[libvirt] [PATCH v2 0/5] Support NBD volumes with LXC containers

[Daniel P. Berrange]

A second version of:

  https://www.redhat.com/archives/libvir-list/2013-March/msg00941.html

Aside from the addressing the previous round of feedbac, this adds
use of the new '--format' flag to qemu-nbd. This is introduced due
to CVE-2013-1922. The upshot is that this code won't work with any
qemu-nbd  binary lacking the --format flag. This is intentionale.