arm-smmu-v3 sharing SID

[Jason Gunthorpe]

On Fri, May 19, 2023 at 10:49:17AM +0800, Baolu Lu wrote:

> This creates an illusion that the iommu core still insists on supporting
> pasid on multiple device groups.

Yeah, it doesn't have an issue itself, the issue with PASID is higher
up..

We actually built a system that requires pasid multi-device groups. It
doesn't work and you have to hack things to make single device groups
(sigh). People have asked about fixing it upstream but nobody has
tried. It seems hard.

Jason