU - ARM PMU overflow interrupt signal
+
+Future versions of kvm may implement additional events. These will get
+indicated by returning a higher number from KVM_CHECK_EXTENSION and will be
+listed above.
+
+8.10 KVM_CAP_PPC_SMT_POSSIBLE
+-----------------------------
+
+:Architectures: ppc
+
+Querying this capability returns a bitmap indicating the possible
+virtual SMT modes that can be set using KVM_CAP_PPC_SMT. If bit N
+(counting from the right) is set, then a virtual SMT mode of 2^N is
+available.
+
+8.11 KVM_CAP_HYPERV_SYNIC2
+--------------------------
+
+:Architectures: x86
+
+This capability enables a newer version of Hyper-V Synthetic interrupt
+controller (SynIC). The only difference with KVM_CAP_HYPERV_SYNIC is that KVM
+doesn't clear SynIC message and event flags pages when they are enabled by
+writing to the respective MSRs.
+
+8.12 KVM_CAP_HYPERV_VP_INDEX
+----------------------------
+
+:Architectures: x86
+
+This capability indicates that userspace can load HV_X64_MSR_VP_INDEX msr. Its
+value is used to denote the target vcpu for a SynIC interrupt. For
+compatibilty, KVM initializes this msr to KVM's internal vcpu index. When this
+capability is absent, userspace can still query this msr's value.
+
+8.13 KVM_CAP_S390_AIS_MIGRATION
+-------------------------------
+
+:Architectures: s390
+:Parameters: none
+
+This capability indicates if the flic device will be able to get/set the
+AIS states for migration via the KVM_DEV_FLIC_AISM_ALL attribute and allows
+to discover this without having to create a flic device.
+
+8.14 KVM_CAP_S390_PSW
+---------------------
+
+:Architectures: s390
+
+This capability indicates that the PSW is exposed via the kvm_run structure.
+
+8.15 KVM_CAP_S390_GMAP
+----------------------
+
+:Architectures: s390
+
+This capability indicates that the user space memory used as guest mapping can
+be anywhere in the user memory address space, as long as the memory slots are
+aligned and sized to a segment (1MB) boundary.
+
+8.16 KVM_CAP_S390_COW
+---------------------
+
+:Architectures: s390
+
+This capability indicates that the user space memory used as guest mapping can
+use copy-on-write semantics as well as dirty pages tracking via read-only page
+tables.
+
+8.17 KVM_CAP_S390_BPB
+---------------------
+
+:Architectures: s390
+
+This capability indicates that kvm will implement the interfaces to handle
+reset, migration and nested KVM for branch prediction blocking. The stfle
+facility 82 should not be provided to the guest without this capability.
+
+8.18 KVM_CAP_HYPERV_TLBFLUSH
+----------------------------
+
+:Architectures: x86
+
+This capability indicates that KVM supports paravirtualized Hyper-V TLB Flush
+hypercalls:
+HvFlushVirtualAddressSpace, HvFlushVirtualAddressSpaceEx,
+HvFlushVirtualAddressList, HvFlushVirtualAddressListEx.
+
+8.19 KVM_CAP_ARM_INJECT_SERROR_ESR
+----------------------------------
+
+:Architectures: arm, arm64
+
+This capability indicates that userspace can specify (via the
+KVM_SET_VCPU_EVENTS ioctl) the syndrome value reported to the guest when it
+takes a virtual SError interrupt exception.
+If KVM advertises this capability, userspace can only specify the ISS field for
+the ESR syndrome. Other parts of the ESR, such as the EC are generated by the
+CPU when the exception is taken. If this virtual SError is taken to EL1 using
+AArch64, this value will be reported in the ISS field of ESR_ELx.
+
+See KVM_CAP_VCPU_EVENTS for more details.
+
+8.20 KVM_CAP_HYPERV_SEND_IPI
+----------------------------
+
+:Architectures: x86
+
+This capability indicates that KVM supports paravirtualized Hyper-V IPI send
+hypercalls:
+HvCallSendSyntheticClusterIpi, HvCallSendSyntheticClusterIpiEx.
+
+8.21 KVM_CAP_HYPERV_DIRECT_TLBFLUSH
+-----------------------------------
+
+:Architectures: x86
+
+This capability indicates that KVM running on top of Hyper-V hypervisor
+enables Direct TLB flush for its guests meaning that TLB flush
+hypercalls are handled by Level 0 hypervisor (Hyper-V) bypassing KVM.
+Due to the different ABI for hypercall parameters between Hyper-V and
+KVM, enabling this capability effectively disables all hypercall
+handling by KVM (as some KVM hypercall may be mistakenly treated as TLB
+flush hypercalls by Hyper-V) so userspace should disable KVM identification
+in CPUID and only exposes Hyper-V identification. In this case, guest
+thinks it's running on Hyper-V and only use Hyper-V hypercalls.
+
+8.22 KVM_CAP_S390_VCPU_RESETS
+-----------------------------
+
+:Architectures: s390
+
+This capability indicates that the KVM_S390_NORMAL_RESET and
+KVM_S390_CLEAR_RESET ioctls are available.
+
+8.23 KVM_CAP_S390_PROTECTED
+---------------------------
+
+:Architectures: s390
+
+This capability indicates that the Ultravisor has been initialized and
+KVM can therefore start protected VMs.
+This capability governs the KVM_S390_PV_COMMAND ioctl and the
+KVM_MP_STATE_LOAD MP_STATE. KVM_SET_MP_STATE can fail for protected
+guests when the state change is invalid.
+
+8.24 KVM_CAP_STEAL_TIME
+-----------------------
+
+:Architectures: arm64, x86
+
+This capability indicates that KVM supports steal time accounting.
+When steal time accounting is supported it may be enabled with
+architecture-specific interfaces. This capability and the architecture-
+specific interfaces must be consistent, i.e. if one says the feature
+is supported, than the other should as well and vice versa. For arm64
+see Documentation/virt/kvm/devices/vcpu.rst "KVM_ARM_VCPU_PVTIME_CTRL".
+For x86 see Documentation/virt/kvm/msr.rst "MSR_KVM_STEAL_TIME".
+
+8.25 KVM_CAP_S390_DIAG318
+-------------------------
+
+:Architectures: s390
+
+This capability enables a guest to set information about its control program
+(i.e. guest kernel type and version). The information is helpful during
+system/firmware service events, providing additional data about the guest
+environments running on the machine.
+
+The information is associated with the DIAGNOSE 0x318 instruction, which sets
+an 8-byte value consisting of a one-byte Control Program Name Code (CPNC) and
+a 7-byte Control Program Version Code (CPVC). The CPNC determines what
+environment the control program is running in (e.g. Linux, z/VM...), and the
+CPVC is used for information specific to OS (e.g. Linux version, Linux
+distribution...)
+
+If this capability is available, then the CPNC and CPVC can be synchronized
+between KVM and userspace via the sync regs mechanism (KVM_SYNC_DIAG318).
+
+8.26 KVM_CAP_X86_USER_SPACE_MSR
+-------------------------------
+
+:Architectures: x86
+
+This capability indicates that KVM supports deflection of MSR reads and
+writes to user space. It can be enabled on a VM level. If enabled, MSR
+accesses that would usually trigger a #GP by KVM into the guest will
+instead get bounced to user space through the KVM_EXIT_X86_RDMSR and
+KVM_EXIT_X86_WRMSR exit notifications.
+
+8.27 KVM_X86_SET_MSR_FILTER
+---------------------------
+
+:Architectures: x86
+
+This capability indicates that KVM supports that accesses to user defined MSRs
+may be rejected. With this capability exposed, KVM exports new VM ioctl
+KVM_X86_SET_MSR_FILTER which user space can call to specify bitmaps of MSR
+ranges that KVM should reject access to.
+
+In combination with KVM_CAP_X86_USER_SPACE_MSR, this allows user space to
+trap and emulate MSRs that are outside of the scope of KVM as well as
+limit the attack surface on KVM's MSR emulation code.
+
+8.28 KVM_CAP_ENFORCE_PV_CPUID
+-----------------------------
+
+Architectures: x86
+
+When enabled, KVM will disable paravirtual features provided to the
+guest according to the bits in the KVM_CPUID_FEATURES CPUID leaf
+(0x40000001). Otherwise, a guest may use the paravirtual features
+regardless of what has actually been exposed through the CPUID leaf.
+
+9. Known KVM API problems
+=========================
+
+In some cases, KVM's API has some inconsistencies or common pitfalls
+that userspace need to be aware of. This section details some of
+these issues.
+
+Most of them are architecture specific, so the section is split by
+architecture.
+
+9.1. x86
+--------
+
+``KVM_GET_SUPPORTED_CPUID`` issues
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+In general, ``KVM_GET_SUPPORTED_CPUID`` is designed so that it is possible
+to take its result and pass it directly to ``KVM_SET_CPUID2``. This section
+documents some cases in which that requires some care.
+
+Local APIC features
+~~~~~~~~~~~~~~~~~~~
+
+CPU[EAX=1]:ECX[21] (X2APIC) is reported by ``KVM_GET_SUPPORTED_CPUID``,
+but it can only be enabled if ``KVM_CREATE_IRQCHIP`` or
+``KVM_ENABLE_CAP(KVM_CAP_IRQCHIP_SPLIT)`` are used to enable in-kernel emulation of
+the local APIC.
+
+The same is true for the ``KVM_FEATURE_PV_UNHALT`` paravirtualized feature.
+
+CPU[EAX=1]:ECX[24] (TSC_DEADLINE) is not reported by ``KVM_GET_SUPPORTED_CPUID``.
+It can be enabled if ``KVM_CAP_TSC_DEADLINE_TIMER`` is present and the kernel
+has enabled in-kernel emulation of the local APIC.
+
+CPU topology
+~~~~~~~~~~~~
+
+Several CPUID values include topology information for the host CPU:
+0x0b and 0x1f for Intel systems, 0x8000001e for AMD systems. Different
+versions of KVM return different values for this information and userspace
+should not rely on it. Currently they return all zeroes.
+
+If userspace wishes to set up a guest topology, it should be careful that
+the values of these three leaves differ for each CPU. In particular,
+the APIC ID is found in EDX for all subleaves of 0x0b and 0x1f, and in EAX
+for 0x8000001e; the latter also encodes the core id and node id in bits
+7:0 of EBX and ECX respectively.
+
+Obsolete ioctls and capabilities
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+KVM_CAP_DISABLE_QUIRKS does not let userspace know which quirks are actually
+available. Use ``KVM_CHECK_EXTENSION(KVM_CAP_DISABLE_QUIRKS2)`` instead if
+available.
+
+Ordering of KVM_GET_*/KVM_SET_* ioctls
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+TBD