[PATCH v11 12/22] vfio: Add notifier callback to parent's ops structure of mdev

From: Kirti Wankhede
Date: Fri Nov 04 2016 - 17:13:55 EST


Add a notifier calback to parent's ops structure of mdev device so that per
device notifer for vfio module is registered through vfio_mdev module.

Signed-off-by: Kirti Wankhede <kwankhede@xxxxxxxxxx>
Signed-off-by: Neo Jia <cjia@xxxxxxxxxx>
Change-Id: Iafa6f1721aecdd6e50eb93b153b5621e6d29b637
---
drivers/vfio/mdev/vfio_mdev.c | 19 +++++++++++++++++++
include/linux/mdev.h | 9 +++++++++
2 files changed, 28 insertions(+)

diff --git a/drivers/vfio/mdev/vfio_mdev.c b/drivers/vfio/mdev/vfio_mdev.c
index bb534d19e321..2b7c24aa9e46 100644
--- a/drivers/vfio/mdev/vfio_mdev.c
+++ b/drivers/vfio/mdev/vfio_mdev.c
@@ -24,6 +24,15 @@
#define DRIVER_AUTHOR "NVIDIA Corporation"
#define DRIVER_DESC "VFIO based driver for Mediated device"

+static int vfio_mdev_notifier(struct notifier_block *nb, unsigned long action,
+ void *data)
+{
+ struct mdev_device *mdev = container_of(nb, struct mdev_device, nb);
+ struct parent_device *parent = mdev->parent;
+
+ return parent->ops->notifier(mdev, action, data);
+}
+
static int vfio_mdev_open(void *device_data)
{
struct mdev_device *mdev = device_data;
@@ -40,6 +49,11 @@ static int vfio_mdev_open(void *device_data)
if (ret)
module_put(THIS_MODULE);

+ if (likely(parent->ops->notifier)) {
+ mdev->nb.notifier_call = vfio_mdev_notifier;
+ if (vfio_register_notifier(&mdev->dev, &mdev->nb))
+ pr_err("Failed to register notifier for mdev\n");
+ }
return ret;
}

@@ -48,6 +62,11 @@ static void vfio_mdev_release(void *device_data)
struct mdev_device *mdev = device_data;
struct parent_device *parent = mdev->parent;

+ if (likely(parent->ops->notifier)) {
+ if (vfio_unregister_notifier(&mdev->dev, &mdev->nb))
+ pr_err("Failed to unregister notifier for mdev\n");
+ }
+
if (likely(parent->ops->release))
parent->ops->release(mdev);

diff --git a/include/linux/mdev.h b/include/linux/mdev.h
index 0352febc1944..2999ef0ddaed 100644
--- a/include/linux/mdev.h
+++ b/include/linux/mdev.h
@@ -37,6 +37,7 @@ struct mdev_device {
struct kref ref;
struct list_head next;
struct kobject *type_kobj;
+ struct notifier_block nb;
};


@@ -84,6 +85,12 @@ struct mdev_device {
* @cmd: mediated device structure
* @arg: mediated device structure
* @mmap: mmap callback
+ * @mdev: mediated device structure
+ * @vma: vma structure
+ * @notifer: Notifier callback
+ * @mdev: mediated device structure
+ * @action: Action for which notifier is called
+ * @data: Data associated with the notifier
* Parent device that support mediated device should be registered with mdev
* module with parent_ops structure.
**/
@@ -105,6 +112,8 @@ struct parent_ops {
ssize_t (*ioctl)(struct mdev_device *mdev, unsigned int cmd,
unsigned long arg);
int (*mmap)(struct mdev_device *mdev, struct vm_area_struct *vma);
+ int (*notifier)(struct mdev_device *mdev, unsigned long action,
+ void *data);
};

/* interface for exporting mdev supported type attributes */
--
2.7.0