Comment 3 for bug 1561497

I don't know if needed after all that time, but the TL;DR is that by default libvirt does not add a pci-root.

You can get around just doing so on your own, add:
  <controller type='pci' index='0' model='pci-root'/>

Mips also supports no custom cpu and I'm not sure on your openvswitch, so I was replacing this.

You can define e.g. [1] just fine, and if I'd have a kernel to boot it might even work.
Yet OTOH don't expect too much from MIPS support in general.

[1]: http://paste.ubuntu.com/25924130/