From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by dpdk.org (Postfix) with ESMTP id 1FB9B2C62 for ; Thu, 7 Apr 2016 18:13:31 +0200 (CEST) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga103.jf.intel.com with ESMTP; 07 Apr 2016 09:13:26 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,449,1455004800"; d="scan'208";a="953851738" Received: from shwdeisgchi083.ccr.corp.intel.com (HELO [10.239.67.193]) ([10.239.67.193]) by fmsmga002.fm.intel.com with ESMTP; 07 Apr 2016 09:13:24 -0700 To: "Loftus, Ciara" , Rich Lane , "dev@dpdk.org" References: <1459988946-5956-1-git-send-email-rich.lane@bigswitch.com> <57064914.4040703@intel.com> <74F120C019F4A64C9B78E802F6AD4CC24F863996@IRSMSX106.ger.corp.intel.com> Cc: Tetsuya Mukawa , Yuanhan Liu From: "Tan, Jianfeng" Message-ID: <57068723.1000007@intel.com> Date: Fri, 8 Apr 2016 00:13:23 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.7.2 MIME-Version: 1.0 In-Reply-To: <74F120C019F4A64C9B78E802F6AD4CC24F863996@IRSMSX106.ger.corp.intel.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [PATCH] vhost: call rte_vhost_enable_guest_notification only on enabled queues X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 07 Apr 2016 16:13:32 -0000 On 4/7/2016 11:29 PM, Loftus, Ciara wrote: >> On 4/7/2016 8:29 AM, Rich Lane wrote: >>> If the vhost PMD were configured with more queues than the guest, the >> old >>> code would segfault in rte_vhost_enable_guest_notification due to a NULL >>> virtqueue pointer. >>> >>> Fixes: ee584e9710b9 ("vhost: add driver on top of the library") >>> Signed-off-by: Rich Lane >>> --- >>> drivers/net/vhost/rte_eth_vhost.c | 5 +++-- >>> 1 file changed, 3 insertions(+), 2 deletions(-) >>> >>> diff --git a/drivers/net/vhost/rte_eth_vhost.c >> b/drivers/net/vhost/rte_eth_vhost.c >>> index b1eb082..310cbef 100644 >>> --- a/drivers/net/vhost/rte_eth_vhost.c >>> +++ b/drivers/net/vhost/rte_eth_vhost.c >>> @@ -265,7 +265,6 @@ new_device(struct virtio_net *dev) >>> vq->device = dev; >>> vq->internal = internal; >>> vq->port = eth_dev->data->port_id; >>> - rte_vhost_enable_guest_notification(dev, vq- >>> virtqueue_id, 0); >>> } >>> for (i = 0; i < eth_dev->data->nb_tx_queues; i++) { >>> vq = eth_dev->data->tx_queues[i]; >>> @@ -274,9 +273,11 @@ new_device(struct virtio_net *dev) >>> vq->device = dev; >>> vq->internal = internal; >>> vq->port = eth_dev->data->port_id; >>> - rte_vhost_enable_guest_notification(dev, vq- >>> virtqueue_id, 0); >>> } >>> >>> + for (i = 0; i < dev->virt_qp_nb * VIRTIO_QNUM; i++) >>> + rte_vhost_enable_guest_notification(dev, i, 0); >>> + >>> dev->flags |= VIRTIO_DEV_RUNNING; >>> dev->priv = eth_dev; >>> eth_dev->data->dev_link.link_status = ETH_LINK_UP; >> Just one question, when qemu starts a vm, usually, only one queue is >> enabled, then only 1 tx and 1 rx are called >> rte_vhost_enable_guest_notification; but after system is up, we use >> "ethtool -K eth0 combined x" to enable multiqueues, there's no chance to >> call rte_vhost_enable_guest_notification for other queues, right? > As far as I know, virt_qp_nb will report the number of queues available, regardless of their state enabled/disabled. So for example if we have 4 queues, but only one enabled, virt_qp_nb should still = 4 and rte_vhost_enable_guest_notification() will be called for all of these queues. Oh, yes. I failed to really get multiqueue configured right, which leads to the wrong conclusion. Sorry. Thanks, Jianfeng > > Thanks, > Ciara > >> Thanks, >> Jianfeng