Re: [PATCH v9 0/5] iommufd: Add iommu hardware info reporting

[Jason Gunthorpe]

On Fri, Aug 18, 2023 at 03:10:28AM -0700, Yi Liu wrote:
> iommufd gives userspace the capability to manipulate iommu subsytem.
> e.g. DMA map/unmap etc. In the near future, it will support iommu nested
> translation. Different platform vendors have different implementations for
> the nested translation. For example, Intel VT-d supports using guest I/O
> page table as the stage-1 translation table. This requires guest I/O page
> table be compatible with hardware IOMMU. So before set up nested translation,
> userspace needs to know the hardware iommu information to understand the
> nested translation requirements.
> 
> This series reports the iommu hardware information for a given device
> which has been bound to iommufd. It is preparation work for userspace to
> allocate hwpt for given device. Like the nested translation support [1].
> 
> This series introduces an iommu op to report the iommu hardware info,
> and an ioctl IOMMU_GET_HW_INFO is added to report such hardware info to
> user. enum iommu_hw_info_type is defined to differentiate the iommu hardware
> info reported to user hence user can decode them. This series adds the
> framework for iommu hw info reporting, and adds the vtd implementation. The
> complete code is available in [2].
> 
> [1] https://lore.kernel.org/linux-iommu/20230724110406.107212-1-yi.l.liu@xxxxxxxxx/
> [2] https://github.com/yiliu1765/iommufd/tree/iommufd_hw_info-v9

> Lu Baolu (1):
>   iommu: Add new iommu op to get iommu hardware information
> 
> Nicolin Chen (1):
>   iommufd/selftest: Add coverage for IOMMU_GET_HW_INFO ioctl
> 
> Yi Liu (3):
>   iommu: Move dev_iommu_ops() to private header
>   iommufd: Add IOMMU_GET_HW_INFO
>   iommu/vt-d: Implement hw_info for iommu capability query


I picked this one up to iommufd for-next, thanks

Jason