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

Cornelia Huck
2020-08-25T10:25:20Z

On Fri, 21 Aug 2020 15:56:03 -0400
Tony Krowiak <akrowiak@linux.ibm.com> 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@linux.ibm.com>
> ---
> 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>

> + 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.