diff options
| -rw-r--r-- | Documentation/vfio-mediated-device.txt | 5 | ||||
| -rw-r--r-- | drivers/vfio/mdev/mdev_core.c | 102 | ||||
| -rw-r--r-- | drivers/vfio/mdev/mdev_private.h | 2 |
3 files changed, 42 insertions, 67 deletions
diff --git a/Documentation/vfio-mediated-device.txt b/Documentation/vfio-mediated-device.txt index 1b3950346532..c3f69bcaf96e 100644 --- a/Documentation/vfio-mediated-device.txt +++ b/Documentation/vfio-mediated-device.txt @@ -145,6 +145,11 @@ The functions in the mdev_parent_ops structure are as follows: * create: allocate basic resources in a driver for a mediated device * remove: free resources in a driver when a mediated device is destroyed +(Note that mdev-core provides no implicit serialization of create/remove +callbacks per mdev parent device, per mdev type, or any other categorization. +Vendor drivers are expected to be fully asynchronous in this respect or +provide their own internal resource protection.) + The callbacks in the mdev_parent_ops structure are as follows: * open: open callback of mediated device diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c index 126991046eb7..0212f0ee8aea 100644 --- a/drivers/vfio/mdev/mdev_core.c +++ b/drivers/vfio/mdev/mdev_core.c @@ -66,34 +66,6 @@ uuid_le mdev_uuid(struct mdev_device *mdev) } EXPORT_SYMBOL(mdev_uuid); -static int _find_mdev_device(struct device *dev, void *data) -{ - struct mdev_device *mdev; - - if (!dev_is_mdev(dev)) - return 0; - - mdev = to_mdev_device(dev); - - if (uuid_le_cmp(mdev->uuid, *(uuid_le *)data) == 0) - return 1; - - return 0; -} - -static bool mdev_device_exist(struct mdev_parent *parent, uuid_le uuid) -{ - struct device *dev; - - dev = device_find_child(parent->dev, &uuid, _find_mdev_device); - if (dev) { - put_device(dev); - return true; - } - - return false; -} - /* Should be called holding parent_list_lock */ static struct mdev_parent *__find_parent_device(struct device *dev) { @@ -221,7 +193,6 @@ int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops) } kref_init(&parent->ref); - mutex_init(&parent->lock); parent->dev = dev; parent->ops = ops; @@ -297,6 +268,10 @@ static void mdev_device_release(struct device *dev) { struct mdev_device *mdev = to_mdev_device(dev); + mutex_lock(&mdev_list_lock); + list_del(&mdev->next); + mutex_unlock(&mdev_list_lock); + dev_dbg(&mdev->dev, "MDEV: destroying\n"); kfree(mdev); } @@ -304,7 +279,7 @@ static void mdev_device_release(struct device *dev) int mdev_device_create(struct kobject *kobj, struct device *dev, uuid_le uuid) { int ret; - struct mdev_device *mdev; + struct mdev_device *mdev, *tmp; struct mdev_parent *parent; struct mdev_type *type = to_mdev_type(kobj); @@ -312,21 +287,28 @@ int mdev_device_create(struct kobject *kobj, struct device *dev, uuid_le uuid) if (!parent) return -EINVAL; - mutex_lock(&parent->lock); + mutex_lock(&mdev_list_lock); /* Check for duplicate */ - if (mdev_device_exist(parent, uuid)) { - ret = -EEXIST; - goto create_err; + list_for_each_entry(tmp, &mdev_list, next) { + if (!uuid_le_cmp(tmp->uuid, uuid)) { + mutex_unlock(&mdev_list_lock); + ret = -EEXIST; + goto mdev_fail; + } } mdev = kzalloc(sizeof(*mdev), GFP_KERNEL); if (!mdev) { + mutex_unlock(&mdev_list_lock); ret = -ENOMEM; - goto create_err; + goto mdev_fail; } memcpy(&mdev->uuid, &uuid, sizeof(uuid_le)); + list_add(&mdev->next, &mdev_list); + mutex_unlock(&mdev_list_lock); + mdev->parent = parent; kref_init(&mdev->ref); @@ -338,35 +320,28 @@ int mdev_device_create(struct kobject *kobj, struct device *dev, uuid_le uuid) ret = device_register(&mdev->dev); if (ret) { put_device(&mdev->dev); - goto create_err; + goto mdev_fail; } ret = mdev_device_create_ops(kobj, mdev); if (ret) - goto create_failed; + goto create_fail; ret = mdev_create_sysfs_files(&mdev->dev, type); if (ret) { mdev_device_remove_ops(mdev, true); - goto create_failed; + goto create_fail; } mdev->type_kobj = kobj; + mdev->active = true; dev_dbg(&mdev->dev, "MDEV: created\n"); - mutex_unlock(&parent->lock); - - mutex_lock(&mdev_list_lock); - list_add(&mdev->next, &mdev_list); - mutex_unlock(&mdev_list_lock); - - return ret; + return 0; -create_failed: +create_fail: device_unregister(&mdev->dev); - -create_err: - mutex_unlock(&parent->lock); +mdev_fail: mdev_put_parent(parent); return ret; } @@ -377,44 +352,39 @@ int mdev_device_remove(struct device *dev, bool force_remove) struct mdev_parent *parent; struct mdev_type *type; int ret; - bool found = false; mdev = to_mdev_device(dev); mutex_lock(&mdev_list_lock); list_for_each_entry(tmp, &mdev_list, next) { - if (tmp == mdev) { - found = true; + if (tmp == mdev) break; - } } - if (found) - list_del(&mdev->next); + if (tmp != mdev) { + mutex_unlock(&mdev_list_lock); + return -ENODEV; + } - mutex_unlock(&mdev_list_lock); + if (!mdev->active) { + mutex_unlock(&mdev_list_lock); + return -EAGAIN; + } - if (!found) - return -ENODEV; + mdev->active = false; + mutex_unlock(&mdev_list_lock); type = to_mdev_type(mdev->type_kobj); parent = mdev->parent; - mutex_lock(&parent->lock); ret = mdev_device_remove_ops(mdev, force_remove); if (ret) { - mutex_unlock(&parent->lock); - - mutex_lock(&mdev_list_lock); - list_add(&mdev->next, &mdev_list); - mutex_unlock(&mdev_list_lock); - + mdev->active = true; return ret; } mdev_remove_sysfs_files(dev, type); device_unregister(dev); - mutex_unlock(&parent->lock); mdev_put_parent(parent); return 0; diff --git a/drivers/vfio/mdev/mdev_private.h b/drivers/vfio/mdev/mdev_private.h index a9cefd70a705..b5819b7d7ef7 100644 --- a/drivers/vfio/mdev/mdev_private.h +++ b/drivers/vfio/mdev/mdev_private.h @@ -20,7 +20,6 @@ struct mdev_parent { struct device *dev; const struct mdev_parent_ops *ops; struct kref ref; - struct mutex lock; struct list_head next; struct kset *mdev_types_kset; struct list_head type_list; @@ -34,6 +33,7 @@ struct mdev_device { struct kref ref; struct list_head next; struct kobject *type_kobj; + bool active; }; #define to_mdev_device(dev) container_of(dev, struct mdev_device, dev) |