$NetBSD: patch-xen_arch_x86_time.c,v 1.1 2013/04/11 19:57:52 joerg Exp $

--- xen/common/grant_table.c.orig	2012-12-18 13:54:26.000000000 +0100
+++ xen/common/grant_table.c	2013-04-16 15:23:33.000000000 +0200
@@ -1688,7 +1688,7 @@
         if ( released_write || released_read )
         {
             trans_dom = rcu_lock_domain_by_id(trans_domid);
-            if ( trans_dom != NULL )
+            if ( trans_dom != NULL && trans_dom->grant_table->gt_version != 0 )
             {
                 /* Recursive calls, but they're tail calls, so it's
                    okay. */