From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <stephen@networkplumber.org>
Received: from mail-qa0-f44.google.com (mail-qa0-f44.google.com
 [209.85.216.44]) by dpdk.org (Postfix) with ESMTP id B3005B577
 for <dev@dpdk.org>; Sun, 15 Feb 2015 15:41:46 +0100 (CET)
Received: by mail-qa0-f44.google.com with SMTP id n8so18870439qaq.3
 for <dev@dpdk.org>; Sun, 15 Feb 2015 06:41:46 -0800 (PST)
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=icEFdQu9ogu9++ewjPcSJFGBeWSjuOS1cp26rU9PG+Q=;
 b=Cgz4V+W/I4Xgm39Y2G5PAy4N3b3zECsdpk8uB63QJX0yQc7Gxle6GpXYJzTkFGZgFV
 u1BYgdkqD9doS6FTObBGNKHuEZvlVuSmCbr8lrrJW7bKacY1W8FlSrzxpz45HkFAaH59
 CyR+SaChCc3c4uPrnQicoocWkn8i7AFdP56dzRMfsft977+opnghxkmZLNQEyYtOzEu2
 J4HQmCjgHKrSspMiWQpEt0Rd+BTKYNKSx0Awu2e108Y3trv6yUVreVS5uRpCvBJSveZ/
 EcgHsyMwNAr4iFKO3zCdNL2gqt2AOB53Zsu22+9jQRUr78HdOK+jiCU390D8RH+idW6a
 IdMQ==
X-Gm-Message-State: ALoCoQlf7rnbek4G1bDuPEMchJjWJzaOhTvjHjDDEXLGOyvNimUx/vkf7z4Q2PfoyagMPY38iGOk
X-Received: by 10.140.144.136 with SMTP id 130mr18924212qhq.55.1424011306255; 
 Sun, 15 Feb 2015 06:41:46 -0800 (PST)
Received: from uryu.home.lan ([67.210.173.2])
 by mx.google.com with ESMTPSA id i185sm2628164qhc.49.2015.02.15.06.41.45
 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128);
 Sun, 15 Feb 2015 06:41:46 -0800 (PST)
Date: Sun, 15 Feb 2015 09:27:47 -0500
From: Stephen Hemminger <stephen@networkplumber.org>
To: "Liu, Jijiang" <jijiang.liu@intel.com>
Message-ID: <20150215092747.2f6a4822@uryu.home.lan>
In-Reply-To: <1ED644BD7E0A5F4091CF203DAFB8E4CC01DDC7CB@SHSMSX101.ccr.corp.intel.com>
References: <1ED644BD7E0A5F4091CF203DAFB8E4CC01DDC7CB@SHSMSX101.ccr.corp.intel.com>
X-Mailer: Claws Mail 3.11.1 (GTK+ 2.24.25; x86_64-pc-linux-gnu)
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Cc: "dev@dpdk.org" <dev@dpdk.org>, Stephen Hemminger <shemming@brocade.com>
Subject: Re: [dpdk-dev] [PATCH 1/4] xen: allow choosing dom0 support at
 runtime
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: Sun, 15 Feb 2015 14:41:47 -0000

On Sun, 15 Feb 2015 04:07:21 +0000
"Liu, Jijiang" <jijiang.liu@intel.com> wrote:

> Hi Stephen,
> 
> What do you mean ' allow choosing dom0 support at runtime'?
> If you mean user can choose DPDK  to run Xen Dom0 or not on DOM0 by a runtime flag, I don't think your change can achieve this goal.
> 
> Thanks
> Jijiang Liu

With the existing DPDK model if application is built with DOM0 support
it will not work (it crashes) if the application is run in a non DOM0
environment (with real huge pages). And vice-versa if application is built
without DOM0 support and it will crash if run in Xen Paravirt mode.

This patch allows the library to be built in such a way that only one
version needs to be shipped which is important for distro's like RHEL
who want to ship a shared library. And also important for users like
Brocade/Vyatta who build one binary that needs to work on bare Linux
and in Xen PV mode.