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 X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D8E77C433E6 for ; Thu, 18 Mar 2021 14:27:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9B97E64EE1 for ; Thu, 18 Mar 2021 14:27:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229634AbhCRO1U convert rfc822-to-8bit (ORCPT ); Thu, 18 Mar 2021 10:27:20 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]:2711 "EHLO frasgout.his.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229508AbhCRO0t (ORCPT ); Thu, 18 Mar 2021 10:26:49 -0400 Received: from fraeml708-chm.china.huawei.com (unknown [172.18.147.201]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4F1ThH0tN4z6806m; Thu, 18 Mar 2021 22:20:31 +0800 (CST) Received: from lhreml710-chm.china.huawei.com (10.201.108.61) by fraeml708-chm.china.huawei.com (10.206.15.36) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2106.2; Thu, 18 Mar 2021 15:26:47 +0100 Received: from localhost (10.47.92.175) by lhreml710-chm.china.huawei.com (10.201.108.61) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2106.2; Thu, 18 Mar 2021 14:26:46 +0000 Date: Thu, 18 Mar 2021 14:25:29 +0000 From: Jonathan Cameron To: Dan Williams CC: Chris Browy , , "Linux PCI" , Ben Widawsky , "Bjorn Helgaas" , Linux ACPI , "Schofield, Alison" , Vishal L Verma , "Weiny, Ira" , "Lorenzo Pieralisi" , Linuxarm , Fangjian Subject: Re: [RFC PATCH 1/2] PCI/doe: Initial support PCI Data Object Exchange Message-ID: <20210318142529.00001507@Huawei.com> In-Reply-To: References: <20210310180306.1588376-1-Jonathan.Cameron@huawei.com> <20210310180306.1588376-2-Jonathan.Cameron@huawei.com> <20210316162952.00001ab7@Huawei.com> <6F0B8DDD-E661-40C8-839B-1B77998EFF23@avery-design.com> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; i686-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT X-Originating-IP: [10.47.92.175] X-ClientProxiedBy: lhreml713-chm.china.huawei.com (10.201.108.64) To lhreml710-chm.china.huawei.com (10.201.108.61) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-cxl@vger.kernel.org On Wed, 17 Mar 2021 18:30:26 -0700 Dan Williams wrote: > Btw your mailer does something odd with the "In-Reply-To:" field, I > need to fix it up manually to include your address. > > On Tue, Mar 16, 2021 at 4:28 PM Chris Browy wrote: > > > > Please address and clarify 2 queries below... > > > > > > > On Mar 16, 2021, at 2:14 PM, Dan Williams wrote: > > > > > > On Tue, Mar 16, 2021 at 9:31 AM Jonathan Cameron > > > wrote: > > >> > > >> On Mon, 15 Mar 2021 12:45:49 -0700 > > >> Dan Williams wrote: > > >> > > >>> Hey Jonathan, happy to see this, some comments below... > > >> > > >> Hi Dan, > > >> > > >> Thanks for taking a look! > > >> > > >>> > > >>> On Wed, Mar 10, 2021 at 10:08 AM Jonathan Cameron > > >>> wrote: > > >>>> > > >>>> Introduced in an ECN to the PCI 5.0, DOE provides a config space > > >>>> based mailbox with standard protocol discovery. Each mailbox > > >>>> is accessed through a DOE PCIE Extended Capability. > > >>>> > > >>>> A device may have 1 or more DOE mailboxes, each of which is allowed > > >>>> to support any number of protocols (some DOE protocols > > >>>> specifications apply additional restrictions). A given protocol > > >>>> may be supported on more than one DOE mailbox on a given function. > > >>> > > >>> Are all those protocol instances shared? > > >>> I'm trying to mental model > > >>> whether, for example, an auxiliary driver instance could be loaded per > > >>> DOE mailbox, or if there would need to be coordination of a given > > >>> protocol no matter how many DOE mailboxes on that device implemented > > >>> that protocol. > > >> > > >> Just to check I've understood corectly, you mean multiple instances of same > > >> protocol across different DOE mailboxes on a given device? > > >> > > > > > > Right. > > > > Could you confirm this case for clarity? A CXL device may have multiple VF/PF. > > For example, PF=0 could have one or more DOE instances for CDAT protocol. > > The driver will scan PF=0 for all DOE instances and finding one or more of CDAT > > protocol will combine/manage them. I had not considered multiple CDAT tables > > for single PF. For CXL devices with multiple PF’s the same process would be > > carried out on PF=1-N. > > This patch has nothing to do with CXL. This is a general discussion of > how a PCIE device implements a DOE mailbox or set of mailboxes. The > DOE definition is PF-only afaics from the DOE specification. > > The CXL specification only says that a device can implement a CDAT per > DOE capability instance, so the CXL spec does not limit the number of > DOE instances to 1, but I can't think of a practical reason to support > more than one. > > [..] > > >>> https://cfp.osfc.io/media/osfc2020/submissions/ECQ88N/resources/An_open_source_SPDM_implementation_for_secure_devi_kmIgAQe.pdf > > >> > > >> Nice! Looking at CMA / IDE emulation was on my todo list and that looks like > > >> it might make that job a lot easier. > > > > Would it be useful to integrate the openspdm’s SpdmResponderEmu.c onto the QEMU’s CXL Type3 Device’s > > DOE backend for CMA/IDE testing? Doesn’t look hard to do. > > Yes, I do think it would be useful. Agreed. Very useful indeed. Jonathan