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-rw-r--r--Documentation/kvm/api.txt208
1 files changed, 174 insertions, 34 deletions
diff --git a/Documentation/kvm/api.txt b/Documentation/kvm/api.txt
index a237518e51b9..5f5b64982b1a 100644
--- a/Documentation/kvm/api.txt
+++ b/Documentation/kvm/api.txt
@@ -126,6 +126,10 @@ user fills in the size of the indices array in nmsrs, and in return
126kvm adjusts nmsrs to reflect the actual number of msrs and fills in 126kvm adjusts nmsrs to reflect the actual number of msrs and fills in
127the indices array with their numbers. 127the indices array with their numbers.
128 128
129Note: if kvm indicates supports MCE (KVM_CAP_MCE), then the MCE bank MSRs are
130not returned in the MSR list, as different vcpus can have a different number
131of banks, as set via the KVM_X86_SETUP_MCE ioctl.
132
1294.4 KVM_CHECK_EXTENSION 1334.4 KVM_CHECK_EXTENSION
130 134
131Capability: basic 135Capability: basic
@@ -160,29 +164,7 @@ Type: vm ioctl
160Parameters: struct kvm_memory_region (in) 164Parameters: struct kvm_memory_region (in)
161Returns: 0 on success, -1 on error 165Returns: 0 on success, -1 on error
162 166
163struct kvm_memory_region { 167This ioctl is obsolete and has been removed.
164 __u32 slot;
165 __u32 flags;
166 __u64 guest_phys_addr;
167 __u64 memory_size; /* bytes */
168};
169
170/* for kvm_memory_region::flags */
171#define KVM_MEM_LOG_DIRTY_PAGES 1UL
172
173This ioctl allows the user to create or modify a guest physical memory
174slot. When changing an existing slot, it may be moved in the guest
175physical memory space, or its flags may be modified. It may not be
176resized. Slots may not overlap.
177
178The flags field supports just one flag, KVM_MEM_LOG_DIRTY_PAGES, which
179instructs kvm to keep track of writes to memory within the slot. See
180the KVM_GET_DIRTY_LOG ioctl.
181
182It is recommended to use the KVM_SET_USER_MEMORY_REGION ioctl instead
183of this API, if available. This newer API allows placing guest memory
184at specified locations in the host address space, yielding better
185control and easy access.
186 168
1874.6 KVM_CREATE_VCPU 1694.6 KVM_CREATE_VCPU
188 170
@@ -226,17 +208,7 @@ Type: vm ioctl
226Parameters: struct kvm_memory_alias (in) 208Parameters: struct kvm_memory_alias (in)
227Returns: 0 (success), -1 (error) 209Returns: 0 (success), -1 (error)
228 210
229struct kvm_memory_alias { 211This ioctl is obsolete and has been removed.
230 __u32 slot; /* this has a different namespace than memory slots */
231 __u32 flags;
232 __u64 guest_phys_addr;
233 __u64 memory_size;
234 __u64 target_phys_addr;
235};
236
237Defines a guest physical address space region as an alias to another
238region. Useful for aliased address, for example the VGA low memory
239window. Should not be used with userspace memory.
240 212
2414.9 KVM_RUN 2134.9 KVM_RUN
242 214
@@ -892,6 +864,174 @@ arguments.
892This ioctl is only useful after KVM_CREATE_IRQCHIP. Without an in-kernel 864This ioctl is only useful after KVM_CREATE_IRQCHIP. Without an in-kernel
893irqchip, the multiprocessing state must be maintained by userspace. 865irqchip, the multiprocessing state must be maintained by userspace.
894 866
8674.39 KVM_SET_IDENTITY_MAP_ADDR
868
869Capability: KVM_CAP_SET_IDENTITY_MAP_ADDR
870Architectures: x86
871Type: vm ioctl
872Parameters: unsigned long identity (in)
873Returns: 0 on success, -1 on error
874
875This ioctl defines the physical address of a one-page region in the guest
876physical address space. The region must be within the first 4GB of the
877guest physical address space and must not conflict with any memory slot
878or any mmio address. The guest may malfunction if it accesses this memory
879region.
880
881This ioctl is required on Intel-based hosts. This is needed on Intel hardware
882because of a quirk in the virtualization implementation (see the internals
883documentation when it pops into existence).
884
8854.40 KVM_SET_BOOT_CPU_ID
886
887Capability: KVM_CAP_SET_BOOT_CPU_ID
888Architectures: x86, ia64
889Type: vm ioctl
890Parameters: unsigned long vcpu_id
891Returns: 0 on success, -1 on error
892
893Define which vcpu is the Bootstrap Processor (BSP). Values are the same
894as the vcpu id in KVM_CREATE_VCPU. If this ioctl is not called, the default
895is vcpu 0.
896
8974.41 KVM_GET_XSAVE
898
899Capability: KVM_CAP_XSAVE
900Architectures: x86
901Type: vcpu ioctl
902Parameters: struct kvm_xsave (out)
903Returns: 0 on success, -1 on error
904
905struct kvm_xsave {
906 __u32 region[1024];
907};
908
909This ioctl would copy current vcpu's xsave struct to the userspace.
910
9114.42 KVM_SET_XSAVE
912
913Capability: KVM_CAP_XSAVE
914Architectures: x86
915Type: vcpu ioctl
916Parameters: struct kvm_xsave (in)
917Returns: 0 on success, -1 on error
918
919struct kvm_xsave {
920 __u32 region[1024];
921};
922
923This ioctl would copy userspace's xsave struct to the kernel.
924
9254.43 KVM_GET_XCRS
926
927Capability: KVM_CAP_XCRS
928Architectures: x86
929Type: vcpu ioctl
930Parameters: struct kvm_xcrs (out)
931Returns: 0 on success, -1 on error
932
933struct kvm_xcr {
934 __u32 xcr;
935 __u32 reserved;
936 __u64 value;
937};
938
939struct kvm_xcrs {
940 __u32 nr_xcrs;
941 __u32 flags;
942 struct kvm_xcr xcrs[KVM_MAX_XCRS];
943 __u64 padding[16];
944};
945
946This ioctl would copy current vcpu's xcrs to the userspace.
947
9484.44 KVM_SET_XCRS
949
950Capability: KVM_CAP_XCRS
951Architectures: x86
952Type: vcpu ioctl
953Parameters: struct kvm_xcrs (in)
954Returns: 0 on success, -1 on error
955
956struct kvm_xcr {
957 __u32 xcr;
958 __u32 reserved;
959 __u64 value;
960};
961
962struct kvm_xcrs {
963 __u32 nr_xcrs;
964 __u32 flags;
965 struct kvm_xcr xcrs[KVM_MAX_XCRS];
966 __u64 padding[16];
967};
968
969This ioctl would set vcpu's xcr to the value userspace specified.
970
9714.45 KVM_GET_SUPPORTED_CPUID
972
973Capability: KVM_CAP_EXT_CPUID
974Architectures: x86
975Type: system ioctl
976Parameters: struct kvm_cpuid2 (in/out)
977Returns: 0 on success, -1 on error
978
979struct kvm_cpuid2 {
980 __u32 nent;
981 __u32 padding;
982 struct kvm_cpuid_entry2 entries[0];
983};
984
985#define KVM_CPUID_FLAG_SIGNIFCANT_INDEX 1
986#define KVM_CPUID_FLAG_STATEFUL_FUNC 2
987#define KVM_CPUID_FLAG_STATE_READ_NEXT 4
988
989struct kvm_cpuid_entry2 {
990 __u32 function;
991 __u32 index;
992 __u32 flags;
993 __u32 eax;
994 __u32 ebx;
995 __u32 ecx;
996 __u32 edx;
997 __u32 padding[3];
998};
999
1000This ioctl returns x86 cpuid features which are supported by both the hardware
1001and kvm. Userspace can use the information returned by this ioctl to
1002construct cpuid information (for KVM_SET_CPUID2) that is consistent with
1003hardware, kernel, and userspace capabilities, and with user requirements (for
1004example, the user may wish to constrain cpuid to emulate older hardware,
1005or for feature consistency across a cluster).
1006
1007Userspace invokes KVM_GET_SUPPORTED_CPUID by passing a kvm_cpuid2 structure
1008with the 'nent' field indicating the number of entries in the variable-size
1009array 'entries'. If the number of entries is too low to describe the cpu
1010capabilities, an error (E2BIG) is returned. If the number is too high,
1011the 'nent' field is adjusted and an error (ENOMEM) is returned. If the
1012number is just right, the 'nent' field is adjusted to the number of valid
1013entries in the 'entries' array, which is then filled.
1014
1015The entries returned are the host cpuid as returned by the cpuid instruction,
1016with unknown or unsupported features masked out. The fields in each entry
1017are defined as follows:
1018
1019 function: the eax value used to obtain the entry
1020 index: the ecx value used to obtain the entry (for entries that are
1021 affected by ecx)
1022 flags: an OR of zero or more of the following:
1023 KVM_CPUID_FLAG_SIGNIFCANT_INDEX:
1024 if the index field is valid
1025 KVM_CPUID_FLAG_STATEFUL_FUNC:
1026 if cpuid for this function returns different values for successive
1027 invocations; there will be several entries with the same function,
1028 all with this flag set
1029 KVM_CPUID_FLAG_STATE_READ_NEXT:
1030 for KVM_CPUID_FLAG_STATEFUL_FUNC entries, set if this entry is
1031 the first entry to be read by a cpu
1032 eax, ebx, ecx, edx: the values returned by the cpuid instruction for
1033 this function/index combination
1034
8955. The kvm_run structure 10355. The kvm_run structure
896 1036
897Application code obtains a pointer to the kvm_run structure by 1037Application code obtains a pointer to the kvm_run structure by