[libvirt] hooking a physical nic to a bridge with net-create

Hi I trying to set up a network configuration using libvirt The setup is: 1. a VM using virtio using a tap device connected to a bridge device 2. on the host side eth0 added to the same bridge device(without ip) using libvirt application (say virsh) I want to launch this set up: virsh net-create for the second part virsh create for the first part(tap, virtio, vm etc) I can set the first part(vm, tap, virtio) using the domain xml but I'm also interested in XMLing the second part and net-create it. I tried but only suceeded in creating the bridge Is it possible? am I missing somthing? Thanks in advance