Re: [SeaBIOS] Regression with latest SeaBIOS booting multi-disk root LVs?

[Stefan Reiter]

On 21/09/2020 15:44, Paul Menzel wrote:
> Dear Stefan,
>
>
> Am 21.09.20 um 15:10 schrieb Stefan Reiter:
>
> > since SeaBIOS 1.14.0 (QEMU 5.1) VMs with LVM root disks spanning more 
> > than one PV fail to boot, if only the first is set as bootable. I 
> > believe this is due to the changes in SeaBIOS only initializing drives 
> > marked as 'bootable' by QEMU.
> >
> > One fix is to mark all disks containing root data as bootable, but 
> > existing setups will still break on upgrade (where only the disk 
> > containing the bootloader is marked). This is not ideal.
> >
> > Discovered by a user in our bugtracker:
> > https://bugzilla.proxmox.com/show_bug.cgi?id=3011
> >
> > and verified by installing Ubuntu 20.04 w/ LVM and GRUB on 
> > virtio-scsi, then expanding the LV to a second disk.
> >
> > I found that just reverting SeaBIOS to 1.13.0 makes it work again, 
> > same guest install, even with QEMU 5.1.
> >
> > Is this intended behaviour? A bug in GRUB? Any fix or workaround?
>
> As SeaBIOS 1.13.0 works and SeaBIOS 1.14.0 does not, please bisect the 
> issue, and tell us the commit introducing the regression.

Bisected for virtio-blk drives:

  2f4d068645 "virtio: Do not init non-bootable devices"

...as expected. Also, untested, but I would strongly assume:

  d6bdb85eb0 "virtio-scsi: skip initializing non-bootable devices"

is the equivalent for virtio-scsi devices, and

  76551856b2 "nvme: skip initializing non-bootable devices"

for NVMe.

> Kind regards,
>
> Paul