Hello!
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