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=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 638F8C432C3 for ; Thu, 21 Nov 2019 04:07:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3AF2120721 for ; Thu, 21 Nov 2019 04:07:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="MeWvJc0+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726038AbfKUEHZ (ORCPT ); Wed, 20 Nov 2019 23:07:25 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:37133 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725842AbfKUEHZ (ORCPT ); Wed, 20 Nov 2019 23:07:25 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1574309243; 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=4xPmtYqEvwApqpheQllbkBpuzyfIA/fCCLuuQtfXsnw=; b=MeWvJc0+e6+UEKMvGJ1XtmwF3H3gN1QAFH+NoSbL9LRKsrZvpdPe+eSuVSWVtlTwknOmv/ 6MwIJ9ucOi7+/MvF6ru0t9CFJ0cxnE3wM4wz4+3czUtVOPV+HGF4OgUQtBQhNlPo7gb2r+ dtlxSjg6/yF2zp6xfSRb8BhFpBmHjtE= 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-345-Xu_mjR_fPQ2kgYFI6ozcxQ-1; Wed, 20 Nov 2019 23:07:20 -0500 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 3C2BF107ACC5; Thu, 21 Nov 2019 04:07:17 +0000 (UTC) Received: from [10.72.12.204] (ovpn-12-204.pek2.redhat.com [10.72.12.204]) by smtp.corp.redhat.com (Postfix) with ESMTP id DFF6960BA9; Thu, 21 Nov 2019 04:06:02 +0000 (UTC) Subject: Re: [net-next v2 1/1] virtual-bus: Implementation of Virtual Bus To: Jason Gunthorpe Cc: Parav Pandit , Jeff Kirsher , "davem@davemloft.net" , "gregkh@linuxfoundation.org" , Dave Ertman , "netdev@vger.kernel.org" , "linux-rdma@vger.kernel.org" , "nhorman@redhat.com" , "sassmann@redhat.com" , Kiran Patil , "Michael S. Tsirkin" , Alex Williamson , Tiwei Bie References: <13946106-dab2-6bbe-df79-ca6dfdeb4c51@redhat.com> <743601510.35622214.1574219728585.JavaMail.zimbra@redhat.com> <21106743-57b2-2ca7-258c-e37a0880c70f@redhat.com> <20191120134126.GD22515@ziepe.ca> From: Jason Wang Message-ID: <2b5db5d9-5421-7277-acde-13862a629381@redhat.com> Date: Thu, 21 Nov 2019 12:06:01 +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: <20191120134126.GD22515@ziepe.ca> Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-MC-Unique: Xu_mjR_fPQ2kgYFI6ozcxQ-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable Sender: linux-rdma-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org On 2019/11/20 =E4=B8=8B=E5=8D=889:41, Jason Gunthorpe wrote: > On Wed, Nov 20, 2019 at 12:07:59PM +0800, Jason Wang wrote: > >> 1) create sub fucntion and do must to have pre configuration through dev= link >> 2) only after sub function is created one more available instance was ad= ded >> and shown through sysfs >> 3) user can choose to create and use that mdev instance as it did for ot= her >> type of device like vGPU >> 4) devlink can still use to report other stuffs > Why do we want the extra step #3? The user already indicated they want > a mdev via #1 It's about the compatibility, but if you wish, I think we can develop=20 devlink based lifecycle for mdev for sure. > > I have the same question for the PF and VF cases, why doesn't a mdev > get created automatically when the VF is probed? Why does this need > the guid stuff? All you said here is possible, it's a design choice for the management=20 interface. > > The guid stuff was intended for, essentially, multi-function devices > that could be sliced up, I don't think it makes sense to use it for > single-function VF devices like the ICF driver. It doesn't harm, and indeed we have other choice, we can do it gradually=20 on top. > > Overall the guid thing should be optional. Drivers providing mdev > should be able to use another scheme, like devlink, to on demand > create their mdevs. Yes, that's for sure. I'm not against to devlink for mdev/subdev, I just=20 say we should not make devlink the only choice for mdev/subdev. Thanks > > Jason >