Re: [PATCH v3 1/1] s390: vfio_ap: link the vfio_ap devices to the vfio_ap bus subsystem

[Halil Pasic <pasic@linux.ibm.com>]

On Thu, 21 Feb 2019 16:09:10 +0100
Cornelia Huck <cohuck@redhat.com> wrote:

> On Thu, 21 Feb 2019 15:14:54 +0100
> Pierre Morel <pmorel@linux.ibm.com> wrote:
> 
> > Libudev relies on having a subsystem link for non-root devices. To
> > avoid libudev (and potentially other userspace tools) choking on the
> > matrix device let us introduce a matrix bus and with it the matrix
> > bus subsytem. Also make the matrix device reside within the matrix
> > bus.
> > 
> > Doing this we remove the forced link from the matrix device to the
> > vfio_ap driver and the device_type we do not need anymore.
> > 
> > Since the associated matrix driver is not the vfio_ap driver any more,
> > we have to change the search for the devices on the vfio_ap driver in
> > the function vfio_ap_verify_queue_reserved.
> > 
> > Fixes: 1fde573413b5 ("s390: vfio-ap: base implementation of VFIO AP device driver")
> > 
> > Cc: stable@vger.kernel.org
> > 
> 
> I'd kill the two empty lines.

The summary/title line is a bit weird. It says link to the vfio_ap bus
subsystem, which sounds like establishing a relationship between two
pre-existing entities.  But this change actually introduces the vfio_bus.
I would prefer something like "introduce vfio_ap bus".

I don't feel strongly about it.

Regards,
Halil

> 
> > Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com>
> > Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
> > Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
> > Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
> > Reviewed-by: Cornelia Huck <cohuck@redhat.com>
> > Acked-by: Halil Pasic <pasic@linux.ibm.com>
> > ---
> >  drivers/s390/crypto/vfio_ap_drv.c     | 44 ++++++++++++++++++++++++++++-------
> >  drivers/s390/crypto/vfio_ap_ops.c     |  4 ++--
> >  drivers/s390/crypto/vfio_ap_private.h |  1 +
> >  3 files changed, 38 insertions(+), 11 deletions(-)
> 
> Otherwise, still looks good.
>