2Virt Devices are meant to be a special type of USB devices that offer USB interfaces for accesing different services of the Virtualization platform.

Different 2Virt Interfaces can be used for adding the to a USB device, that a client program, running in a Hardware Virtual Machine can use to take control of platform services, even from priviledged domains.
A sample of USB interfaces that can be added to a 2Virt device are:

• Web Service Interface  - accessing a cluster of Web Servers in a transparent manner, with no ip address needed

• Point to Point Interface - directly and secureky connecting to another virtual machine through a device link

• Libvirt Interface              - leverages virtualization platform services by offering the unsecure HVM guest a on demand libvirt virtualization service capability 

• Point to Multi Interface  - interconnects a whole cluster of virtualized machines in a manner similar to a VPN connection.

One of the merit of the 2Virt device architecture is that it clearly separated the consumer role of a virtualized service in a guest virtual machine and that of the provider role played by the 2Virt device implementator
for the virtualization platform. In this way the HVM guest is offered virtualized services in a transparent manner without relying on platform specific implementations. The following sub-chapters better explain this design:

1. Device Concept        - best describes the overrall 2Virt device functionality as seen from the user perspective in an unpriviledged HVM guest

2. Simulated firmware - shows how a 2Virt device implementator can set up it's developing environment on a Windows NT machine

3. Emulated firmware  - shows how the implemented 2Virt device can be migrated to be emulated in a real virtualization platform, in our case Qemu over Xen

4. PnP UDDI                  - describes a fully functional .Net application, comunicating with a 2Virt device for accesing Web Services found on a localhost interface of another machine