[RFC PATCH v13 0/4] Report vfio-ap configuration changes

[Rorie Reyes <rreyes@linux.ibm.com>]

Changelog:
v13:
- added lock to 'vfio_ap_cfg_chg_notifier_handler' in patch 2
- added RBs for patch 2 and 3 from Tony

v12:
- adding locks to 'ap_chsc_sei_nt0_have_event' and 'ap_chsc_sei_nt0_get_event'

v11:
- reverted return type to int for 'ap_chsc_sei_nt0_get_event'
   - files reflected are 'ap.c', 'ap-bridge'h, and 'ap-stub.c'
- using defined variables to represent return 0 and 1 to reflect logical sense
- update documentation for 'ap_chsc_sei_nt0_get_event' to reflect return types

v10:
- Added reviewed by for patch 4 by Tony and Cedric
   - review needed for patch 2 and 3
- changed 'cfg_chg_events' to a static variable
- locked 'cfg_chg_events' using QemuMutex
- removed ';' at the end of the definition for NT0
- returning bools for 'ap_chsc_sei_nt0_get_event' and
'ap_chsc_sei_nt0_have_event'
- updated the header file that contains 'ap_chsc_sei_nt0_get_event' and
'ap_chsc_sei_nt0_have_event' to a bool function
- added documentation explaining the returning bool functions
- whitespace clean up

v9:
- added SPDX licensing to newly created file 'hw/s390x/ap-stub.c'

v8:
- fixed windows cross-compile build
- moved /hw/vfio/ap-stub.c to /hw/s390x/ap-stub.c
- updated the use of stub file to MAINTAINERS to reflect new location
- removed if_false for 'CONFIG_VFIO_AP' statement from /hw/vfio/meson.build
- added if_false for 'CONFIG_VFIO_AP' to use ap-stub.c in /hw/s390x/meson.build
- all those changes still address '--without-default-devices' issue from v5

v7:
- Dropped initial commit for linux-header file vfio.h since I created two new commits
to address the changes made in v6
- Moved patches 6 and 7 to the beginning of the series after dropping the first patch
   - Because I dropped the initial commit for linux-header file vfio.h, I had to add
VFIO_AP_CFG_CHG_IRQ_INDEX
- Resyncing latest to v6.15-rc3
- Still need Thomas Huth's review of v5 changes for patch 6/6

v6:
- Updating the update-linux-headers script to address kernel commit change 8a14
- Update headers to retrieve uapi information for vfio-ap for update to Linux v6.15-rc1
- Still need Thomas Huth's review of v5 changes for patch 7/7 (see below)

v5:
- configuring using the '--without-default-devices' fails when building the code
- created a stub file for functions ap_chsc_sei_nt0_get_event and ap_chsc_sei_nt0_have_event
- add if_false for 'CONFIG_VFIO_AP' use ap-stub.c in meson.build
- add the use of the stub file to MAINTAINERS since it's a new file

v4:
- allocating cfg_chg_event before inserting into the queue
- calling nt0_have_event in if loop to check if there are any
elemenets in the queue, then calling QTAILQ_FIRST when the check
passes
- moving memset() after the check

v3:
- changes that were made to patch 3/5 should have been made in
patch 2/5

v2:
- removed warnings that weren't needed
- added unregister function
- removed whitelines
- changed variable names for consistency
- removed rc variable and returning 1 or 0 outright
- reversed logics for if statements
- using g_free() instead of free()
- replaced hardcoded numeric values by defining them with #define
in the header

--------------------------------------------------------------------------

Rorie Reyes (4):
  hw/vfio/ap: notification handler for AP config changed event
  hw/vfio/ap: store object indicating AP config changed in a queue
  hw/vfio/ap: Storing event information for an AP configuration change
    event
  s390: implementing CHSC SEI for AP config change

 MAINTAINERS                  |  1 +
 hw/s390x/ap-stub.c           | 21 +++++++++
 hw/s390x/meson.build         |  1 +
 hw/vfio/ap.c                 | 88 ++++++++++++++++++++++++++++++++++++
 include/hw/s390x/ap-bridge.h | 39 ++++++++++++++++
 target/s390x/ioinst.c        | 11 ++++-
 6 files changed, 159 insertions(+), 2 deletions(-)
 create mode 100644 hw/s390x/ap-stub.c

-- 
2.48.1