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

Hyper-V partition must possess 'HV_POST_MESSAGES' privilege to issue
HVCALL_POST_MESSAGE hypercalls.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210521095204.2161214-23-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 13bfa4e0b93dba96b52adf32d7021cb1c7ca5283..293619998c3855c2a87a3d75ab986fd5497ec4f7 100644 (file)
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -2099,6 +2099,8 @@ static bool hv_check_hypercall_access(struct kvm_vcpu_hv *hv_vcpu, u16 code)
        case HVCALL_NOTIFY_LONG_SPIN_WAIT:
                return hv_vcpu->cpuid_cache.enlightenments_ebx &&
                        hv_vcpu->cpuid_cache.enlightenments_ebx != U32_MAX;
+       case HVCALL_POST_MESSAGE:
+               return hv_vcpu->cpuid_cache.features_ebx & HV_POST_MESSAGES;
        default:
                break;
        }