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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,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 842E9C33CA1 for ; Mon, 20 Jan 2020 07:50:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4FB3C2073D for ; Mon, 20 Jan 2020 07:50:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="WHFUwt/1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726586AbgATHuc (ORCPT ); Mon, 20 Jan 2020 02:50:32 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:55411 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726039AbgATHuc (ORCPT ); Mon, 20 Jan 2020 02:50:32 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1579506631; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=U004lfJPbgC8DDvgY0vYrnnQi6voPmz5PbAj1bvuBr0=; b=WHFUwt/1xYWgox8NL8DpKdh7AARRj+DDNhEiPPIqz/4jgUQDy36BRzxOW6+RbOV1SHEqBH ZPj2D2JOg2BXlorJvMwrEIABnl9/kvFqyHDoeKqGKy6MyWzejYbwfJum75Ii0wSFyOFAo8 jZReMH4sVGHYQPwCBzAR1gCbNoRpUz0= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-113-8P1DRx1hN7GiWnnH17Bchg-1; Mon, 20 Jan 2020 02:50:28 -0500 X-MC-Unique: 8P1DRx1hN7GiWnnH17Bchg-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id CCE4F10054E3; Mon, 20 Jan 2020 07:50:25 +0000 (UTC) Received: from [10.72.12.173] (ovpn-12-173.pek2.redhat.com [10.72.12.173]) by smtp.corp.redhat.com (Postfix) with ESMTP id 23C8E84DB4; Mon, 20 Jan 2020 07:50:02 +0000 (UTC) Subject: Re: [PATCH 3/5] vDPA: introduce vDPA bus To: Jason Gunthorpe Cc: "mst@redhat.com" , "linux-kernel@vger.kernel.org" , "kvm@vger.kernel.org" , "virtualization@lists.linux-foundation.org" , "netdev@vger.kernel.org" , "tiwei.bie@intel.com" , "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" , "jakub.kicinski@netronome.com" , Jiri Pirko , Shahaf Shuler , "hanand@xilinx.com" , "mhabets@solarflare.com" References: <20200116124231.20253-1-jasowang@redhat.com> <20200116124231.20253-4-jasowang@redhat.com> <20200116152209.GH20978@mellanox.com> <03cfbcc2-fef0-c9d8-0b08-798b2a293b8c@redhat.com> <20200117135435.GU20978@mellanox.com> From: Jason Wang Message-ID: Date: Mon, 20 Jan 2020 15:50:01 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20200117135435.GU20978@mellanox.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Content-Transfer-Encoding: quoted-printable Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On 2020/1/17 =E4=B8=8B=E5=8D=889:54, Jason Gunthorpe wrote: > On Fri, Jan 17, 2020 at 11:03:12AM +0800, Jason Wang wrote: >> On 2020/1/16 =E4=B8=8B=E5=8D=8811:22, Jason Gunthorpe wrote: >>> On Thu, Jan 16, 2020 at 08:42:29PM +0800, Jason Wang wrote: >>>> vDPA device is a device that uses a datapath which complies with the >>>> virtio specifications with vendor specific control path. vDPA device= s >>>> can be both physically located on the hardware or emulated by >>>> software. vDPA hardware devices are usually implemented through PCIE >>>> with the following types: >>>> >>>> - PF (Physical Function) - A single Physical Function >>>> - VF (Virtual Function) - Device that supports single root I/O >>>> virtualization (SR-IOV). Its Virtual Function (VF) represents a >>>> virtualized instance of the device that can be assigned to diffe= rent >>>> partitions >>>> - VDEV (Virtual Device) - With technologies such as Intel Scalable >>>> IOV, a virtual device composed by host OS utilizing one or more >>>> ADIs. >>>> - SF (Sub function) - Vendor specific interface to slice the Physica= l >>>> Function to multiple sub functions that can be assigned to diffe= rent >>>> partitions as virtual devices. >>> I really hope we don't end up with two different ways to spell this >>> same thing. >> I think you meant ADI vs SF. It looks to me that ADI is limited to the= scope >> of scalable IOV but SF not. > I think if one looks carefully you'd find that SF and ADI are using > very similar techiniques. For instance we'd also like to use the code > reorg of the MSIX vector setup with SFs that Intel is calling IMS. > > Really SIOV is simply a bundle of pre-existing stuff under a tidy > name, whatever code skeleton we come up with for SFs should be re-used > for ADI. Ok, but do you prefer to mention ADI only for the next version? > >>> Shouldn't there be a device/driver matching process of some kind? >> >> The question is what do we want do match here. >> >> 1) "virtio" vs "vhost", I implemented matching method for this in mdev >> series, but it looks unnecessary for vDPA device driver to know about = this. >> Anyway we can use sysfs driver bind/unbind to switch drivers >> 2) virtio device id and vendor id. I'm not sure we need this consider = the >> two drivers so far (virtio/vhost) are all bus drivers. > As we seem to be contemplating some dynamic creation of vdpa devices I > think upon creation time it should be specified what mode they should > run it and then all driver binding and autoloading should happen > automatically. Telling the user to bind/unbind is a very poor > experience. > > Jason Ok, I will add the type (virtio vs vhost) and driver matching method back= . Thanks