Hello,
I installed Fedora 7 on my Asus L3400Tp (5 GB partition for /, 34 GB for /home), and included vairtualisation with xen in the install. My laptop only supports para-virtualisation, but that doesn't bother me.

$ grep pae /proc/cpuinfo
flags           : fpu vme de pse tsc msr pae mce cx8 mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm up

After install I did yum update, so now I´m with the kernels as shown in the
following exerpt of grub.conf:

title Fedora (2.6.22.1-41.fc7)
   root (hd0,0)
   kernel /boot/vmlinuz-2.6.22.1-41.fc7 ro root=LABEL=/ rhgb quiet
   initrd /boot/initrd-2.6.22.1-41.fc7.img
title Fedora (2.6.20-2925.13.fc7xen)
   root (hd0,0)
   kernel /boot/xen.gz-2.6.20-2925.13.fc7
   module /boot/vmlinuz-2.6.20-2925.13.fc7xen ro root=LABEL=/ rhgb quiet
   module /boot/initrd-2.6.20-2925.13.fc7xen.img

However, when I try to start xen, de following messages appear:
mount: could not find file system '/dev/root'
setuproot: moving /dev failed: No such file or directory
setuproot: error mounting /procs: No such file or directory
setuproot: error mounting /sys: No such file or directory
switchroot: mount failed: No such file or directory
Kernel panic - Not syncing: Attempted to kill init!

And a reboot follows.
I start suspecting a bit that the 'module' vmlinuz-2.6.20-2925.13.fc7xen for xen has a different approach of the hardware, that kernel
xen.gz-2.6.20-2925.13.fc7 does something strange with it? But what?

Some people suggested to use a LVM designater instead of /dev/sda, others to rebuild initrd, or to remove the 'module' in front of initrd and vmlinuz in grub.conf, but none of those suggestions were successful.

Anybody any hint?
Thanks