5 files changed, 97 insertions, 133 deletions

diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c
index 86d9e428357b..7f5402fe857a 100644
--- a/drivers/s390/cio/vfio_ccw_drv.c
+++ b/drivers/s390/cio/vfio_ccw_drv.c
@@ -12,7 +12,6 @@
 
 #include <linux/module.h>
 #include <linux/init.h>
-#include <linux/device.h>
 #include <linux/slab.h>
 #include <linux/mdev.h>
 
@@ -142,7 +141,6 @@ static struct vfio_ccw_private *vfio_ccw_alloc_private(struct subchannel *sch)
 	INIT_LIST_HEAD(&private->crw);
 	INIT_WORK(&private->io_work, vfio_ccw_sch_io_todo);
 	INIT_WORK(&private->crw_work, vfio_ccw_crw_todo);
-	atomic_set(&private->avail, 1);
 
 	private->cp.guest_cp = kcalloc(CCWCHAIN_LEN_MAX, sizeof(struct ccw1),
 				       GFP_KERNEL);
@@ -203,7 +201,6 @@ static void vfio_ccw_free_private(struct vfio_ccw_private *private)
 	mutex_destroy(&private->io_mutex);
 	kfree(private);
 }
-
 static int vfio_ccw_sch_probe(struct subchannel *sch)
 {
 	struct pmcw *pmcw = &sch->schib.pmcw;
@@ -222,7 +219,12 @@ static int vfio_ccw_sch_probe(struct subchannel *sch)
 
 	dev_set_drvdata(&sch->dev, private);
 
-	ret = mdev_register_device(&sch->dev, &vfio_ccw_mdev_driver);
+	private->mdev_type.sysfs_name = "io";
+	private->mdev_type.pretty_name = "I/O subchannel (Non-QDIO)";
+	private->mdev_types[0] = &private->mdev_type;
+	ret = mdev_register_parent(&private->parent, &sch->dev,
+				   &vfio_ccw_mdev_driver,
+				   private->mdev_types, 1);
 	if (ret)
 		goto out_free;
 
@@ -241,7 +243,7 @@ static void vfio_ccw_sch_remove(struct subchannel *sch)
 {
 	struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev);
 
-	mdev_unregister_device(&sch->dev);
+	mdev_unregister_parent(&private->parent);
 
 	dev_set_drvdata(&sch->dev, NULL);
 
diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c
index 4a806a2273b5..6ae4d012d800 100644
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -11,7 +11,6 @@
  */
 
 #include <linux/vfio.h>
-#include <linux/mdev.h>
 #include <linux/nospec.h>
 #include <linux/slab.h>
 
@@ -45,47 +44,14 @@ static void vfio_ccw_dma_unmap(struct vfio_device *vdev, u64 iova, u64 length)
 	vfio_ccw_mdev_reset(private);
 }
 
-static ssize_t name_show(struct mdev_type *mtype,
-			 struct mdev_type_attribute *attr, char *buf)
-{
-	return sprintf(buf, "I/O subchannel (Non-QDIO)\n");
-}
-static MDEV_TYPE_ATTR_RO(name);
-
-static ssize_t device_api_show(struct mdev_type *mtype,
-			       struct mdev_type_attribute *attr, char *buf)
-{
-	return sprintf(buf, "%s\n", VFIO_DEVICE_API_CCW_STRING);
-}
-static MDEV_TYPE_ATTR_RO(device_api);
-
-static ssize_t available_instances_show(struct mdev_type *mtype,
-					struct mdev_type_attribute *attr,
-					char *buf)
+static int vfio_ccw_mdev_init_dev(struct vfio_device *vdev)
 {
 	struct vfio_ccw_private *private =
-		dev_get_drvdata(mtype_get_parent_dev(mtype));
+		container_of(vdev, struct vfio_ccw_private, vdev);
 
-	return sprintf(buf, "%d\n", atomic_read(&private->avail));
+	init_completion(&private->release_comp);
+	return 0;
 }
-static MDEV_TYPE_ATTR_RO(available_instances);
-
-static struct attribute *mdev_types_attrs[] = {
-	&mdev_type_attr_name.attr,
-	&mdev_type_attr_device_api.attr,
-	&mdev_type_attr_available_instances.attr,
-	NULL,
-};
-
-static struct attribute_group mdev_type_group = {
-	.name  = "io",
-	.attrs = mdev_types_attrs,
-};
-
-static struct attribute_group *mdev_type_groups[] = {
-	&mdev_type_group,
-	NULL,
-};
 
 static int vfio_ccw_mdev_probe(struct mdev_device *mdev)
 {
@@ -95,12 +61,9 @@ static int vfio_ccw_mdev_probe(struct mdev_device *mdev)
 	if (private->state == VFIO_CCW_STATE_NOT_OPER)
 		return -ENODEV;
 
-	if (atomic_dec_if_positive(&private->avail) < 0)
-		return -EPERM;
-
-	memset(&private->vdev, 0, sizeof(private->vdev));
-	vfio_init_group_dev(&private->vdev, &mdev->dev,
-			    &vfio_ccw_dev_ops);
+	ret = vfio_init_device(&private->vdev, &mdev->dev, &vfio_ccw_dev_ops);
+	if (ret)
+		return ret;
 
 	VFIO_CCW_MSG_EVENT(2, "sch %x.%x.%04x: create\n",
 			   private->sch->schid.cssid,
@@ -109,16 +72,32 @@ static int vfio_ccw_mdev_probe(struct mdev_device *mdev)
 
 	ret = vfio_register_emulated_iommu_dev(&private->vdev);
 	if (ret)
-		goto err_atomic;
+		goto err_put_vdev;
 	dev_set_drvdata(&mdev->dev, private);
 	return 0;
 
-err_atomic:
-	vfio_uninit_group_dev(&private->vdev);
-	atomic_inc(&private->avail);
+err_put_vdev:
+	vfio_put_device(&private->vdev);
 	return ret;
 }
 
+static void vfio_ccw_mdev_release_dev(struct vfio_device *vdev)
+{
+	struct vfio_ccw_private *private =
+		container_of(vdev, struct vfio_ccw_private, vdev);
+
+	/*
+	 * We cannot free vfio_ccw_private here because it includes
+	 * parent info which must be free'ed by css driver.
+	 *
+	 * Use a workaround by memset'ing the core device part and
+	 * then notifying the remove path that all active references
+	 * to this device have been released.
+	 */
+	memset(vdev, 0, sizeof(*vdev));
+	complete(&private->release_comp);
+}
+
 static void vfio_ccw_mdev_remove(struct mdev_device *mdev)
 {
 	struct vfio_ccw_private *private = dev_get_drvdata(mdev->dev.parent);
@@ -130,8 +109,16 @@ static void vfio_ccw_mdev_remove(struct mdev_device *mdev)
 
 	vfio_unregister_group_dev(&private->vdev);
 
-	vfio_uninit_group_dev(&private->vdev);
-	atomic_inc(&private->avail);
+	vfio_put_device(&private->vdev);
+	/*
+	 * Wait for all active references on mdev are released so it
+	 * is safe to defer kfree() to a later point.
+	 *
+	 * TODO: the clean fix is to split parent/mdev info from ccw
+	 * private structure so each can be managed in its own life
+	 * cycle.
+	 */
+	wait_for_completion(&private->release_comp);
 }
 
 static int vfio_ccw_mdev_open_device(struct vfio_device *vdev)
@@ -592,6 +579,8 @@ static void vfio_ccw_mdev_request(struct vfio_device *vdev, unsigned int count)
 }
 
 static const struct vfio_device_ops vfio_ccw_dev_ops = {
+	.init = vfio_ccw_mdev_init_dev,
+	.release = vfio_ccw_mdev_release_dev,
 	.open_device = vfio_ccw_mdev_open_device,
 	.close_device = vfio_ccw_mdev_close_device,
 	.read = vfio_ccw_mdev_read,
@@ -602,6 +591,8 @@ static const struct vfio_device_ops vfio_ccw_dev_ops = {
 };
 
 struct mdev_driver vfio_ccw_mdev_driver = {
+	.device_api = VFIO_DEVICE_API_CCW_STRING,
+	.max_instances = 1,
 	.driver = {
 		.name = "vfio_ccw_mdev",
 		.owner = THIS_MODULE,
@@ -609,5 +600,4 @@ struct mdev_driver vfio_ccw_mdev_driver = {
 	},
 	.probe = vfio_ccw_mdev_probe,
 	.remove = vfio_ccw_mdev_remove,
-	.supported_type_groups  = mdev_type_groups,
 };
diff --git a/drivers/s390/cio/vfio_ccw_private.h b/drivers/s390/cio/vfio_ccw_private.h
index cd24b7fada91..bd5fb81456af 100644
--- a/drivers/s390/cio/vfio_ccw_private.h
+++ b/drivers/s390/cio/vfio_ccw_private.h
@@ -18,6 +18,7 @@
 #include <linux/workqueue.h>
 #include <linux/vfio_ccw.h>
 #include <linux/vfio.h>
+#include <linux/mdev.h>
 #include <asm/crw.h>
 #include <asm/debug.h>
 
@@ -72,7 +73,6 @@ struct vfio_ccw_crw {
  * @sch: pointer to the subchannel
  * @state: internal state of the device
  * @completion: synchronization helper of the I/O completion
- * @avail: available for creating a mediated device
  * @io_region: MMIO region to input/output I/O arguments/results
  * @io_mutex: protect against concurrent update of I/O regions
  * @region: additional regions for other subchannel operations
@@ -88,13 +88,14 @@ struct vfio_ccw_crw {
  * @req_trigger: eventfd ctx for signaling userspace to return device
  * @io_work: work for deferral process of I/O handling
  * @crw_work: work for deferral process of CRW handling
+ * @release_comp: synchronization helper for vfio device release
+ * @parent: parent data structures for mdevs created
  */
 struct vfio_ccw_private {
 	struct vfio_device vdev;
 	struct subchannel	*sch;
 	int			state;
 	struct completion	*completion;
-	atomic_t		avail;
 	struct ccw_io_region	*io_region;
 	struct mutex		io_mutex;
 	struct vfio_ccw_region *region;
@@ -113,6 +114,12 @@ struct vfio_ccw_private {
 	struct eventfd_ctx	*req_trigger;
 	struct work_struct	io_work;
 	struct work_struct	crw_work;
+
+	struct completion	release_comp;
+
+	struct mdev_parent	parent;
+	struct mdev_type	mdev_type;
+	struct mdev_type	*mdev_types[1];
 } __aligned(8);
 
 int vfio_ccw_sch_quiesce(struct subchannel *sch);
diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index ee82207b4e60..0b4cc8c597ae 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -684,42 +684,41 @@ static bool vfio_ap_mdev_filter_matrix(unsigned long *apm, unsigned long *aqm,
 			     AP_DOMAINS);
 }
 
-static int vfio_ap_mdev_probe(struct mdev_device *mdev)
+static int vfio_ap_mdev_init_dev(struct vfio_device *vdev)
 {
-	struct ap_matrix_mdev *matrix_mdev;
-	int ret;
-
-	if ((atomic_dec_if_positive(&matrix_dev->available_instances) < 0))
-		return -EPERM;
-
-	matrix_mdev = kzalloc(sizeof(*matrix_mdev), GFP_KERNEL);
-	if (!matrix_mdev) {
-		ret = -ENOMEM;
-		goto err_dec_available;
-	}
-	vfio_init_group_dev(&matrix_mdev->vdev, &mdev->dev,
-			    &vfio_ap_matrix_dev_ops);
+	struct ap_matrix_mdev *matrix_mdev =
+		container_of(vdev, struct ap_matrix_mdev, vdev);
 
-	matrix_mdev->mdev = mdev;
+	matrix_mdev->mdev = to_mdev_device(vdev->dev);
 	vfio_ap_matrix_init(&matrix_dev->info, &matrix_mdev->matrix);
 	matrix_mdev->pqap_hook = handle_pqap;
 	vfio_ap_matrix_init(&matrix_dev->info, &matrix_mdev->shadow_apcb);
 	hash_init(matrix_mdev->qtable.queues);
 
+	return 0;
+}
+
+static int vfio_ap_mdev_probe(struct mdev_device *mdev)
+{
+	struct ap_matrix_mdev *matrix_mdev;
+	int ret;
+
+	matrix_mdev = vfio_alloc_device(ap_matrix_mdev, vdev, &mdev->dev,
+					&vfio_ap_matrix_dev_ops);
+	if (IS_ERR(matrix_mdev))
+		return PTR_ERR(matrix_mdev);
+
 	ret = vfio_register_emulated_iommu_dev(&matrix_mdev->vdev);
 	if (ret)
-		goto err_list;
+		goto err_put_vdev;
 	dev_set_drvdata(&mdev->dev, matrix_mdev);
 	mutex_lock(&matrix_dev->mdevs_lock);
 	list_add(&matrix_mdev->node, &matrix_dev->mdev_list);
 	mutex_unlock(&matrix_dev->mdevs_lock);
 	return 0;
 
-err_list:
-	vfio_uninit_group_dev(&matrix_mdev->vdev);
-	kfree(matrix_mdev);
-err_dec_available:
-	atomic_inc(&matrix_dev->available_instances);
+err_put_vdev:
+	vfio_put_device(&matrix_mdev->vdev);
 	return ret;
 }
 
@@ -766,6 +765,11 @@ static void vfio_ap_mdev_unlink_fr_queues(struct ap_matrix_mdev *matrix_mdev)
 	}
 }
 
+static void vfio_ap_mdev_release_dev(struct vfio_device *vdev)
+{
+	vfio_free_device(vdev);
+}
+
 static void vfio_ap_mdev_remove(struct mdev_device *mdev)
 {
 	struct ap_matrix_mdev *matrix_mdev = dev_get_drvdata(&mdev->dev);
@@ -779,54 +783,9 @@ static void vfio_ap_mdev_remove(struct mdev_device *mdev)
 	list_del(&matrix_mdev->node);
 	mutex_unlock(&matrix_dev->mdevs_lock);
 	mutex_unlock(&matrix_dev->guests_lock);
-	vfio_uninit_group_dev(&matrix_mdev->vdev);
-	kfree(matrix_mdev);
-	atomic_inc(&matrix_dev->available_instances);
+	vfio_put_device(&matrix_mdev->vdev);
 }
 
-static ssize_t name_show(struct mdev_type *mtype,
-			 struct mdev_type_attribute *attr, char *buf)
-{
-	return sprintf(buf, "%s\n", VFIO_AP_MDEV_NAME_HWVIRT);
-}
-
-static MDEV_TYPE_ATTR_RO(name);
-
-static ssize_t available_instances_show(struct mdev_type *mtype,
-					struct mdev_type_attribute *attr,
-					char *buf)
-{
-	return sprintf(buf, "%d\n",
-		       atomic_read(&matrix_dev->available_instances));
-}
-
-static MDEV_TYPE_ATTR_RO(available_instances);
-
-static ssize_t device_api_show(struct mdev_type *mtype,
-			       struct mdev_type_attribute *attr, char *buf)
-{
-	return sprintf(buf, "%s\n", VFIO_DEVICE_API_AP_STRING);
-}
-
-static MDEV_TYPE_ATTR_RO(device_api);
-
-static struct attribute *vfio_ap_mdev_type_attrs[] = {
-	&mdev_type_attr_name.attr,
-	&mdev_type_attr_device_api.attr,
-	&mdev_type_attr_available_instances.attr,
-	NULL,
-};
-
-static struct attribute_group vfio_ap_mdev_hwvirt_type_group = {
-	.name = VFIO_AP_MDEV_TYPE_HWVIRT,
-	.attrs = vfio_ap_mdev_type_attrs,
-};
-
-static struct attribute_group *vfio_ap_mdev_type_groups[] = {
-	&vfio_ap_mdev_hwvirt_type_group,
-	NULL,
-};
-
 #define MDEV_SHARING_ERR "Userspace may not re-assign queue %02lx.%04lx " \
 			 "already assigned to %s"
 
@@ -1824,6 +1783,8 @@ static const struct attribute_group vfio_queue_attr_group = {
 };
 
 static const struct vfio_device_ops vfio_ap_matrix_dev_ops = {
+	.init = vfio_ap_mdev_init_dev,
+	.release = vfio_ap_mdev_release_dev,
 	.open_device = vfio_ap_mdev_open_device,
 	.close_device = vfio_ap_mdev_close_device,
 	.ioctl = vfio_ap_mdev_ioctl,
@@ -1831,6 +1792,8 @@ static const struct vfio_device_ops vfio_ap_matrix_dev_ops = {
 };
 
 static struct mdev_driver vfio_ap_matrix_driver = {
+	.device_api = VFIO_DEVICE_API_AP_STRING,
+	.max_instances = MAX_ZDEV_ENTRIES_EXT,
 	.driver = {
 		.name = "vfio_ap_mdev",
 		.owner = THIS_MODULE,
@@ -1839,20 +1802,22 @@ static struct mdev_driver vfio_ap_matrix_driver = {
 	},
 	.probe = vfio_ap_mdev_probe,
 	.remove = vfio_ap_mdev_remove,
-	.supported_type_groups = vfio_ap_mdev_type_groups,
 };
 
 int vfio_ap_mdev_register(void)
 {
 	int ret;
 
-	atomic_set(&matrix_dev->available_instances, MAX_ZDEV_ENTRIES_EXT);
-
 	ret = mdev_register_driver(&vfio_ap_matrix_driver);
 	if (ret)
 		return ret;
 
-	ret = mdev_register_device(&matrix_dev->device, &vfio_ap_matrix_driver);
+	matrix_dev->mdev_type.sysfs_name = VFIO_AP_MDEV_TYPE_HWVIRT;
+	matrix_dev->mdev_type.pretty_name = VFIO_AP_MDEV_NAME_HWVIRT;
+	matrix_dev->mdev_types[0] = &matrix_dev->mdev_type;
+	ret = mdev_register_parent(&matrix_dev->parent, &matrix_dev->device,
+				   &vfio_ap_matrix_driver,
+				   matrix_dev->mdev_types, 1);
 	if (ret)
 		goto err_driver;
 	return 0;
@@ -1864,7 +1829,7 @@ err_driver:
 
 void vfio_ap_mdev_unregister(void)
 {
-	mdev_unregister_device(&matrix_dev->device);
+	mdev_unregister_parent(&matrix_dev->parent);
 	mdev_unregister_driver(&vfio_ap_matrix_driver);
 }
 
diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h
index d782cf463eab..2eddd5f34ed3 100644
--- a/drivers/s390/crypto/vfio_ap_private.h
+++ b/drivers/s390/crypto/vfio_ap_private.h
@@ -13,7 +13,6 @@
 #define _VFIO_AP_PRIVATE_H_
 
 #include <linux/types.h>
-#include <linux/device.h>
 #include <linux/mdev.h>
 #include <linux/delay.h>
 #include <linux/mutex.h>
@@ -30,7 +29,6 @@
  * struct ap_matrix_dev - Contains the data for the matrix device.
  *
  * @device:	generic device structure associated with the AP matrix device
- * @available_instances: number of mediated matrix devices that can be created
  * @info:	the struct containing the output from the PQAP(QCI) instruction
  * @mdev_list:	the list of mediated matrix devices created
  * @mdevs_lock: mutex for locking the AP matrix device. This lock will be
@@ -47,12 +45,14 @@
  */
 struct ap_matrix_dev {
 	struct device device;
-	atomic_t available_instances;
 	struct ap_config_info info;
 	struct list_head mdev_list;
 	struct mutex mdevs_lock; /* serializes access to each ap_matrix_mdev */
 	struct ap_driver  *vfio_ap_drv;
 	struct mutex guests_lock; /* serializes access to each KVM guest */
+	struct mdev_parent parent;
+	struct mdev_type mdev_type;
+	struct mdev_type *mdev_types[];
 };
 
 extern struct ap_matrix_dev *matrix_dev;