From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Chen, Junjie J" Subject: Re: [PATCH] net/vhost: fix segfault when creating vdev dynamically Date: Tue, 27 Mar 2018 09:24:40 +0000 Message-ID: References: <1522166726-42025-1-git-send-email-junjie.j.chen@intel.com> <20388d18-796f-7dd5-e596-f8cc290063d0@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Cc: "dev@dpdk.org" To: "Tan, Jianfeng" , "maxime.coquelin@redhat.com" , "mtetsuyah@gmail.com" Return-path: Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by dpdk.org (Postfix) with ESMTP id 764D54CB3 for ; Tue, 27 Mar 2018 11:24:43 +0200 (CEST) In-Reply-To: <20388d18-796f-7dd5-e596-f8cc290063d0@intel.com> Content-Language: en-US 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 3/28/2018 12:05 AM, Junjie Chen wrote: > >>> when creating vdev dynamically, vhost pmd driver start directly > >>> without checking TX/RX queues ready or not, and thus cause > >>> segmentation fault when vhost library accessing queues. This patch > >>> add flag to check whether queues setup or not, and add driver start > >>> call into dev_start to allow user start it after setting up queue. > >> The issue is clear now. But this patch just puts the situation before = below > fix: > >> "it doesn't create the actual datagram socket until you call .dev_star= t()." > > No, if the queue exist, the datagram socket still get created in vhost_= create > API, since the vhost_driver_register still exist in vhost_create. >=20 > The queue can never be created, as it's still not probed. I think we need to separate this into two cases: Statically create vdev, the datagram recreate logical is still there since= queues are exist already, this patch doesn't change anything. Dynamic create vdev, as you pointed out, queue can never be created, while= this should be not valid since In normal process of creating vdev dynamica= lly, we always need to config queues. Correct me if I'm wrong. In summary, I think the previously commit fixes the static code path and th= is patch fixes the dynamic code path (we need to at least setup queue once)= .