Setting up the Xen-kernel for Virtual Machines

Since many days, I've been trying hard to install xen on various architectures using various methods.. but with a very low success rate. Here are the steps that worked for me (These steps are taken from here, with some modifications):

1. Take a machine with 64 bit architecture. To check the config of a machine:
$uname -a
If the line contains i386 or i686, the machine is 32-bit. If it contains x86_64, the machine is 64-bit.
(Alternatively, you can do:
$egrep -c ' lm ' /proc/cpuinfo
If the result is 1 or higher, it is a 64-bit machine; if it is a 0, it is not a 64-bit machine)


2. Install Ubuntu 8.10.

3.

$sudo su

Configure network, sources, etc.

4.

$apt-get install linux-image-server linux-server

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

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

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

5.

In the kernel configuration menu, make sure that you select the following options:

General setup ---> Choose SLAB allocator (SLUB (Unqueued Allocator)) ---> (X) SLAB

Processor type and features ---> Subarchitecture Type (PC-compatible) ---> (X) Enable Xen compatible kernel

Bus options (PCI etc.)  ---> [*] PCI support
                             [*]   Xen PCI Frontend
                             [ ]     Xen PCI Frontend Debugging (NEW)

Networking support ---> Networking options ---> <*> 802.1d Ethernet Bridging

Device Drivers ---> [*] Network device support ---> [ ] Ethernet (10000 Mbit) --->

Make the Xen section look as follows (make sure you select Xen version compatibility (3.0.4 and later) instead of Xen version compatibility (3.0.2 and later)):

Device Drivers  ---> XEN  ---> [*] Privileged Guest (domain 0)
                               <*> Backend driver support (NEW)
                               <*>   Block-device backend driver (NEW)
                               <*>   Block-device tap backend driver (NEW)
                               <*>   Network-device backend driver (NEW)
                               (8)     Maximum simultaneous transmit requests (as a power of 2) (NEW)
                               [ ]     Pipelined transmitter (DANGEROUS) (NEW)
                               < >     Network-device loopback driver (NEW)
                               <*>   PCI-device backend driver (NEW)
                                       PCI Backend Mode (Virtual PCI)  --->
                               [ ]     PCI Backend Debugging (NEW)
                               < >   TPM-device backend driver (NEW)
                                  SCSI backend driver (NEW)
                                Block-device frontend driver
                                Network-device frontend driver
                                  Network-device frontend driver acceleration for Solarflare NICs (NEW)
                                SCSI frontend driver (NEW)
                               <*> User-space granted page access driver (NEW)
                               <*> Framebuffer-device frontend driver (NEW)
                               <*>   Keyboard-device frontend driver (NEW)
                               [*] Disable serial port drivers (NEW)
                               <*> Export Xen attributes in sysfs (NEW)
                               (256) Number of guest devices (NEW)
                                   Xen version compatibility (3.0.4 and later)  --->

6. After this, you need to do the following:
Open the file /usr/src/linux-2.6.29.2-xen/arch/x86/kernel/time_32-xen.c

$vim /usr/src/linux-2.6.29.2-xen/arch/x86/kernel/time_32-xen.c

Add the following line (highlighted) to the code at around line 500:

/* System-wide jiffy work. */
 if (delta >= NS_PER_TICK) {
         do_div(delta, NS_PER_TICK);
         processed_system_time += delta * NS_PER_TICK;
         while (delta > HZ) {

         asm("":"+r"(delta));

         do_timer(HZ);
         delta -= HZ;
    }
    do_timer(delta);
 }

(Note: if you don't add this line in the code, then while building the kernel in the next step, you may see too many warnings flashing on the screen and the build process may terminate after throwing an error.
Note2 (imp): The above step applies to the linux-2.6.29.2-xen sources. I have tried it on linux-2.6.27-xen and it worked. It may not apply to later releases. If you have a later release, try skipping this step)


7.

$make O=~/build/linux-2.6.27-xen/
$make O=~/build/linux-2.6.27-xen/ modules_install install

$depmod 2.6.27.5
$update-initramfs -c -k 2.6.27.5

$update-grub

8.

$vim /etc/modules

 and append the line:

loop max_loop=64

9.

$reboot

And after the reboot,

$uname -r

should show the xen kernel version (2.6.27.5).

10. After this you may think it is all done. Thats right, except that networking might have been screwed up!
If that is the case, continue with the following steps:

$apt-get remove network-manager

11.

$vim /etc/network/interfaces

and add the following lines:

auto eth0
iface eth0 inet static
        address         <dom0 IP>
        gateway         <a relevant gateway>
        netmask         <a relevant netmask>
        broadcast       <a relevant broadcast address>

You may get most of this info by doing 'ifconfig' on a similar machine.

12.

$vim /etc/resolv.conf

and add an entry for the DNS server you use:

nameserver <nameserver-IP>

you may add more than one entries.

Further, you may want to try out the following:
1. Create and Start Virtual Machines
     - this is a very good reference for creating image based virtual machines.
2. Migrating Virtual Machines
     - see this.


Other Ref:
http://www.infohit.net/blog/post/running-xen-on-ubuntu-intrepid-and-jaunty.html