From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tiwei Bie Subject: Re: [PATCH V2 3/5] vDPA: introduce vDPA bus Date: Wed, 19 Feb 2020 10:59:48 +0800 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 Return-path: Content-Disposition: inline In-Reply-To: <20200218135608.GS4271@mellanox.com> Sender: linux-kernel-owner@vger.kernel.org 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" List-Id: virtualization@lists.linuxfoundation.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