Re: [PATCH V4 05/18] iommu/ioasid: Redefine IOASID set and allocation APIs

[Jason Gunthorpe]

On Mon, May 10, 2021 at 03:28:54PM -0700, Jacob Pan wrote:

> To satisfy your "give me a PASID for this RID" proposal, can we just use
> the RID's struct device as the token? Also add a type field to explicitly
> indicate global vs per-set(per-RID). i.e.

You've got it backwards, the main behavior should be to allocate PASID
per RID.

The special behavior is to bundle a bunch of PASIDs into a grouping
and then say the PASID number space is shared between all the group
members. 

/dev/ioasid should create and own this grouping either implicitly or
explicitly. Jumping ahead to in-kernel APIs has missed the critical
step of defining the uAPI and all the behaviors together in a
completed RFC proposal.

Jason