Re: [PATCH 0/6] iommufd: Add iommu capability reporting

From: Jason Gunthorpe
Date: Wed Feb 22 2023 - 16:08:17 EST


On Wed, Feb 08, 2023 at 08:16:36PM -0800, Yi Liu wrote:
> iommufd gives userspace the capabilty to manipulating iommu subsytem.
> e.g. DMA map/unmap etc. In the near future, it will also support iommu
> nested translation. Different platform vendors have different implementation
> for the nested translation. So before set up nested translation, userspace
> needs to know the hardware iommu capabilities. For example, Intel platform
> supports guest I/O page table to be the first stage translation structure.
>
> This series reports the iommu capability for a given iommufd_device which
> has been bound to iommufd. It is a preparation work for nested translation
> support[1]. In this series, Intel VT-d capability reporting is added. Other
> vendors may add their own reporting based on this series.
>
> [1] https://github.com/yiliu1765/iommufd/tree/iommufd_nesting_vtd_v1

Let's have the comments addressed and this rebased on top of
https://github.com/jgunthorpe/linux/commits/iommufd_hwpt

Which should address eg the selftest issue

I want to start chipping away at bits of the nesting patch pile and
this part looks close

Thanks,
Jason