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 84FAD1B49F; Thu, 11 Oct 2018 15:36:54 +0200 (CEST) Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D333665996; Thu, 11 Oct 2018 13:36:53 +0000 (UTC) Received: from redhat.com (ovpn-125-61.rdu2.redhat.com [10.10.125.61]) by smtp.corp.redhat.com (Postfix) with ESMTP id E332784542; Thu, 11 Oct 2018 13:36:48 +0000 (UTC) Date: Thu, 11 Oct 2018 09:36:48 -0400 From: "Michael S. Tsirkin" To: Jason Wang Cc: Tiwei Bie , maxime.coquelin@redhat.com, zhihong.wang@intel.com, dev@dpdk.org, stable@dpdk.org Message-ID: <20181011093628-mutt-send-email-mst@kernel.org> References: <20181011130655.5485-1-tiwei.bie@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Thu, 11 Oct 2018 13:36:53 +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 13:36:54 -0000 On Thu, Oct 11, 2018 at 09:34:06PM +0800, Jason Wang wrote: > > > 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 Good point, I agree. Besides that Reviewed-by: Michael S. Tsirkin > > vq->device_event->flags = flags;