Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030971AbbD1Tux (ORCPT ); Tue, 28 Apr 2015 15:50:53 -0400 Received: from alln-iport-6.cisco.com ([173.37.142.93]:38635 "EHLO alln-iport-6.cisco.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030762AbbD1Tuu convert rfc822-to-8bit (ORCPT ); Tue, 28 Apr 2015 15:50:50 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: A0ChBQCO4z9V/4kNJK1cgwxTXAXHG4FThgQCgTs6EgEBAQEBAQGBCoQhAQEDATo/EAIBCDYQMiUCBA4FG4gICA3HVAEBAQEBAQEBAQEBAQEBAQEBAQEBGIs4hFIzB4MXgRYFkWWEBIY7gWCKRolGI2CDFG+BRIEBAQEB X-IronPort-AV: E=Sophos;i="5.11,665,1422921600"; d="scan'208";a="145373138" From: "Dave Goodell (dgoodell)" To: "Hefty, Sean" CC: Tom Talpey , Doug Ledford , "Weiny, Ira" , Michael Wang , "Liran Liss" , Roland Dreier , Hal Rosenstock , "linux-rdma@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Steve Wise , Jason Gunthorpe , Tom Tucker , Hoang-Nam Nguyen , "raisch@de.ibm.com" , infinipath , Eli Cohen , "Latif, Faisal" , "Jack Morgenstein" , Or Gerlitz , Haggai Eran Subject: Re: [PATCH v6 01/26] IB/Verbs: Implement new callback query_transport() Thread-Topic: [PATCH v6 01/26] IB/Verbs: Implement new callback query_transport() Thread-Index: AQHQfomOUvs+HNY8lEy/xelJkPOzZZ1cmNSAgAQ4ZICAAO5xAIAAKDWAgAAFeQCAAATZgIAACLqAgAAG4QCAAEoOgIAA5CWA Date: Tue, 28 Apr 2015 19:50:48 +0000 Message-ID: References: <1429878230-11749-1-git-send-email-yun.wang@profitbricks.com> <1429878230-11749-2-git-send-email-yun.wang@profitbricks.com> <553DE799.5050608@profitbricks.com> <20150427215229.GD5347@phlsvsds.ph.intel.com> <553ED159.2090006@talpey.com> <1430181360.44548.35.camel@redhat.com> <553EDA01.9040708@talpey.com> <1430184275.44548.44.camel@redhat.com> <553EE718.1030502@talpey.com> <1828884A29C6694DAF28B7E6B8A82373A8FC819C@ORSMSX109.amr.corp.intel.com> In-Reply-To: <1828884A29C6694DAF28B7E6B8A82373A8FC819C@ORSMSX109.amr.corp.intel.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.27.35.215] Content-Type: text/plain; charset="us-ascii" Content-ID: Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2283 Lines: 30 On Apr 28, 2015, at 1:14 AM, Hefty, Sean wrote: >>> Keep in mind that this enum was Liran's response to Michael's original >>> patch. In the enum in Michael's patch, there was both USNIC and >>> USNIC_UDP. >> >> Right! That's why I'm confused. Seems wrong to drop it, right? > > I think the original USNIC protocol is layered directly over Ethernet. The protocol basically stole an Ethertype (the one used for IBoE/RoCE) and implemented a proprietary protocol instead. I have no idea how you resolve that, but I also don't think it's used anymore. USNIC_UDP is just UDP. Sean is correct. The legacy RDMA_TRANSPORT_USNIC code used a proprietary protocol over plain Ethernet frames. The newer RDMA_TRANSPORT_USNIC_UDP code is just standard UDP/IP/Ethernet packets exposed to user space via the uverbs stack. The current kernel module will support both formats, it just depends on which user space requests at create_qp time. From the kernel point of view there is no common protocol between the two TRANSPORTs (other than sharing partially similar Ethernet frames at L2). I posted last week to clarify some of this: http://marc.info/?l=linux-rdma&m=142972177830718&w=2 >> Well, if RoCEv2 uses the same protocol enum, that may introduce new >> confusion, for example there will be some new CM handling for UDP encap, >> source port selection, and of course vlan/tag assignment, etc. But if >> there is support under way, and everyone is clear, then, ok. > > RoCEv2/IBoUDP shares the same port space as UDP. It has a similar issues as iWarp does sharing state with the main network stack. I'm not aware of any proposal for resolving that. Does it require using a separate IP address? Does it use a port mapper function? Does netdev care for UDP? I'm not sure what USNIC does for this either, but a common solution between USNIC and IBoUDP seems reasonable. Is the concern here about CM issues or the UDP ports used by the actual usNIC RQs? CM is not used/supported for usNIC at this time. -Dave -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/