Re: [PATCH v11 00/13] SMMUv3 Nested Stage Setup (IOMMU part)

[Zhangfei Gao]

On 2020/4/14 äå11:05, Eric Auger wrote:
> This version fixes an issue observed by Shameer on an SMMU 3.2,
> when moving from dual stage config to stage 1 only config.
> The 2 high 64b of the STE now get reset. Otherwise, leaving the
> S2TTB set may cause a C_BAD_STE error.
>
> This series can be found at:
> https://github.com/eauger/linux/tree/v5.6-2stage-v11_10.1
> (including the VFIO part)
> The QEMU fellow series still can be found at:
> https://github.com/eauger/qemu/tree/v4.2.0-2stage-rfcv6
>
> Users have expressed interest in that work and tested v9/v10:
> - https://patchwork.kernel.org/cover/11039995/#23012381
> - https://patchwork.kernel.org/cover/11039995/#23197235
>
> Background:
>
> This series brings the IOMMU part of HW nested paging support
> in the SMMUv3. The VFIO part is submitted separately.
>
> The IOMMU API is extended to support 2 new API functionalities:
> 1) pass the guest stage 1 configuration
> 2) pass stage 1 MSI bindings
>
> Then those capabilities gets implemented in the SMMUv3 driver.
>
> The virtualizer passes information through the VFIO user API
> which cascades them to the iommu subsystem. This allows the guest
> to own stage 1 tables and context descriptors (so-called PASID
> table) while the host owns stage 2 tables and main configuration
> structures (STE).

Thanks Eric

Tested v11 on Hisilicon kunpeng920 board via hardware zip accelerator.
1. no-sva works, where guest app directly use physical address via ioctl.
2. vSVA still not work, same as v10,
3. the v10 issue reported by Shameer has been solved, first start qemu 
with iommu=smmuv3, then start qemu without iommu=smmuv3
4. no-sva also works without iommu=smmuv3

Test details in https://docs.qq.com/doc/DRU5oR1NtUERseFNL

Thanks