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+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 three 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).
+
+   Only run VM ioctls 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.
+
+   Only run vcpu ioctls from the same thread that was used to create the
+   vcpu.
+
+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 ioctl on a VM fd will create a virtual cpu
+and return a file descriptor pointing to it.  Finally, ioctls on a vcpu
+fd can be used to control the vcpu, including 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.  The only supported use is one virtual machine per process,
+and one vcpu per thread.
+
+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 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), or a KVM_CAP_xyz constant, which
+      means availability needs to be checked with KVM_CHECK_EXTENSION
+      (see section 4.4).
+
+  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: none
+Returns: a VM fd that can be used to control the new virtual machine.
+
+The new VM has no virtual cpus and no memory.  An mmap() of a VM fd
+will access the virtual machine's physical address space; offset zero
+corresponds to guest physical address zero.  Use of mmap() on a VM fd
+is discouraged if userspace memory allocation (KVM_CAP_USER_MEMORY) is
+available.
+
+4.3 KVM_GET_MSR_INDEX_LIST
+
+Capability: basic
+Architectures: x86
+Type: system
+Parameters: struct kvm_msr_list (in/out)
+Returns: 0 on success; -1 on error
+Errors:
+  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];
+};
+
+This ioctl returns the guest msrs that are supported.  The list varies
+by kvm version and host processor, but does not change otherwise.  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.
+
+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.
+
+4.4 KVM_CHECK_EXTENSION
+
+Capability: basic
+Architectures: all
+Type: system 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.
+
+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.  The vcpu id is a small integer
+in the range [0, max_vcpus).  You can use KVM_CAP_NR_VCPUS of the
+KVM_CHECK_EXTENSION ioctl() to determine the value for max_vcpus at run-time.
+If the KVM_CAP_NR_VCPUS does not exist, you should assume that max_vcpus is 4
+cpus max.
+
+4.8 KVM_GET_DIRTY_LOG (vm ioctl)
+
+Capability: basic
+Architectures: x86
+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.
+
+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
+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;
+};
+
+4.12 KVM_SET_REGS
+
+Capability: basic
+Architectures: all
+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/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
+Type: vcpu ioctl
+Parameters: struct kvm_interrupt (in)
+Returns: 0 on success, -1 on error
+
+Queues a hardware interrupt vector to be injected.  This is only
+useful if in-kernel local APIC or equivalent is not used.
+
+/* for KVM_INTERRUPT */
+struct kvm_interrupt {
+        /* in */
+        __u32 irq;
+};
+
+X86:
+
+Note 'irq' is an interrupt vector, not an interrupt pin or line.
+
+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.
+
+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
+Architectures: x86
+Type: vcpu ioctl
+Parameters: struct kvm_msrs (in/out)
+Returns: 0 on success, -1 on error
+
+Reads model-specific registers from the vcpu.  Supported msr indices can
+be obtained using KVM_GET_MSR_INDEX_LIST.
+
+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: 0 on success, -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.
+
+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.
+
+
+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: x86
+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
+Architectures: x86, ia64
+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 ia64, a IOSAPIC is created.
+
+4.25 KVM_IRQ_LINE
+
+Capability: KVM_CAP_IRQCHIP
+Architectures: x86, ia64
+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.
+Requires 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.
+
+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, ia64
+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, ia64
+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.
+
+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
+Type: vm ioctl
+Parameters: struct kvm_vcpu_event (out)
+Returns: 0 on success, -1 on error
+
+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 pad;
+                __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;
+};
+
+KVM_VCPUEVENT_VALID_SHADOW may be set in the flags field to signal that
+interrupt.shadow contains a valid state. Otherwise, this field is undefined.
+
+4.32 KVM_SET_VCPU_EVENTS
+
+Capability: KVM_CAP_VCPU_EVENTS
+Extended by: KVM_CAP_INTR_SHADOW
+Architectures: x86
+Type: vm ioctl
+Parameters: struct kvm_vcpu_event (in)
+Returns: 0 on success, -1 on error
+
+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 and sipi_vector. 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
+
+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.
+
+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_MEM
+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
+
+This ioctl allows the user to create or modify a guest physical memory
+slot.  When changing an existing slot, it may be moved in the guest
+physical memory space, or its flags may be modified.  It may not be
+resized.  Slots may not overlap in guest physical address space.
+
+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.
+
+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 just one flag, KVM_MEM_LOG_DIRTY_PAGES, which
+instructs kvm to keep track of writes to memory within the slot.  See
+the KVM_GET_DIRTY_LOG ioctl.
+
+When the KVM_CAP_SYNC_MMU capability, 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: ppc
+Type: vcpu ioctl
+Parameters: struct kvm_enable_cap (in)
+Returns: 0 on success; -1 on error
+
++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];
+};
+
+4.38 KVM_GET_MP_STATE
+
+Capability: KVM_CAP_MP_STATE
+Architectures: x86, ia64
+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
+ - KVM_MP_STATE_UNINITIALIZED:   the vcpu is an application processor (AP)
+                                 which has not yet received an INIT signal
+ - KVM_MP_STATE_INIT_RECEIVED:   the vcpu has received an INIT signal, and is
+                                 now ready for a SIPI
+ - KVM_MP_STATE_HALTED:          the vcpu has executed a HLT instruction and
+                                 is waiting for an interrupt
+ - KVM_MP_STATE_SIPI_RECEIVED:   the vcpu has just received a SIPI (vector
+                                 accessible via KVM_GET_VCPU_EVENTS)
+
+This ioctl is only useful after KVM_CREATE_IRQCHIP.  Without an in-kernel
+irqchip, the multiprocessing state must be maintained by userspace.
+
+4.39 KVM_SET_MP_STATE
+
+Capability: KVM_CAP_MP_STATE
+Architectures: x86, ia64
+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.
+
+This ioctl is only useful after KVM_CREATE_IRQCHIP.  Without an in-kernel
+irqchip, the multiprocessing state must be maintained by userspace.
+
+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.
+
+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).
+
+4.41 KVM_SET_BOOT_CPU_ID
+
+Capability: KVM_CAP_SET_BOOT_CPU_ID
+Architectures: x86, ia64
+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 1
+#define KVM_CPUID_FLAG_STATEFUL_FUNC    2
+#define KVM_CPUID_FLAG_STATE_READ_NEXT  4
+
+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.  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).
+
+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
+        KVM_CPUID_FLAG_STATEFUL_FUNC:
+           if cpuid for this function returns different values for successive
+           invocations; there will be several entries with the same function,
+           all with this flag set
+        KVM_CPUID_FLAG_STATE_READ_NEXT:
+           for KVM_CPUID_FLAG_STATEFUL_FUNC entries, set if this entry is
+           the first entry to be read by a cpu
+   eax, ebx, ecx, edx: the values returned by the cpuid instruction for
+         this function/index combination
+
+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.
+
+For now the only implemented piece of information distributed here is an array
+of 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.
+
+4.48 KVM_ASSIGN_PCI_DEVICE
+
+Capability: KVM_CAP_DEVICE_ASSIGNMENT
+Architectures: x86 ia64
+Type: vm ioctl
+Parameters: struct kvm_assigned_pci_dev (in)
+Returns: 0 on success, -1 on error
+
+Assigns a host PCI device to the VM.
+
+struct kvm_assigned_pci_dev {
+        __u32 assigned_dev_id;
+        __u32 busnr;
+        __u32 devfn;
+        __u32 flags;
+        __u32 segnr;
+        union {
+                __u32 reserved[11];
+        };
+};
+
+The PCI device is specified by the triple segnr, busnr, and devfn.
+Identification in succeeding service requests is done via assigned_dev_id. The
+following flags are specified:
+
+/* Depends on KVM_CAP_IOMMU */
+#define KVM_DEV_ASSIGN_ENABLE_IOMMU     (1 << 0)
+
+4.49 KVM_DEASSIGN_PCI_DEVICE
+
+Capability: KVM_CAP_DEVICE_DEASSIGNMENT
+Architectures: x86 ia64
+Type: vm ioctl
+Parameters: struct kvm_assigned_pci_dev (in)
+Returns: 0 on success, -1 on error
+
+Ends PCI device assignment, releasing all associated resources.
+
+See KVM_CAP_DEVICE_ASSIGNMENT for the data structure. Only assigned_dev_id is
+used in kvm_assigned_pci_dev to identify the device.
+
+4.50 KVM_ASSIGN_DEV_IRQ
+
+Capability: KVM_CAP_ASSIGN_DEV_IRQ
+Architectures: x86 ia64
+Type: vm ioctl
+Parameters: struct kvm_assigned_irq (in)
+Returns: 0 on success, -1 on error
+
+Assigns an IRQ to a passed-through device.
+
+struct kvm_assigned_irq {
+        __u32 assigned_dev_id;
+        __u32 host_irq;
+        __u32 guest_irq;
+        __u32 flags;
+        union {
+                struct {
+                        __u32 addr_lo;
+                        __u32 addr_hi;
+                        __u32 data;
+                } guest_msi;
+                __u32 reserved[12];
+        };
+};
+
+The following flags are defined:
+
+#define KVM_DEV_IRQ_HOST_INTX    (1 << 0)
+#define KVM_DEV_IRQ_HOST_MSI     (1 << 1)
+#define KVM_DEV_IRQ_HOST_MSIX    (1 << 2)
+
+#define KVM_DEV_IRQ_GUEST_INTX   (1 << 8)
+#define KVM_DEV_IRQ_GUEST_MSI    (1 << 9)
+#define KVM_DEV_IRQ_GUEST_MSIX   (1 << 10)
+
+It is not valid to specify multiple types per host or guest IRQ. However, the
+IRQ type of host and guest can differ or can even be null.
+
+4.51 KVM_DEASSIGN_DEV_IRQ
+
+Capability: KVM_CAP_ASSIGN_DEV_IRQ
+Architectures: x86 ia64
+Type: vm ioctl
+Parameters: struct kvm_assigned_irq (in)
+Returns: 0 on success, -1 on error
+
+Ends an IRQ assignment to a passed-through device.
+
+See KVM_ASSIGN_DEV_IRQ for the data structure. The target device is specified
+by assigned_dev_id, flags must correspond to the IRQ type specified on
+KVM_ASSIGN_DEV_IRQ. Partial deassignment of host or guest IRQ is allowed.
+
+4.52 KVM_SET_GSI_ROUTING
+
+Capability: KVM_CAP_IRQ_ROUTING
+Architectures: x86 ia64
+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.
+
+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;
+                __u32 pad[8];
+        } u;
+};
+
+/* gsi routing entry types */
+#define KVM_IRQ_ROUTING_IRQCHIP 1
+#define KVM_IRQ_ROUTING_MSI 2
+
+No flags are specified so far, the corresponding field must be set to zero.
+
+struct kvm_irq_routing_irqchip {
+        __u32 irqchip;
+        __u32 pin;
+};
+
+struct kvm_irq_routing_msi {
+        __u32 address_lo;
+        __u32 address_hi;
+        __u32 data;
+        __u32 pad;
+};
+
+4.53 KVM_ASSIGN_SET_MSIX_NR
+
+Capability: KVM_CAP_DEVICE_MSIX
+Architectures: x86 ia64
+Type: vm ioctl
+Parameters: struct kvm_assigned_msix_nr (in)
+Returns: 0 on success, -1 on error
+
+Set the number of MSI-X interrupts for an assigned device. This service can
+only be called once in the lifetime of an assigned device.
+
+struct kvm_assigned_msix_nr {
+        __u32 assigned_dev_id;
+        __u16 entry_nr;
+        __u16 padding;
+};
+
+#define KVM_MAX_MSIX_PER_DEV            256
+
+4.54 KVM_ASSIGN_SET_MSIX_ENTRY
+
+Capability: KVM_CAP_DEVICE_MSIX
+Architectures: x86 ia64
+Type: vm ioctl
+Parameters: struct kvm_assigned_msix_entry (in)
+Returns: 0 on success, -1 on error
+
+Specifies the routing of an MSI-X assigned device interrupt to a GSI. Setting
+the GSI vector to zero means disabling the interrupt.
+
+struct kvm_assigned_msix_entry {
+        __u32 assigned_dev_id;
+        __u32 gsi;
+        __u16 entry; /* The index of entry in the MSI-X table */
+        __u16 padding[3];
+};
+
+4.54 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.
+
+4.55 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.
+
+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 padding1[7];
+
+        /* 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.
+
+        __u8 padding2[2];
+
+        /* 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;
+                } 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.
+
+                struct {
+                        struct kvm_debug_exit_arch arch;
+                } debug;
+
+Unused.
+
+                /* 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.
+
+NOTE: For KVM_EXIT_IO, KVM_EXIT_MMIO and KVM_EXIT_OSI, 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_DCR */
+                struct {
+                        __u32 dcrn;
+                        __u32 data;
+                        __u8  is_write;
+                } dcr;
+
+powerpc specific.
+
+                /* 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.
+
+                /* Fix the size of the union. */
+                char padding[256];
+        };
+};