Shutdown requests are normally hardware dependent.
By extending pvpanic to also handle shutdown requests, guests can
submit such requests with an easily implementable and cross-platform
mechanism.

The background is the usage of minimal Linux kernels with different
architectures for testing purposes.
Poweroff support varies highly per architecture and requires a bunch of
code to be compiled to work.
pvpanic on the other hand is very small and uniform.

I sent an RFC[0] for this before to qemu-devel and lkml which didn't
generate feedback, so let's discuss the concrete proposal.

Patch 1 and 2 are general cleanups, that seems useful even without this
proposal being implemented.

A corresponding patch has been submitted for Linux [1].
This is also where the request was voiced to drop move away from a
pvpanic uapi header in Linux.

[0] https://lore.kernel.org/all/984794aa-4af0-4c68-a74e-7420ec3151a5@t-8ch.de/
[1] https://lore.kernel.org/lkml/20231104-pvpanic-shutdown-v1-1-5ee7c9b3e301@weissschuh.net/

Signed-off-by: Thomas Weißschuh <thomas@t-8ch.de>
---
Changes in v4:
- Rebase on 8.2 master
- Resend after tree reopened and holidays
- Link to v3: https://lore.kernel.org/r/20231129-pvpanic-shutdown-v3-0-c9a2892fc523@t-8ch.de

Changes in v3:
- Drop from Linux imported pvpanic header as discussed with Cornelia and
  requested by Greg
- Link to v2: https://lore.kernel.org/r/20231128-pvpanic-shutdown-v2-0-830393b45cb6@t-8ch.de

Changes in v2:
- Remove RFC status
- Add Ack from Thomas to 2nd patch
- Fix typo in title of 2nd patch
- Link to v1: https://lore.kernel.org/r/20231104-pvpanic-shutdown-v1-0-02353157891b@t-8ch.de

---
Thomas Weißschuh (4):
      linux-headers: drop pvpanic.h
      hw/misc/pvpanic: centralize definition of supported events
      tests/qtest/pvpanic: use centralized definition of supported events
      hw/misc/pvpanic: add support for normal shutdowns

 docs/specs/pvpanic.rst                   | 2 ++
 hw/misc/pvpanic-isa.c                    | 3 +--
 hw/misc/pvpanic-pci.c                    | 3 +--
 hw/misc/pvpanic.c                        | 8 ++++++--
 include/hw/misc/pvpanic.h                | 5 +++++
 include/standard-headers/linux/pvpanic.h | 9 ---------
 scripts/update-linux-headers.sh          | 3 +--
 tests/qtest/pvpanic-pci-test.c           | 5 +++--
 tests/qtest/pvpanic-test.c               | 5 +++--
 9 files changed, 22 insertions(+), 21 deletions(-)
---
base-commit: 0c1eccd368af8805ec0fb11e6cf25d0684d37328
change-id: 20231104-pvpanic-shutdown-02e4b4cb4949

Best regards,
-- 
Thomas Weißschuh <thomas@t-8ch.de>