Code review comment for ~newell-jensen/maas:lp1788756

> Looks good; one question inline below that I won't block you on. (I think the
> same issue happens in the block devices loop, too.)

All the block devices are created first (see top part of the create_domain method in provisioningserver.drivers.pod.virsh.py) and then attached after the domain has been defined within virsh. Good question though.