On Tue, 26 Feb 2019 13:27:57 -0500 Tony Krowiak <[email protected]> wrote:
> On 2/22/19 10:29 AM, Pierre Morel wrote: > > When the device is remove, we must make sure to > > clear the interruption and reset the AP device. > > > > We also need to clear the CRYCB of the guest. > > > > Signed-off-by: Pierre Morel <[email protected]> > > --- > > drivers/s390/crypto/vfio_ap_drv.c | 35 > > +++++++++++++++++++++++++++++++++++ > > drivers/s390/crypto/vfio_ap_ops.c | 3 ++- > > drivers/s390/crypto/vfio_ap_private.h | 3 +++ > > 3 files changed, 40 insertions(+), 1 deletion(-) (...) > > /** > > + * vfio_ap_update_crycb > > + * @q: A pointer to the queue being removed > > + * > > + * We clear the APID of the queue, making this queue unusable for the > > guest. > > + * After this function we can reset the queue without to fear a race with > > + * the guest to access the queue again. > > + * We do not fear race with the host as we still get the device. > > + */ > > +static void vfio_ap_update_crycb(struct vfio_ap_queue *q) > > +{ > > + struct ap_matrix_mdev *matrix_mdev = q->matrix_mdev; > > + > > + if (!matrix_mdev) > > + return; > > + > > + clear_bit_inv(AP_QID_CARD(q->apqn), matrix_mdev->matrix.apm); > > + > > + if (!matrix_mdev->kvm) > > + return; > > + > > + kvm_arch_crypto_set_masks(matrix_mdev->kvm, > > + matrix_mdev->matrix.apm, > > + matrix_mdev->matrix.aqm, > > + matrix_mdev->matrix.adm); > > +} > > + > > +/** > > * vfio_ap_queue_dev_remove: > > * > > * Free the associated vfio_ap_queue structure > > @@ -70,6 +100,11 @@ static void vfio_ap_queue_dev_remove(struct ap_device > > *apdev) > > struct vfio_ap_queue *q; > > > > q = dev_get_drvdata(&apdev->device); > > + if (!q) > > + return; > > + > > + vfio_ap_update_crycb(q); > > + vfio_ap_mdev_reset_queue(q); > > The reset is unnecessary because once the card is removed from the > CRYCB, the ZAPQ may fail with because the queue may not exist anymore. > Besides, once the card is removed from the guest's CRYCB, the bus > running in the guest will do a reset. You cannot rely on whatever a sane guest would do, any needed cleanup needs to be done by the host. (No idea what actually needs to be done here :) > > > list_del(&q->list); > > kfree(q); > > }
