From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by dpdk.org (Postfix) with ESMTP id 2EC661B42E for ; Thu, 28 Jun 2018 16:32:58 +0200 (CEST) Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id A7F18406F8B0; Thu, 28 Jun 2018 14:32:57 +0000 (UTC) Received: from [10.36.112.57] (ovpn-112-57.ams2.redhat.com [10.36.112.57]) by smtp.corp.redhat.com (Postfix) with ESMTPS id BE40F2142F20; Thu, 28 Jun 2018 14:32:56 +0000 (UTC) To: Marvin Liu , tiwei.bie@intel.com Cc: zhihong.wang@intel.com, dev@dpdk.org References: <20180628215235.106069-1-yong.liu@intel.com> <20180628215235.106069-2-yong.liu@intel.com> From: Maxime Coquelin Message-ID: <49ce4761-e598-816e-3110-8e37cf1ff002@redhat.com> Date: Thu, 28 Jun 2018 16:32:54 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: <20180628215235.106069-2-yong.liu@intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Thu, 28 Jun 2018 14:32:57 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Thu, 28 Jun 2018 14:32:57 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'maxime.coquelin@redhat.com' RCPT:'' Subject: Re: [dpdk-dev] [PATCH v3 01/11] vhost: advertise support in-order feature X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 28 Jun 2018 14:32:58 -0000 On 06/28/2018 11:52 PM, Marvin Liu wrote: > If devices always use descriptors in the same order in which they have > been made available. These devices can offer the VIRTIO_F_IN_ORDER > feature. If negotiated, this knowledge allows devices to notify the use > of a batch of buffers to virtio driver by only writing used ring index. > > Vhost user device has supported this feature by default. If vhost > dequeue zero is enabled, should disable VIRTIO_F_IN_ORDER as vhost can’t > assure that descriptors returned from NIC are in order. > > Signed-off-by: Marvin Liu > Reviewed-by: Maxime Coquelin Thanks, Maxime