From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by dpdk.org (Postfix) with ESMTP id 2319314E8 for ; Wed, 13 Dec 2017 12:23:41 +0100 (CET) Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 6BACF72D0F; Wed, 13 Dec 2017 11:23:40 +0000 (UTC) Received: from lacos-laptop-7.usersys.redhat.com (ovpn-120-40.rdu2.redhat.com [10.10.120.40]) by smtp.corp.redhat.com (Postfix) with ESMTP id 2F802614FF; Wed, 13 Dec 2017 11:23:33 +0000 (UTC) To: Paolo Bonzini , Maxime Coquelin , dev@dpdk.org, yliu@fridaylinux.org, tiwei.bie@intel.com, jianfeng.tan@intel.com, lprosek@redhat.com, "Michael S. Tsirkin" References: <20171213085109.9891-1-maxime.coquelin@redhat.com> <5fda0d3d-72e0-6506-29a7-c05e8c916858@redhat.com> From: Laszlo Ersek Message-ID: <73a31f43-4c21-457e-dd2d-8e99e6edeabb@redhat.com> Date: Wed, 13 Dec 2017 12:23:32 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.5.0 MIME-Version: 1.0 In-Reply-To: <5fda0d3d-72e0-6506-29a7-c05e8c916858@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Wed, 13 Dec 2017 11:23:40 +0000 (UTC) Subject: Re: [dpdk-dev] [PATCH v5 0/4] Vhost: fix mq=on but VIRTIO_NET_F_MQ not negotiated 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, 13 Dec 2017 11:23:41 -0000 On 12/13/17 11:24, Paolo Bonzini wrote: > On 13/12/2017 11:11, Maxime Coquelin wrote: >>> Hi Maxime, >>> >>> I think this series is wrong from the virtio spec's point of view.  If >>> the driver requests VIRTIO_NET_F_MQ, that does not mean "the driver >>> knows about multiqueue", it only means that "the driver wants to read >>> max_virtqueue_pairs" from configuration space. >> >> Actually, my series fixes half of the problem, the case where driver >> does not know about multiqueue. >> >> In this case, there is no point in the backend to wait for the >> initialization of queues that does not exist. >> >> So I think my series is not enough, but not wrong. > > You're right; what I meant by "wrong" is that it becomes unnecessary if > you do VIRTIO_NET_CTRL_MQ_VQ_PAIRS_SET. But since this requires a > vhost-user update, doing both makes sense. Based on this, plus reviewing patch #4 for: + vq = dev->virtqueue[--dev->nr_vring]; + if (!vq) + continue; + + dev->virtqueue[dev->nr_vring] = NULL; Acked-by: Laszlo Ersek Thanks Laszlo