Re: [PATCH v10 03/16] s390/vfio-ap: manage link between queue struct and matrix mdev

[Tony Krowiak]

On 8/25/20 6:25 AM, Cornelia Huck wrote:
> On Fri, 21 Aug 2020 15:56:03 -0400
> Tony Krowiak <akrowiak@xxxxxxxxxxxxx> wrote:
>
> > Let's create links between each queue device bound to the vfio_ap device
> > driver and the matrix mdev to which the queue is assigned. The idea is to
> > facilitate efficient retrieval of the objects representing the queue
> > devices and matrix mdevs as well as to verify that a queue assigned to
> > a matrix mdev is bound to the driver.
> >
> > The links will be created as follows:
> >
> >     * When the queue device is probed, if its APQN is assigned to a matrix
> >       mdev, the structures representing the queue device and the matrix mdev
> >       will be linked.
> >
> >     * When an adapter or domain is assigned to a matrix mdev, for each new
> >       APQN assigned that references a queue device bound to the vfio_ap
> >       device driver, the structures representing the queue device and the
> >       matrix mdev will be linked.
> >
> > The links will be removed as follows:
> >
> >     * When the queue device is removed, if its APQN is assigned to a matrix
> >       mdev, the structures representing the queue device and the matrix mdev
> >       will be unlinked.
> >
> >     * When an adapter or domain is unassigned from a matrix mdev, for each
> >       APQN unassigned that references a queue device bound to the vfio_ap
> >       device driver, the structures representing the queue device and the
> >       matrix mdev will be unlinked.
> >
> > Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxx>
> > ---
> >   drivers/s390/crypto/vfio_ap_ops.c     | 132 +++++++++++++++++++++++++-
> >   drivers/s390/crypto/vfio_ap_private.h |   2 +
> >   2 files changed, 129 insertions(+), 5 deletions(-)
> (...)
>
> > @@ -548,6 +557,87 @@ static int vfio_ap_mdev_verify_no_sharing(struct ap_matrix_mdev *matrix_mdev)
> >   	return 0;
> >   }
> >   
> > +enum qlink_type {
> <bikeshed>I think this is less of a type, and more of an action, so
> maybe call this 'qlink_action' (and the function parameter below
> 'action'?)</bikeshed>

Sure, but what is this <bikeshed> tag?

> > +	LINK_APID,
> > +	LINK_APQI,
> > +	UNLINK_APID,
> > +	UNLINK_APQI,
> > +};
> > +
> > +static void vfio_ap_mdev_link_queue(struct ap_matrix_mdev *matrix_mdev,
> > +				    unsigned long apid, unsigned long apqi)
> > +{
> > +	struct vfio_ap_queue *q;
> > +
> > +	q = vfio_ap_get_queue(AP_MKQID(apid, apqi));
> > +	if (q) {
> > +		q->matrix_mdev = matrix_mdev;
> > +		hash_add(matrix_mdev->qtable,
> > +			 &q->mdev_qnode, q->apqn);
> > +	}
> > +}
> > +
> > +static void vfio_ap_mdev_unlink_queue(unsigned long apid, unsigned long apqi)
> > +{
> > +	struct vfio_ap_queue *q;
> > +
> > +	q = vfio_ap_get_queue(AP_MKQID(apid, apqi));
> > +	if (q) {
> > +		q->matrix_mdev = NULL;
> > +		hash_del(&q->mdev_qnode);
> > +	}
> > +}
> > +
> > +/**
> > + * vfio_ap_mdev_link_queues
> > + *
> > + * @matrix_mdev: The matrix mdev to link.
> > + * @type:	 The type of @qlink_id.
> > + * @qlink_id:	 The APID or APQI of the queues to link.
> > + *
> > + * Sets or clears the links between the queues with the specified @qlink_id
> > + * and the @matrix_mdev:
> > + *     @type == LINK_APID: Set the links between the @matrix_mdev and the
> > + *                         queues with the specified @qlink_id (APID)
> > + *     @type == LINK_APQI: Set the links between the @matrix_mdev and the
> > + *                         queues with the specified @qlink_id (APQI)
> > + *     @type == UNLINK_APID: Clear the links between the @matrix_mdev and the
> > + *                           queues with the specified @qlink_id (APID)
> > + *     @type == UNLINK_APQI: Clear the links between the @matrix_mdev and the
> > + *                           queues with the specified @qlink_id (APQI)
> > + */
> > +static void vfio_ap_mdev_link_queues(struct ap_matrix_mdev *matrix_mdev,
> > +				     enum qlink_type type,
> > +				     unsigned long qlink_id)
> > +{
> > +	unsigned long id;
> > +
> > +	switch (type) {
> > +	case LINK_APID:
> > +		for_each_set_bit_inv(id, matrix_mdev->matrix.aqm,
> > +				     matrix_mdev->matrix.aqm_max + 1)
> > +			vfio_ap_mdev_link_queue(matrix_mdev, qlink_id, id);
> > +		break;
> > +	case UNLINK_APID:
> > +		for_each_set_bit_inv(id, matrix_mdev->matrix.aqm,
> > +				     matrix_mdev->matrix.aqm_max + 1)
> > +			vfio_ap_mdev_unlink_queue(qlink_id, id);
> > +		break;
> > +	case LINK_APQI:
> > +		for_each_set_bit_inv(id, matrix_mdev->matrix.apm,
> > +				     matrix_mdev->matrix.apm_max + 1)
> > +			vfio_ap_mdev_link_queue(matrix_mdev, id, qlink_id);
> > +		break;
> > +	case UNLINK_APQI:
> > +		for_each_set_bit_inv(id, matrix_mdev->matrix.apm,
> > +				     matrix_mdev->matrix.apm_max + 1)
> > +			vfio_ap_mdev_link_queue(matrix_mdev, id, qlink_id);
> > +		break;
> > +	default:
> > +		WARN_ON_ONCE(1);
> > +	}
> > +}
> > +
> (...)
>
> I have not reviewed this deeply, but at a glance, it seems fine.