From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6E7F6C677F1 for ; Fri, 24 Feb 2023 06:56:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229610AbjBXG4f (ORCPT ); Fri, 24 Feb 2023 01:56:35 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48426 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229498AbjBXG4e (ORCPT ); Fri, 24 Feb 2023 01:56:34 -0500 Received: from bmailout2.hostsharing.net (bmailout2.hostsharing.net [83.223.78.240]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C2A8D57D09; Thu, 23 Feb 2023 22:56:33 -0800 (PST) Received: from h08.hostsharing.net (h08.hostsharing.net [IPv6:2a01:37:1000::53df:5f1c:0]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "*.hostsharing.net", Issuer "RapidSSL Global TLS RSA4096 SHA256 2022 CA1" (verified OK)) by bmailout2.hostsharing.net (Postfix) with ESMTPS id 395CD28055542; Fri, 24 Feb 2023 07:56:29 +0100 (CET) Received: by h08.hostsharing.net (Postfix, from userid 100393) id 1C0723EC36; Fri, 24 Feb 2023 07:56:29 +0100 (CET) Date: Fri, 24 Feb 2023 07:56:29 +0100 From: Lukas Wunner To: Brian van der Beek Cc: "linux-pci@vger.kernel.org" , "linux-cxl@vger.kernel.org" , Christophe Therene , Jonathan Cameron Subject: Re: Question on DOE requirements for CXL/CDAT and CMA/SPDM Message-ID: <20230224065629.GA15827@wunner.de> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org 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