[Pkg-libvirt-maintainers] Bug#731815: virsh: Unable to start any VM with custom cpu model

[Ariel Malves]

Dear Maintainer,

Just to confirm the bug:

I'm running Debian stable, with libvirt, qemu and kvm from 
wheezy-backports (libvirt 1.2.1, API QEMU 1.2.1, hypervisor QEMU 1.7.1), 
in a HP ProLiant G7 server, with Xeon E5649 processor.

I can't start a domain, through virsh start, with any type of custom cpu 
model, even 486. E.g.:

   <cpu mode='custom' match='exact'>
     <model fallback='allow'>486</model>
   </cpu>

virsh start DomTest1 output:

error: Failed to start domain DomTest1
error: internal error: Cannot find suitable CPU model for given data

/var/log/libvirt/libvirtd.log related contents:

2014-04-25 13:26:48.174+0000: 9968: warning : x86Decode:1511 : Preferred 
CPU model 486 not allowed by hypervisor; closest supported model will be 
used
2014-04-25 13:26:48.174+0000: 9968: error : x86Decode:1564 : internal 
error: Cannot find suitable CPU model for given data

Running qemu-system-x86_64 by hand do not show any errors 
(qemu-system-x86_64 -enable-kvm -name DomTest1 -S -machine 
pc-i440fx-1.7,accel=kvm,usb=off -cpu 486 -m 1024.....)

Please, is there any workaround for this bug?

Ariel