Commit f139862b authored by Tony Krowiak's avatar Tony Krowiak Committed by Heiko Carstens
Browse files

s390/vfio-ap: add status attribute to AP queue device's sysfs dir 



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: default avatarHarald Freudenberger <freude@linux.ibm.com>
[akrowiak@linux.ibm.com: added check for queue in use by guest]
Signed-off-by: default avatarTony Krowiak <akrowiak@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
parent 402ff5a3

drivers/s390/crypto/vfio_ap_drv.c

+76 −3
Original line number Diff line number Diff line
@@ -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);