Re: [Qemu-devel] [PATCH v4 2/2] vfio-ccw: support async command subregion

[Cornelia Huck <cohuck@redhat.com>]

On Tue, 21 May 2019 16:47:45 -0400
Eric Farman <farman@linux.ibm.com> wrote:

> On 5/21/19 12:32 PM, Cornelia Huck wrote:

> > Why mostly? I'm not sure yet whether we handling multiple requests for
> > passthrough devices correctly yet (virtual should be fine.)
> > 
> > Start vs. (start|halt|clear) is fine, as the code checks whether
> > something is already pending before poking the kernel interface.
> > Likewise, halt vs. (start|halt|clear) is fine, as the code checks for
> > halt or clear and start and halt use different regions. The problematic
> > one is clear, as that's something that's always supposed to go through.
> > Probably fine if clear should always "win", but I need to think some
> > more about that.  
> 
> I suspect you are right, because of the check on the halt side, and
> considering that the clear is the biggest recovery action we have.  So
> this does seem like things are okay.  I'll ponder this overnight and
> finish my review tomorrow.

Ok, what's the verdict here? :)

(I'm trying to clean up my pending stuff :)