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

[Thomas Huth]

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.
>
> A subsequent Libvirt patch will be necessary to allow assignment of per-device
> loadparms in the guest XML
>
> Jared Rossi (5):
>    Create include files for s390x IPL definitions
>    Add loadparm to CcwDevice
>    Build IPLB chain for multiple boot devices
>    Add boot device fallback infrastructure
>    Enable and document boot device fallback on panic
>
>   docs/system/bootindex.rst         |   7 +-
>   docs/system/s390x/bootdevices.rst |   9 +-
>   hw/s390x/ccw-device.h             |   2 +
>   hw/s390x/ipl.h                    | 117 +-------------------
>   include/hw/s390x/ipl/qipl.h       | 128 ++++++++++++++++++++++
>   pc-bios/s390-ccw/bootmap.h        |   5 +
>   pc-bios/s390-ccw/iplb.h           | 108 +++++--------------
>   pc-bios/s390-ccw/s390-ccw.h       |   6 ++
>   hw/s390x/ccw-device.c             |  49 +++++++++
>   hw/s390x/ipl.c                    | 170 ++++++++++++++++++++++--------
>   hw/s390x/s390-virtio-ccw.c        |  18 +---
>   hw/s390x/sclp.c                   |   3 +-
>   pc-bios/s390-ccw/bootmap.c        |  41 ++++---
>   pc-bios/s390-ccw/main.c           |  25 +++--
>   pc-bios/s390-ccw/netmain.c        |   4 +
>   pc-bios/s390-ccw/Makefile         |   2 +-

 Hi Jared!

For v2, could you please add at least two tests: one that check booting from 
the second disk and one that checks booting from the last boot disk when the 
previous ones are invalid?

I could think of two easy ways for adding such tests, up to you what you prefer:

- Extend the tests/qtest/cdrom-test.c - see add_s390x_tests() there

- Add an avocado test - see "grep -l s390 tests/avocado/*.py" for examples.

 Thomas