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=-13.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 BD797C76186 for ; Wed, 17 Jul 2019 12:30:52 +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 8D33620880 for ; Wed, 17 Jul 2019 12:30:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8D33620880 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]:56684 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hnj59-0005qW-RN for qemu-devel@archiver.kernel.org; Wed, 17 Jul 2019 08:30:51 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:59354) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hnj4w-0005IB-4M for qemu-devel@nongnu.org; Wed, 17 Jul 2019 08:30:39 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hnj4u-0004aJ-TQ for qemu-devel@nongnu.org; Wed, 17 Jul 2019 08:30:38 -0400 Received: from mx1.redhat.com ([209.132.183.28]:38636) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hnj4u-0004ZV-Nl; Wed, 17 Jul 2019 08:30:36 -0400 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 mx1.redhat.com (Postfix) with ESMTPS id F1E0D30C1321; Wed, 17 Jul 2019 12:30:34 +0000 (UTC) Received: from [10.72.12.61] (ovpn-12-61.pek2.redhat.com [10.72.12.61]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3206D6013A; Wed, 17 Jul 2019 12:30:30 +0000 (UTC) To: "Michael S. Tsirkin" , Tiwei Bie References: <20190611065137.16329-1-tiwei.bie@intel.com> <20190611085441-mutt-send-email-mst@kernel.org> <20190612021157.GA23850@___> <20190717065951-mutt-send-email-mst@kernel.org> From: Jason Wang Message-ID: <500677c2-8743-a68e-61e6-99ac699efe16@redhat.com> Date: Wed, 17 Jul 2019 20:30:29 +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: <20190717065951-mutt-send-email-mst@kernel.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.45]); Wed, 17 Jul 2019 12:30:35 +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] [RFC] vhost-user: don't ignore CTRL_VLAN feature 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, qemu-stable@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 2019/7/17 =E4=B8=8B=E5=8D=887:00, Michael S. Tsirkin wrote: > On Wed, Jun 12, 2019 at 10:11:57AM +0800, Tiwei Bie wrote: >> On Tue, Jun 11, 2019 at 10:10:14AM -0400, Michael S. Tsirkin wrote: >>> On Tue, Jun 11, 2019 at 02:51:37PM +0800, Tiwei Bie wrote: >>>> The VIRTIO_NET_F_CTRL_VLAN feature requires the support of >>>> vhost-user backend. But it will be advertised to guest driver >>>> as long as it's enabled by users in QEMU, while it's not >>>> supported by vhost-user backend. This patch fixes this issue. >>> Fixes by making guest refuse to send vlan tags? >> Fixes by not advertising this feature bit to guest driver >> when it's not supported, and guest won't expect the device >> to do vlan filtering then. >> >>> I agree it seems cleaner, but which guests does this actually help? >>> >>>> Fixes: 72018d1e1917 ("vhost-user: ignore qemu-only features") >>>> Cc: qemu-stable@nongnu.org >>>> >>>> Signed-off-by: Tiwei Bie >>> A change like that will break migration compatibility, will it not? >> Yeah, that's a problem... >> >>> Maybe we need to tie it to a machine version somehow... >>> >>> >>>> --- >>>> It's not clear in the spec that, whether vlan filtering is >>>> also best-effort: >>>> https://github.com/oasis-tcs/virtio-spec/blob/37057052e7/content.tex= #L3372 >>> So what breaks if we declare it best effort for now? >>> And does it really help if we report that vlan filtering >>> is not supported to guests? >> If it's best effort, then it won't violate the spec to >> advertise this feature when it's not supported in backends. >> > OK so it's up to you. Want to propose a spec patch? > We already say mac filter is best effort ... This probably need more thought. Consider in the future, we want to have=20 filters that can steering packet based on its mac address to a specific=20 queue. Then we can add e.g macvlan offloading support. Saying "best=20 effort" might be wrong in that cases. Thanks >>> >>> >>>> hw/net/vhost_net.c | 2 ++ >>>> 1 file changed, 2 insertions(+) >>>> >>>> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c >>>> index a6b719035c..1444fc9230 100644 >>>> --- a/hw/net/vhost_net.c >>>> +++ b/hw/net/vhost_net.c >>>> @@ -75,6 +75,8 @@ static const int user_feature_bits[] =3D { >>>> VIRTIO_NET_F_MTU, >>>> VIRTIO_F_IOMMU_PLATFORM, >>>> =20 >>>> + VIRTIO_NET_F_CTRL_VLAN, >>>> + >>>> /* This bit implies RARP isn't sent by QEMU out of band */ >>>> VIRTIO_NET_F_GUEST_ANNOUNCE, >>>> =20 >>>> --=20 >>>> 2.17.1