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);
--
2.31.1
