[PATCH v3] mdev: Send uevents around parent device registration

From: Alex Williamson
Date: Wed Jul 10 2019 - 13:41:52 EST


This allows udev to trigger rules when a parent device is registered
or unregistered from mdev.

Reviewed-by: Cornelia Huck <cohuck@xxxxxxxxxx>
Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
---

v3: Add Connie's R-b
Add comment clarifying expected device requirements for unreg

drivers/vfio/mdev/mdev_core.c | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
index ae23151442cb..23976db6c6c7 100644
--- a/drivers/vfio/mdev/mdev_core.c
+++ b/drivers/vfio/mdev/mdev_core.c
@@ -146,6 +146,8 @@ int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops)
{
int ret;
struct mdev_parent *parent;
+ char *env_string = "MDEV_STATE=registered";
+ char *envp[] = { env_string, NULL };

/* check for mandatory ops */
if (!ops || !ops->create || !ops->remove || !ops->supported_type_groups)
@@ -197,6 +199,8 @@ int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops)
mutex_unlock(&parent_list_lock);

dev_info(dev, "MDEV: Registered\n");
+ kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
+
return 0;

add_dev_err:
@@ -220,6 +224,8 @@ EXPORT_SYMBOL(mdev_register_device);
void mdev_unregister_device(struct device *dev)
{
struct mdev_parent *parent;
+ char *env_string = "MDEV_STATE=unregistered";
+ char *envp[] = { env_string, NULL };

mutex_lock(&parent_list_lock);
parent = __find_parent_device(dev);
@@ -243,6 +249,9 @@ void mdev_unregister_device(struct device *dev)
up_write(&parent->unreg_sem);

mdev_put_parent(parent);
+
+ /* We still have the caller's reference to use for the uevent */
+ kobject_uevent_env(&dev->kobj, KOBJ_CHANGE, envp);
}
EXPORT_SYMBOL(mdev_unregister_device);