[libvirt] [PATCH 0/4] Support macvlan devices for LXC containers

This series does the bare minimum required to support the network inteface type=direct for LXC containers, using macvlan devices as the implementation. There is a slight complication though... For bridged container NICs we create a veth pair of devices. One of the devices lives host side, and is enslaved in a bridge. The other veth device gets moved to the container namespace to form the eth0. So we both both a host & container side device visible. For direct container NICS we create a macvlan device, which is moved to the container namespace. There is no host side interface that is dedicated for the container - only the general ethernet device the macvlan is bound to. Since there is no host side interface for the container we are unable to create network filter rules, or network bandwidth controls. In addition while we could perform the 8021.Qb{gh} association during container startup, before moving the macvlan device to the container namespace, we can't perform any disassociation on container shutdown. By the time we see the container has shutdown, the macvlan device has already been killed off. The inability to setup iptables/tc rules against devices that are only visible in the container namespace is arguably a flaw in the Linux kernel's namespace code support for iptables/tc. There ought to be a syntax for iptables/tc to write rules which affect NICs in other namespaces