[Qemu-devel] qemu-kvm guest which won't 'cont' (emulation failure?)

[Chris Webb]

I have a qemu-kvm guest (apparently a Ubuntu 11.04 x86-64 install) which has
stopped and refuses to continue:

  (qemu) info status
  VM status: paused
  (qemu) cont
  (qemu) info status
  VM status: paused

The host is running linux 2.6.39.2 with qemu-kvm 0.14.1 on 24-core Opteron
6176 box, and has nine other 2GB production guests on it running absolutely
fine.

It's been a while since I've seen one of these. When I last saw a cluster of
them, they were emulation failures (big real mode instructions, maybe?). I
also remember a message about abnormal exit in the dmesg previously, but I
don't have that here. This time, there is no host kernel output at all, just
the paused guest.

I have qemu monitor access and can even strace the relevant qemu process if
necessary: is it possible to use this to diagnose what's caused this guest
to stop, e.g. the unsupported instruction if it's an emulation failure?

Cheers,

Chris.