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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 23017C31E51 for ; Tue, 18 Jun 2019 05:49:52 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id DD6042147A for ; Tue, 18 Jun 2019 05:49:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DD6042147A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:53896 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hd70A-00047g-W7 for qemu-devel@archiver.kernel.org; Tue, 18 Jun 2019 01:49:51 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:59828) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hd6zG-0003fq-NP for qemu-devel@nongnu.org; Tue, 18 Jun 2019 01:48:55 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hd6zF-0002xk-K0 for qemu-devel@nongnu.org; Tue, 18 Jun 2019 01:48:54 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51522) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hd6zF-0002wS-E6 for qemu-devel@nongnu.org; Tue, 18 Jun 2019 01:48:53 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D1082356CA for ; Tue, 18 Jun 2019 05:48:43 +0000 (UTC) Received: from [10.72.12.155] (ovpn-12-155.pek2.redhat.com [10.72.12.155]) by smtp.corp.redhat.com (Postfix) with ESMTP id EFEE51001DCB; Tue, 18 Jun 2019 05:48:42 +0000 (UTC) To: Markus Armbruster References: <20190604115221.28364-1-armbru@redhat.com> <20190604115221.28364-3-armbru@redhat.com> <10f1a64b-cbc7-600f-7a52-cdd57ec5f71f@redhat.com> <87imt3zces.fsf@dusky.pond.sub.org> From: Jason Wang Message-ID: <42a29307-00cc-5b30-ea8d-1a960a90f599@redhat.com> Date: Tue, 18 Jun 2019 13:48:40 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <87imt3zces.fsf@dusky.pond.sub.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Tue, 18 Jun 2019 05:48:52 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [PATCH 2/3] net: Deprecate tap backend's parameter "helper" X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 2019/6/18 =E4=B8=8B=E5=8D=881:32, Markus Armbruster wrote: > Jason Wang writes: > >> On 2019/6/4 =E4=B8=8B=E5=8D=887:52, Markus Armbruster wrote: >>> -netdev tap,helper=3D... is a useless duplicate of -netdev bridge. >>> Deprecate and de-document. >>> >>> Signed-off-by: Markus Armbruster >> >> This requires more thought as TAP could be used independently. Force >> using a "bridge" backend may lead some confusion. > Can you explain your qualms in a bit more detail? > > The thoughts that led to this patch: > https://lists.gnu.org/archive/html/qemu-devel/2019-05/msg03164.html > > Consensus back then: > > 1. Add qemu-bridge-helper.c to Jason's "Network device backends" > > 2. Deprecate -netdev tap parameter "helper" The problem comes from this point. The main reason is TAP could be used=20 without bridge e.g: - you can simply assign an IP and and properly configure route table on=20 host to make it work - or setup tc actions or using XDP to transfer packets between TAP and=20 another interfaces - using AF_PACKET or other socket to capture the traffic and do the=20 forwarding in userspace So it looks to me switching to use -netdev bridge is inappropriate. Thanks > > 3. Improve documentation of -netdev bridge > > 4. Create a manual page for qemu-bridge-helper that also covers > /etc/qemu/bridge.conf. > > 5. Fix the nutty error handling in parse_acl_file() > > This series covers the first two [PATCH 1+2], and records the remaining > three more permanently [PATCH 3]. >