[Qemu-devel] [PATCH v3 0/7] improve error handling for IO instr

[Halil Pasic]

Abstract
=======

The basic idea is: tell how to handle an unusual condition where it's
identified, instead of mapping it to an errno (more or less arbitrarily),
then possibly mapping these errnos around, to finally (mentally) map the
errno back to the condition and take appropriate action.

According to Dong Jia the patch-set also has a functional value: for ccw
pass-through, he is planing to pass-through the instruction completion
information (cc or interruption condition) from the kernel, and this
patch set can pretty much be seen as a preparation for that.

Changelog
=========

Patch 1 should be already applied to Conny's tree. I've included it
nevertheless so guys working on top of current master have everything in
place.

v2 -> v3:
* somewhat uwillingly traded the type safe struct to a somewhat
  type safe enum (because considered ugly) (Thomas, Conny)
* dropped 'template approach' patch which intended to further
  consolidate IO inst. handlers having lot's of logic and code in
  common (Conny)
* added warning if vfio-ccw ORB does not have the flags required
  by the vfio-ccw implementation as suggested (Dong Jia)
* got rid of some unintentional changes (Dong Jia)
* reworded some stuff (comments, commit messages) (Dong Jia)

v1 -> v2:
* use assert if do_subchannel_work without any functions being
  accepted 
* generate unit-exception if ccw-vfio can't handle an otherwise
  good channel program (due to extra limitations) 
* keep using return values opposed to recording into SubchDev
* split out 'add infrastructure' from 'refactor first handler'
* reworded some commit messanges and comments
* rebased on top of current master
* dropped r-b's and acks because of the magnitude of the
  changes

Testing
=======

Nothing happened since v2 except for a quick smoke test. Dong Jia gave v2
a spin with a focus on vfio-ccw. @Dong Jia I would appreciate some proper
testing, especially regarding the changes in vfio-ccw (patch #3).

Halil Pasic (7):
  s390x/css: be more consistent if broken beyond repair
  s390x/css: IO instr handler ending control
  s390x: improve error handling for SSCH and RSCH
  s390x: refactor error handling for XSCH handler
  s390x: refactor error handling for CSCH handler
  s390x: refactor error handling for HSCH handler
  s390x: refactor error handling for MSCH handler

 hw/s390x/css.c              | 163 ++++++++++++--------------------------------
 hw/s390x/s390-ccw.c         |  11 ++-
 hw/vfio/ccw.c               |  28 ++++++--
 include/hw/s390x/css.h      |  47 ++++++++++---
 include/hw/s390x/s390-ccw.h |   2 +-
 target/s390x/ioinst.c       | 136 +++++++-----------------------------
 6 files changed, 132 insertions(+), 255 deletions(-)

-- 
2.13.5