Newer libvirt fails with host-model

[Vish Ishaya]

Newer installs of libvirt reject our host-model xml with the following error:

$ sudo virsh -d0 start instance-00000002
start: domain(optdata): instance-00000002
start: found option <domain>: instance-00000002
start: <domain> trying as domain NAME
error: Failed to start domain instance-00000002
error: internal error Cannot find suitable CPU model for given data
Manually running cpu-compare gives the exact error:

$ sudo virsh cpu-compare libvirt.xml

error: Failed to compare host CPU with libvirt.xml
error: XML error: 'arch' element element cannot be used inside 'cpu' element with 'match' attribute'

According to the following patch, I believe our xml generation is incorrect and older versions of libvirt were silently ignoring the error:

http://osdir.com/ml/libvir-list/2010-07/msg00240.html

[Vish Ishaya (vishvananda)]

ok the Cannot find suitable CPU model seems to be a different error. Investigating

[Vish Ishaya (vishvananda)]

Ok i think my issue was due to incompatible versions of libvirt and qemu. That said it seems like passing in the arch element is probably incorrect.