2Virt device framework has the advantage of easily migrating devices from one platform to another. To prove this all we had to do to the USB-Char device implemented in the Simulated firmware section was to replace the firmware with the serial USB-Convertor found in the Qemu emulator, handling the EHCI USB controller emulation for the HVM Vista guest running over Xen. Basically all a 2Virt platform implementator had to do was:
- replace the simulated DSF firmware with a Qemu Monitor command: usb_add serial:vendorid=02a0, productid=a123 :tcp:localhost:8080 , where the last is the char device connection to a Web Server found on the priviledged domain localhost interface
- Provide to the guest HVM file system the usb2virt.sys driver with no modification
- Install the sample Box2Virt .Net application for communicating with the device
This setup demonstrates how a 2Virt platform implementator can use such a device to connect to a restricted domain without using any real Ethernet component, only shared memory components between guests(Domain0 and DomainU) and between userspace applications in the priviledged Domain0.