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 670411B49F; Thu, 11 Oct 2018 15:34:20 +0200 (CEST) Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id AA244308AA14; Thu, 11 Oct 2018 13:34:19 +0000 (UTC) Received: from [10.72.12.114] (ovpn-12-114.pek2.redhat.com [10.72.12.114]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 11C3E6BC3E; Thu, 11 Oct 2018 13:34:08 +0000 (UTC) To: Tiwei Bie , maxime.coquelin@redhat.com, zhihong.wang@intel.com, dev@dpdk.org Cc: mst@redhat.com, stable@dpdk.org References: <20181011130655.5485-1-tiwei.bie@intel.com> From: Jason Wang Message-ID: Date: Thu, 11 Oct 2018 21:34:06 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20181011130655.5485-1-tiwei.bie@intel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.41]); Thu, 11 Oct 2018 13:34:19 +0000 (UTC) Subject: Re: [dpdk-dev] [PATCH] vhost: fix notification for packed ring 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: Thu, 11 Oct 2018 13:34:20 -0000 On 2018年10月11日 21:06, Tiwei Bie wrote: > The notification can't be disabled in packed ring when > application tries to disable notification, because the > device event flags field is overwritten by an unexpected > value. This patch fixes this issue. > > Fixes: b1cce26af1dc ("vhost: add notification for packed ring") > Cc: stable@dpdk.org > > Signed-off-by: Tiwei Bie > --- > lib/librte_vhost/vhost.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c > index e62f4c594..c9270bdec 100644 > --- a/lib/librte_vhost/vhost.c > +++ b/lib/librte_vhost/vhost.c > @@ -667,8 +667,10 @@ vhost_enable_notify_packed(struct virtio_net *dev, > { > uint16_t flags; > > - if (!enable) > - vq->device_event->flags = VRING_EVENT_F_DISABLE; > + if (!enable) { > + flags = VRING_EVENT_F_DISABLE; > + goto out; > + } > > flags = VRING_EVENT_F_ENABLE; > if (dev->features & (1ULL << VIRTIO_RING_F_EVENT_IDX)) { > @@ -677,6 +679,7 @@ vhost_enable_notify_packed(struct virtio_net *dev, > vq->avail_wrap_counter << 15; > } > > +out: > rte_smp_wmb(); > It looks to me the barrier is even not needed for !enable. Thanks > vq->device_event->flags = flags;