[RFC,v4,0/5] Report vfio-ap configuration changes

Message

Rorie Reyes March 11, 2025, 3:16 p.m. UTC

Changelog:

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

--------------------------------------------------------------------------
This patch series creates and registers a handler that is called when
userspace is notified by the kernel that a guest's AP configuration has
changed. The handler in turn notifies the guest that its AP configuration
has changed. This allows the guest to immediately respond to AP
configuration changes rather than relying on polling or some other
inefficient mechanism for detecting config changes.

Rorie Reyes (5):
  linux-headers: NOTFORMERGE - placeholder uapi updates for AP config
    change
  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

 hw/vfio/ap.c                 | 82 ++++++++++++++++++++++++++++++++++++
 include/hw/s390x/ap-bridge.h | 22 ++++++++++
 linux-headers/linux/vfio.h   |  1 +
 target/s390x/ioinst.c        | 11 ++++-
 4 files changed, 114 insertions(+), 2 deletions(-)