> On 24 Jan 2019, at 19:15, Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> wrote: > > We shouldn't probably be suggesting using Enlightened VMCS when it's not > enabled (not supported from guest's point of view). System reset through > synthetic MSR is not recommended neither by genuine Hyper-V nor my QEMU. > > Windows seems to be fine either way but let's be consistent. > > Fixes: 2bc39970e932 ("x86/kvm/hyper-v: Introduce KVM_GET_SUPPORTED_HV_CPUID") > Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> > --- > arch/x86/kvm/hyperv.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c > index ac44a681f065..4730fcaa70cf 100644 > --- a/arch/x86/kvm/hyperv.c > +++ b/arch/x86/kvm/hyperv.c > @@ -1847,11 +1847,11 @@ int kvm_vcpu_ioctl_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid, > case HYPERV_CPUID_ENLIGHTMENT_INFO: > ent->eax |= HV_X64_REMOTE_TLB_FLUSH_RECOMMENDED; > ent->eax |= HV_X64_APIC_ACCESS_RECOMMENDED; > - ent->eax |= HV_X64_SYSTEM_RESET_RECOMMENDED; > ent->eax |= HV_X64_RELAXED_TIMING_RECOMMENDED; > ent->eax |= HV_X64_CLUSTER_IPI_RECOMMENDED; > ent->eax |= HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED; > - ent->eax |= HV_X64_ENLIGHTENED_VMCS_RECOMMENDED; > + if (evmcs_ver) > + ent->eax |= HV_X64_ENLIGHTENED_VMCS_RECOMMENDED; > > /* > * Default number of spinlock retry attempts, matches > -- > 2.20.1 > Seems to me that there are 2 unrelated separated patches here. Why not split them? For content itself: Reviewed-by: Liran Alon <liran.alon@xxxxxxxxxx>