Re: [PATCH 2/2] iommu/ioasid: Remove custom IOASID allocator

Jacob Pan
2023-02-13T19:08:54Z

Hi Jason,

On Mon, 13 Feb 2023 12:24:15 -0400, Jason Gunthorpe <jgg@nvidia.com> wrote:

> > We could also merge ioasid.c into iommu-sva.c at this point, since I
> > haven't seen any interest for having multiple IOASID sets on Arm, but
> > I'm not sure what the current plan is for vSVA on x86.
>
> Once the customer allocator is removed this is bascially a thin
> wrapper around xarray
>
> So anything that needs multiple pasid spaces should just create it on
> its own directly with xarray
>
Just wanted to double check that for devices on VT-d platforms that support
both SVA and DMA API with PASID, we will still need a single global pasid
space (due to IOTLB tagging). So this is not the "multiple pasid spaces"
case here, right?

As I replied to Jean as well, we could use the ioasid_set to separate SVA
and DMA API PASIDs.

Thanks,

Jacob