[libvirt] Clock problems with Windows guests and Xen

[Matthew Donovan <matthew atc-nycorp com>]

When I start Windows guests with libvirt my clocks are 5 hours off.  When I
use a Xen configuration file, I can specify an offset (rtc_timeoffset =
-18000) to get my clock to sync with the host.  Is there a way to do specify
this offset in XML with libvirt?  

Right now, I'm using version 0.4.4 but I downloaded the source for 0.5.1 and
it looks like that part of domain_conf.c hasn't changed.

Thanks for any help!
-matthew