Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> writes: > Changes since v2: > - Keep vCPU version of the ioctl intact but make it 'deprecated' in > api.rst [Paolo Bonzini] > - First two patches of v2 series already made it to kvm/queue > > QEMU series using the feature: > https://lists.gnu.org/archive/html/qemu-devel/2020-09/msg02017.html > > Original description: > > KVM_GET_SUPPORTED_HV_CPUID was initially implemented as a vCPU ioctl but > this is not very useful when VMM is just trying to query which Hyper-V > features are supported by the host prior to creating VM/vCPUs. The data > in KVM_GET_SUPPORTED_HV_CPUID is mostly static with a few exceptions but > it seems we can change this. Add support for KVM_GET_SUPPORTED_HV_CPUID as > a system ioctl as well. > > QEMU specific description: > In some cases QEMU needs to collect the information about which Hyper-V > features are supported by KVM and pass it up the stack. For non-hyper-v > features this is done with system-wide KVM_GET_SUPPORTED_CPUID/ > KVM_GET_MSRS ioctls but Hyper-V specific features don't get in the output > (as Hyper-V CPUIDs intersect with KVM's). In QEMU, CPU feature expansion > happens before any KVM vcpus are created so KVM_GET_SUPPORTED_HV_CPUID > can't be used in its current shape. > > Vitaly Kuznetsov (2): > KVM: x86: hyper-v: allow KVM_GET_SUPPORTED_HV_CPUID as a system ioctl > KVM: selftests: test KVM_GET_SUPPORTED_HV_CPUID as a system ioctl > > Documentation/virt/kvm/api.rst | 16 ++-- > arch/x86/kvm/hyperv.c | 6 +- > arch/x86/kvm/hyperv.h | 4 +- > arch/x86/kvm/vmx/evmcs.c | 3 +- > arch/x86/kvm/x86.c | 45 ++++++---- > include/uapi/linux/kvm.h | 3 +- > .../testing/selftests/kvm/include/kvm_util.h | 2 + > tools/testing/selftests/kvm/lib/kvm_util.c | 26 ++++++ > .../selftests/kvm/x86_64/hyperv_cpuid.c | 87 +++++++++++-------- > 9 files changed, 123 insertions(+), 69 deletions(-) Ping) Still hoping this can be picked up for 5.10. the latest QEMU patchset was posted last Friday: https://lists.gnu.org/archive/html/qemu-devel/2020-10/msg02443.html -- Vitaly
