From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Michael S. Tsirkin" <mst@redhat.com>
Subject: Re: [PATCH 2/2] net/virtio: enable any layout feature
Date: Thu, 29 Sep 2016 21:01:53 +0300
Message-ID: <20160929210110-mutt-send-email-mst@kernel.org>
References: <1474872056-24665-1-git-send-email-yuanhan.liu@linux.intel.com>
 <1474872056-24665-3-git-send-email-yuanhan.liu@linux.intel.com>
 <20160929205815-mutt-send-email-mst@kernel.org>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Cc: dev@dpdk.org, Stephen Hemminger <stephen@networkplumber.org>,
 Maxime Coquelin <maxime.coquelin@redhat.com>
To: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Return-path: <dev-bounces@dpdk.org>
Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28])
 by dpdk.org (Postfix) with ESMTP id 501145597
 for <dev@dpdk.org>; Thu, 29 Sep 2016 20:01:55 +0200 (CEST)
Content-Disposition: inline
In-Reply-To: <20160929205815-mutt-send-email-mst@kernel.org>
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>
Errors-To: dev-bounces@dpdk.org
Sender: "dev" <dev-bounces@dpdk.org>

On Thu, Sep 29, 2016 at 09:00:47PM +0300, Michael S. Tsirkin wrote:
> On Mon, Sep 26, 2016 at 02:40:56PM +0800, Yuanhan Liu wrote:
> > The feature VIRTIO_F_ANY_LAYOUT was actually supported by commit
> > dd856dfcb9e7 ("virtio: use any layout on Tx"). But it's not enabled.
> > Here this patch enables it.
> > 
> > Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
> 
> Well this will break cross-version migration if just done
> unconditionally.
> Let's add a protocol feature for this bugfix?

Hmm OTOH the bug is in dpdk not qemu ... this needs some thought.

> > ---
> >  drivers/net/virtio/virtio_ethdev.h | 1 +
> >  1 file changed, 1 insertion(+)
> > 
> > diff --git a/drivers/net/virtio/virtio_ethdev.h b/drivers/net/virtio/virtio_ethdev.h
> > index 04d626b..3e31e6a 100644
> > --- a/drivers/net/virtio/virtio_ethdev.h
> > +++ b/drivers/net/virtio/virtio_ethdev.h
> > @@ -64,6 +64,7 @@
> >  	 1u << VIRTIO_NET_F_CTRL_VLAN	  |	\
> >  	 1u << VIRTIO_NET_F_MRG_RXBUF	  |	\
> >  	 1u << VIRTIO_RING_F_INDIRECT_DESC |    \
> > +	 1u << VIRTIO_F_ANY_LAYOUT |    \
> >  	 1ULL << VIRTIO_F_VERSION_1)
> >  
> >  /*
> > -- 
> > 1.9.0