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 3DA66A0A0B; Mon, 1 Feb 2021 14:52:02 +0100 (CET) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id B163940693; Mon, 1 Feb 2021 14:52:01 +0100 (CET) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [63.128.21.124]) by mails.dpdk.org (Postfix) with ESMTP id 9DAFF40687 for ; Mon, 1 Feb 2021 14:52:00 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1612187519; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=4v4iczZSsFYqZSiABhrTEeMErkj36tgXBYxT3y/b/is=; b=RZ15Lh2djbr6ZSELAKgT7W36LyCQXxiFRg+qwYxai+TsrbePMtHebwtDf4mGewz6MxvNhz 1vC4SiTbSKa7juI7QmULMrJ6N/8BG9XNQf0SRg9sEJyhDsQnxnqGFtu/ro4x0EDrMVgU8M Ln/bD5KRqHRd0aPefk2w1095fFkGvQE= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-256-cb410hTSMJKtB2hn_CAGDA-1; Mon, 01 Feb 2021 08:51:58 -0500 X-MC-Unique: cb410hTSMJKtB2hn_CAGDA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id BADCCB8104; Mon, 1 Feb 2021 13:51:56 +0000 (UTC) Received: from [10.36.110.37] (unknown [10.36.110.37]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 92FED60C66; Mon, 1 Feb 2021 13:51:51 +0000 (UTC) To: 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> <29242f3d-ea42-8977-2ea8-de8a54e165a1@ovn.org> From: Maxime Coquelin Message-ID: <6ff1dce2-80e0-a4fc-23a4-64887e30accf@redhat.com> Date: Mon, 1 Feb 2021 14:51:50 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.7.0 MIME-Version: 1.0 In-Reply-To: <29242f3d-ea42-8977-2ea8-de8a54e165a1@ovn.org> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=maxime.coquelin@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: 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 2:42 PM, Ilya Maximets wrote: > 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? 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.) This is correct, even though I don't know a use-case for it (chained OVS-DPDK?). Thanks, Maxime > >> >> 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 >> >