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

[Alex Williamson]

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

Reviewed-by: Cornelia Huck <coh...@redhat.com>
Signed-off-by: Alex Williamson <alex.william...@redhat.com>
---

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);