Connect physical device to virtual Xen-network

Question

I have a large Xen-server running multiple virtual hosts in a variety of virtual networks. Now there is also the need for physical devices that cannot be virtualized easily to be connected to some of these virtual networks.

If we assume that the device to connect to a virtual network of Xen is in the same local network as the physical Xen-server hosting all virtual environments, what options do I have?

I want the physical device to behave like it is a direct part of the virtual network. As the Xen-server and the networks were already setup when I got my hands on it, I'm not really familiar with the bridging interfaces and how I can utilize them. I also thought about a VPN-based solution to allow the physical device access into the virtual network by creating a virtual VPN server that is part of the target virtual network.