[PATCH] KVM: Make the GET_SREGS and SET_SREGS ioctls symmetric

This makes the SET_SREGS ioctl behave symmetrically to the GET_SREGS ioctl wrt
the segment access rights flag.
Signed-off-by: NUri Lublin <uril@qumranet.com>
Signed-off-by: NAvi Kivity <avi@qumranet.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

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);
 }