Index: i386/intel/pmap.c
===================================================================
RCS file: /cvsroot/hurd/gnumach/i386/intel/pmap.c,v
retrieving revision 1.4.2.16.2.31
diff -u -p -r1.4.2.16.2.31 pmap.c
--- i386/intel/pmap.c	24 Mar 2009 01:48:03 -0000	1.4.2.16.2.31
+++ i386/intel/pmap.c	1 Oct 2009 14:20:09 -0000
@@ -619,6 +619,40 @@ void pmap_bootstrap()
 			|| kernel_virtual_end > VM_MAX_KERNEL_ADDRESS)
 		kernel_virtual_end = VM_MAX_KERNEL_ADDRESS;
 
+#ifdef	MACH_XEN
+	/* Xen only provides 512KB extra bootstrap linear memory, which is far
+	 * from enough to map all available memory, so we need to map more
+	 * bootstrap linear memory. */
+	{
+		pt_entry_t *l1_map = (pt_entry_t*) phystokv(pmap_grab_page());
+		pt_entry_t *base = (pt_entry_t*) boot_info.pt_base;
+		int i;
+#ifdef	PAE
+		pt_entry_t *l2_map = (pt_entry_t*) phystokv(pte_to_pa(base[0]));
+#else	/* PAE */
+		pt_entry_t *l2_map = base;
+#endif	/* PAE */
+		for (i = 0; i < NPTES; i++) {
+			if (!(l2_map[i] & INTEL_PTE_VALID)) {
+				struct mmu_update update;
+				int j, n;
+
+				for (j = 0; j < NPTES; j++)
+					l1_map[j] = intel_ptob(pfn_to_mfn(i * NPTES + j)) | INTEL_PTE_VALID | INTEL_PTE_WRITE;
+				pmap_set_page_readonly_init(l1_map);
+				if (!hyp_mmuext_op_mfn (MMUEXT_PIN_L1_TABLE, kv_to_mfn (l1_map)))
+					panic("couldn't pin page %p(%p)", l1_map, kv_to_ma (l1_map));
+				update.ptr = kv_to_ma(&l2_map[i]);
+				update.val = pa_to_ma(l1_map) | INTEL_PTE_VALID;
+				hyp_mmu_update(kvtolin(&update), 1, kvtolin(&n), DOMID_SELF);
+				if (n != 1)
+					panic("couldn't complete bootstrap map");
+				break;
+			}
+		}
+	}
+#endif	/* MACH_XEN */
+
 	/*
 	 * Allocate and clear a kernel page directory.
 	 */