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 X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1F196C34031 for ; Wed, 19 Feb 2020 03:00:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EAE6522B48 for ; Wed, 19 Feb 2020 03:00:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728295AbgBSDAE (ORCPT ); Tue, 18 Feb 2020 22:00:04 -0500 Received: from mga11.intel.com ([192.55.52.93]:6619 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728196AbgBSDAE (ORCPT ); Tue, 18 Feb 2020 22:00:04 -0500 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 18 Feb 2020 19:00:03 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,458,1574150400"; d="scan'208";a="348830245" Received: from dpdk-virtio-tbie-2.sh.intel.com (HELO ___) ([10.67.104.74]) by fmsmga001.fm.intel.com with ESMTP; 18 Feb 2020 18:59:58 -0800 Date: Wed, 19 Feb 2020 10:59:48 +0800 From: Tiwei Bie To: Jason Gunthorpe Cc: Jason Wang , "mst@redhat.com" , "linux-kernel@vger.kernel.org" , "kvm@vger.kernel.org" , "virtualization@lists.linux-foundation.org" , "netdev@vger.kernel.org" , "maxime.coquelin@redhat.com" , "cunming.liang@intel.com" , "zhihong.wang@intel.com" , "rob.miller@broadcom.com" , "xiao.w.wang@intel.com" , "haotian.wang@sifive.com" , "lingshan.zhu@intel.com" , "eperezma@redhat.com" , "lulu@redhat.com" , Parav Pandit , "kevin.tian@intel.com" , "stefanha@redhat.com" , "rdunlap@infradead.org" , "hch@infradead.org" , "aadam@redhat.com" , Jiri Pirko , Shahaf Shuler , "hanand@xilinx.com" , "mhabets@solarflare.com" Subject: Re: [PATCH V2 3/5] vDPA: introduce vDPA bus Message-ID: <20200219025948.GA972742@___> References: <20200212125108.GS4271@mellanox.com> <12775659-1589-39e4-e344-b7a2c792b0f3@redhat.com> <20200213134128.GV4271@mellanox.com> <20200213150542.GW4271@mellanox.com> <8b3e6a9c-8bfd-fb3c-12a8-2d6a3879f1ae@redhat.com> <20200214135232.GB4271@mellanox.com> <01c86ebb-cf4b-691f-e682-2d6f93ddbcf7@redhat.com> <20200218135608.GS4271@mellanox.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20200218135608.GS4271@mellanox.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 18, 2020 at 01:56:12PM +0000, Jason Gunthorpe wrote: > On Mon, Feb 17, 2020 at 02:08:03PM +0800, Jason Wang wrote: > > > I thought you were copied in the patch [1], maybe we can move vhost related > > discussion there to avoid confusion. > > > > [1] https://lwn.net/Articles/811210/ > > Wow, that is .. confusing. > > So this is supposed to duplicate the uAPI of vhost-user? But it is > open coded and duplicated because .. vdpa? Do you mean the vhost-user in DPDK? There is no vhost-user in Linux kernel. Thanks, Tiwei > > > So it's cheaper and simpler to introduce a new bus instead of refactoring a > > well known bus and API where brunches of drivers and devices had been > > implemented for years. > > If you reason for this approach is to ease the implementation then you > should talk about it in the cover letters/etc > > Maybe it is reasonable to do this because the rework is too great, I > don't know, but to me this whole thing looks rather messy. > > Remember this stuff is all uAPI as it shows up in sysfs, so you can > easilly get stuck with it forever. > > Jason