Xen paravirtualized guests have been around for a long time, but during that period only one BSD OS was able to fully support them, that is NetBSD. With the arrival of hardware extensions to help virtualization, the Xen community has started to develop a new kind of paravirtualized guest that make use of hardware extensions to provide better performance.

This new type of paravirtualized guest, called PVH, makes use of hardware-assisted pagetable virtualization to get rid of one of the most difficult parts to implement when porting a new Operating System to Xen, the paravirtualized MMU. This, apart from the obvious benefit of having a performance boost, also benefits Operating System that don't have a virtualization solution, with the aid of hardware extensions, the required code changes to port a new OS to Xen are reduced.

This talk will focus on the features of the new paravirtualization mode, and how it can simplify the port of new Operating Systems to Xen.