Re: [PATCH v13 07/13] iommu/vt-d: Add SVA domain support

[Baolu Lu]

On 2022/9/23 20:15, Jason Gunthorpe wrote:
> On Fri, Sep 23, 2022 at 10:21:51AM +0800, Baolu Lu wrote:
>
> > At the beginning of this project, I wanted to consolidate the mm
> > notifications into the core. However, ARM SMMUv3 and Intel handle the mm
> > notifications a little differently. Then I decided to do this work
> > separately from the current series.
>
> It doesn't look really different..

They are essentially the same, but slightly different. For example, arm
smmuv3 provides .free_notifier, and I don't think it could be merged to
the release callback.

> The SVA iommu domain needs two new ops triggered by the notifier:
>
>   - 'stop using the mm, subsitute a blocking domain' tied to release
>   - Cache invalidate a range, maybe this is just iotlb_sync_map()
>
> And we could even think about the first as the core code literally
> attaching a dummy blocking domain and releasing the SVA domain. There
> is no reason we need to have every driver do this tricky bit of
> lifecycle management.

Yes. I have similar ideas. We can further discuss it with the real code
later.

Best regards,
baolu