From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:39905) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Sdy7k-0006nC-D0 for qemu-devel@nongnu.org; Mon, 11 Jun 2012 02:29:13 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Sdy7i-00064n-L3 for qemu-devel@nongnu.org; Mon, 11 Jun 2012 02:29:11 -0400 Received: from mx1.redhat.com ([209.132.183.28]:61632) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Sdy7i-00064f-CW for qemu-devel@nongnu.org; Mon, 11 Jun 2012 02:29:10 -0400 Message-ID: <4FD59029.5040204@redhat.com> Date: Mon, 11 Jun 2012 08:28:57 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <1338787767-3443-1-git-send-email-zwu.kernel@gmail.com> <1338787767-3443-7-git-send-email-zwu.kernel@gmail.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v4 06/16] net: Remove vlan qdev property List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Zhi Yong Wu Cc: aliguori@us.ibm.com, stefanha@linux.vnet.ibm.com, Stefan Hajnoczi , qemu-devel@nongnu.org, Zhi Yong Wu , luowenj@cn.ibm.com, jan.kiszka@siemens.com Il 09/06/2012 05:04, Zhi Yong Wu ha scritto: >>>> This commit looks suspicious because it removes a user-visible qdev >>>> property but we're trying to preserve backward compatibility. This >>>> command-line will break: >>>> >>>> x86_64-softmmu/qemu-system-x86_64 -net user,vlan=1 -device virtio-net-pci,vlan=1 >>>> >>>> Instead of dropping the qdev_prop_vlan completely the >>>> hw/qdev-properties.c code needs to call net/hub.h external functions >>>> to implement equivalent functionality: >>>> >>>> 1. Setting the vlan= property looks up the hub port and assigns >>>> the NICConf->peer field. >>>> 2. Getting the vlan property looks up the hub id (i.e. vlan id) given >>>> the peer. If the peer is not a hub port the result is -1. >>>> >>>> When I wrote this patch I missed the big picture and forgot about >>>> backwards compatibility :(. >>>> > To be honest, i am concerned if anyone uses this syntax. Since the > feature will finally be discarded, i suggest that we don't support > this now. If someone complains this later, we can fix it. If nobody > complains, that is what we hope. I think you're missing the big picture of this series, which is exactly _not_ to discard the VLAN feature, but just to rewrite it in a better way. That said, I agree that this is a somewhat fringe usage; most people will use -net nic,model=virtio,vlan=1 rather than "-device". We may get by with dropping it. I have no strong opinion either way. Paolo