Hyper-V Synthetic timers require SynIC but we don't seem to check that upon HV_X64_MSR_STIMER[X]_CONFIG/HV_X64_MSR_STIMER0_COUNT writes. Make the behavior match synic_set_msr(). Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> --- arch/x86/kvm/hyperv.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index af9cdb426dd2..4291943d1028 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -633,6 +633,11 @@ static int stimer_set_config(struct kvm_vcpu_hv_stimer *stimer, u64 config, { union hv_stimer_config new_config = {.as_uint64 = config}, old_config = {.as_uint64 = stimer->config.as_uint64}; + struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer); + struct kvm_vcpu_hv_synic *synic = vcpu_to_synic(vcpu); + + if (!synic->active && !host) + return 1; trace_kvm_hv_stimer_set_config(stimer_to_vcpu(stimer)->vcpu_id, stimer->index, config, host); @@ -652,6 +657,12 @@ static int stimer_set_config(struct kvm_vcpu_hv_stimer *stimer, u64 config, static int stimer_set_count(struct kvm_vcpu_hv_stimer *stimer, u64 count, bool host) { + struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer); + struct kvm_vcpu_hv_synic *synic = vcpu_to_synic(vcpu); + + if (!synic->active && !host) + return 1; + trace_kvm_hv_stimer_set_count(stimer_to_vcpu(stimer)->vcpu_id, stimer->index, count, host); -- 2.25.4