To hot-plug the interface that is specified by the r1.xml file (shown in the figure in Hot-plugging a nonpersistent network interface) in a persistent manner, enter the following command:

# virsh attach-device R1 --persistent ./r1.xml

For a persistent interface, to detach the interface in a persistent manner, enter the following command on your VM guest:

# virsh detach-device R1 --persistent ./r1.xml