From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Reply-To: pmorel@linux.ibm.com Subject: Re: [PATCH v2 1/1] s390: vfio_ap: link the vfio_ap devices to the vfio_ap bus subsystem References: <1550513328-12646-1-git-send-email-pmorel@linux.ibm.com> <1550513328-12646-2-git-send-email-pmorel@linux.ibm.com> <8e6853ba-12ed-a4f3-1263-0e15f715b644@linux.ibm.com> <6cc5b478-4678-9a82-b902-cc9aed22becf@linux.ibm.com> <20190220102731.4fca4f91.cohuck@redhat.com> <20190220135108.49f8f891@oc2783563651> From: Pierre Morel Date: Thu, 21 Feb 2019 13:10:10 +0100 MIME-Version: 1.0 In-Reply-To: <20190220135108.49f8f891@oc2783563651> Content-Type: text/plain; charset="utf-8"; format="flowed" Content-Language: en-US Content-Transfer-Encoding: 8bit Message-Id: Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: Halil Pasic , Cornelia Huck Cc: Tony Krowiak , borntraeger@de.ibm.com, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, frankja@linux.ibm.com, david@redhat.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, freude@linux.ibm.com List-ID: On 20/02/2019 13:51, Halil Pasic wrote: > On Wed, 20 Feb 2019 10:27:31 +0100 > Cornelia Huck wrote: > >> On Tue, 19 Feb 2019 22:31:17 +0100 >> Pierre Morel wrote: >> >>> On 19/02/2019 19:52, Tony Krowiak wrote: >>>> On 2/18/19 1:08 PM, Pierre Morel wrote: >>>>> Libudev relies on having a subsystem link for non-root devices. To ...snip... >>>>> + >>>>> +static struct device_driver matrix_driver = { >>>>> +    .name = "vfio_ap", >>>> >>>> This is the same name used for the original device driver. I think >>>> this driver ought to have a different name to avoid confusion. >>>> How about vfio_ap_matrix or some other name to differentiate the >>>> two. >>> >>> I would like too, but changing this will change the path to the mediated >>> device supported type. >> >> Yes, we don't want to change that. >> > > Nod. However if I cannot change the driver name, I can change the bus name to matrix. At least one less "vfio_ap" name > >>> >>> >>>> >>>>> +    .bus = &matrix_bus, >>>>> +    .probe = matrix_probe, >>>> >>>> I would add: >>>>     .suppress_bind_attrs = true; >>>> >>>> This will remove the sysfs bind/unbind interfaces. Since there is only >>>> one matrix device and it's lifecycle is controlled herein, there is no >>>> sense in allowing a root user to bind/unbind it. >>>> >>> >>> OTOH bind/unbind has no impact. >>> If no one else ask for this I will not change what has already been >>> reviewed by Conny and Christian. >> >> As we only have one driver, it does not really make sense anyway. >> > > I see this as a reason to suppress_bind_attrs. It is much easier than to > think about what should happen when one unbinds the matrix device from > the vfio_ap driver on the vfio_ap bus. With the code as is it seems to > just keep working as if nothing happened. > And /sys/devices/vfio_ap/matrix/mdev_supported_types/ referencing the > name of the driver that is already gone sounds a bit weird. > > Regards, > Halil > If there is no objection I will do this, It seems more logical to me too. Regards, Pierre -- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany