diff -r aa1ab056bfbf xen/include/public/hvm/ioreq.h
--- a/xen/include/public/hvm/ioreq.h	Wed Aug 02 17:42:38 2006 +0100
+++ b/xen/include/public/hvm/ioreq.h	Thu Aug 03 10:39:16 2006 +0800
@@ -80,6 +79,14 @@ struct shared_iopage {
 };
 typedef struct shared_iopage shared_iopage_t;
 
+#define IOREQ_BUFFER_SLOT_NUM     80
+struct buffered_iopage {
+    unsigned long   read_pointer;
+    unsigned long   write_pointer;
+    ioreq_t         ioreq[IOREQ_BUFFER_SLOT_NUM];
+};            /* sizeof this structure must be in one page */
+typedef struct buffered_iopage buffered_iopage_t;
+
 #endif /* _IOREQ_H_ */
 
 /*