On Thu, 21 Apr 2022 13:28:38 -0300 Jason Gunthorpe <jgg@xxxxxxxxxx> wrote: > When the open_device() op is called the container_users is incremented and > held incremented until close_device(). Thus, so long as drivers call > functions within their open_device()/close_device() region they do not > need to worry about the container_users. > > These functions can all only be called between open_device() and > close_device(): > > vfio_pin_pages() > vfio_unpin_pages() > vfio_dma_rw() > vfio_register_notifier() > vfio_unregister_notifier() > > Eliminate the calls to vfio_group_add_container_user() and add > vfio_assert_device_open() to detect driver mis-use. A comment here explaining that decrementing open_count is pushed until after close_device to support this feature would help to explain the somewhat subtle change in vfio_group_get_device_fd(). Otherwise the series looks ok with fixes noted by previous reviews. Thanks, Alex
