Re: [PATCH 0/5] s390x: Add Full Boot Order Support

[Jared Rossi]

On 6/5/24 4:02 AM, Thomas Huth wrote:
> On 29/05/2024 17.43, jrossi@linux.ibm.com wrote:
> > From: Jared Rossi <jrossi@linux.ibm.com>
> >
> > This patch set primarily adds support for the specification of 
> > multiple boot
> > devices, allowing for the guest to automatically use an alternative 
> > device on
> > a failed boot without needing to be reconfigured. It additionally 
> > provides the
> > ability to define the loadparm attribute on a per-device bases, which 
> > allows
> > boot devices to use different loadparm values if needed.
> >
> > In brief, an IPLB is generated for each designated boot device (up to 
> > a maximum
> > of 8) and stored in guest memory immediately before BIOS. If a device 
> > fails to
> > boot, the next IPLB is retrieved and we jump back to the start of BIOS.
> >
> > Devices can be specified using the standard qemu device tag 
> > "bootindex" as with
> > other architectures. Lower number indices are tried first, with 
> > "bootindex=0"
> > indicating the first device to try.
>
> Is this supposed with multiple scsi-hd devices, too? I tried to boot a 
> guest with two scsi disks (attached to a single virtio-scsi-ccw 
> adapter) where only the second disk had a bootable installation, but 
> that failed...?
>
>  Thomas

Hi Thomas,

Yes, I would expect that to work. I tried to reproduce this using a 
non-bootable scsi disk as the first boot device and then a known-good 
bootable scsi disk as the second boot device, with one controller.  In 
my instance the BIOS was not able to identify the first disk as bootable 
and so that device failed to IPL, but it did move on to the next disk 
after that, and the guest successfully IPL'd from the second device.

When you say it failed, do you mean the first disk failed to boot (as 
expected), but then the guest died without attempting to boot from the 
second disk?  Or did something else happen? I am either not 
understanding your configuration or I am not understanding your error.

Regards,

Jared Rossi