From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1032194AbeCAP6q (ORCPT ); Thu, 1 Mar 2018 10:58:46 -0500 Received: from mail-eopbgr660109.outbound.protection.outlook.com ([40.107.66.109]:22645 "EHLO CAN01-QB1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1031567AbeCAP6n (ORCPT ); Thu, 1 Mar 2018 10:58:43 -0500 From: "Stephen Bates" To: Sagi Grimberg , Logan Gunthorpe , "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" CC: Christoph Hellwig , Jens Axboe , Keith Busch , Bjorn Helgaas , Jason Gunthorpe , Max Gurtovoy , Dan Williams , =?utf-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Benjamin Herrenschmidt , "Alex Williamson" , "Martin K. Petersen" Subject: Re: [PATCH v2 08/10] nvme-pci: Add support for P2P memory in requests Thread-Topic: [PATCH v2 08/10] nvme-pci: Add support for P2P memory in requests Thread-Index: AQHTsO2D/pI4MI4aGk+ocic9Kzv7zqO7OS2A///b9AA= Date: Thu, 1 Mar 2018 15:58:40 +0000 Message-ID: <1CE68E79-E5FD-4EE2-BD88-B3EE57E43ACE@raithlin.com> References: <20180228234006.21093-1-logang@deltatee.com> <20180228234006.21093-9-logang@deltatee.com> In-Reply-To: Accept-Language: en-CA, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: user-agent: Microsoft-MacOutlook/10.a.0.180210 authentication-results: spf=none (sender IP is ) smtp.mailfrom=sbates@raithlin.com; x-originating-ip: [70.65.224.121] x-ms-publictraffictype: Email x-microsoft-exchange-diagnostics: 1;YTXPR0101MB1407;7:Uzz1nyyFNZgoTy7Q+AIKASIVThfr+rhk9OV1Rdpct2W+DyH/ItDeR8Y5QV2extcHb7gzm3g7aouOrsgTztnr4298S3A9eFXmaYA6cPxCDEr0vKVd040Rj2u7AuvqjU2DeMwvCCuRR+tLu+OvzhFMkaNXgxnw1Y0xkNM+LaHAdJ3ubMQ1B7lAvM+nV0GbIKR3d/jYQWSyZDKuSCoMegFxSV+i43xw6gKN37hjQTxnFVrDdGuiGsO28FT40Ysc8f/G x-ms-exchange-antispam-srfa-diagnostics: SSOS; x-ms-office365-filtering-correlation-id: 3e5154b3-0b1e-4a54-f339-08d57f8d4d91 x-microsoft-antispam: UriScan:;BCL:0;PCL:0;RULEID:(7020095)(4652020)(7021125)(4534165)(7022125)(4603075)(4627221)(201702281549075)(7048125)(7024125)(7027125)(7028125)(7023125)(5600026)(4604075)(3008032)(2017052603307)(7153060)(7193020);SRVR:YTXPR0101MB1407; x-ms-traffictypediagnostic: YTXPR0101MB1407: x-microsoft-antispam-prvs: x-exchange-antispam-report-test: UriScan:; x-exchange-antispam-report-cfa-test: BCL:0;PCL:0;RULEID:(6040501)(2401047)(5005006)(8121501046)(3231220)(944501161)(52105095)(10201501046)(93006095)(93001095)(3002001)(6041288)(20161123562045)(2016111802025)(20161123558120)(20161123564045)(20161123560045)(6072148)(6043046)(201708071742011);SRVR:YTXPR0101MB1407;BCL:0;PCL:0;RULEID:;SRVR:YTXPR0101MB1407; x-forefront-prvs: 05986C03E0 x-forefront-antispam-report: SFV:NSPM;SFS:(10019020)(366004)(346002)(39380400002)(376002)(396003)(39830400003)(199004)(189003)(14454004)(186003)(97736004)(5660300001)(5250100002)(6486002)(7416002)(3846002)(6116002)(53936002)(7736002)(305945005)(86362001)(102836004)(5890100001)(2501003)(6512007)(2201001)(2900100001)(26005)(6436002)(478600001)(83716003)(229853002)(3280700002)(66066001)(81156014)(81166006)(68736007)(99286004)(106356001)(3660700001)(105586002)(4326008)(8676002)(58126008)(33656002)(36756003)(316002)(25786009)(110136005)(2950100002)(8936002)(54906003)(6246003)(82746002)(2906002)(76176011)(6506007);DIR:OUT;SFP:1102;SCL:1;SRVR:YTXPR0101MB1407;H:YTXPR0101MB2045.CANPRD01.PROD.OUTLOOK.COM;FPR:;SPF:None;PTR:InfoNoRecords;A:1;MX:1;LANG:en; x-microsoft-antispam-message-info: tYM0GMfCQXDHsANv6wP7SCYJyA+jZ1I2R8yu1hC4tqWKL+C0mzMJ8E5JA+TISLVQ/J1iGzVyOVfUoyXvukk6WSUcLwhtHG5rsBPkh2gJpru6980TjhO2f219IGwS2P7MY1xsgjuMMqSiKdtlb2ld15fPZtHvopDu1kwt+04ER5g= spamdiagnosticoutput: 1:99 spamdiagnosticmetadata: NSPM Content-Type: text/plain; charset="utf-8" Content-ID: MIME-Version: 1.0 X-OriginatorOrg: raithlin.com X-MS-Exchange-CrossTenant-Network-Message-Id: 3e5154b3-0b1e-4a54-f339-08d57f8d4d91 X-MS-Exchange-CrossTenant-originalarrivaltime: 01 Mar 2018 15:58:40.9913 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 18519031-7ff4-4cbb-bbcb-c3252d330f4b X-MS-Exchange-Transport-CrossTenantHeadersStamped: YTXPR0101MB1407 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 w21FwpvV014691 > Any plans adding the capability to nvme-rdma? Should be > straight-forward... In theory, the use-case would be rdma backend > fabric behind. Shouldn't be hard to test either... Nice idea Sagi. Yes we have been starting to look at that. Though again we would probably want to impose the "attached to the same PCIe switch" rule which might be less common to satisfy in initiator systems. Down the road I would also like to discuss the best way to use this P2P framework to facilitate copies between NVMe namespaces (on both PCIe and fabric attached namespaces) without having to expose the CMB up to user space. Wasn't something like that done in the SCSI world at some point Martin? Stephen