$ sudo bash -c 'cat <<EOF > /usr/share/libvirt/networks/br0.xml
<network>
<name>br0</name>
<forward mode='bridge'/>
<bridge name='br0'/>
<virtualport type='openvswitch'/>
</network>
EOF'
$ sudo virsh net-define /usr/share/libvirt/networks/br0.xml
$ sudo virsh net-start br0
$ sudo virsh net-autostart br0