From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 6198AA0A0B; Mon, 1 Feb 2021 14:42:52 +0100 (CET) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id DFF5C40693; Mon, 1 Feb 2021 14:42:51 +0100 (CET) Received: from relay10.mail.gandi.net (relay10.mail.gandi.net [217.70.178.230]) by mails.dpdk.org (Postfix) with ESMTP id 92F1340687 for ; Mon, 1 Feb 2021 14:42:50 +0100 (CET) Received: from [192.168.1.23] (ip-78-45-89-65.net.upcbroadband.cz [78.45.89.65]) (Authenticated sender: i.maximets@ovn.org) by relay10.mail.gandi.net (Postfix) with ESMTPSA id 2B3CE240008; Mon, 1 Feb 2021 13:42:47 +0000 (UTC) To: Maxime Coquelin , Ilya Maximets , dev@dpdk.org, chenbo.xia@intel.com, olivier.matz@6wind.com, amorenoz@redhat.com, david.marchand@redhat.com, Ian Stokes , Kevin Traynor , Flavio Leitner Cc: ovs-dev References: <20210126101639.250481-1-maxime.coquelin@redhat.com> <971e37fb-3889-ee94-c45c-e05f51b036ba@ovn.org> <5379d25e-e33f-4dae-f53b-b57c00da3d64@ovn.org> <47b6ea0d-0f8d-e569-c2ae-009782e4dfc9@redhat.com> From: Ilya Maximets Message-ID: <29242f3d-ea42-8977-2ea8-de8a54e165a1@ovn.org> Date: Mon, 1 Feb 2021 14:42:47 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: <47b6ea0d-0f8d-e569-c2ae-009782e4dfc9@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [PATCH v4 00/44] net/virtio: Virtio PMD rework X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On 2/1/21 2:16 PM, Maxime Coquelin wrote: > Hi Ilya, > > On 2/1/21 2:03 PM, Ilya Maximets wrote: >> CC: ovs-dev >> >> On 2/1/21 2:00 PM, Ilya Maximets wrote: >>> On 1/26/21 11:15 AM, Maxime Coquelin wrote: >>>> >>>> Only functionnal change in this second part is making the >>>> Vhost-user server mode blocking at init time, as long as >>>> a client is not connected. The goal of this change is to >>>> make the Vhost-user support much more robust, as without >>>> blocking, the driver has to assume features that are going >>>> to be supported by the client, which is very fragile and >>>> error prone. As a side-effect, it also simplifies the >>>> logic nin several place of the virtio-user PMD. >>> >>> Hi, Maxime. >>> >>> I didn't actually look at the code, but I have a question. >>> Does above text mean that with this change OVS will hang inside >>> driver_register() or similar function until client is connected >>> to dpdkvhostuser (server mode) port? >>> >>> If so, I think, we will not be able to support server mode >>> in OVS anymore and will have to actually remove it. It's >>> deprecated for a long time now, but I think it might still be in >>> use by some people, especially for virtio-user usecase. > > No, there is no impact for OVS. My explanation was maybe a bit > confusion, sorry about that. > > I meant that Virtio-user PMD, acting as Vhost-user master in server > mode, will be blocking waiting for client (OVS dpdkvhostuserclient in > your case) connection. This makes the Virtio-user PMD in server mode to > behave the same as QEMU Vhost-user port in server mode. Oh. OK. So the only affected party is 'net_virtio_user' PMD and vhost library is not affected, right? And in this case the following command will block OVS: ovs-vsctl add-port br0 vu -- set Interface vu type=dpdk \ options:dpdk-devargs="net_virtio_user,path=vu.sock,server=1" Is that correct? (I'm not sure if this works right now, though. I didn't test it.) > > Only noticeable effect on OVS side should be more reliability, as > without this change, Virtio-user PMD could assume OVS Vhost-user backend > would support features before the connection happens. > >>> Best regards, Ilya Maximets. >>> >> > > Regards, > Maxime >