On Mon, Jun 21, 2021 at 06:04:54PM +0200, Christian Borntraeger wrote: > > > On 21.06.21 17:57, Tony Krowiak wrote: > > The mdev remove callback for the vfio_ap device driver bails out with > > -EBUSY if the mdev is in use by a KVM guest (i.e., the KVM pointer in the > > struct ap_matrix_mdev is not NULL). The intended purpose was > > to prevent the mdev from being removed while in use. There are two > > problems with this scenario: > > > > 1. Returning a non-zero return code from the remove callback does not > > prevent the removal of the mdev. > > > > 2. The KVM pointer in the struct ap_matrix_mdev will always be NULL because > > the remove callback will not get invoked until the mdev fd is closed. > > When the mdev fd is closed, the mdev release callback is invoked and > > clears the KVM pointer from the struct ap_matrix_mdev. > > > > Let's go ahead and remove the check for KVM in the remove callback and > > allow the cleanup of mdev resources to proceed. > > > > Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxx> > > Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx> > > Cc: stable@xxxxxxxxxxxxxxx > > This one is already queued on > > https://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git/log/?h=fixes > > Jason. Do you want this in stable? Then we should write a mail after > merging. It is fine as is, we are already at rc7, so long as it goes to some tree for this merge window Jason
