Re: [PATCH 05/10] vfio: Move vfio_external_user_iommu_id() to vfio_file_ops

Christoph Hellwig
2022-04-15T14:37:44Z

On Fri, Apr 15, 2022 at 09:25:10AM -0300, Jason Gunthorpe wrote:
> The PPC specific iommu_table_group is PPC's "drvdata" for the common
> struct iommu_group - it is obtained trivially by group->iommu_data
>
> I think using iommu_group as the handle for it in common code is the
> right thing to do.
>
> What I don't entirely understand is what is 'tablefd' doing in all
> this, or why the lookup of the kvmppc_spapr_tce_table is so
> weird. PPC's unique iommu uapi is still a mystery to me.

Yeah. So I guess we should go with something like this patch for now.
Eventually as part of the actual iommufd work we'll need to unwind
the PPC stuff anyway.