Re: [PATCH v11 04/13] PCI: Allow PASID only when ACS enforced on upstreaming path

[Jason Gunthorpe]

On Wed, Aug 17, 2022 at 04:17:43PM -0500, Bjorn Helgaas wrote:

> Does the PCIe spec really allow TLPs with PASID to be routed anywhere
> except upstream?

I think yes:

 2.2.10.2 End-End TLP Prefix Processing:

 The presence of an End-End TLP Prefix does not alter the routing of a
 TLP. TLPs are routed based on the routing rules covered in Section
 2.2.4 .

Which I read as saying that routing is done after stripping all the
prefixes. PASID is a prefix.

Lu, you may want to quote the spec in the commit message to make it
clear.

A strange choice in my opinion, but there it is..

Jason