Re: [PATCH v4 05/12] iommu/arm-smmu-v3: Support IOMMU_GET_HW_INFO via struct arm_smmu_hw_info

Nicolin Chen
2024-11-06T21:53:33Z

On Wed, Nov 06, 2024 at 09:05:26PM +0000, Robin Murphy wrote:
> On 2024-11-06 6:05 pm, Jason Gunthorpe wrote:
> > If you still feel strongly about this please let me know by Friday and
> > I will drop the idr[] array from this cycle. We can continue to
> > discuss a solution for the next cycle.
>
> It already can't work as-is, I don't see how making it even more broken
> would help. IMO it doesn't seem like a good idea to be merging UAPI at
> all while it's still clearly incomplete and by its own definition unusable.

Robin, would you please give a clear suggestion for the hw_info?

My takeaway is that you would want the unsupported features (per
firmware overrides and errata) to be stripped from the reporting
IDR array. Alternatively, we could start with some basic nesting
features less those advanced ones (HTTU/PRI or so), and then add
then later once we're comfortable to advertise.

Does this sound okay to you?

Thanks
Nicolin