| 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: 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. 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. |
| You most certainly 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). |
| |
| |
| 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). |
| |
| 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. |
| |
| 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: 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 except ARM |
| 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 except ARM |
| 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 |
| 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, ARM |
| 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. On ARM, a GIC is |
| created. |
| |
| |
| 4.25 KVM_IRQ_LINE |
| |
| Capability: KVM_CAP_IRQCHIP |
| Architectures: x86, ia64, arm |
| 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. |
| |
| ARM 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: |
| |
| Â bits: | 31 ... 24 | 23 ... 16 | 15 ... 0 | |
| field: | 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 raise/lower the line. |
| |
| 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 << 0) |
| #define KVM_MEM_READONLY (1UL << 1) |
| |
| 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 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: ppc, s390 |
| 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 |
| |
| 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) |
| |
| 4.48 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) |
| /* The following two depend on KVM_CAP_PCI_2_3 */ |
| #define KVM_DEV_ASSIGN_PCI_2_3 (1 << 1) |
| #define KVM_DEV_ASSIGN_MASK_INTX (1 << 2) |
| |
| If KVM_DEV_ASSIGN_PCI_2_3 is set, the kernel will manage legacy INTx interrupts |
| via the PCI-2.3-compliant device-level mask, thus enable IRQ sharing with other |
| assigned devices or host devices. KVM_DEV_ASSIGN_MASK_INTX specifies the |
| guest's view on the INTx mask, see KVM_ASSIGN_SET_INTX_MASK for details. |
| |
| The KVM_DEV_ASSIGN_ENABLE_IOMMU flag is a mandatory option to ensure |
| isolation of the device. Usages not specifying this flag are deprecated. |
| |
| Only PCI header type 0 devices with PCI BAR resources are supported by |
| device assignment. The user requesting this ioctl must have read/write |
| access to the PCI sysfs resource files associated with the device. |
| |
| |
| 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; /* ignored (legacy field) */ |
| __u32 guest_irq; |
| __u32 flags; |
| union { |
| __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. The number is |
| reset again by terminating the MSI-X assignment of the device via |
| KVM_DEASSIGN_DEV_IRQ. Calling this service more than once at any earlier |
| point will fail. |
| |
| 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]; |
| }; |
| |
| |
| 4.55 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. |
| |
| |
| 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 the Local APIC registers. The data format |
| and layout are the same as documented in the architecture manual. |
| |
| |
| 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; /* 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. |
| |
| |
| 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. |
| |
| |
| 4.61 KVM_ASSIGN_SET_INTX_MASK |
| |
| Capability: KVM_CAP_PCI_2_3 |
| Architectures: x86 |
| Type: vm ioctl |
| Parameters: struct kvm_assigned_pci_dev (in) |
| Returns: 0 on success, -1 on error |
| |
| Allows userspace to mask PCI INTx interrupts from the assigned device. The |
| kernel will not deliver INTx interrupts to the guest between setting and |
| clearing of KVM_ASSIGN_SET_INTX_MASK via this interface. This enables use of |
| and emulation of PCI 2.3 INTx disable command register behavior. |
| |
| This may be used for both PCI 2.3 devices supporting INTx disable natively and |
| older devices lacking this support. Userspace is responsible for emulating the |
| read value of the INTx disable bit in the guest visible PCI command register. |
| When modifying the INTx disable state, userspace should precede updating the |
| physical device command register by calling this ioctl to inform the kernel of |
| the new intended INTx mask state. |
| |
| Note that the kernel uses the device INTx disable bit to internally manage the |
| device interrupt state for PCI 2.3 devices. Reads of this register may |
| therefore not match the expected value. Writes should always use the guest |
| intended INTx disable value rather than attempting to read-copy-update the |
| current physical device state. Races between user and kernel updates to the |
| INTx disable bit are handled lazily in the kernel. It's possible the device |
| may generate unintended interrupts, but they will not be injected into the |
| guest. |
| |
| See KVM_ASSIGN_DEV_IRQ for the data structure. The target device is specified |
| by assigned_dev_id. In the flags field, only KVM_DEV_ASSIGN_MASK_INTX is |
| evaluated. |
| |
| |
| 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 vpcu |
| - 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 alligned 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 alligned 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 |
| |
| 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_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 |
| |
| 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: |
| 0x4002 0000 0010 <index into the kvm_regs struct:16> |
| |
| ARM 32-bit CP15 registers have the following id bit patterns: |
| 0x4002 0000 000F <zero:1> <crn:4> <crm:4> <opc1:4> <opc2:3> |
| |
| ARM 64-bit CP15 registers have the following id bit patterns: |
| 0x4003 0000 000F <zero:1> <zero:4> <crm:4> <opc1:4> <zero:3> |
| |
| ARM CCSIDR registers are demultiplexed by CSSELR value: |
| 0x4002 0000 0011 00 <csselr:8> |
| |
| ARM 32-bit VFP control registers have the following id bit patterns: |
| 0x4002 0000 0012 1 <regno:12> |
| |
| ARM 64-bit FP registers have the following id bit patterns: |
| 0x4002 0000 0012 0 <regno:12> |
| |
| 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 |
| |
| 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 signals to the host kernel that the specified guest is being paused by |
| 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 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 |
| 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; |
| __u8 pad[16]; |
| }; |
| |
| No flags are defined so far. The corresponding field must be 0. |
| |
| |
| 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 appropariate |
| device-tree properties for the guest operating system. |
| |
| The structure contains some global informations, 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. |
| |
| 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. Similarily, 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 |
| 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 tiggered 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 notifed 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. |
| |
| 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, it will have been updated with the order of the hash table that |
| was allocated. |
| |
| 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, |
| the kernel will clear out the existing hash table (zero all HPTEs) and |
| return the hash table order in the parameter. (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 restart |
| 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_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) |
| |
| Note that the vcpu ioctl is asynchronous to vcpu execution. |
| |
| 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 |
| Type: device 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 |
| 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 |
| Type: device 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 |
| |
| 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. |
| |
| 4.77 KVM_ARM_VCPU_INIT |
| |
| Capability: basic |
| Architectures: arm |
| Type: vcpu ioctl |
| Parameters: struct struct kvm_vcpu_init (in) |
| Returns: 0 on success; -1 on error |
| Errors: |
| Â EINVAL: Â Â Â the target is unknown, or the combination of features is invalid. |
| Â ENOENT: Â Â Â 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. Â This will cause a reset of the cpu |
| registers to their initial values. Â 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. |
| |
| Possible features: |
| - KVM_ARM_VCPU_POWER_OFF: Starts the CPU in a power-off state. |
| Depends on KVM_CAP_ARM_PSCI. |
| |
| |
| 4.78 KVM_GET_REG_LIST |
| |
| Capability: basic |
| Architectures: arm |
| Type: vcpu ioctl |
| Parameters: struct kvm_reg_list (in/out) |
| Returns: 0 on success; -1 on error |
| Errors: |
| Â E2BIG: Â Â Â Â the reg index list is too big to fit in the array specified by |
| Â Â Â Â Â Â Â Â Â Â Â Â 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. |
| |
| |
| 4.80 KVM_ARM_SET_DEVICE_ADDR |
| |
| Capability: KVM_CAP_ARM_SET_DEVICE_ADDR |
| Architectures: arm |
| 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 divides the id field into two parts, a device id and an address type id |
| specific to the individual device. |
| |
| Â bits: | 63 ... 32 | 31 ... 16 | 15 ... 0 | |
| field: | 0x00000000 | device id | addr type id | |
| |
| ARM 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. |
| |
| |
| 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, KVM_EXIT_OSI, KVM_EXIT_DCR, |
| KVM_EXIT_PAPR and KVM_EXIT_EPR 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; |
| |
| 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. |
| |
| /* 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. |
| |
| /* 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[1024]; |
| } 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) |
| |
| }; |
| |
| |
| 6. Capabilities that can be enabled |
| ----------------------------------- |
| |
| There are certain capabilities that change the behavior of the virtual CPU 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 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. |
| |
| |
| 6.1 KVM_CAP_PPC_OSI |
| |
| Architectures: ppc |
| 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 |
| 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 |
| 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 |
| 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. |
| |
| 6.5 KVM_CAP_PPC_EPR |
| |
| Architectures: ppc |
| 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. |