[meta-virtualization] [yocto] Question about XEN-hypervisor and Yocto build system

[Chris Patterson]

(CCing meta-virtualization)

On Wed, Mar 23, 2016 at 8:46 AM, Olsson Rikard (RBSN/ESW1)
<Rikard.Olsson at se.bosch.com> wrote:
> Hello Yocto Members,
>
> I am looking into xen-hypervisor and have downloaded the meta-virtualization layer and updated bblayers.conf to pull in the layer. However I am unsure how to proceed:
> 1) How do I configure the meta-virtualization to use Xen hypervisor

You will need to add "xen" to your DISTRO_FEATURES to toggle on the
yocto kernel config fragment for xen support, as well as libvirt.

> 2) What target do I build/bb file do I build.
>
> I usually build either:
> bitbake core-image-minimal ==> Standard Linux for our HW board
> bitbake core-image-XXX--XXX ==> Standard Linux for our HW board + additional application layers.
>
> I am however unable to understand the connection between the images I currently build and the Xen-hypervisor, for example:
> recipes-extended/libvirt/libvirt_1.2.19.bb:# xen-minimal config
> recipes-extended/images/kvm-image-minimal.bb:DESCRIPTION = "A minimal kvm image"
> recipes-extended/images/xen-image-minimal.bb:DESCRIPTION = "A minimal xen image"
> What are above bitbake recipes, should I build xen-image-minimal.bb instead of core-image-minimal or....
>

This largely depends on what you are trying to do, your BSP, if you
are using the yocto kernel, etc..  Building xen-image-minimal should
provide a bootable dom0 out of the box (at least for typical x86-64)
that can start/stop VMs using xl toolstack (not libvirt).

Adding xen support is largely about getting the appropriate kernel
bits enabled (meta-virtualization provides a config fragment).  For
dom0, you will also need to configure your bootloader to boot xen, and
then you will need to add the packages you desire (qemu, libvirt,
xen-base, etc.) to your specific image.

Good luck!