From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Thu, 3 Dec 2020 18:01:41 +0100 From: Halil Pasic Subject: Re: [PATCH] s390/vfio-ap: Clean up vfio_ap resources when KVM pointer invalidated Message-ID: <20201203180141.19425931.pasic@linux.ibm.com> In-Reply-To: <20201203111907.72a89884.cohuck@redhat.com> References: <20201202234101.32169-1-akrowiak@linux.ibm.com> <20201203111907.72a89884.cohuck@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8bit List-ID: To: Cornelia Huck Cc: Tony Krowiak , linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, borntraeger@de.ibm.com, alex.williamson@redhat.com, kwankhede@nvidia.com, david@redhat.com On Thu, 3 Dec 2020 11:19:07 +0100 Cornelia Huck wrote: > > @@ -1095,7 +1106,7 @@ static int vfio_ap_mdev_group_notifier(struct notifier_block *nb, > > matrix_mdev = container_of(nb, struct ap_matrix_mdev, group_notifier); > > > > if (!data) { > > - matrix_mdev->kvm = NULL; > > + vfio_ap_mdev_put_kvm(matrix_mdev); > > Hm. I'm wondering whether you need to hold the maxtrix_dev lock here as > well? In v12 we eventually did come along and patch "s390/vfio-ap: allow hot plug/unplug of AP resources using mdev device" made this a part of a critical section protected by the matrix_dev->lock. IMHO the cleanup should definitely happen with the matrix_dev->lock held. Regards, Halil