From: Rik van Riel <riel@redhat.com>
Date: Mon, 26 Jan 2009 18:39:47 -0500
Subject: [xen] guest crash when host has >= 64G RAM
Message-id: 20090126183947.433359da@bree.surriel.com
O-Subject: [RHEL 5.4 PATCH] guest crash when host has >= 64G RAM bz 448115
Bugzilla: 448115
RH-Acked-by: Markus Armbruster <armbru@redhat.com>
RH-Acked-by: Bill Burns <bburns@redhat.com>
RH-Acked-by: Chris Lalancette <clalance@redhat.com>
RH-Acked-by: Chris Lalancette <clalance@redhat.com>

Fixes bug 448115

Going any higher than 40 makes little sense, since the Xen hypervisor
has a 1TB physical memory limit.

# HG changeset patch
# User kfraser@localhost.localdomain
# Date 1169481439 0
# Node ID f3670081945342a91aabd9c5198b0ec9161653fe
# Parent  cc819d81be2a887fbed1ef48731747b45d8faa11
linux/i386: widen physical address range

32on64 supports 168Gb for 32-bit guests, hence at least 38 bits must
be specified here. The foreign frame bit is MFN bit 31, so the maximum
valid value here would be 43.

Signed-off-by: Jan Beulich <jbeulich@novell.com>

diff --git a/include/asm-i386/mach-xen/asm/page.h b/include/asm-i386/mach-xen/asm/page.h
index 5300c86..a142ce2 100644
--- a/include/asm-i386/mach-xen/asm/page.h
+++ b/include/asm-i386/mach-xen/asm/page.h
@@ -7,7 +7,7 @@
 #define PAGE_MASK	(~(PAGE_SIZE-1))
 
 #ifdef CONFIG_X86_PAE
-#define __PHYSICAL_MASK_SHIFT	36
+#define __PHYSICAL_MASK_SHIFT	40
 #define __PHYSICAL_MASK		((1ULL << __PHYSICAL_MASK_SHIFT) - 1)
 #define PHYSICAL_PAGE_MASK	(~((1ULL << PAGE_SHIFT) - 1) & __PHYSICAL_MASK)
 #else