Domains configured with autostart may fail to start if the host
network stack has not been started. E.g. when using bridged
networking autostarting a domain can fail with
libvirtd[1403]: 2012-06-20 13:23:49.833+0000: 1485: error :
qemuAutostartDomain:177 : Failed to autostart VM 'test': Cannot get
interface MTU on 'br0': No such device
(cherry picked from commit 4036aa91bff6482cf4c136c93277619fa8ec6f94)