On 23.03.22 15:33, Xiaoguang Wang wrote: ... snip ...
What happens if the tcmu device currently is not open / mapped?I'm not sure how it will happen. But we may check whether udev->vma has a valid value. If yes, it'll enter tcmu_cmd_zerocopy_map().
Yeah, but what I also wanted to suggest is, that if userspace maps the uio device while zero copy cmds already being in the ring, you have to iterate over those cmds and populate the mapping. Bodo