Index: xen-unstable.hg/xen/arch/ia64/xen/mm.c
===================================================================
--- xen-unstable.hg.orig/xen/arch/ia64/xen/mm.c	2008-01-15 11:06:21.000000000 +0900
+++ xen-unstable.hg/xen/arch/ia64/xen/mm.c	2008-01-15 11:08:24.000000000 +0900
@@ -591,6 +591,7 @@ u64 translate_domain_pte(u64 pteval, u64
 			pteval = (pteval & ~_PAGE_MA_MASK) | _PAGE_MA_WB;
 		}
 		break;
+#if 0
 	case _PAGE_MA_WB:
 		if (maflags2 != _PAGE_MA_WB) {
 			/* Forbid non-coherent access to coherent memory. */
@@ -598,6 +599,7 @@ u64 translate_domain_pte(u64 pteval, u64
 			             "UC page, mpaddr=%lx\n", mpaddr);
 		}
 		break;
+#endif
 	default:
 		panic_domain(NULL, "try to use unknown mem attribute\n");
 	}
Index: xen-unstable.hg/xen/include/asm-ia64/linux-xen/asm/pgtable.h
===================================================================
--- xen-unstable.hg.orig/xen/include/asm-ia64/linux-xen/asm/pgtable.h	2008-01-15 11:03:47.000000000 +0900
+++ xen-unstable.hg/xen/include/asm-ia64/linux-xen/asm/pgtable.h	2008-01-15 11:06:49.000000000 +0900
@@ -37,7 +37,8 @@
 #define _PAGE_D_BIT		6
 
 #define _PAGE_P			(1 << _PAGE_P_BIT)	/* page present bit */
-#define _PAGE_MA_WB		(0x0 <<  2)	/* write back memory attribute */
+//#define _PAGE_MA_WB		(0x0 <<  2)	/* write back memory attribute */
+#define _PAGE_MA_WB             _PAGE_MA_UC
 #ifdef XEN
 #define _PAGE_RV1_BIT		1
 #define _PAGE_RV2_BIT		50