Linuxers posted a guide about installing the Nvidia driver on a Xen kernel CentOS 5.5 system

TweetWe have already discussed the installation of Nvidia driver on CentOS. But this method only applies to regular kernels. Xen, the virtual machine monitor, requires you to install a modified linux kernel and guess what, nVidia officially doesn't support it. The regular installation is aborted when this kernel is detected and working without the driver is not possible because the performance degradation is unbearable(at least on my system). So, after some searching and trying out different methods, I finally found this work around to make nvidia drivers work on Xen kernels.
Lets start by updating the system. Run the following commands.

  How to install Nvidia driver on a Xen kernel, CentOS 5.5(Final)