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 1342CC76196 for ; Thu, 6 Apr 2023 11:14:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236782AbjDFLOm (ORCPT ); Thu, 6 Apr 2023 07:14:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43268 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229771AbjDFLOl (ORCPT ); Thu, 6 Apr 2023 07:14:41 -0400 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6EE91E6; Thu, 6 Apr 2023 04:14:40 -0700 (PDT) Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 3368qPG8011886; Thu, 6 Apr 2023 11:14:36 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=message-id : date : mime-version : subject : to : cc : references : from : in-reply-to : content-type : content-transfer-encoding; s=pp1; bh=WjEAuWLkS9VAxEzf203T1+TPUhyVG+CqnTJOgnevsgM=; b=hIfsr24GJBPrrREnaBWIwEALiXZwnLtAkeqY+V3yjr64Z5gA7FDotLDDdFxMlMkYY+db X6WVN65GdJf7DaV2YMmSminAVkRGd3lBGD4ZYnWck6UYe24RqsmMnhXo9DT38HygnjMb mHE0JgWmKR6/7rPFautu1KUyK+kReZTIp/wgHO2DOIa4Sosv89w2a1qNqOrur8h/sgVC qpXXMzV/8XGq/FDbQc3X227ifSUkBbTj21TiTtB0tIeRqv+Ai+OjSxME2MMhStTkdEGd rjVG4kY24mh6DPc+llYVXWDTbMTgkHXeBaDdRE9eeVjoa+sxRKbUYT2fyp8wcWfVuiwd yw== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3psar79fvj-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 06 Apr 2023 11:14:35 +0000 Received: from m0098399.ppops.net (m0098399.ppops.net [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 336B07qr030927; Thu, 6 Apr 2023 11:14:35 GMT Received: from ppma04ams.nl.ibm.com (63.31.33a9.ip4.static.sl-reverse.com [169.51.49.99]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3psar79fut-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 06 Apr 2023 11:14:35 +0000 Received: from pps.filterd (ppma04ams.nl.ibm.com [127.0.0.1]) by ppma04ams.nl.ibm.com (8.17.1.19/8.17.1.19) with ESMTP id 3364GjDZ027288; Thu, 6 Apr 2023 11:14:33 GMT Received: from smtprelay01.fra02v.mail.ibm.com ([9.218.2.227]) by ppma04ams.nl.ibm.com (PPS) with ESMTPS id 3ppc87c8pw-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 06 Apr 2023 11:14:32 +0000 Received: from smtpav03.fra02v.mail.ibm.com (smtpav03.fra02v.mail.ibm.com [10.20.54.102]) by smtprelay01.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 336BETMu61866262 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 6 Apr 2023 11:14:29 GMT Received: from smtpav03.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 0CBFC2004D; Thu, 6 Apr 2023 11:14:29 +0000 (GMT) Received: from smtpav03.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 9F8C220043; Thu, 6 Apr 2023 11:14:28 +0000 (GMT) Received: from [9.152.224.183] (unknown [9.152.224.183]) by smtpav03.fra02v.mail.ibm.com (Postfix) with ESMTP; Thu, 6 Apr 2023 11:14:28 +0000 (GMT) Message-ID: <33ab688e-88c9-d950-be66-f0f79774ff6c@linux.ibm.com> Date: Thu, 6 Apr 2023 13:14:28 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.9.1 Subject: Re: [RFC PATCH net-next v4 0/9] net/smc: Introduce SMC-D-based OS internal communication acceleration To: Niklas Schnelle , Wen Gu , kgraul@linux.ibm.com, wenjia@linux.ibm.com, jaka@linux.ibm.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com Cc: linux-s390@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org References: <1679887699-54797-1-git-send-email-guwen@linux.alibaba.com> <6156aaad710bc7350cbae6cb821289c8a37f44bb.camel@linux.ibm.com> Content-Language: en-US From: Alexandra Winter In-Reply-To: <6156aaad710bc7350cbae6cb821289c8a37f44bb.camel@linux.ibm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: I5uCFC6L47uNjIs2DB9yjf9t5XvJvDUe X-Proofpoint-GUID: n3LH0WtZmqozgv_4YrVMHpESp8mAnFCi X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.942,Hydra:6.0.573,FMLib:17.11.170.22 definitions=2023-04-06_04,2023-04-05_01,2023-02-09_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 lowpriorityscore=0 malwarescore=0 bulkscore=0 phishscore=0 impostorscore=0 adultscore=0 mlxscore=0 priorityscore=1501 spamscore=0 suspectscore=0 mlxlogscore=999 clxscore=1011 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2303200000 definitions=main-2304060096 Precedence: bulk List-ID: X-Mailing-List: linux-s390@vger.kernel.org On 05.04.23 19:04, Niklas Schnelle wrote: > One more question though, what about the SEID why does that have to be > fixed and at least partially match what ISM devices use? I think I'm > missing some SMC protocol/design detail here. I'm guessing this would > require a protocol change? > > Thanks, > Niklas Niklas, in the initial SMC CLC handshake the client and server exchange the SEID (one per peer system) and up to 8 proposals for SMC-D interfaces. Wen's current proposal assumes that smc-d loopback can be one of these 8 proposed interfaces, iiuc. So on s390 the proposal can contain ISM devices and a smc-d loopback device at the same time. If one of the peers is e.g. an older Linux version, it will just ignore the loopback-device in the list (Don't find a match for CHID 0xFFFF) and use an ISM interface for SMC-D if possible. Therefor it is important that the SEID is used in the same way as it is today in the handshake. If we decide for some reason (virtio-ism open issues?) that a protocol change/extension is required/wanted, then it is a new game and we can come up with new identifiers, but we may lose compatibility to backlevel systems. Alexandra