Re: [PATCH 3/5] iommu/virtio: Move to domain_alloc_paging()

Jason Gunthorpe
2025-02-18T20:01:19Z

On Wed, Feb 12, 2025 at 09:47:23PM -0800, Jacob Pan wrote:
> Hi Jason,
>
> On Wed, 12 Feb 2025 19:30:53 -0400
> Jason Gunthorpe <jgg@nvidia.com> wrote:
>
> > On Wed, Feb 12, 2025 at 11:22:35AM -0800, Jacob Pan wrote:
> >
> > > Do you foresee the implementation can leverage your generic iommu_pt
> > > work? i.e. for building guest IO page tables. It will add a new
> > > flavor (page table based in addition to map/unmap) to
> > > viommu_domain_alloc_paging() i think.
> >
> > Yes I do, I think it should be no problem and it will bring the
> > missing x86 formats that are currently not available in iopgtbl
> > wrappers.
> I guess the missing x86 formats are AMDv2 and VT-d S1?

Those are the same thing :)

> It would be great if you could help adding/accommodating such usage to
> the generic iommu_pt. I think it will be a subset of features as
> intended for iommufd. I.e. map/unmap operation.

Yeah it should be no problem. hyperv handling the invalidation queue
in its own way should not effect the logic that drives the page table.

Jason