Xen kernel what parameters do I need to compile
I compiled a xen kernel on my Ubuntu 9.04 ,
I am not clear with modules that I need to enable or disable to be able to use the Xen Kernel,everything went when when I did the following steps,except an error at the last of the compilation



The machine I am using is having Ubuntu 9.04 and the steps above are described for Ubuntu 8.10 but then more or less with minor modifications the steps should be same ,
The following commands executed successfully
Step1

apt-get upgrade

Step2
apt-get install linux-image-server linux-server

Step 3
apt-get install ubuntu-xen-server build-essential libncurses5-dev gawk mercurial

Step 4
mkdir -p ~/build/linux-2.6.27-xen
cd /usr/src/
hg clone http://xenbits.xensource.com/ext/linux-2.6.27-xen.hg

Step 5

cd linux-2.6.27-xen.hg
make O=~/build/linux-2.6.27-xen/ menuconfig

Step 6
in the
In the kernel configuration menu, after selecting the options which were described on the link


Step 7
when I started compiling the kernel
make O=~/build/linux-2.6.27-xen/

here I got the error at the last step

arch/x86/kernel/built-in.o: In function `timer_interrupt':
/usr/src/linux-2.6.27-xen.hg/arch/x86/kernel/time_32-xen.c:469: undefined reference to `__udivdi3'
make: *** [.tmp_vmlinux1] Error 1


So if some one can help me with what went wrong or tell me where more should I look for the solution.
I had a look on Gentoo xen documentation here
http://www.gentoo.org/doc/en/xen-guide.xml

Some one please tell some right guide or document that help me with Xen on Ubuntu I want to run Dom0 on it.