On Wed, 23 Jan 2019 11:21:12 +0100
Cornelia Huck <cohuck@xxxxxxxxxx> wrote:
> On Tue, 22 Jan 2019 19:33:46 +0100
> Halil Pasic <pasic@xxxxxxxxxxxxx> wrote:
>
> > On Mon, 21 Jan 2019 12:03:51 +0100
> > Cornelia Huck <cohuck@xxxxxxxxxx> 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 there was something. I usually do review by sanity checking the
resulting code. IMHO the fsm stuff is broken now and differently broken
after this series. If we don't want to fix what we are touching, maybe a
pointing out ignored problems in patch descriptions and a
minimal-invasive approach could help ease review.
Regards,
Halil
> >
> > > * @cp: channel program for the current I/O operation
> > > * @irb: irb info received from interrupt
> > > * @scsw: scsw info
> > > @@ -42,6 +43,7 @@ struct vfio_ccw_private {
> > > struct mdev_device *mdev;
> > > struct notifier_block nb;
> > > struct ccw_io_region *io_region;
> > > + struct mutex io_mutex;
> > >
> > > struct channel_program cp;
> > > struct irb irb;
> > > --
> >
>
>
