From f139862b92cf85bd25cbe7c8683d63c037e6562c Mon Sep 17 00:00:00 2001 From: Tony Krowiak Date: Wed, 27 Oct 2021 11:20:14 -0400 Subject: [PATCH] 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: Harald Freudenberger [akrowiak@linux.ibm.com: added check for queue in use by guest] Signed-off-by: Tony Krowiak Signed-off-by: Heiko Carstens --- 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);