--- init-xen.c.orig	2009-02-17 18:58:58.716954000 -0800
+++ init-xen.c	2009-02-17 19:33:57.310074000 -0800
@@ -587,35 +587,45 @@ void __init xen_init_pt(void)
 static void __init extend_init_mapping(unsigned long tables_space)
 {
 	unsigned long va = __START_KERNEL_map;
-	unsigned long phys, addr, *pte_page;
+	unsigned long phys, addr, *pte_page, *pmd_page;
+	pud_t *pud;
 	pmd_t *pmd;
 	pte_t *pte, new_pte;
-	unsigned long *page = (unsigned long *)init_level4_pgt;
+	unsigned long *pud_page = (unsigned long *)init_level4_pgt;
 
-	addr = page[pgd_index(va)];
-	addr_to_page(addr, page);
-	addr = page[pud_index(va)];
-	addr_to_page(addr, page);
-
-	/* Kill mapping of low 1MB. */
+	/* Kill low mappings */
 	while (va < (unsigned long)&_text) {
 		if (HYPERVISOR_update_va_mapping(va, __pte_ma(0), 0))
 			BUG();
 		va += PAGE_SIZE;
 	}
+	addr = pud_page[pgd_index(va)];    /* get pud entry from pgd tbl */
+	addr_to_page(addr, pud_page);      /* pud_page now va of pud tbl */
 
 	/* Ensure init mappings cover kernel text/data and initial tables. */
 	while (va < (__START_KERNEL_map
 		     + (start_pfn << PAGE_SHIFT)
 		     + tables_space)) {
-		pmd = (pmd_t *)&page[pmd_index(va)];
+
+                pud = (pud_t *)&pud_page[pud_index(va)];    /* get pud entry */
+                if (pud_none(*pud)) {
+                        pmd_page = alloc_static_page(&phys);
+                        early_make_page_readonly(
+                                pmd_page, XENFEAT_writable_page_tables);
+                        set_pud(pud, __pud(phys | _KERNPG_TABLE));
+                } else {
+                        addr = pud_page[pud_index(va)];
+                        addr_to_page(addr, pmd_page);
+                }
+
+		pmd = (pmd_t *)&pmd_page[pmd_index(va)];
 		if (pmd_none(*pmd)) {
 			pte_page = alloc_static_page(&phys);
 			early_make_page_readonly(
 				pte_page, XENFEAT_writable_page_tables);
 			set_pmd(pmd, __pmd(phys | _KERNPG_TABLE));
 		} else {
-			addr = page[pmd_index(va)];
+			addr = pmd_page[pmd_index(va)];
 			addr_to_page(addr, pte_page);
 		}
 		pte = (pte_t *)&pte_page[pte_index(va)];
@@ -630,7 +640,7 @@ static void __init extend_init_mapping(u
 
 	/* Finally, blow away any spurious initial mappings. */
 	while (1) {
-		pmd = (pmd_t *)&page[pmd_index(va)];
+		pmd = (pmd_t *)&pmd_page[pmd_index(va)];
 		if (pmd_none(*pmd))
 			break;
 		if (HYPERVISOR_update_va_mapping(va, __pte_ma(0), 0))
@@ -719,6 +729,7 @@ static void xen_finish_init_mapping(void
 	table_end = start_pfn;
 }
 
+
 /* Setup the direct mapping of the physical memory at PAGE_OFFSET.
    This runs before bootmem is initialized and gets pages directly from the 
    physical memory. To access them they are temporarily mapped. */