From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net-next] be2net: Learn and program mac to avoid packet replication in nPAR mode. Date: Fri, 05 Sep 2014 17:34:56 -0700 (PDT) Message-ID: <20140905.173456.2115240943907507122.davem@davemloft.net> References: <206ffa9c-915e-4a1e-affe-68616cbef2f8@CMEXHTCAS1.ad.emulex.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: VenkatKumar.Duvvuru@Emulex.com Return-path: Received: from shards.monkeyblade.net ([149.20.54.216]:57990 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750725AbaIFAe5 (ORCPT ); Fri, 5 Sep 2014 20:34:57 -0400 In-Reply-To: <206ffa9c-915e-4a1e-affe-68616cbef2f8@CMEXHTCAS1.ad.emulex.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Venkat Duvvuru Date: Thu, 4 Sep 2014 20:00:59 +0530 > In a multi-channel setup, when an interface (channel/partition) is used > by a bridge or ovs, it is placed in promiscuous mode and the MAC addresses > of the VMs attached to the bridge are not configured on the base interface. > As a result of that, when a packet arrives to the port with > virtual machine's mac address, the card cannot determine which ring to > send the packet to, so replicates the packet on all the PFs of that port, > hence resulting in wastage of PCI bandwidth and CPU cycles. Packet replication > is also considered security risk as it can cause packets to reach an undesired VM. > > This patch will help solve the problem by learning the mac address and > programming it in the adapter. This patch also unlearns the MAC, if the MAC is > moved out of the machine or if the MAC is inactive for more than 5 minutes. > > Signed-off-by: Venkat Duvvuru This is non-trivial overhead to add to the fast paths of your primary packet input and output paths. I think you need to find a different solution to this problem.