KVM: x86: hyper-v: Honor HV_SIGNAL_EVENTS privilege bit

Hyper-V partition must possess 'HV_SIGNAL_EVENTS' privilege to issue
HVCALL_SIGNAL_EVENT hypercalls.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210521095204.2161214-24-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index 293619998c3855c2a87a3d75ab986fd5497ec4f7..ce057827da03bf9ee53602405f45607b26acd124 100644 (file)
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -2101,6 +2101,8 @@ static bool hv_check_hypercall_access(struct kvm_vcpu_hv *hv_vcpu, u16 code)
                        hv_vcpu->cpuid_cache.enlightenments_ebx != U32_MAX;
        case HVCALL_POST_MESSAGE:
                return hv_vcpu->cpuid_cache.features_ebx & HV_POST_MESSAGES;
+       case HVCALL_SIGNAL_EVENT:
+               return hv_vcpu->cpuid_cache.features_ebx & HV_SIGNAL_EVENTS;
        default:
                break;
        }