From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f43.google.com (mail-pa0-f43.google.com [209.85.220.43]) by dpdk.org (Postfix) with ESMTP id D3D1618F for ; Wed, 27 Aug 2014 20:00:53 +0200 (CEST) Received: by mail-pa0-f43.google.com with SMTP id lf10so825815pab.2 for ; Wed, 27 Aug 2014 11:04:58 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-type:content-transfer-encoding; bh=Rt6OBDrYQXE/P8pEyeZ2q+CxkBhpwfbxEsxmC04W9Mc=; b=Df2Xe81syb4HzIsLZrx+VRmVuT3JdKrIp+9Stx+MvZoTDx7ODXVeMAb1aUORDQP8bM sbfWdxYAd0a3cZzA/tAF/msZqM7O9EY39mWZ4Kw4ef2kumDEgyEuGnMcDzKQaCJ3Njzf 0+w27OA974gT/Rspnzvg2XdmaVQKmysRtpjP1BTK2TSire6KDTxz5+BJHLr2T7RGGhC0 1GGZExcFoPhspQsSsbWM1vLrJfa34GDt3Q8DW/rp/Od2C7A260JgbT6CdQ7FNxz9X6m/ kmsULfkdzDjCyNFSZH9x/MF18UkV8gmBhj0RK0t0wqQjjNRUzKQWZcWv618nlKAyDWNo 0XUw== X-Gm-Message-State: ALoCoQmNQAj5bwGAbLPDbCbgYwtosebezkY/IP+4kesZQLCeKzjnIwnpAYeSGduceYX4wakVYny8 X-Received: by 10.68.65.101 with SMTP id w5mr44105224pbs.5.1409162698192; Wed, 27 Aug 2014 11:04:58 -0700 (PDT) Received: from urahara (static-50-53-65-80.bvtn.or.frontiernet.net. [50.53.65.80]) by mx.google.com with ESMTPSA id ah2sm3727997pad.10.2014.08.27.11.04.57 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 27 Aug 2014 11:04:57 -0700 (PDT) Date: Wed, 27 Aug 2014 11:04:52 -0700 From: Stephen Hemminger To: "Ouyang, Changchun" Message-ID: <20140827110452.1cba26e3@urahara> In-Reply-To: References: <20140826020746.062748014@networkplumber.org> <20140826020848.386074683@networkplumber.org> <20140826092420.57e95493@urahara> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: "dev@dpdk.org" Subject: Re: [dpdk-dev] [RFC 06/10] virtio: use software vlan stripping X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 27 Aug 2014 18:00:54 -0000 On Wed, 27 Aug 2014 05:42:09 +0000 "Ouyang, Changchun" wrote: > > > -----Original Message----- > > From: Stephen Hemminger [mailto:stephen@networkplumber.org] > > Sent: Wednesday, August 27, 2014 12:24 AM > > To: Ouyang, Changchun > > Cc: dev@dpdk.org > > Subject: Re: [RFC 06/10] virtio: use software vlan stripping > > > > On Tue, 26 Aug 2014 08:37:11 +0000 > > "Ouyang, Changchun" wrote: > > > > > Hi Stephen, > > > > > > Would you please describe the use scenario for the front end rx vlan strip > > and tx vlan insertion? > > > In our current implementation, backend will strip vlan tag for RX, and insert > > vlan tag for TX. > > > > > > Thanks > > > Changchun > > > > First, we don't have to do software VLAN strip on our backend if we do this. > > And this way we can always use VLAN insert on transmit. Otherwise you > > have to introduce special case because there is no DPDK API to determine if > > device does or does not do VLAN handling. > > > > How the virtio frontend tell backend whether it has software VLAN strip feature or not? > It seems no feature bit to negotiate it. > > Thanks > Changchun > All other drivers have VLAN stripping as option under rte_eth_rxmode / hw_vlan_strip. There is negotiation in DPDK, it is strictly ask for feature and either get it or an error. Therefore we went ahead and emulated the feature in software.