Unable to boot guest on kernel 2.6.29.1 with kvm-84 or kvm-85

[Kenni Lund <kelu@kelu.dk>]

Hi

When updating to kernel 2.6.29.1, I'm unable to boot my Windows XP Pro 32bit guest. The problem is consistent (actually on both of my laptops, with two different WinXP guests) and it is fixed immediately when downgrading to kernel 2.6.28.8 or an older kernel version.


Scenario:
I'm booting the guest with the command
qemu-kvm -smp 2 -m 1024 -net nic -net user -daemonize -vnc :1 -hda /data/virtualization/winxp.img -boot c

I connect with VNC and see the QEMU BIOS, followed by the Windows menu which lets me select if I want to boot Windows in safe mode or not. It counts down from 30, but when it get to 0 or once I hit the "Start Windows Normally" it freezes and nothing more happens.

The following is written to dmesg when qemu-kvm is launched:
kvm: 4609: cpu1 unhandled wrmsr: 0xc0010117 data 0
kvm: 4609: cpu0 unhandled wrmsr: 0xc0010117 data 0


Further information:
KVM version: 84+85 (userspace only, kernel modules from stock kernel)

I've tested -no-kvm-irqchip and -no-kvm-pit as the bugs-page describes, but it doesn't make a difference.

Adding -no-kvm actually FIXES the issue and make Windows boot...so it doesn't seem to be QEMU related.

# uname -a
Linux T61 2.6.29-ARCH #1 SMP PREEMPT Fri Apr 17 12:46:01 UTC 2009 i686 Intel(R) Core(TM)2 Duo CPU T7250 @ 2.00GHz GenuineIntel GNU/Linux

# lsmod|grep kvm
kvm_intel              39208  0
kvm                   144944  1 kvm_intel


Is this a known problem with this kernel version? If not, what can I do to help debugging it further?

Best Regards
Kenni Lund