diff -r 4e78528e3480 xen/arch/ia64/linux-xen/efi.c
--- a/xen/arch/ia64/linux-xen/efi.c	Tue Jun 06 09:11:25 2006 -0600
+++ b/xen/arch/ia64/linux-xen/efi.c	Wed Jun 07 09:36:51 2006 -0600
@@ -273,8 +273,13 @@ trim_bottom (efi_memory_desc_t *md, u64 
 	 * descriptor list to become unsorted.  In such a case, md->num_pages will be
 	 * zero, so the Right Thing will happen.
 	 */
-	md->phys_addr += num_skipped_pages << EFI_PAGE_SHIFT;
-	md->num_pages -= num_skipped_pages;
+	if (!(md->attribute & EFI_MEMORY_UC)) {
+		md->phys_addr += num_skipped_pages << EFI_PAGE_SHIFT;
+		md->num_pages -= num_skipped_pages;
+	} else {
+		/* If range supports multiple attributes, turn off WB */
+		md->attribute &= ~EFI_MEMORY_WB;
+	}
 }
 
 static void
@@ -296,7 +301,10 @@ trim_top (efi_memory_desc_t *md, u64 end
 		       "at 0x%lx\n", __FUNCTION__,
 		       (num_dropped_pages << EFI_PAGE_SHIFT) >> 10,
 		       md->phys_addr, end_addr);
-	md->num_pages -= num_dropped_pages;
+	if (!(md->attribute & EFI_MEMORY_UC))
+		md->num_pages -= num_dropped_pages;
+	else
+		md->attribute &= ~EFI_MEMORY_WB;
 }
 
 /*