On 24/09/20 16:57, Vitaly Kuznetsov wrote: > Changes since v1: > - Rebased to kvm/queue [KVM_CAP_SYS_HYPERV_CPUID -> 188] > > 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 (7): > KVM: x86: hyper-v: Mention SynDBG CPUID leaves in api.rst > KVM: x86: hyper-v: disallow configuring SynIC timers with no SynIC > KVM: x86: hyper-v: make KVM_GET_SUPPORTED_HV_CPUID output independent > of eVMCS enablement > KVM: x86: hyper-v: always advertise HV_STIMER_DIRECT_MODE_AVAILABLE > KVM: x86: hyper-v: drop now unneeded vcpu parameter from > kvm_vcpu_ioctl_get_hv_cpuid() > 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 | 12 +-- > arch/x86/include/asm/kvm_host.h | 2 +- > arch/x86/kvm/hyperv.c | 30 ++++---- > arch/x86/kvm/hyperv.h | 3 +- > arch/x86/kvm/vmx/evmcs.c | 8 +- > arch/x86/kvm/vmx/evmcs.h | 2 +- > arch/x86/kvm/x86.c | 44 ++++++----- > 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 | 77 +++++++++---------- > 11 files changed, 120 insertions(+), 89 deletions(-) > Queued patches 1-2 while we discuss the rest, thanks. Paolo
