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 470F02BBD for ; Wed, 28 Mar 2018 10:57:18 +0200 (CEST) Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D856484257; Wed, 28 Mar 2018 08:57:17 +0000 (UTC) Received: from [10.36.112.44] (ovpn-112-44.ams2.redhat.com [10.36.112.44]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 5D03710B2B34; Wed, 28 Mar 2018 08:57:16 +0000 (UTC) To: Tomasz Kulasek , yliu@fridaylinux.org Cc: daniel.verkamp@intel.com, james.r.harris@intel.com, pawelx.wodkowski@intel.com, dev@dpdk.org, Dariusz Stojaczyk References: <20180305155959.21212-1-tomaszx.kulasek@intel.com> From: Maxime Coquelin Message-ID: <9e7643db-0736-1768-d4eb-972d926c7021@redhat.com> Date: Wed, 28 Mar 2018 10:57:14 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <20180305155959.21212-1-tomaszx.kulasek@intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Wed, 28 Mar 2018 08:57:17 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Wed, 28 Mar 2018 08:57:17 +0000 (UTC) for IP:'10.11.54.3' DOMAIN:'int-mx03.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'maxime.coquelin@redhat.com' RCPT:'' Subject: Re: [dpdk-dev] [PATCH] vhost: add API for getting last_idx of vrings 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: Wed, 28 Mar 2018 08:57:18 -0000 Hi Tomasz, On 03/05/2018 04:59 PM, Tomasz Kulasek wrote: > vhost-net devices might keep track of last descriptors indices by > themselves, and assuming they initially start at 0, but that is not the > case for vhost-scsi. Initial last descriptor indices are set via > VHOST_USER_SET_VRING_BASE message, and we cannot possibly predict what > will they be. Setting these to vqueue->used->idx is also not an option, > because there might be some yet unprocessed requests between these and > the actual last_idx. This patch adds API for getting/setting last > descriptor indices of vrings, so that they can be synchronized between > user-device and rte_vhost. > > The last_idx flow could be as following: > > * vhost start, > * received SET_VRING_BASE msg, last_idx is set on rte_vhost side, > * created user-device, last_idx pulled from rte_vhost, > * requests are being processed by user-device, last_idx changes, > * destroyed user-device, last_idx pushed to rte_vhost, > * at this point, vrings could be recreated and another SET_VRING_BASE > message could arrive, so last_idx would be set > * recreated user-device, last_idx pulled from rte_vhost. > > > Signed-off-by: Dariusz Stojaczyk > Signed-off-by: Tomasz Kulasek > --- > lib/librte_vhost/rte_vhost.h | 24 ++++++++++++++++++++++++ > lib/librte_vhost/vhost.c | 27 +++++++++++++++++++++++++++ > 2 files changed, 51 insertions(+) > I agree with the patch, but it is missing the declaration of the new API in rte_vhost_version.map. Thanks, Maxime