Re: Grub xen_pvh platform does not seem to support uncompressed kernels

[Jürgen Groß]

On 02.11.20 07:22, Andy Smith wrote:
> Hi,
>
> [ xen-users in CC as I know a few there are using a decompressed
>    kernel workaround for LZ4 and might be hit by this too ]
>
> I'm currently evaluating switching from booting Xen guests with grub
> Xen PV (grub-mkimage -O x86_64-xen) to Xen PVH (grub-mkimage -O
> i386-xen_pvh). I've noticed that a decompressed guest kernel refuses
> to boot under PVH with the following error:
>
> Loading Linux 5.4.0-52-generic ...
> error: invalid magic number.
>
> That same kernel boots with PV.
>
> If I use the LZ4-compressed version of that kernel as supplied by
> the distribution (Ubuntu 20.04), it works PVH. I therefore can only
> conclude that PVH grub doesn't like kernels with no compression. Is
> that expected?

Can you boot the decompressed kernel on bare metal or in an HVM
domain using grub?

I'm asking because PVH grub is using the standard i386 kernel loading
functions, so I wouldn't expect any differences here compared to bare
metal.

It might still be that PVH grub is missing some code due to wrong
configure parameters, of course.


Juergen