Bug#958311: cloud kernel 5.5.0-2 does not boot under xen

[Samuel Thibault <sthibault@debian.org>]

Hello,

Getting the same issue :)

Andy Smith, le jeu. 09 juin 2022 15:32:38 +0000, a ecrit:
> On Thu, Jun 09, 2022 at 02:00:30PM +0300, Aleksi Suhonen wrote:
> > The underlying problem is that the cloud kernel is compressed with an
> > algorithm that grub can't uncompress. What I've been doing as a workaround
> > is that I decompress the kernel myself in a kernel install hook.
> 
> Can you show us your xen domu config file? I'm interested in what
> method you are using to boot these.

Using /usr/lib/grub-xen/grub-x86_64-xen.bin here.

> If you're using pvgrub2 to boot PV mode then the bad news is that it
> seems to be largely abandoned as nobody wants to alter it to support
> different kernel compression methods.

Uh... I wonder how it is that it's not just orthogonal to whether
booting in native/PV/PVH...

> The good news is that you should be able to easily switch to PVH
> mode with pvhgrub which uses grub's core routines to decompress the
> kernel and therefore supports whatever compression methods that grub
> normally does.

Ok, so why not switch to PVH indeed. I just replaced

kernel      = '/usr/lib/grub-xen/grub-x86_64-xen.bin'

with

type="pvh"
kernel      = '/usr/lib/grub-xen/grub-i386-xen_pvh.bin'

and it went fine with the cloud image indeed!

Though now I have to fix the default console, to get kernel messages on
hvc0:

console=hvc0

Samuel