On Fri, Apr 22, 2022 at 01:50:00AM +0000, Tian, Kevin wrote:
From: Jason Gunthorpe jgg@nvidia.com Sent: Friday, April 22, 2022 12:29 AM
Every caller has a readily available vfio_device pointer, use that instead of passing in a generic struct device. The struct vfio_device already contains the group we need so this avoids complexity, extra refcountings, and a confusing lifecycle model.
Using the same description as last patch leaves the impression that the two patches do the exactly same type of change. But this patch actually includes one more change to grab a reference on the container. This is worth an explanation.
How about this:
Every caller has a readily available vfio_device pointer, use that instead of passing in a generic struct device. Change vfio_dma_rw() to take in the struct vfio_device and move the container users that would have been held by vfio_group_get_external_user_from_dev() to vfio_dma_rw() directly, like vfio_pin/unpin_pages().
Thanks, Jason