From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Tue, 19 Feb 2019 10:22:04 +0100 From: Cornelia Huck Subject: Re: [PATCH v2 1/1] s390: vfio_ap: link the vfio_ap devices to the vfio_ap bus subsystem Message-ID: <20190219102204.5e050b76.cohuck@redhat.com> In-Reply-To: <1550513328-12646-2-git-send-email-pmorel@linux.ibm.com> References: <1550513328-12646-1-git-send-email-pmorel@linux.ibm.com> <1550513328-12646-2-git-send-email-pmorel@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: Pierre Morel Cc: borntraeger@de.ibm.com, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, frankja@linux.ibm.com, akrowiak@linux.ibm.com, pasic@linux.ibm.com, david@redhat.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, freude@linux.ibm.com List-ID: On Mon, 18 Feb 2019 19:08:48 +0100 Pierre Morel 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 vfio_ap bus and with that the vfio_ap > bus subsytem, and make the matrix device reside within it. > > Doing this we need to suppress the forced link from the matrix device to > the vfio_ap driver and we suppress the device_type we do not need s/suppress/remove/ ? > 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. > > Reported-by: Marc Hartmayer > Reported-by: Christian Borntraeger > Signed-off-by: Pierre Morel > --- > drivers/s390/crypto/vfio_ap_drv.c | 48 +++++++++++++++++++++++++++++------ > drivers/s390/crypto/vfio_ap_ops.c | 4 +-- > drivers/s390/crypto/vfio_ap_private.h | 1 + > 3 files changed, 43 insertions(+), 10 deletions(-) (...) > @@ -62,6 +58,27 @@ static void vfio_ap_matrix_dev_release(struct device *dev) > kfree(matrix_dev); > } > > +static int matrix_bus_match(struct device *dev, struct device_driver *drv) > +{ > + return 1; > +} > + > +static struct bus_type matrix_bus = { > + .name = "vfio_ap", > + .match = &matrix_bus_match, > +}; > + > +static int matrix_probe(struct device *dev) > +{ > + return 0; > +} I don't think you need this (the important function is the match function of the bus). > + > +static struct device_driver matrix_driver = { > + .name = "vfio_ap", > + .bus = &matrix_bus, > + .probe = matrix_probe, > +}; > + > static int vfio_ap_matrix_dev_create(void) > { > int ret; It's a bit annoying that we need to introduce a bus that basically does nothing, but I think this looks sane. Reviewed-by: Cornelia Huck