From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <stephen@networkplumber.org>
Received: from mail-pa0-f54.google.com (mail-pa0-f54.google.com
 [209.85.220.54]) by dpdk.org (Postfix) with ESMTP id A19DA9655
 for <dev@dpdk.org>; Thu, 22 Oct 2015 18:59:13 +0200 (CEST)
Received: by pasz6 with SMTP id z6so91400797pas.2
 for <dev@dpdk.org>; Thu, 22 Oct 2015 09:59:12 -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=l0xciyD6EFWtnYK3RNibc7YCfQ3iIa6Jks+S4ykDJuk=;
 b=RAdL9Y/nUklGreqwZE6DcCnMWXULYHnq+vgRI7MjQ5ygf7FmkqOl0cfy0Ktzd/VZTi
 GA4oDF3gSGvNZdLAViXJUEVDdhx0Db1cbXcH8NRSJ4qLahmOEDMlzN2PKbEjROhtpVIa
 Rc3NTBjziLgE8JD8RCa35502Wb9I0EW7oe+gHuwPTcqP0XPE/6sLDcfVqsWOUtaEZMyC
 oUxuAu/BqidjZaOsWauu1Mg2uvwNDk+2hrt8+Gyh5Eu6BTsawPFAs6W1yUnJ9zMjGk8Z
 BSqwZvXyBsuFw2xhw4zvEPXn0B93ZIqOoI2j4e2y0h1x/MpcBRHDxiDEfIxf0RGeD/If
 2uLw==
X-Gm-Message-State: ALoCoQmtEqpio2H7TKkK24TEUMt93D9DoQBWanD/YIW9aaqzDwX1/FMKyIcsyn5jGpz3ZuRw7uO0
X-Received: by 10.68.239.165 with SMTP id vt5mr18432463pbc.15.1445533152822;
 Thu, 22 Oct 2015 09:59:12 -0700 (PDT)
Received: from xeon-e3 (static-50-53-82-155.bvtn.or.frontiernet.net.
 [50.53.82.155])
 by smtp.gmail.com with ESMTPSA id qa5sm14711547pbc.70.2015.10.22.09.59.09
 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128);
 Thu, 22 Oct 2015 09:59:09 -0700 (PDT)
Date: Thu, 22 Oct 2015 09:58:56 -0700
From: Stephen Hemminger <stephen@networkplumber.org>
To: Huawei Xie <huawei.xie@intel.com>
Message-ID: <20151022095856.5cbcf8c3@xeon-e3>
In-Reply-To: <1445515791-25909-8-git-send-email-huawei.xie@intel.com>
References: <1443537953-23917-1-git-send-email-huawei.xie@intel.com>
 <1445515791-25909-1-git-send-email-huawei.xie@intel.com>
 <1445515791-25909-8-git-send-email-huawei.xie@intel.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH v4 7/7] virtio: pick simple rx/tx func
X-BeenThere: dev@dpdk.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: patches and discussions about DPDK <dev.dpdk.org>
List-Unsubscribe: <http://dpdk.org/ml/options/dev>,
 <mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://dpdk.org/ml/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <http://dpdk.org/ml/listinfo/dev>,
 <mailto:dev-request@dpdk.org?subject=subscribe>
X-List-Received-Date: Thu, 22 Oct 2015 16:59:14 -0000

On Thu, 22 Oct 2015 20:09:51 +0800
Huawei Xie <huawei.xie@intel.com> wrote:

> +	/* Use simple rx/tx func if single segment and no offloads */
> +	if ((tx_conf->txq_flags & VIRTIO_SIMPLE_FLAGS) == VIRTIO_SIMPLE_FLAGS &&
> +	     !vtpci_with_feature(hw, VIRTIO_NET_F_MRG_RXBUF))

Since with QEMU/KVM the code will negotiate to use MRG_RXBUF, this
code path will not get used in common case anyway.