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 096A7C76191 for ; Thu, 18 Jul 2019 07:06:39 +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 D1A4321019 for ; Thu, 18 Jul 2019 07:06:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D1A4321019 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:34952 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1ho0Uv-0004LZ-VW for qemu-devel@archiver.kernel.org; Thu, 18 Jul 2019 03:06:37 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:57969) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1ho0Uk-0003ou-EL for qemu-devel@nongnu.org; Thu, 18 Jul 2019 03:06:27 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ho0Ui-0000BO-4v for qemu-devel@nongnu.org; Thu, 18 Jul 2019 03:06:26 -0400 Received: from mga09.intel.com ([134.134.136.24]:6415) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ho0Uh-00007e-Sz; Thu, 18 Jul 2019 03:06:24 -0400 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 18 Jul 2019 00:06:17 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,276,1559545200"; d="scan'208";a="173097159" Received: from npg-dpdk-virtio-tbie-2.sh.intel.com (HELO ___) ([10.67.104.66]) by orsmga006.jf.intel.com with ESMTP; 18 Jul 2019 00:06:16 -0700 Date: Thu, 18 Jul 2019 15:04:36 +0800 From: Tiwei Bie To: "Michael S. Tsirkin" Message-ID: <20190718070436.GA8148@___> References: <20190611065137.16329-1-tiwei.bie@intel.com> <20190611085441-mutt-send-email-mst@kernel.org> <20190612021157.GA23850@___> <20190717065951-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20190717065951-mutt-send-email-mst@kernel.org> User-Agent: Mutt/1.9.4 (2018-02-28) X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 134.134.136.24 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: jasowang@redhat.com, qemu-devel@nongnu.org, qemu-stable@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, Jul 17, 2019 at 07:00:25AM -0400, 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 ... Done, below is the link: https://lists.oasis-open.org/archives/virtio-dev/201907/msg00035.html > > > > > > > > > > > > > > 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[] = { > > > > VIRTIO_NET_F_MTU, > > > > VIRTIO_F_IOMMU_PLATFORM, > > > > > > > > + VIRTIO_NET_F_CTRL_VLAN, > > > > + > > > > /* This bit implies RARP isn't sent by QEMU out of band */ > > > > VIRTIO_NET_F_GUEST_ANNOUNCE, > > > > > > > > -- > > > > 2.17.1