diff -r 37fae02cc335 xen/include/public/io/xs_wire.h
--- a/xen/include/public/io/xs_wire.h	Fri Jul 25 15:03:03 2008 +0100
+++ b/xen/include/public/io/xs_wire.h	Mon Jul 28 11:12:07 2008 +0200
@@ -106,8 +106,8 @@ struct xenstore_domain_interface {
 struct xenstore_domain_interface {
     char req[XENSTORE_RING_SIZE]; /* Requests to xenstore daemon. */
     char rsp[XENSTORE_RING_SIZE]; /* Replies and async watch events. */
-    XENSTORE_RING_IDX req_cons, req_prod;
-    XENSTORE_RING_IDX rsp_cons, rsp_prod;
+    volatile XENSTORE_RING_IDX req_cons, req_prod;
+    volatile XENSTORE_RING_IDX rsp_cons, rsp_prod;
 };
 
 /* Violating this is very bad.  See docs/misc/xenstore.txt. */