[libvirt] [PATCH 0/5] macvtap support for Qemu/KVM VMs via libvirt

[Stefan Berger]

Hello!

  This is a re-post of previously posted patches following Daniel
Berrange's request for changes along with other fixes.

  The following patches provide support for making the macvtap
networking device type available to Qemu/KVM VMs. The patches rely on
the macvtap driver that just became available through the Linux net-next
tree (fixes still may be necessary) and make the device available to
Qemu/KVM via a tap file descriptor similar to a 'regular' tap device.
  Following up on previous discussions, the libvirt patches allow using
the following XML in the domain description to enable qemu network
connectivity via this type of device:

    <interface type='direct'>
      <source dev='eth1' mode='vepa'/>
      <model type='virtio'/>
    </interface>

  The above XML indicates that eth1 is the Ethernet interface to link
the macvtap device to and communicate to the network. As a consequence,
libvirt will create an instance of a macvtap device, assign it the same
MAC address as the VM's interface has and open a file descriptor of the
associated character device /dev/tap%d and pass it via command line to
Qemu/kvm. In the above XML the mode can be chosen as 'vepa', 'private'
or 'bridge' and is by default set to 'vepa'(by the driver) if omitted.

Attachment and detachment of macvtap to/from a running VM also works.

Regards,
   Stefan