diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
index 3cc1a05fde1c9de281900d8768dfd16bf0e3dbad..ae23151442cbd727d80633c0cbc6dd1ecb7ec7ff 100644
--- a/drivers/vfio/mdev/mdev_core.c
+++ b/drivers/vfio/mdev/mdev_core.c
@@ -102,56 +102,35 @@ static void mdev_put_parent(struct mdev_parent *parent)
kref_put(&parent->ref, mdev_release_parent);
}
-static int mdev_device_create_ops(struct kobject *kobj,
- struct mdev_device *mdev)
+/* Caller must hold parent unreg_sem read or write lock */
+static void mdev_device_remove_common(struct mdev_device *mdev)
{
- struct mdev_parent *parent = mdev->parent;
- int ret;
-
- ret = parent->ops->create(kobj, mdev);
- if (ret)
- return ret;
-
- ret = sysfs_create_groups(&mdev->dev.kobj,
- parent->ops->mdev_attr_groups);
- if (ret)
- parent->ops->remove(mdev);
-
- return ret;
-}
-
-/*
- * mdev_device_remove_ops gets called from sysfs's 'remove' and when parent
- * device is being unregistered from mdev device framework.
- * - 'force_remove' is set to 'false' when called from sysfs's 'remove' which
- * indicates that if the mdev device is active, used by VMM or userspace
- * application, vendor driver could return error then don't remove the device.
- * - 'force_remove' is set to 'true' when called from mdev_unregister_device()
- * which indicate that parent device is being removed from mdev device
- * framework so remove mdev device forcefully.
- */
-static int mdev_device_remove_ops(struct mdev_device *mdev, bool force_remove)
-{
- struct mdev_parent *parent = mdev->parent;
+ struct mdev_parent *parent;
+ struct mdev_type *type;
int ret;
- /*
- * Vendor driver can return error if VMM or userspace application is
- * using this mdev device.
- */
+ type = to_mdev_type(mdev->type_kobj);
+ mdev_remove_sysfs_files(&mdev->dev, type);
+ device_del(&mdev->dev);
+ parent = mdev->parent;
+ lockdep_assert_held(&parent->unreg_sem);
ret = parent->ops->remove(mdev);
- if (ret && !force_remove)
- return ret;
+ if (ret)
+ dev_err(&mdev->dev, "Remove failed: err=%d\n", ret);
- sysfs_remove_groups(&mdev->dev.kobj, parent->ops->mdev_attr_groups);
- return 0;
+ /* Balances with device_initialize() */
+ put_device(&mdev->dev);
+ mdev_put_parent(parent);
}
static int mdev_device_remove_cb(struct device *dev, void *data)
{
- if (dev_is_mdev(dev))
- mdev_device_remove(dev, true);
+ if (dev_is_mdev(dev)) {
+ struct mdev_device *mdev;
+ mdev = to_mdev_device(dev);
+ mdev_device_remove_common(mdev);
+ }
return 0;
}
@@ -193,6 +172,7 @@ int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops)
}
kref_init(&parent->ref);
+ init_rwsem(&parent->unreg_sem);
parent->dev = dev;
parent->ops = ops;
@@ -251,21 +231,23 @@ void mdev_unregister_device(struct device *dev)
dev_info(dev, "MDEV: Unregistering\n");
list_del(&parent->next);
+ mutex_unlock(&parent_list_lock);
+
+ down_write(&parent->unreg_sem);
+
class_compat_remove_link(mdev_bus_compat_class, dev, NULL);
device_for_each_child(dev, NULL, mdev_device_remove_cb);
parent_remove_sysfs_files(parent);
+ up_write(&parent->unreg_sem);
- mutex_unlock(&parent_list_lock);
mdev_put_parent(parent);
}
EXPORT_SYMBOL(mdev_unregister_device);
-static void mdev_device_release(struct device *dev)
+static void mdev_device_free(struct mdev_device *mdev)
{
- struct mdev_device *mdev = to_mdev_device(dev);
-
mutex_lock(&mdev_list_lock);
list_del(&mdev->next);
mutex_unlock(&mdev_list_lock);
@@ -274,6 +256,13 @@ static void mdev_device_release(struct device *dev)
kfree(mdev);
}
+static void mdev_device_release(struct device *dev)
+{
+ struct mdev_device *mdev = to_mdev_device(dev);
+
+ mdev_device_free(mdev);
+}
+
int mdev_device_create(struct kobject *kobj,
struct device *dev, const guid_t *uuid)
{
@@ -310,46 +299,55 @@ int mdev_device_create(struct kobject *kobj,
mdev->parent = parent;
+ /* Check if parent unregistration has started */
+ if (!down_read_trylock(&parent->unreg_sem)) {
+ mdev_device_free(mdev);
+ ret = -ENODEV;
+ goto mdev_fail;
+ }
+
+ device_initialize(&mdev->dev);
mdev->dev.parent = dev;
mdev->dev.bus = &mdev_bus_type;
mdev->dev.release = mdev_device_release;
dev_set_name(&mdev->dev, "%pUl", uuid);
+ mdev->dev.groups = parent->ops->mdev_attr_groups;
+ mdev->type_kobj = kobj;
- ret = device_register(&mdev->dev);
- if (ret) {
- put_device(&mdev->dev);
- goto mdev_fail;
- }
+ ret = parent->ops->create(kobj, mdev);
+ if (ret)
+ goto ops_create_fail;
- ret = mdev_device_create_ops(kobj, mdev);
+ ret = device_add(&mdev->dev);
if (ret)
- goto create_fail;
+ goto add_fail;
ret = mdev_create_sysfs_files(&mdev->dev, type);
- if (ret) {
- mdev_device_remove_ops(mdev, true);
- goto create_fail;
- }
+ if (ret)
+ goto sysfs_fail;
- mdev->type_kobj = kobj;
mdev->active = true;
dev_dbg(&mdev->dev, "MDEV: created\n");
+ up_read(&parent->unreg_sem);
return 0;
-create_fail:
- device_unregister(&mdev->dev);
+sysfs_fail:
+ device_del(&mdev->dev);
+add_fail:
+ parent->ops->remove(mdev);
+ops_create_fail:
+ up_read(&parent->unreg_sem);
+ put_device(&mdev->dev);
mdev_fail:
mdev_put_parent(parent);
return ret;
}
-int mdev_device_remove(struct device *dev, bool force_remove)
+int mdev_device_remove(struct device *dev)
{
struct mdev_device *mdev, *tmp;
struct mdev_parent *parent;
- struct mdev_type *type;
- int ret;
mdev = to_mdev_device(dev);
@@ -372,19 +370,13 @@ int mdev_device_remove(struct device *dev, bool force_remove)
mdev->active = false;
mutex_unlock(&mdev_list_lock);
- type = to_mdev_type(mdev->type_kobj);
parent = mdev->parent;
+ /* Check if parent unregistration has started */
+ if (!down_read_trylock(&parent->unreg_sem))
+ return -ENODEV;
- ret = mdev_device_remove_ops(mdev, force_remove);
- if (ret) {
- mdev->active = true;
- return ret;
- }
-
- mdev_remove_sysfs_files(dev, type);
- device_unregister(dev);
- mdev_put_parent(parent);
-
+ mdev_device_remove_common(mdev);
+ up_read(&parent->unreg_sem);
return 0;
}
diff --git a/drivers/vfio/mdev/mdev_private.h b/drivers/vfio/mdev/mdev_private.h
index 36cbbdb754deade31338b715a0750b0172553617..39876752627679149180e19492893a24109f5597 100644
--- a/drivers/vfio/mdev/mdev_private.h
+++ b/drivers/vfio/mdev/mdev_private.h
@@ -23,6 +23,8 @@ struct mdev_parent {
struct list_head next;
struct kset *mdev_types_kset;
struct list_head type_list;
+ /* Synchronize device creation/removal with parent unregistration */
+ struct rw_semaphore unreg_sem;
};
struct mdev_device {
@@ -60,6 +62,6 @@ void mdev_remove_sysfs_files(struct device *dev, struct mdev_type *type);
int mdev_device_create(struct kobject *kobj,
struct device *dev, const guid_t *uuid);
-int mdev_device_remove(struct device *dev, bool force_remove);
+int mdev_device_remove(struct device *dev);
#endif /* MDEV_PRIVATE_H */
diff --git a/drivers/vfio/mdev/mdev_sysfs.c b/drivers/vfio/mdev/mdev_sysfs.c
index cbf94b8165ea8a78c77cbd45515b3945a250fcb8..ffa3dcebf20187609bb3c47a27aa984607ca26d1 100644
--- a/drivers/vfio/mdev/mdev_sysfs.c
+++ b/drivers/vfio/mdev/mdev_sysfs.c
@@ -236,11 +236,9 @@ static ssize_t remove_store(struct device *dev, struct device_attribute *attr,
if (val && device_remove_file_self(dev, attr)) {
int ret;
- ret = mdev_device_remove(dev, false);
- if (ret) {
- device_create_file(dev, attr);
+ ret = mdev_device_remove(dev);
+ if (ret)
return ret;
- }
}
return count;