Eduardo Habkost <ehabk...@redhat.com> writes: >> [...] Some time ago when merging direct mode stimers for KVM >> Paolo suggested we stop adding capabilities to KVM for each individulat >> feature and replace them with something like KVM_GET_SUPPORTED_HV_CPUID >> ioctl returning all Hyper-V related feature words. When this is done we >> can reconsider how Qemu discoveres Hyper-V related KVM features and as >> part of this work we can take a closer look at feature words and >> feat_names. > > Why a separate ioctl instead of extending GET_SUPPORTED_CPUID?
Unfortunatelly both KVM and Hyper-V use feature leaves 0x40000000, 0x40000001 (so it's up to the userspace - qemu in our case - what to expose to the guest) and GET_SUPPORTED_CPUID already returns KVM's. Not sure this can be changed (to e.g. returning these leaves twice with different flags) without breaking userspace. New ioctl is safer. -- Vitaly
