CentOS 5 :: Guest OS In XEN 5.4 Doesn't Work?

1) Installed Cent os 5.4 in my system (name it as "guest os").

2) Downloaded the full kernel source, and patched the vanilla kernel to export symbol table (2 line change) [URL] (Yes I know that kernel should not be touched, if touched you should not seek help here . but I felt I didnt do any big change in kernel there). Besides we unset the config_smp & config_preempt parameter to make the kernel as not SMP and not preemptive .

3) Then compiled and booted with the new kernel 2.6.18, everything went fine . Now my gust os box is loading fine and I dont have any issue .

So now I need to install this above machine as guest OS in one more XEN machine cent os 5.4 (name it as "xen os").

So we created the image out of the above box "guest os" and added it as VM in xen os . But while booting it always hangs under some error like "/usb device sort of thing" (I dont have the screen where it hangs, but I do have the equivalent xen log from XEN OS linked to [URL] .

1) what the error is, and what need to be changed in my guest os build .

2) In general I am new to this VM and XEN installation, to be frank I am completely zero . Does changing the native os 5.4 to guest os need any change in kernel or something.

3) Does this case possible, install plain cent os in xen machine. After then patch the kernel in VM and boot with that . I guess it should not be possible ...

4) If possible guide me to some documentation where I can learn few basics over this.