Comment 30 for bug 362691

You're correct - neither Intrepid nor Jaunty ship a Xen dom0-capable kernel. I've been using the Hardy xen kernel in my testing. If you want to replicate that, you can duplicate the Jaunty entries in your /etc/apt/sources.list, replacing jaunty with hardy. This should only affect packages that were present in Hardy but removed before Jaunty. Once you've done that, you can install the linux-xen package to get a Xen dom0 kernel.

Your error about xen.lowlevel.xc makes me think that python-xen-3.3 isn't installed properly - xen.lowlevel.xc is one of the 5 or so C extensions included in that package. Did you somehow force the installation of xen-utils-3.3 without python-xen-3.3?