Defines the vcpu responses to the cpuid instruction. Applications
should use the KVM_SET_CPUID2 ioctl if available.
-Note, when this IOCTL fails, KVM gives no guarantees that previous valid CPUID
-configuration (if there is) is not corrupted. Userspace can get a copy of the
-resulting CPUID configuration through KVM_GET_CPUID2 in case.
+Caveat emptor:
+ - If this IOCTL fails, KVM gives no guarantees that previous valid CPUID
+ configuration (if there is) is not corrupted. Userspace can get a copy
+ of the resulting CPUID configuration through KVM_GET_CPUID2 in case.
+ - Using KVM_SET_CPUID{,2} after KVM_RUN, i.e. changing the guest vCPU model
+ after running the guest, may cause guest instability.
+ - Using heterogeneous CPUID configurations, modulo APIC IDs, topology, etc...
+ may cause guest instability.
::
of bytes successfully copied is returned. If the call completes successfully
then ``length`` is returned.
+4.131 KVM_GET_SREGS2
+------------------
+
+:Capability: KVM_CAP_SREGS2
+:Architectures: x86
+:Type: vcpu ioctl
+:Parameters: struct kvm_sregs2 (out)
+:Returns: 0 on success, -1 on error
+
+Reads special registers from the vcpu.
+This ioctl (when supported) replaces the KVM_GET_SREGS.
+
+::
+
+struct kvm_sregs2 {
+ /* out (KVM_GET_SREGS2) / in (KVM_SET_SREGS2) */
+ 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 flags;
+ __u64 pdptrs[4];
+};
+
+flags values for ``kvm_sregs2``:
+
+``KVM_SREGS2_FLAGS_PDPTRS_VALID``
+
+ Indicates thats the struct contain valid PDPTR values.
+
+
+4.132 KVM_SET_SREGS2
+------------------
+
+:Capability: KVM_CAP_SREGS2
+:Architectures: x86
+:Type: vcpu ioctl
+:Parameters: struct kvm_sregs2 (in)
+:Returns: 0 on success, -1 on error
+
+Writes special registers into the vcpu.
+See KVM_GET_SREGS2 for the data structures.
+This ioctl (when supported) replaces the KVM_SET_SREGS.
+
+4.133 KVM_GET_STATS_FD
+----------------------
+
+:Capability: KVM_CAP_STATS_BINARY_FD
+:Architectures: all
+:Type: vm ioctl, vcpu ioctl
+:Parameters: none
+:Returns: statistics file descriptor on success, < 0 on error
+
+Errors:
+
+ ====== ======================================================
+ ENOMEM if the fd could not be created due to lack of memory
+ EMFILE if the number of opened files exceeds the limit
+ ====== ======================================================
+
+The returned file descriptor can be used to read VM/vCPU statistics data in
+binary format. The data in the file descriptor consists of four blocks
+organized as follows:
+
++-------------+
+| Header |
++-------------+
+| id string |
++-------------+
+| Descriptors |
++-------------+
+| Stats Data |
++-------------+
+
+Apart from the header starting at offset 0, please be aware that it is
+not guaranteed that the four blocks are adjacent or in the above order;
+the offsets of the id, descriptors and data blocks are found in the
+header. However, all four blocks are aligned to 64 bit offsets in the
+file and they do not overlap.
+
+All blocks except the data block are immutable. Userspace can read them
+only one time after retrieving the file descriptor, and then use ``pread`` or
+``lseek`` to read the statistics repeatedly.
+
+All data is in system endianness.
+
+The format of the header is as follows::
+
+ struct kvm_stats_header {
+ __u32 flags;
+ __u32 name_size;
+ __u32 num_desc;
+ __u32 id_offset;
+ __u32 desc_offset;
+ __u32 data_offset;
+ };
+
+The ``flags`` field is not used at the moment. It is always read as 0.
+
+The ``name_size`` field is the size (in byte) of the statistics name string
+(including trailing '\0') which is contained in the "id string" block and
+appended at the end of every descriptor.
+
+The ``num_desc`` field is the number of descriptors that are included in the
+descriptor block. (The actual number of values in the data block may be
+larger, since each descriptor may comprise more than one value).
+
+The ``id_offset`` field is the offset of the id string from the start of the
+file indicated by the file descriptor. It is a multiple of 8.
+
+The ``desc_offset`` field is the offset of the Descriptors block from the start
+of the file indicated by the file descriptor. It is a multiple of 8.
+
+The ``data_offset`` field is the offset of the Stats Data block from the start
+of the file indicated by the file descriptor. It is a multiple of 8.
+
+The id string block contains a string which identifies the file descriptor on
+which KVM_GET_STATS_FD was invoked. The size of the block, including the
+trailing ``'\0'``, is indicated by the ``name_size`` field in the header.
+
+The descriptors block is only needed to be read once for the lifetime of the
+file descriptor contains a sequence of ``struct kvm_stats_desc``, each followed
+by a string of size ``name_size``.
+
+ #define KVM_STATS_TYPE_SHIFT 0
+ #define KVM_STATS_TYPE_MASK (0xF << KVM_STATS_TYPE_SHIFT)
+ #define KVM_STATS_TYPE_CUMULATIVE (0x0 << KVM_STATS_TYPE_SHIFT)
+ #define KVM_STATS_TYPE_INSTANT (0x1 << KVM_STATS_TYPE_SHIFT)
+ #define KVM_STATS_TYPE_PEAK (0x2 << KVM_STATS_TYPE_SHIFT)
+
+ #define KVM_STATS_UNIT_SHIFT 4
+ #define KVM_STATS_UNIT_MASK (0xF << KVM_STATS_UNIT_SHIFT)
+ #define KVM_STATS_UNIT_NONE (0x0 << KVM_STATS_UNIT_SHIFT)
+ #define KVM_STATS_UNIT_BYTES (0x1 << KVM_STATS_UNIT_SHIFT)
+ #define KVM_STATS_UNIT_SECONDS (0x2 << KVM_STATS_UNIT_SHIFT)
+ #define KVM_STATS_UNIT_CYCLES (0x3 << KVM_STATS_UNIT_SHIFT)
+
+ #define KVM_STATS_BASE_SHIFT 8
+ #define KVM_STATS_BASE_MASK (0xF << KVM_STATS_BASE_SHIFT)
+ #define KVM_STATS_BASE_POW10 (0x0 << KVM_STATS_BASE_SHIFT)
+ #define KVM_STATS_BASE_POW2 (0x1 << KVM_STATS_BASE_SHIFT)
+
+ struct kvm_stats_desc {
+ __u32 flags;
+ __s16 exponent;
+ __u16 size;
+ __u32 offset;
+ __u32 unused;
+ char name[];
+ };
+
+The ``flags`` field contains the type and unit of the statistics data described
+by this descriptor. Its endianness is CPU native.
+The following flags are supported:
+
+Bits 0-3 of ``flags`` encode the type:
+ * ``KVM_STATS_TYPE_CUMULATIVE``
+ The statistics data is cumulative. The value of data can only be increased.
+ Most of the counters used in KVM are of this type.
+ The corresponding ``size`` field for this type is always 1.
+ All cumulative statistics data are read/write.
+ * ``KVM_STATS_TYPE_INSTANT``
+ The statistics data is instantaneous. Its value can be increased or
+ decreased. This type is usually used as a measurement of some resources,
+ like the number of dirty pages, the number of large pages, etc.
+ All instant statistics are read only.
+ The corresponding ``size`` field for this type is always 1.
+ * ``KVM_STATS_TYPE_PEAK``
+ The statistics data is peak. The value of data can only be increased, and
+ represents a peak value for a measurement, for example the maximum number
+ of items in a hash table bucket, the longest time waited and so on.
+ The corresponding ``size`` field for this type is always 1.
+
+Bits 4-7 of ``flags`` encode the unit:
+ * ``KVM_STATS_UNIT_NONE``
+ There is no unit for the value of statistics data. This usually means that
+ the value is a simple counter of an event.
+ * ``KVM_STATS_UNIT_BYTES``
+ It indicates that the statistics data is used to measure memory size, in the
+ unit of Byte, KiByte, MiByte, GiByte, etc. The unit of the data is
+ determined by the ``exponent`` field in the descriptor.
+ * ``KVM_STATS_UNIT_SECONDS``
+ It indicates that the statistics data is used to measure time or latency.
+ * ``KVM_STATS_UNIT_CYCLES``
+ It indicates that the statistics data is used to measure CPU clock cycles.
+
+Bits 8-11 of ``flags``, together with ``exponent``, encode the scale of the
+unit:
+ * ``KVM_STATS_BASE_POW10``
+ The scale is based on power of 10. It is used for measurement of time and
+ CPU clock cycles. For example, an exponent of -9 can be used with
+ ``KVM_STATS_UNIT_SECONDS`` to express that the unit is nanoseconds.
+ * ``KVM_STATS_BASE_POW2``
+ The scale is based on power of 2. It is used for measurement of memory size.
+ For example, an exponent of 20 can be used with ``KVM_STATS_UNIT_BYTES`` to
+ express that the unit is MiB.
+
+The ``size`` field is the number of values of this statistics data. Its
+value is usually 1 for most of simple statistics. 1 means it contains an
+unsigned 64bit data.
+
+The ``offset`` field is the offset from the start of Data Block to the start of
+the corresponding statistics data.
+
+The ``unused`` field is reserved for future support for other types of
+statistics data, like log/linear histogram. Its value is always 0 for the types
+defined above.
+
+The ``name`` field is the name string of the statistics data. The name string
+starts at the end of ``struct kvm_stats_desc``. The maximum length including
+the trailing ``'\0'``, is indicated by ``name_size`` in the header.
+
+The Stats Data block contains an array of 64-bit values in the same order
+as the descriptors in Descriptors block.
+
5. The kvm_run structure
========================
This capability can be used to check / enable 2nd DAWR feature provided
by POWER10 processor.
+
7.24 KVM_CAP_VM_COPY_ENC_CONTEXT_FROM
-------------------------------------
See Documentation/x86/sgx/2.Kernel-internals.rst for more details.
-7.26 KVM_CAP_ARM_MTE
+7.26 KVM_CAP_PPC_RPT_INVALIDATE
+-------------------------------
+
+:Capability: KVM_CAP_PPC_RPT_INVALIDATE
+:Architectures: ppc
+:Type: vm
+
+This capability indicates that the kernel is capable of handling
+H_RPT_INVALIDATE hcall.
+
+In order to enable the use of H_RPT_INVALIDATE in the guest,
+user space might have to advertise it for the guest. For example,
+IBM pSeries (sPAPR) guest starts using it if "hcall-rpt-invalidate" is
+present in the "ibm,hypertas-functions" device-tree property.
+
+This capability is enabled for hypervisors on platforms like POWER9
+that support radix MMU.
+
+7.27 KVM_CAP_EXIT_ON_EMULATION_FAILURE
+--------------------------------------
+
+:Architectures: x86
+:Parameters: args[0] whether the feature should be enabled or not
+
+When this capability is enabled, an emulation failure will result in an exit
+to userspace with KVM_INTERNAL_ERROR (except when the emulator was invoked
+to handle a VMware backdoor instruction). Furthermore, KVM will now provide up
+to 15 instruction bytes for any exit to userspace resulting from an emulation
+failure. When these exits to userspace occur use the emulation_failure struct
+instead of the internal struct. They both have the same layout, but the
+emulation_failure struct matches the content better. It also explicitly
+defines the 'flags' field which is used to describe the fields in the struct
+that are valid (ie: if KVM_INTERNAL_ERROR_EMULATION_FLAG_INSTRUCTION_BYTES is
+set in the 'flags' field then both 'insn_size' and 'insn_bytes' have valid data
+in them.)
+
+7.28 KVM_CAP_ARM_MTE
--------------------
:Architectures: arm64
This capability indicates that the KVM virtual PTP service is
supported in the host. A VMM can check whether the service is
available to the guest on migration.
+
+8.33 KVM_CAP_HYPERV_ENFORCE_CPUID
+-----------------------------
+
+Architectures: x86
+
+When enabled, KVM will disable emulated Hyper-V features provided to the
+guest according to the bits Hyper-V CPUID feature leaves. Otherwise, all
+currently implmented Hyper-V features are provided unconditionally when
+Hyper-V identification is set in the HYPERV_CPUID_INTERFACE (0x40000001)
+leaf.
+
+8.34 KVM_CAP_EXIT_HYPERCALL
+---------------------------
+
+:Capability: KVM_CAP_EXIT_HYPERCALL
+:Architectures: x86
+:Type: vm
+
+This capability, if enabled, will cause KVM to exit to userspace
+with KVM_EXIT_HYPERCALL exit reason to process some hypercalls.
+
+Calling KVM_CHECK_EXTENSION for this capability will return a bitmask
+of hypercalls that can be configured to exit to userspace.
+Right now, the only such hypercall is KVM_HC_MAP_GPA_RANGE.
+
+The argument to KVM_ENABLE_CAP is also a bitmask, and must be a subset
+of the result of KVM_CHECK_EXTENSION. KVM will forward to userspace
+the hypercalls whose corresponding bit is in the argument, and return
+ENOSYS for the others.
projects / mirror_ubuntu-jammy-kernel.git / blobdiff