BUG: unable to handle kernel paging request - balloon_init - xen-4.1.0 - 2.6.32.39

[Scott Garron <xen-devel@sce.pridelands.org>]

      It appears that a bug that I had reported back in August
(
http://lists.xensource.com/archives/html/xen-devel/2010-08/msg01798.html
) seems to have been fixed in a recent update (
http://lists.xensource.com/archives/html/xen-devel/2011-04/msg00742.html
) ... at least it looks like the same bug to me.  I've been trying, over
the past few days, to move to using a newer version with the fix applied
on a test machine and once I get it working, would like to update my
production server.  It would be nice to be able to get back to doing
backups again.  :)

      I don't know whether or not the fix for that bug worked, though,
because I can't seem to get any combination of a newer hypervisor and
Jeremy's xen.git xen/stable-2.6.32.x branch to boot at all.  I can get
the kernel to boot without Xen, but not with it.

      Here a snippet of serial output near the crash:

[    0.310132] xen_balloon: Initialising balloon driver with page order 0.
[    0.313482] last_pfn = 0x1d9ff0 max_arch_pfn = 0x400000000
[    0.316665] BUG: unable to handle kernel paging request at
ffffea0003800028
[    0.316665] IP: [<ffffffff819a8aea>] balloon_init+0x20b/0x25e
[    0.316665] PGD c402067 PUD c403067 PMD 0
[    0.316665] Oops: 0002 [#1] SMP

Full serial output, lspci -vvv, .config, dmidecode, and grub2 conf can
be retrieved here:

http://www.pridelands.org/~simba/xen-debug/

git log:

commit 057b171345d94c785d7e8bb21302c5d1a23ea048
Merge: 6dfaa17 145fff1
Author: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Date:   Fri Apr 22 13:46:05 2011 -0700

git branch:
   xen/next-2.6.32
* xen/stable-2.6.32.x


hg log:
changeset:   23246:eb4505f8dd97
tag:         tip
user:        Tim Deegan <Tim.Deegan@citrix.com>
date:        Wed Apr 20 12:02:51 2011 +0100
summary:     xen/x86: re-enable xsave by default now that it supports
live migration.

      I've tried booting with no dom0_mem option just to see if that made
any difference.  I also tried using the stable tarball of xen-4.1.0, the
current xen-4.1-testing.hg, as well as xen-unstable.hg.  All yield
exactly the same results.  Any ideas?

-- 
Scott Garron