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 5138EC433FE for ; Sat, 25 Dec 2021 03:36:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229622AbhLYDg5 (ORCPT ); Fri, 24 Dec 2021 22:36:57 -0500 Received: from out30-131.freemail.mail.aliyun.com ([115.124.30.131]:55105 "EHLO out30-131.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229559AbhLYDg4 (ORCPT ); Fri, 24 Dec 2021 22:36:56 -0500 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R191e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04394;MF=chengyou@linux.alibaba.com;NM=1;PH=DS;RN=7;SR=0;TI=SMTPD_---0V.gZjWo_1640403413; Received: from 192.168.0.121(mailfrom:chengyou@linux.alibaba.com fp:SMTPD_---0V.gZjWo_1640403413) by smtp.aliyun-inc.com(127.0.0.1); Sat, 25 Dec 2021 11:36:54 +0800 Message-ID: Date: Sat, 25 Dec 2021 11:36:51 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Thunderbird/91.4.1 Subject: Re: [PATCH rdma-next 10/11] RDMA/erdma: Add the ABI definitions Content-Language: en-US To: Leon Romanovsky Cc: Yanjun Zhu , jgg@ziepe.ca, dledford@redhat.com, linux-rdma@vger.kernel.org, KaiShen@linux.alibaba.com, tonylu@linux.alibaba.com References: <20211221024858.25938-1-chengyou@linux.alibaba.com> <20211221024858.25938-11-chengyou@linux.alibaba.com> <6cb90490-d21c-e76e-19b9-2a7fe0669e04@linux.dev> From: Cheng Xu In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org On 12/25/21 2:19 AM, Leon Romanovsky wrote: > On Fri, Dec 24, 2021 at 03:12:35PM +0800, Cheng Xu wrote: >> >> >> On 12/24/21 6:55 AM, Yanjun Zhu wrote: >>> 在 2021/12/24 2:45, Leon Romanovsky 写道: >>>> On Thu, Dec 23, 2021 at 11:46:03PM +0800, Yanjun Zhu wrote: >>>>> 在 2021/12/21 10:48, Cheng Xu 写道: >>>>>> Signed-off-by: Cheng Xu >>>>>> --- >>>>>>    include/uapi/rdma/erdma-abi.h | 49 >>>>>> +++++++++++++++++++++++++++++++++++ >>>>>>    1 file changed, 49 insertions(+) >>>>>>    create mode 100644 include/uapi/rdma/erdma-abi.h >>>>>> >>>>>> diff --git a/include/uapi/rdma/erdma-abi.h >>>>>> b/include/uapi/rdma/erdma-abi.h >>>>>> new file mode 100644 >>>>>> index 000000000000..6bcba10c1e41 >>>>>> --- /dev/null >>>>>> +++ b/include/uapi/rdma/erdma-abi.h >>>>>> @@ -0,0 +1,49 @@ >>>>>> +/* SPDX-License-Identifier: ((GPL-2.0 WITH >>>>>> Linux-syscall-note) OR Linux-OpenIB) */ >>>>>> +/* >>>>>> + * Copyright (c) 2020-2021, Alibaba Group. >>>>>> + */ >>>>>> + >>>>>> +#ifndef __ERDMA_USER_H__ >>>>>> +#define __ERDMA_USER_H__ >>>>>> + >>>>>> +#include >>>>>> + >>>>>> +#define ERDMA_ABI_VERSION       1 >>>>> >>>>> ERDMA_ABI_VERSION should be 2？ >>>> >>>> Why? >>>> >>>> This field is for rdma-core and we don't have erdma provider in that >>>> library yet. It always starts from 1 for new drivers. >>> Please check this link: >>> http://mail.spinics.net/lists/linux-rdma/msg63012.html >>> >>> Jason mentioned in this link: >>> >>> " >>> /* >>>  * For 64 bit machines ABI version 1 and 2 are the same. Otherwise 32 >>>  * bit machines require ABI version 2 which guarentees the user and >>>  * kernel use the same ABI. >>>  */ >>> " >>> >>> Zhu Yanjun >> >> Even though I do not understand the reason, but as mentioned above, I think >> ERDMA_ABI_VERSION = 1 is fine, because ERDMA can only work in 64bit >> machines. > > Jason's comment came after we discovered that many of our API structures had > problematic layout and weren't aligned to 64bits. This caused to issues when > the 32bits software tried to use 64bit kernel. > > So we didn't have many choices but bump ABI versions for broken drivers > and RXE was one of them. > > You are proposing new driver, it should start from 1. Thanks for your explanation. Thanks, Cheng Xu > Thanks