Re: Nvidia support for Xen
You say you followed the guide but it doesn't tell you to boot the Xenified kernel to install the drivers.
My guess is the xorg.log complaining about missing module is not the nvidia binary driver module but the xorg module nvidia_drv.so perhaps. Perhaps the userland files for the driver are not in the state you expect to them to be. If you haven't already, you need to install the driver while booted on generic kernel including the 32 bit compatibility libraries.