kvm_intel kernel module crash with via nano vmx

kvm module for hardware virtualisation not work properly on via nano processors.

Tested with processor: VIA Nano processor U2250.
Processors flags (visible in /proc/cpuinfo): fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat clflush acpi mmx fxsr sse sse2 ss tm syscall nx lm constant_tsc up rep_good pni monitor vmx est tm2 ssse3 cx16 xtpr rng rng_en ace ace_en ace2 phe phe_en lahf_lm

With kernel 2.6.32: kvm not work and dmesg contains a lot of:
handle_exception: unexpected, vectoring info 0x8000000d intr info 0x80000b0d

With kernel 2.6.35: all the system crash. Nothing visible in logs

I confirm that. Same dmesg log all over the place trying to use KVM with a VIA Nano U2250.

Thanks for reporting this bug and helping to make Ubuntu better.

A bit of searching suggests that VIA Nano was until recently very little tested and supported.   The kernels you are working with are rather old compared to upstream.  So in order to see whether you should be talking to us or kvm upstream, could you please test this with the latest daily kernel build (see http://kernel.ubuntu.com/~kernel-ppa/mainline/daily/current/) and the latest qemu-kvm build (see https://launchpad.net/~ubuntu-server-edgers/+archive/server-edgers-qemu-kvm).

Note that this appears to be a dup of http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=570244.  See also thread at http://www.spinics.net/lists/kvm/msg41122.html.

yes this appears to be a duplication but the original bugreport has been posted one year ago and there is no evolution. Moreover, it's not posted on the officiel qemu / kvm bugtracker ;).

I'm waiting that my current installation complete and i test the new kernel / kvm, but i've tested one week ago with the linux kernel kvm git branch and the git master version of kvm, and it crashed directly.

Confirmation: totaly crash with latest build. Nothing in logs.

Quoting khetzal (<email address hidden>):
> Confirmation: totaly crash with latest build. Nothing in logs.

Thanks for testing.  Are you able to get in touch with the kvm
(<email address hidden>) and linux-kernel (<email address hidden>)
mailing list to follow up with upstream?


Thanks for your help. I've subscribed to these mailing list. Have i do report the bug in these mailing list too ? (or is it a useless other duplication ?)

Quoting khetzal (<email address hidden>):
> Thanks for your help. I've subscribed to these mailing list. Have i do
> report the bug in these mailing list too ? (or is it a useless other
> duplication ?)

It will not be duplication.  These are development lists, not support
lists, so you won't be filing a bug report.  Rather, report your
failures and ask whether (a) they are aware of it, (b) it is expected,
(c) anyone is currently working on support for via nano, and
(d) how others can help.


> yes this appears to be a duplication but the original bugreport 
> has been posted one year ago and there is no evolution. Moreover,
> it's not posted on the officiel qemu / kvm bugtracker ;).

Not really. KVM module bugs should be reported to the kernel's bug tracker as explained on http://www.linux-kvm.org/page/Bugs .

Retargetting at the kernel as this is a kernel bug.

khetzal, can you confirm whether you are still having this bug?

Hello, yes i still have this bug on ubuntu 12.04 (kernel 3.2)

This bug is missing log files that will aid in diagnosing the problem. From a terminal window please run:

apport-collect 712416

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

It's impossible to run any command because the system is frozen

I can confirm this is still an issue. I have tried myself with this and it crashes the whole system and has to be rebooted again to even get it useable again.

This does not sound like a QEMU bug, so let's remove it from the QEMU bug tracker