and in the guest:
<interface type='direct'> <source physical='eth0'> ... </interface>
I like the simplicity of just having this in the guest XML and a way to just indicate macvlan vs macvtap somehow.
macvlan and macvtap devices have to be created per-VM. How they're created is non-trivial as you need to set flags which eventually get down to twiddling bits on the physical interface. So you essentially have two options: 1) punt the creation fo these devices and just let it be specified per-device. libvirt would be incapable of starting these guests automatically without some helper tool. 2) allow the twiddling bits to be specified as part of the per-domain information. <source physical='eth0' mode='vepa'> might be enough but I'm not entirely qualified to understand exactly what the various cases are. Regards, Anthony Liguori