From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752163AbeDMV4M (ORCPT ); Fri, 13 Apr 2018 17:56:12 -0400 Received: from mail-eopbgr660113.outbound.protection.outlook.com ([40.107.66.113]:61026 "EHLO CAN01-QB1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751847AbeDMV4J (ORCPT ); Fri, 13 Apr 2018 17:56:09 -0400 From: "Stephen Bates" To: Jonathan Cameron , Logan Gunthorpe CC: Bjorn Helgaas , Sinan Kaya , "linux-kernel@vger.kernel.org" , "linux-pci@vger.kernel.org" , "linux-nvme@lists.infradead.org" , "linux-rdma@vger.kernel.org" , "linux-nvdimm@lists.01.org" , "linux-block@vger.kernel.org" , "Christoph Hellwig" , Jens Axboe , Keith Busch , Sagi Grimberg , Bjorn Helgaas , Jason Gunthorpe , Max Gurtovoy , Dan Williams , =?utf-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Benjamin Herrenschmidt , Alex Williamson , Eric Wehage Subject: Re: [PATCH v3 01/11] PCI/P2PDMA: Support peer-to-peer memory Thread-Topic: [PATCH v3 01/11] PCI/P2PDMA: Support peer-to-peer memory Thread-Index: AQHTujlZo8bTZRn+4ECdETRRU1rPhqPNgjSAgADeTICAFBF4AIAAL2gAgAAdXQCAAR0ogIAbL4UA Date: Fri, 13 Apr 2018 21:56:06 +0000 Message-ID: <178FD8FA-53BA-49DA-807F-F8736157F179@raithlin.com> References: <20180312193525.2855-1-logang@deltatee.com> <20180312193525.2855-2-logang@deltatee.com> <59fd2f5d-177f-334a-a9c4-0f8a6ec7c303@codeaurora.org> <24d8e5c2-065d-8bde-3f5d-7f158be9c578@deltatee.com> <20180326121138.00005e30@huawei.com> <20180326140118.GA221690@bhelgaas-glaptop.roam.corp.google.com> <20180327094701.0000300d@huawei.com> In-Reply-To: <20180327094701.0000300d@huawei.com> Accept-Language: en-CA, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: user-agent: Microsoft-MacOutlook/10.c.0.180410 authentication-results: spf=none (sender IP is ) smtp.mailfrom=sbates@raithlin.com; x-originating-ip: [70.65.253.218] x-ms-publictraffictype: Email x-microsoft-exchange-diagnostics: 1;YTXPR0101MB1934;7:lq9dVTLn9pV4e2ZoQwRf32YWQjsL4jWBWw2rJ6QD6/AJo1Dgl4B86lb//WWnwtFfapuwgaOcTz42V0ET1R/4EQNQstDEalZGRBZJQxDoGMI7qKIq9SLR/Euf+k6NiwU29vapHWAKjEcbuLx+mQYunFFvM1mnuDk+rSZFV1QN2+ME5w3K/5Gn7Xy/G5VysilvRJ1VkEpKNa02aKu+Q9OcpqybePxZmPBVi52y7ze1OgEIEYO2GneqNcQiVzK2lL5W x-microsoft-antispam: UriScan:;BCL:0;PCL:0;RULEID:(7020095)(4652020)(7021125)(5600026)(4534165)(7022125)(4603075)(4627221)(201702281549075)(7048125)(7024125)(7027125)(7028125)(7023125)(2017052603328)(7153060)(7193020);SRVR:YTXPR0101MB1934; x-ms-traffictypediagnostic: YTXPR0101MB1934: x-microsoft-antispam-prvs: x-exchange-antispam-report-test: UriScan:; x-exchange-antispam-report-cfa-test: BCL:0;PCL:0;RULEID:(6040522)(2401047)(8121501046)(5005006)(3002001)(93006095)(93001095)(3231232)(944501327)(52105095)(10201501046)(6041310)(20161123564045)(20161123558120)(20161123560045)(20161123562045)(2016111802025)(6072148)(6043046)(201708071742011);SRVR:YTXPR0101MB1934;BCL:0;PCL:0;RULEID:;SRVR:YTXPR0101MB1934; x-forefront-prvs: 0641678E68 x-forefront-antispam-report: SFV:NSPM;SFS:(10019020)(39830400003)(396003)(39380400002)(376002)(366004)(346002)(189003)(199004)(99286004)(6246003)(58126008)(186003)(102836004)(54906003)(4326008)(53936002)(110136005)(478600001)(106356001)(105586002)(25786009)(7416002)(83716003)(486006)(36756003)(8676002)(8936002)(86362001)(476003)(81156014)(81166006)(76176011)(5660300001)(66066001)(7736002)(97736004)(2616005)(229853002)(2900100001)(33656002)(2906002)(3280700002)(3660700001)(5250100002)(6436002)(6506007)(305945005)(14454004)(68736007)(26005)(6512007)(446003)(11346002)(316002)(93886005)(6486002)(3846002)(82746002)(6116002);DIR:OUT;SFP:1102;SCL:1;SRVR:YTXPR0101MB1934;H:YTXPR0101MB2045.CANPRD01.PROD.OUTLOOK.COM;FPR:;SPF:None;LANG:en;PTR:InfoNoRecords;MX:1;A:1; x-microsoft-antispam-message-info: 1GspblcErftozeBs+6hhjS/UjlxAYNfHI6RyD2lcunxYs9cPeaq0G2KhyYcGSWgVF+7XvoG5BWhfrFzNWscZ3FHTAiXcgD25vFovfs7xdABuIVnj6uAH9koYGseJgXe93bifrJ3H2ItFTeRL5NSmtzzYeDBEQtPvB4rMGtQ9+5+BzBSMsAJDfrwjsJoPu5zO spamdiagnosticoutput: 1:99 spamdiagnosticmetadata: NSPM Content-Type: text/plain; charset="utf-8" Content-ID: MIME-Version: 1.0 X-MS-Office365-Filtering-Correlation-Id: f5a82b3a-a5c4-4fc6-02da-08d5a1895c12 X-OriginatorOrg: raithlin.com X-MS-Exchange-CrossTenant-Network-Message-Id: f5a82b3a-a5c4-4fc6-02da-08d5a1895c12 X-MS-Exchange-CrossTenant-originalarrivaltime: 13 Apr 2018 21:56:06.8818 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 18519031-7ff4-4cbb-bbcb-c3252d330f4b X-MS-Exchange-Transport-CrossTenantHeadersStamped: YTXPR0101MB1934 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id w3DLuHGi027985 > I'll see if I can get our PCI SIG people to follow this through Hi Jonathan Can you let me know if this moves forward within PCI-SIG? I would like to track it. I can see this being doable between Root Ports that reside in the same Root Complex but might become more challenging to standardize for RPs that reside in different RCs in the same (potentially multi-socket) system. I know in the past we have seem MemWr TLPS cross the QPI bus in Intel systems but I am sure that is not something that would work in all systems and must fall outside the remit of PCI-SIG ;-). I agree such a capability bit would be very useful but it's going to be quite some time before we can rely on hardware being available that supports it. Stephen