Re: [PATCH 04/14] iommufd: Use the iommufd_group to avoid duplicate reserved groups and msi setup

Jason Gunthorpe
2023-03-02T12:55:13Z

On Thu, Mar 02, 2023 at 08:06:27AM +0000, Tian, Kevin wrote:
> > From: Jason Gunthorpe <jgg@nvidia.com>
> > Sent: Saturday, February 25, 2023 8:28 AM
> >
> > These items only needs to be done once per group, not once per device. The
> > once per device was a way to make the device list work. Since we are
> > abandoning this we can optimize things a bit.
> >
>
> Are we sure that a device hot-plugged into the group won't increase the
> list of reserved IOVA ranges?
>
> Currently iommu_get_group_resv_regions() queries reserved regions per
> device and then merge them into the specified list.

So, maybe we should export the device API from the core code and use
it here instead of this group stuff. We don't need the core code to
merge each device together for us anyhow.

Jason