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

[Cornelia Huck <cohuck@redhat.com>]

On Tue, 17 Oct 2017 18:19:20 +0200
Halil Pasic <pasic@linux.vnet.ibm.com> wrote:

> On 10/17/2017 05:13 PM, Cornelia Huck wrote:
> > 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.
> >   
> 
> Of course, I'm fine with the fixes (won't answer individually). I think
> both Dong Jia and Pierre have already put enough work in this to be credited
> with a tag, so I really hope they will get around to review this. I would
> be especially happy with an Tested-by: Dong Jia since this series is quite
> under-tested, and the changes in vfio-ccw aren't just minor.
> 
> Of course I could come up with a test setup myself, but I hope Dong Jia
> already has one, and he is certainly more involved with vfio-ccw.

FTR: I'll wait until tomorrow for more tags and then go ahead and apply
(well, if no problem comes up in the meantime). I need to get a pull
request out of the door this week.