RE: [PATCH 3/6] vfio: remove the unused mdev iommu hook

Tian, Kevin
2021-07-23T05:36:29Z

> From: Christoph Hellwig <hch@lst.de>
> Sent: Thursday, July 22, 2021 9:35 PM
>
> On Wed, Jun 30, 2021 at 09:08:19AM +0000, Tian, Kevin wrote:
> > The iommu layer should maintain above attaching status per device and
> per
> > iommu domain. There is no mdev/subdev concept in the iommu layer. It's
> > just about RID or PASID.
>
> Yes, I think that makes sense.
>
> > And a new set of IOMMU-API:
> >
> > - iommu_{un}bind_pgtable(domain, dev, addr);
> > - iommu_{un}bind_pgtable_pasid(domain, dev, addr, pasid);
> > - iommu_cache_invalidate(domain, dev, invalid_info);
>
> What caches is this supposed to "invalidate"?

pasid cache, iotlb or dev_iotlb entries that are related to the bound
pgtable. the actual affected cache type and granularity (device-wide,
pasid-wide, selected addr-range) are specified by the caller.

Thanks
Kevin