====== Gentoo Xen ======

  * [[Xen]]
  * [[xl]]

  * [[https://wiki.gentoo.org/wiki/Xen|Gentoo Wiki: Xen]]

Kernel configuration for Xen domain0:

<code>
Processor type and features  --->
   [*] Linux guest support  --->
      [*]   Enable paravirtualization code
      [*]     Xen guest support
      [*]       Support for running as a PVH guest
      [*]     Paravirtualization layer for spinlocks
</code>

<code>
Power management and ACPI options  --->
   [*] ACPI (Advanced Configuration and Power Interface) Support  --->
</code>

<code>
Bus options (PCI etc.)  --->
   <*> Xen PCI Frontend
</code>

<code>
[*] Networking support --->
   Networking options  --->
         <*> 802.1d Ethernet Bridging
	 [*] Network packet filtering framework (Netfilter) --->
            [*] Advanced netfilter configuration
            [*]   Bridged IP/ARP packets filtering
</code>

<code>
Device Drivers  --->
   Character devices  --->
      [*] Xen Hypervisor Console support
      [*]   Xen Hypervisor Multiple Consoles support
</code>

<code>
Device Drivers  --->
   [*] Block devices  --->
      <*>   Xen virtual block device support
      <*>   Xen block-device backend driver
</code>

<code>
Device Drivers  --->
   Input device support  --->
      [*] Miscellaneous devices  --->
         <*>   Xen virtual keyboard and mouse support
</code>

<code>
Device Drivers  --->
   [*] Network device support  --->
      <*>   Xen network device frontend driver
      <*>   Xen backend network device
</code>

<code>
Device Drivers  --->
   Graphics support  --->
         Frame buffer Devices  --->
            <*> Xen virtual frame buffer support
</code>

<code>
Device Drivers  --->
   Xen driver support  --->
         [*] Xen memory balloon driver
         [*]   Scrub pages before returning them to system
         <*> Xen /dev/xen/evtchn device
         [*] Backend driver support
         <*> Xen filesystem
         [*]   Create compatibility mount point /proc/xen
         [*] Create xen entries under /sys/hypervisor
         <*> userspace grant access device driver
         <*> User-space grant reference allocator driver
         <*> Xen PCI-device backend driver
         <*> Xen ACPI processor
         [*] Xen platform mcelog
         [*] Xen symbols
</code>

You can install ''pygrub'' with the USE flag on the xen-tools package, which is a python wrapper to the old GRUB installs. Alternatively, you can use the newer ''pvgrub'' instead.

<code>
emerge xen-pvgrub xen-tools xen
</code>

Once you've emerged the packages, there will be a ''xen.gz'' kernel located in ''/boot''. You'll need to update your bootloader to use that as the kernel. Your original kernel is passed in as a module.

A sample GRUB legacy configuration:

<code>
title Xen Gentoo Linux 4.1.12
root (hd0,0)
kernel /boot/xen.gz
module /boot/vmlinuz-4.1.12-gentoo root=/dev/sda3
</code>

Update the Xen services to start on boot:

<code>
rc-update add xencommons default
rc-update add xenconsoled default
rc-update add xenstored default
</code>

If you want Xen domains to start on boot, put the configuration files in ''/etc/xen/auto'', and add ''xendomains'' to the startup sequence:

<code>
ln -s /etc/xen/configs/openbsd-5.9_amd64 /etc/xen/configs/auto/
</code>

<code>
rc-update add xendomains default
</code>

Update ''/etc/inittab'':

<code>
c0:2345:respawn:/sbin/agetty 38400 hvc0 linux
</code>

Reload your new inittab:

<code>
telinit q
</code>