Re: [PATCH v9 0/7] IOMMU user API enhancement

Joerg Roedel
2020-09-18T10:02:41Z

Hi Jacob,

On Fri, Sep 11, 2020 at 02:57:49PM -0700, Jacob Pan wrote:
> IOMMU user API header was introduced to support nested DMA translation and
> related fault handling. The current UAPI data structures consist of three
> areas that cover the interactions between host kernel and guest:
> - fault handling
> - cache invalidation
> - bind guest page tables, i.e. guest PASID
>
> Future extensions are likely to support more architectures and vIOMMU features.
>
> In the previous discussion, using user-filled data size and feature flags is
> made a preferred approach over a unified version number.
> https://lkml.org/lkml/2020/1/29/45
>
> In addition to introduce argsz field to data structures, this patchset is also
> trying to document the UAPI design, usage, and extension rules. VT-d driver
> changes to utilize the new argsz field is included, VFIO usage is to follow.
>
> This set is available at:
> https://github.com/jacobpan/linux.git vsva_v5.9_uapi_v9

This changes user visible structs in incompatible ways, are you sure
those are not used yet anywhere?

Please address Randy's comments on patch 1 and my comment about the
build-time checking and repost with linux-api@vger.kernel.org on Cc.

Regards,

Joerg