From mboxrd@z Thu Jan  1 00:00:00 1970
From: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Subject: Re: [PATCH v2] net/virtio-user: fix cannot get
	initialized
Date: Fri, 14 Apr 2017 12:24:23 +0800
Message-ID: <20170414042423.GI7333@yliu-dev.sh.intel.com>
References: <1491551860-15005-1-git-send-email-jianfeng.tan@intel.com>
 <1492078287-138040-1-git-send-email-jianfeng.tan@intel.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Cc: dev@dpdk.org, maxime.coquelin@redhat.com
To: Jianfeng Tan <jianfeng.tan@intel.com>
Return-path: <dev-bounces@dpdk.org>
Received: from mga09.intel.com (mga09.intel.com [134.134.136.24])
 by dpdk.org (Postfix) with ESMTP id EF203316B
 for <dev@dpdk.org>; Fri, 14 Apr 2017 06:27:21 +0200 (CEST)
Content-Disposition: inline
In-Reply-To: <1492078287-138040-1-git-send-email-jianfeng.tan@intel.com>
List-Id: DPDK patches and discussions <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>
Errors-To: dev-bounces@dpdk.org
Sender: "dev" <dev-bounces@dpdk.org>

On Thu, Apr 13, 2017 at 10:11:27AM +0000, Jianfeng Tan wrote:
> The feature negotiation in virtio-user is proven to be broken,
> which results in device initialization failure.
> 
> Originally, we get features from vhost backend, and remove those
> that are not supported. But when new feature is added, for example,
> VIRTIO_NET_F_MTU, we fail to remove this new feature. Then, this
> new feature will be negotiated, as both frontend and backend claim
> to support this feature.
> 
> To fix it, we add a macro to record supported featues, as a filter
> to remove newly added features.

Yes, this is much better! You now don't have to worry that virtio-user
will be broken every time we add a new feature.

Applied to dpdk-next-virtio, with the title changed to "fix feature
negotitation".

Thanks.

	--yliu