Re: [Qemu-devel] [PATCH v2 2/5] vfio-ccw: concurrent I/O handling

[Pierre Morel]

On 23/01/2019 11:21, Cornelia Huck wrote:
> On Tue, 22 Jan 2019 19:33:46 +0100
> Halil Pasic <address@hidden> wrote:
>
> > On Mon, 21 Jan 2019 12:03:51 +0100
> > Cornelia Huck <address@hidden> wrote:
> >
> > > --- a/drivers/s390/cio/vfio_ccw_private.h
> > > +++ b/drivers/s390/cio/vfio_ccw_private.h
> > > @@ -28,6 +28,7 @@
> > >    * @mdev: pointer to the mediated device
> > >    * @nb: notifier for vfio events
> > >    * @io_region: MMIO region to input/output I/O arguments/results
> > > + * @io_mutex: protect against concurrent update of I/O structures
> >
> > We could be a bit more specific about what does this mutex guard.
> > Is it only io_region, or cp, irb and the new regions a well? ->state does
> > not seem to be covered, but should need some sort of synchronisation
> > too, or?
>
> I'm not sure. IIRC Pierre had some ideas about locking in the fsm?

Yes I postponed this work to not collide with your patch series.

Do you think I should provide a new version of the FSM reworking series 
based on the last comment I got?

I would take into account that the asynchronous commands will come with 
your patch series and only provide the framework changes.


Regards,
Pierre



--
Pierre Morel
Linux/KVM/QEMU in Böblingen - Germany