diff -r 4adaea8679cf linux-2.6-xen-sparse/arch/xen/x86_64/mm/ioremap.c
--- a/linux-2.6-xen-sparse/arch/xen/x86_64/mm/ioremap.c	Mon Aug 22 06:45:10 2005
+++ b/linux-2.6-xen-sparse/arch/xen/x86_64/mm/ioremap.c	Mon Aug 22 09:40:47 2005
@@ -442,7 +442,7 @@
 		 * __direct_remap_area_pages(). 
 		 */
 		v->val = (machine_addr & PAGE_MASK) | pgprot_val(prot);
-
+		v->val &= __supported_pte_mask;
 		machine_addr += PAGE_SIZE;
 		address += PAGE_SIZE; 
 		v++;