[libvirt-users] F13-x86_64 - New version of qemu in raw virt repo breaks virsh and virt-manager?

[Matthias Bolte]

2010/8/15 Mike Hinz <mike.hinz at yr20.com>:
> Without actually thoroughly thinking about it, I updated my system
> yesterday with the latest qemu-kvm.  rpm -qa shows
>
>  qemu-kvm-0.13.0-0.5.20100809git25fdf4a.fc13.x86_64
>
> See also:
>
> virsh # version
> Compiled against library: libvir 0.8.2
> Using library: libvir 0.8.2
> Using API: QEMU 0.8.2
> Running hypervisor: QEMU 0.13.50
>
> Now when I attempt to start a domain that was working perfectly well
> prior to this update, I get the following:
>
> virsh # start winxp1
> error: Failed to start domain winxp1
> error: internal error Process exited while reading console log output:
> Supported machines are:
> pc         Standard PC (alias of pc-0.13)
> pc-0.13    Standard PC (default)
> pc-0.12    Standard PC
> pc-0.11    Standard PC, qemu 0.11
> pc-0.10    Standard PC, qemu 0.10
> isapc      ISA-only PC
>
> Virt-Manager throws the same error when attempt to start an existing
> domain.
>
> I'm assuming that there's now some sort of compatibility issue between
> the current versions of libvirt/virt-manager and qemu-kvm?

I think this is a machine type compatibility issue between your
previous and current QEMU version.

See 'virsh dumpxml winxp1' for a line like this:

<os>
  <type arch='i686' machine='pc'>hvm</type>
</os>

The machine attribute will probably have a value that your current
QEMU doesn't understand anymore. Therefore, it complains about the
machine type and list the ones it understands.

> Is there a way to get around this and somehow use my existing domains
> with this updated version of qemu-kvm?

You can try to 'virsh edit winxp1' and replace the value of the
machine attribute with something your current QEMU understands, e.g.
'pc-0.13'.

> Interestingly, just out of curiosity, I've started a new installation of
> a WinXP vm.  This seems to be going perfectly well so far, so I assume
> that the issue is only with domains previously created with the older
> version of qemu??

If you define a new guest then libvirt (actually virt-install called
from virt-manager) will pick a machine type that your current QEMU
understands. Therefore, a newly defined guest works.

Matthias