Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> writes: > 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. > Ping ;-) I know Hyper-V emulation in KVM is a very specific topic so it's not very easy to find reviewers but I'd be very happy if someone could provide any feedback on the idea (above) in general. -- Vitaly
