diff options
| author | Andrew Jones | 2020-08-04 19:06:04 +0200 |
|---|---|---|
| committer | Marc Zyngier | 2020-08-21 14:05:19 +0100 |
| commit | 004a01241c5a0d375266ebf1c72f208de99294e9 (patch) | |
| tree | 956e8aee5d5a69cbbdf3d5dff427bae747a003b1 /Documentation/virt/kvm | |
| parent | 739c7af7daeede8e2ec78392f2617c965ce0342a (diff) | |
arm64/x86: KVM: Introduce steal-time cap
arm64 requires a vcpu fd (KVM_HAS_DEVICE_ATTR vcpu ioctl) to probe
support for steal-time. However this is unnecessary, as only a KVM
fd is required, and it complicates userspace (userspace may prefer
delaying vcpu creation until after feature probing). Introduce a cap
that can be checked instead. While x86 can already probe steal-time
support with a kvm fd (KVM_GET_SUPPORTED_CPUID), we add the cap there
too for consistency.
Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Steven Price <steven.price@arm.com>
Link: https://lore.kernel.org/r/20200804170604.42662-7-drjones@redhat.com
Diffstat (limited to 'Documentation/virt/kvm')
| -rw-r--r-- | Documentation/virt/kvm/api.rst | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index 49af23d2b462..d2b733dc7892 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -6160,3 +6160,16 @@ KVM can therefore start protected VMs. This capability governs the KVM_S390_PV_COMMAND ioctl and the KVM_MP_STATE_LOAD MP_STATE. KVM_SET_MP_STATE can fail for protected guests when the state change is invalid. + +8.24 KVM_CAP_STEAL_TIME +----------------------- + +:Architectures: arm64, x86 + +This capability indicates that KVM supports steal time accounting. +When steal time accounting is supported it may be enabled with +architecture-specific interfaces. This capability and the architecture- +specific interfaces must be consistent, i.e. if one says the feature +is supported, than the other should as well and vice versa. For arm64 +see Documentation/virt/kvm/devices/vcpu.rst "KVM_ARM_VCPU_PVTIME_CTRL". +For x86 see Documentation/virt/kvm/msr.rst "MSR_KVM_STEAL_TIME". |