From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Krowiak Subject: Re: [PATCH v3 1/9] s390: vfio_ap: link the vfio_ap devices to the vfio_ap bus subsystem Date: Mon, 18 Feb 2019 11:35:45 -0500 Message-ID: <602fd1f8-0ac1-42dc-30fd-ea16bb7bbc99@linux.ibm.com> References: <1550152269-6317-1-git-send-email-pmorel@linux.ibm.com> <1550152269-6317-2-git-send-email-pmorel@linux.ibm.com> <20190214155441.087d2a68.cohuck@redhat.com> <9403117a-04a6-8f69-2a61-f96d35a59555@linux.ibm.com> <20190214175730.4ab609ae.cohuck@redhat.com> <9200b1f8-874f-ffa7-bef0-19ca570d7ac1@linux.ibm.com> <20190215101118.5417d725.cohuck@redhat.com> <20190218130147.5ed3edbe.cohuck@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: pmorel@linux.ibm.com, borntraeger@de.ibm.com, alex.williamson@redhat.com, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org, frankja@linux.ibm.com, pasic@linux.ibm.com, david@redhat.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, freude@linux.ibm.com, mimu@linux.ibm.com To: Cornelia Huck Return-path: In-Reply-To: <20190218130147.5ed3edbe.cohuck@redhat.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On 2/18/19 7:01 AM, Cornelia Huck wrote: > On Fri, 15 Feb 2019 16:59:33 -0500 > Tony Krowiak wrote: > >> On 2/15/19 4:11 AM, Cornelia Huck wrote: >>> On Thu, 14 Feb 2019 13:30:59 -0500 >>> Tony Krowiak wrote: >>> >>>> On 2/14/19 12:36 PM, Pierre Morel wrote: >>>>> On 14/02/2019 17:57, Cornelia Huck wrote: > >>>>>> (And reading further in the current code, it seems we clear that >>>>>> structure _after_ the matrix device had been setup, so how can that >>>>>> even work? Where am I confused?) >>>>> >>>>> On device_register there were no bus, so the core just do not look for a >>>>> driver and this field was nor tested nor overwritten. >>> >>> Hm... so has the callback in driver_for_each_device() in >>> vfio_ap_verify_queue_reserved() ever been invoked at all? It seems this >>> patch fixes more than just libudev issues... >> >> It is this patch that rendered the driver_for_each_device() in >> vfio_ap_verify_queue_reserved() erroneous. That function gets called >> every time an adapter or domain is assigned to the mdev. This patch >> introduced the problem with driver_for_each_device(). > > So, does this function need to be removed or called from another place, > then? (It looks like it was dead code before.) I don't see why you think it's dead code: assign_adapter_store ==> vfio_ap_mdev_verify_queues_reserved_for_apid ==> vfio_ap_verify_queue_reserved ==> driver_for_each_device The only way that the vfio_ap_verify_queue_reserved - the function that calls driver_for_each_device - does not get called is if no bits have yet been set in matrix_mdev->matrix.aqm. >