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 78E57A0A0B; Mon, 1 Feb 2021 14:16:38 +0100 (CET) Received: from [217.70.189.124] (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id E82C840693; Mon, 1 Feb 2021 14:16:37 +0100 (CET) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by mails.dpdk.org (Postfix) with ESMTP id B8ABF40687 for ; Mon, 1 Feb 2021 14:16:36 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1612185395; 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=X2l795GR+3BtvF/PnceQdiFVmSWvjXmlQhKLk5XFNKM=; b=BxRXKcyqPpuzHtzpVsBLH7CkaTv+PJnZFM7Qt7QSkcSr4Fw3NQlLmeNuOh8IGeefgH8EIh +fA49leaQChwjZCzqopW6Nf+qYOv/9Q4fpmI8CMY+JbO1veJ/GwRittokowOxyCkW5f8v+ 1Gl+rxo45EUS3Rcr+t2J880XUpHK1lk= 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-35-9d2Vwkz2Nimp4woLSou9JQ-1; Mon, 01 Feb 2021 08:16:34 -0500 X-MC-Unique: 9d2Vwkz2Nimp4woLSou9JQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A1FA4107ACE4; Mon, 1 Feb 2021 13:16:32 +0000 (UTC) Received: from [10.36.110.37] (unknown [10.36.110.37]) by smtp.corp.redhat.com (Postfix) with ESMTPS id A125E5C1A3; Mon, 1 Feb 2021 13:16:24 +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> From: Maxime Coquelin Message-ID: <47b6ea0d-0f8d-e569-c2ae-009782e4dfc9@redhat.com> Date: Mon, 1 Feb 2021 14:16:23 +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: <5379d25e-e33f-4dae-f53b-b57c00da3d64@ovn.org> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 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: 8bit 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" 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. 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