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

[Cornelia Huck <cohuck@redhat.com>]

On Tue, 17 Oct 2017 16:04:46 +0200
Halil Pasic <pasic@linux.vnet.ibm.com> wrote:

> 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).

Looks sane to me (if needed, I can fix up the minor things I found).

In addition to some testing, I'd appreciate some review from others as
well.

> 
> 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(-)
>