From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by dpdk.org (Postfix) with ESMTP id CA04D2965 for ; Thu, 7 Apr 2016 17:40:15 +0200 (CEST) Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga102.fm.intel.com with ESMTP; 07 Apr 2016 08:40:15 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,449,1455004800"; d="scan'208";a="80966584" Received: from yliu-dev.sh.intel.com (HELO yliu-dev) ([10.239.67.191]) by fmsmga004.fm.intel.com with ESMTP; 07 Apr 2016 08:40:13 -0700 Date: Thu, 7 Apr 2016 23:42:07 +0800 From: Yuanhan Liu To: "Loftus, Ciara" Cc: "Tan, Jianfeng" , Rich Lane , "dev@dpdk.org" , Tetsuya Mukawa Message-ID: <20160407154207.GC3080@yliu-dev.sh.intel.com> References: <1459988946-5956-1-git-send-email-rich.lane@bigswitch.com> <57064914.4040703@intel.com> <74F120C019F4A64C9B78E802F6AD4CC24F863996@IRSMSX106.ger.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <74F120C019F4A64C9B78E802F6AD4CC24F863996@IRSMSX106.ger.corp.intel.com> User-Agent: Mutt/1.5.23 (2014-03-12) 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 15:40:16 -0000 On Thu, Apr 07, 2016 at 03:29:32PM +0000, 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. Yes. --yliu