HV_X64_MSR_VP_RUNTIME is only available to guest when HV_MSR_VP_RUNTIME_AVAILABLE bit is exposed. Note, writing to HV_X64_MSR_VP_RUNTIME is only available from the host so kvm_hv_set_msr() doesn't need an additional check. Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> --- arch/x86/kvm/hyperv.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index 781f9da9a418..b39445aabbc2 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -1504,6 +1504,10 @@ static int kvm_hv_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata, data = hv_vcpu->hv_vapic; break; case HV_X64_MSR_VP_RUNTIME: + if (unlikely(!host && !(hv_vcpu->cpuid_cache.features_eax & + HV_MSR_VP_RUNTIME_AVAILABLE))) + return 1; + data = current_task_runtime_100ns() + hv_vcpu->runtime_offset; break; case HV_X64_MSR_SCONTROL: -- 2.30.2