virtualization xm console

In vm.cfg of virtual machine check for this entry:

serial="pty"

In the guest, edit the /boot/grub/menu.lst or /boot/grub/grub.conf with the following lines, add them somewhere above the first kernel entry, probably just below the default and timeout directives.

serial --unit=0 --speed=9600
terminal --timeout=5 serial console

Then, in the relevant GRUB entry add to the kernel line:
(append to the kernel line)
console=ttyS0

Reboot the guest and you should have the console. Now to check, you must attach the console to the guest from your dom0. This is done as follows:

# xm create -c vm.cfg