[PATCH 22/30] KVM: x86: hyper-v: Honor HV_POST_MESSAGES privilege bit

[Vitaly Kuznetsov]

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

Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
---
 arch/x86/kvm/hyperv.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index bd424f2d4294..ff86c00d1396 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -2031,6 +2031,8 @@ 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;
 	}
-- 
2.30.2