On Mon, Jul 19, 2021 at 02:58:58PM +0200, Cornelia Huck wrote: > > - ret = device->ops->open(device); > > - if (ret) { > > - module_put(device->dev->driver->owner); > > - vfio_device_put(device); > > - return ret; > > + mutex_lock(&device->dev_set->lock); > > + device->open_count++; > > + if (device->open_count == 1 && device->ops->open_device) { > > + ret = device->ops->open_device(device); > > + if (ret) > > + goto err_undo_count; > > Won't that fail for mdev devices, until the patches later in this series > have been applied? (i.e. bad for bisect) What are you seeing? At this point all devices will have a NULL open_device and skip this logic? Jason