# HG changeset patch
# User yamahata@xxxxxxxxxxxxx
# Date 1165199493 -32400
# Node ID 6747f2c0583648ced1ffc0b0bd74613d23fb0cb2
# Parent  6fdbf173142d6b4da68d2019f594f9a81fa70d28
Allocate frame table/mpt table at mfn=0 even when memory isn't assigned at
mfn=0 as work around of transate_domain_pte().
It returns mfn=0 when the machine page isn't present as a work around
for memory mapped I/O where no device is assigned.
Xen might access page_info of mfn=0, so it must be gurantted
that it exists. Otherwise xen panics with tlb miss fault in xen virtual
address area.
Once transate_domain_pte() is fixed correctly, this will be removed.
PATCHNAME: allocate_table_at_mfn_0

Signed-off-by: Isaku Yamahata <yamahata@xxxxxxxxxxxxx>

diff -r 6fdbf173142d -r 6747f2c05836 xen/arch/ia64/xen/xenmem.c
--- a/xen/arch/ia64/xen/xenmem.c	Sat Dec 02 15:19:50 2006 -0700
+++ b/xen/arch/ia64/xen/xenmem.c	Mon Dec 04 11:31:33 2006 +0900
@@ -181,6 +181,22 @@ void init_virtual_frametable(void)
 	printk("virtual machine to physical table: %p size: %lukB\n"
 	       "max_page: 0x%lx\n",
 	       mpt_table, ((table_size << PAGE_SHIFT) >> 10), max_page);
+
+	/*
+	 * XXX work around of translate_domain_pte().
+	 * It returns mfn=0 when the machine page isn't present as
+	 * a work around for memory mapped I/O where no device is assigned.
+	 * Xen might access page_info of mfn=0, so it must be gurantted
+	 * that it exists. Otherwise xen panics with tlb miss fault in xen
+	 * virtual address area.
+	 * Once transate_domain_pte() is fixed correctly, this will
+	 * be removed.
+	 */
+	if (!mfn_valid(0)) {
+		printk("allocating frame table/mpt table at mfn 0.\n");
+		create_frametable_page_table(0, PAGE_SIZE, NULL);
+		create_mpttable_page_table(0, PAGE_SIZE, NULL);
+	}
 }
 
 int