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author | Jim Mattson <jmattson@google.com> | 2018-05-24 11:59:54 -0700 |
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committer | Radim Krčmář <rkrcmar@redhat.com> | 2018-05-26 15:37:34 +0200 |
commit | df9cb9cc5bcd36127a820c09b4c40adfdc17c547 (patch) | |
tree | 72807026f8d9a48b86a06adc72a7ed597956df74 /Documentation | |
parent | c1aea9196ef4f6b64a8ef7e62a933f7e4164aed9 (diff) | |
download | linux-stable-df9cb9cc5bcd36127a820c09b4c40adfdc17c547.tar.gz linux-stable-df9cb9cc5bcd36127a820c09b4c40adfdc17c547.tar.bz2 linux-stable-df9cb9cc5bcd36127a820c09b4c40adfdc17c547.zip |
kvm: x86: Amend the KVM_GET_SUPPORTED_CPUID API documentation
Document the subtle nuances that KVM_CAP_X86_DISABLE_EXITS induces in
the KVM_GET_SUPPORTED_CPUID API.
Fixes: 4d5422cea3b6 ("KVM: X86: Provide a capability to disable MWAIT intercepts")
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/virtual/kvm/api.txt | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index c563da4244da..495b7742ab58 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -1269,12 +1269,18 @@ struct kvm_cpuid_entry2 { __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). +This ioctl returns x86 cpuid features which are supported by both the +hardware and kvm in its default configuration. Userspace can use the +information returned by this ioctl to construct cpuid information (for +KVM_SET_CPUID2) that is consistent with hardware, kernel, and +userspace capabilities, and with user requirements (for example, the +user may wish to constrain cpuid to emulate older hardware, or for +feature consistency across a cluster). + +Note that certain capabilities, such as KVM_CAP_X86_DISABLE_EXITS, may +expose cpuid features (e.g. MONITOR) which are not supported by kvm in +its default configuration. If userspace enables such capabilities, it +is responsible for modifying the results of this ioctl appropriately. Userspace invokes KVM_GET_SUPPORTED_CPUID by passing a kvm_cpuid2 structure with the 'nent' field indicating the number of entries in the variable-size |