Xen-4.1-unstable hypervisor booting error

[Michal Novotny <minovotn@redhat.com>]

Hi,
I've installed latest PVops kernel 2.6.32.21 (upgraded from 2.6.32.15 
using the very same kernel build configuration - i.e. copied the 
config-2.6.32.15 file to the kernel source directory) and I can boot 
without hypervisor (using the standard kernel/initrd directives in grub) 
but not with the hypervisor since it fails.

Call trace is:
  [ <ffffffff8100faf2> ] ? check_events+0x12/0x20
  [ <ffffffff8108f94f> ] ? lock_acquire+0xe3/0xf2
  [ <ffffffff812cd2f3> ] ? balloon_process+0x0/0x555
  [ <ffffffff8107793f> ] worker_thread+0x1b2/0x2b1
  [ <ffffffff810778e6> ] ? worker_thread+0x159/0x2b1
  [ <ffffffff8107bf13> ] ? autoremove_wake_function+0x0/0x3d
  [ <ffffffff8107778d> ] ? worker_thread+0x0/0x2b1
  [ <ffffffff8107bcc1> ] kthread+0x6e/0x76
  [ <ffffffff81013eea> ] child_rip+0xa/0x20
  [ <ffffffff81013850> ] ? restore_args+0x0/0x30
  [ <ffffffff8107bdb6> ] ? kthreadd+x0ed/0x10f
  [ <ffffffff8100fadf> ] ? xen_restore_fl_direct_end+0x0/0x1
  [ <ffffffff81013ee0> ] ? child_rip+0x0/0x20

Code: 49 c1 fd 03 4c 8b 34 d5 e0 a6 61 82 4c 0f af e8 80 3d 3b 65 5a 00 
00 75 0d 4c 89 ef e8 32 fa d3 ff 48 ff c0 75 05 45 31 ff eb 5a <0f> 0b 
eb fe 4c 89 f6 48 89 df e8 4b 03 d4 ff 48 3b 1d 97 f7 1c

RIP [ <ffffffff812cd49b> ] balloon_process+0x1a8/0x555
  RSP [ <ffff8801e9435d50> ]
--- [ end trace e93713a9d40cd06c ] ---
events/0 used greatest stack depth: 4664 bytes left

And the host is stuck and can't boot.

Was it OK to use the config from 2.6.32.15 for 2.6.32.21 build or any 
pointers what may be going on? The kernel/system is x86_64 system 
running on RHEL-5 with the PVops kernel now but as I said, it can't boot 
with the hypervisor but everything is fine (except Xen) when booting 
without the hypervisor.

Thanks,
Michal

-- 
Michal Novotny<minovotn@redhat.com>, RHCE
Virtualization Team (xen userspace), Red Hat