diff --git a/docs/interop/vhost-user.rst b/docs/interop/vhost-user.rst index d1ed39dfa0..d8419fd2f1 100644 --- a/docs/interop/vhost-user.rst +++ b/docs/interop/vhost-user.rst @@ -1839,7 +1839,9 @@ is sent by the front-end. When the ``VHOST_USER_PROTOCOL_F_SHARED_OBJECT`` protocol feature has been successfully negotiated, this message can be submitted by the backend to remove themselves from to the virtio-dmabuf shared - table API. The shared table will remove the back-end device associated with + table API. Only the back-end owning the entry (i.e., the one that first added + it) will have permission to remove it. Otherwise, the message is ignored. + The shared table will remove the back-end device associated with the UUID. If ``VHOST_USER_PROTOCOL_F_REPLY_ACK`` is negotiated, and the back-end sets the ``VHOST_USER_NEED_REPLY`` flag, the front-end must respond with zero when operation is successfully completed, or non-zero otherwise. diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c index a1eea8547e..9d654efd3d 100644 --- a/hw/virtio/vhost-user.c +++ b/hw/virtio/vhost-user.c @@ -1611,11 +1611,27 @@ vhost_user_backend_handle_shared_object_add(struct vhost_dev *dev, } static int -vhost_user_backend_handle_shared_object_remove(VhostUserShared *object) +vhost_user_backend_handle_shared_object_remove(struct vhost_dev *dev, + VhostUserShared *object) { QemuUUID uuid; memcpy(uuid.data, object->uuid, sizeof(object->uuid)); + switch (virtio_object_type(&uuid)) { + case TYPE_VHOST_DEV: + { + struct vhost_dev *owner = virtio_lookup_vhost_device(&uuid); + if (dev != owner) { + /* Not allowed to remove non-owned entries */ + return 0; + } + break; + } + default: + /* Not allowed to remove non-owned entries */ + return 0; + } + return virtio_remove_resource(&uuid); } @@ -1794,7 +1810,8 @@ static gboolean backend_read(QIOChannel *ioc, GIOCondition condition, ret = vhost_user_backend_handle_shared_object_add(dev, &payload.object); break; case VHOST_USER_BACKEND_SHARED_OBJECT_REMOVE: - ret = vhost_user_backend_handle_shared_object_remove(&payload.object); + ret = vhost_user_backend_handle_shared_object_remove(dev, + &payload.object); break; case VHOST_USER_BACKEND_SHARED_OBJECT_LOOKUP: ret = vhost_user_backend_handle_shared_object_lookup(dev->opaque, ioc,