Re: [PATCH v3 3/6] vfio-ccw: protect the I/O region

Cornelia Huck
2019-02-11T15:57:04Z

On Fri, 8 Feb 2019 16:26:06 -0500
Eric Farman <farman@linux.ibm.com> wrote:

> On 01/30/2019 08:22 AM, Cornelia Huck wrote:
> > Introduce a mutex to disallow concurrent reads or writes to the
> > I/O region. This makes sure that the data the kernel or user
> > space see is always consistent.
> >
> > The same mutex will be used to protect the async region as well.
> >
> > Signed-off-by: Cornelia Huck <cohuck@redhat.com>
>
> I keep wondering how the FSM could provide this, but I end up getting
> into chicken/egg rabbit holes.

Yes, if the fsm is able to provide this, it is probably not in an
easy-to-understand way...

> So, until my brain becomes wiser...
>
> Reviewed-by: Eric Farman <farman@linux.ibm.com>

Thanks!

>
> > ---
> > drivers/s390/cio/vfio_ccw_drv.c | 3 +++
> > drivers/s390/cio/vfio_ccw_ops.c | 28 +++++++++++++++++++---------
> > drivers/s390/cio/vfio_ccw_private.h | 2 ++
> > 3 files changed, 24 insertions(+), 9 deletions(-)