On Thu, Feb 23, 2023 at 01:06:47PM +0000, Brian van der Beek wrote: > For a CXL device that support both CMA/SPDM and CXL Table Access DOE > (CDAT) data objects, is it mandatory to have a dedicated DOE instance > for the CMA/SPMA protocol data objects? Yes, that follows from the requirements you quoted from the PCIe spec. > Or is it permitted for the CMA/SPDM and CXL protocols to share a > single DOE instance? You'd violate the PCIe spec and depend on software to handle such non-standard behavior gracefully. > I am reaching out to you, as I am hoping you could provide some > insight on the Linux CMA/SPDM implementation and whether it allows > for a DOE instance to be shared with CXL/CDAT data objects. The code as it currently is will allow that. > PCI-SIG replied that the requirement of a dedicated DOE instance for > CMA/SPDM was an intentional choice based on the idea that the software > attached to the DOE instances would be different. The PCISIG has published the DOE 1.1 ECN in the meantime and it allows for concurrent use of a mailbox by different software entities (kernel, BIOS, ...) through the use of a unique Connection ID. You could ask the PCISIG to revisit the spec's protocol restriction for CMA/SPDM in light of DOE 1.1. There's an ECR for CMA/SPDM currently under development. Thanks, Lukas
