diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index ad97014aa6eb..fc01c4b08fd5 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -884,6 +884,8 @@ static void vmx_set_segment(struct kvm_vcpu *vcpu,
 		ar |= (var->db & 1) << 14;
 		ar |= (var->g & 1) << 15;
 	}
+	if (ar == 0) /* a 0 value means unusable */
+		ar = AR_UNUSABLE_MASK;
 	vmcs_write32(sf->ar_bytes, ar);
 }