On 27.10.21 18:48, Tony Krowiak wrote:
> This patch adds a sysfs 'status' attribute to a queue device when it is
> bound to the vfio_ap device driver. The field displays a string indicating
> the status of the queue device:
>
> Status String: Indicates:
> ------------- ---------
> "assigned" the queue is assigned to an mdev, but is not in use by a
> KVM guest.
> "in use" the queue is assigned to an mdev and is in use by a KVM
> guest.
> "unassigned" the queue is not assigned to an mdev.
>
> The status string will be displayed by the 'lszcrypt' command if the queue
> device is bound to the vfio_ap device driver.
>
> Signed-off-by: Harald Freudenberger <freude@xxxxxxxxxxxxx>
> [akrowiak@xxxxxxxxxxxxx: added check for queue in use by guest]
> Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxx>
> ---
> drivers/s390/crypto/vfio_ap_drv.c | 79 +++++++++++++++++++++++++++++--
> 1 file changed, 76 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/s390/crypto/vfio_ap_drv.c b/drivers/s390/crypto/vfio_ap_drv.c
> index 03311a476366..e043ae236630 100644
> --- a/drivers/s390/crypto/vfio_ap_drv.c
> +++ b/drivers/s390/crypto/vfio_ap_drv.c
> @@ -17,6 +17,9 @@
>
> #define VFIO_AP_ROOT_NAME "vfio_ap"
> #define VFIO_AP_DEV_NAME "matrix"
> +#define AP_QUEUE_ASSIGNED "assigned"
> +#define AP_QUEUE_UNASSIGNED "unassigned"
> +#define AP_QUEUE_IN_USE "in use"
>
> MODULE_AUTHOR("IBM Corporation");
> MODULE_DESCRIPTION("VFIO AP device driver, Copyright IBM Corp. 2018");
> @@ -41,26 +44,95 @@ static struct ap_device_id ap_queue_ids[] = {
>
> MODULE_DEVICE_TABLE(vfio_ap, ap_queue_ids);
>
> +static struct ap_matrix_mdev *vfio_ap_mdev_for_queue(struct vfio_ap_queue *q)
> +{
> + struct ap_matrix_mdev *matrix_mdev;
> + unsigned long apid = AP_QID_CARD(q->apqn);
> + unsigned long apqi = AP_QID_QUEUE(q->apqn);
> +
> + list_for_each_entry(matrix_mdev, &matrix_dev->mdev_list, node) {
> + if (test_bit_inv(apid, matrix_mdev->matrix.apm) &&
> + test_bit_inv(apqi, matrix_mdev->matrix.aqm))
> + return matrix_mdev;
> + }
> +
> + return NULL;
> +}
> +
> +static ssize_t status_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + ssize_t nchars = 0;
> + struct vfio_ap_queue *q;
> + struct ap_matrix_mdev *matrix_mdev;
> + struct ap_device *apdev = to_ap_dev(dev);
> +
> + mutex_lock(&matrix_dev->lock);
> + q = dev_get_drvdata(&apdev->device);
> + matrix_mdev = vfio_ap_mdev_for_queue(q);
> +
> + if (matrix_mdev) {
> + if (matrix_mdev->kvm)
> + nchars = scnprintf(buf, PAGE_SIZE, "%s\n",
> + AP_QUEUE_IN_USE);
> + else
> + nchars = scnprintf(buf, PAGE_SIZE, "%s\n",
> + AP_QUEUE_ASSIGNED);
> + } else {
> + nchars = scnprintf(buf, PAGE_SIZE, "%s\n",
> + AP_QUEUE_UNASSIGNED);
> + }
> +
> + mutex_unlock(&matrix_dev->lock);
> +
> + return nchars;
> +}
> +
> +static DEVICE_ATTR_RO(status);
> +
> +static struct attribute *vfio_queue_attrs[] = {
> + &dev_attr_status.attr,
> + NULL,
> +};
> +
> +static const struct attribute_group vfio_queue_attr_group = {
> + .attrs = vfio_queue_attrs,
> +};
> +
> /**
> * vfio_ap_queue_dev_probe: Allocate a vfio_ap_queue structure and associate it
> * with the device as driver_data.
> *
> * @apdev: the AP device being probed
> *
> - * Return: returns 0 if the probe succeeded; otherwise, returns -ENOMEM if
> - * storage could not be allocated for a vfio_ap_queue object.
> + * Return: returns 0 if the probe succeeded; otherwise, returns an error if
> + * storage could not be allocated for a vfio_ap_queue object or the
> + * sysfs 'status' attribute could not be created for the queue device.
> */
> static int vfio_ap_queue_dev_probe(struct ap_device *apdev)
> {
> + int ret;
> struct vfio_ap_queue *q;
>
> q = kzalloc(sizeof(*q), GFP_KERNEL);
> if (!q)
> return -ENOMEM;
> +
> + mutex_lock(&matrix_dev->lock);
> dev_set_drvdata(&apdev->device, q);
> q->apqn = to_ap_queue(&apdev->device)->qid;
> q->saved_isc = VFIO_AP_ISC_INVALID;
> - return 0;
> +
> + ret = sysfs_create_group(&apdev->device.kobj, &vfio_queue_attr_group);
> + if (ret) {
> + dev_set_drvdata(&apdev->device, NULL);
> + kfree(q);
> + }
> +
> + mutex_unlock(&matrix_dev->lock);
> +
> + return ret;
> }
>
> /**
> @@ -75,6 +147,7 @@ static void vfio_ap_queue_dev_remove(struct ap_device *apdev)
> struct vfio_ap_queue *q;
>
> mutex_lock(&matrix_dev->lock);
> + sysfs_remove_group(&apdev->device.kobj, &vfio_queue_attr_group);
> q = dev_get_drvdata(&apdev->device);
> vfio_ap_mdev_reset_queue(q, 1);
> dev_set_drvdata(&apdev->device, NULL);
Looks good to me, add my "Reviewed-by: Harald Freudenberger <freude@xxxxxxxxxxxxx>"
