Hi, > + if (vgdev->has_resource_assign_uuid) { > + spin_lock(&vgdev->resource_export_lock); > + if (bo->uuid_state == UUID_NOT_INITIALIZED) { > + bo->uuid_state = UUID_INITIALIZING; > + needs_init = true; > + } > + spin_unlock(&vgdev->resource_export_lock); > + > + if (needs_init) { > + ret = virtio_gpu_cmd_resource_assign_uuid(vgdev, bo); You can submit a fenced command, then wait on the fence here. Removes the need for UUID_INITIALIZING. Also note that this function will be called only once, on the first export. When exporting the same object again drm will simply reuse the existing dmabuf. You can drop UUID_NOT_INITIALIZED and needs_init. So you are left with only two uuid_state states. You could turn uuid into a pointer, so it gets only allocated when needed. Also uuid == NULL can be used for "uuid not available" then. cheers, Gerd