xen discuss - Apr 2011 - PV Driver

Hi,

As of now I have been using xVM on Solaris 11 Express b151a.
And I am looking for PV Driver for Windows 2008 and Windows 2008R2.
So which open source PV driver can I use for these OSs?

And I feel the the performance of PV drvier on Windows 2003 I downloaded from
Sun site, this is early driver,  is bad. The network performance is usually
20kbp/s.
So I want to know how I can get better performance.

Thanks 

Ryo