From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37752) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WSOHT-0005UD-3l for qemu-devel@nongnu.org; Tue, 25 Mar 2014 06:08:32 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WSOHO-0006Hr-9t for qemu-devel@nongnu.org; Tue, 25 Mar 2014 06:08:27 -0400 Received: from mx1.redhat.com ([209.132.183.28]:34860) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WSOHO-0006Hi-0L for qemu-devel@nongnu.org; Tue, 25 Mar 2014 06:08:22 -0400 Date: Tue, 25 Mar 2014 12:08:20 +0200 From: "Michael S. Tsirkin" Message-ID: <20140325100820.GA25011@redhat.com> References: <20140225030633.GA29423@amosk.info> <1907885.BLXM6R4UH8@k> <20140325093912.GA2071@amosk.info> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140325093912.GA2071@amosk.info> Subject: Re: [Qemu-devel] [PATCH] virtio-net: Do not filter VLANs without F_CTRL_VLAN List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Amos Kong Cc: vyasevic@redhat.com, Stefan Fritsch , qemu-devel@nongnu.org, Anthony Liguori On Tue, Mar 25, 2014 at 05:39:12PM +0800, Amos Kong wrote: > On Wed, Mar 19, 2014 at 11:38:57PM +0100, Stefan Fritsch wrote: > > Hi, > > > > Am Dienstag, 25. Februar 2014, 11:06:33 schrieb Amos Kong: > > > > > On Wed, Feb 12, 2014 at 10:46:28PM +0100, Stefan Fritsch wrote: > > > > > > If VIRTIO_NET_F_CTRL_VLAN is not negotiated, do not filter out > > > > > > all > > > > > > VLAN-tagged packets but send them to the guest. > > > > > > AFAICS, no fix has been committed, yet. Is there anything I need to do > > to get this fixed? > > Michael asked in IRC to continually add a RxState for vlan in > RxFilter notification through QMP events. > > (sorry I didn't talk too much becaused I'm in meeting) > > I mentioned in [1] [2], we don't need to add this new state > if we apply patch Stefan's patch[3] > > Michael said Stefan's fix is wrong, but the problem exists. > The problem is the bug fixed by [3], not the problem that was > mentioned in [4] > > > Michael, what's wrong with Stefan's patch? > > > Thanks, Amos > > [1] http://lists.gnu.org/archive/html/qemu-devel/2014-02/msg03835.html > [2] https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg04434.html > [3] virtio-net: Do not filter VLANs without F_CTRL_VLAN > [4] https://lists.gnu.org/archive/html/qemu-devel/2014-02/msg02604.html > Mainly what's wrong is the effect this has on the output of query-rx-filter. the patch is incomplete: management should be able to see that vlan filtering is disabled. Besides, looking at guest features at reset time is also not a good idea, it works by luck. A better place would be virtio_net_set_features. > > > > > Can we just update receive_filter() to filter out VLAN-tagged > > > > > packets only when VIRTIO_NET_F_CTRL_VLAN is negotiated? > > > > > > If we change receive_filter(), we also need a flag to indicate > > > management this feature isn't negotiated, management will do some > > > additional operation to host device to get same effect. > > > > > > > > > > We could. But this adds a (very small) per-packet overhead while > > > > my patch only adds overhead during reset. Therefore I didn't > > > > take that approach. But if changing receive_filter() makes > > > > management much easier, that could be acceptable. > > > > > > Actually your solution is better, QEMU will return a long list > > > [0,1,2,...4095] to management, host device will filter all the vlan > > > packets and send to QEMU. > > > > > > So the problem raised by mst doesn't exist. > > > > Cheers, > > Stefan > > > > -- > Amos.