From patchwork Wed Dec 5 09:49:54 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Maxime Coquelin X-Patchwork-Id: 48538 X-Patchwork-Delegate: maxime.coquelin@redhat.com Return-Path: X-Original-To: patchwork@dpdk.org Delivered-To: patchwork@dpdk.org Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 598F71B1EE; Wed, 5 Dec 2018 10:50:37 +0100 (CET) Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by dpdk.org (Postfix) with ESMTP id 20AD71B1EB; Wed, 5 Dec 2018 10:50:36 +0100 (CET) Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 735C1C058CB2; Wed, 5 Dec 2018 09:50:35 +0000 (UTC) Received: from localhost.localdomain (ovpn-112-38.ams2.redhat.com [10.36.112.38]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0B79E5D780; Wed, 5 Dec 2018 09:50:32 +0000 (UTC) From: Maxime Coquelin To: dev@dpdk.org, jfreimann@redhat.com, tiwei.bie@intel.com, zhihong.wang@intel.com, jasowang@redhat.com Cc: Maxime Coquelin , stable@dpdk.org Date: Wed, 5 Dec 2018 10:49:54 +0100 Message-Id: <20181205094957.1938-3-maxime.coquelin@redhat.com> In-Reply-To: <20181205094957.1938-1-maxime.coquelin@redhat.com> References: <20181205094957.1938-1-maxime.coquelin@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Wed, 05 Dec 2018 09:50:35 +0000 (UTC) Subject: [dpdk-dev] [PATCH 2/5] vhost: enforce desc flags and content read ordering 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: , Errors-To: dev-bounces@dpdk.org Sender: "dev" A read barrier is required to ensure that the ordering between descriptor's flags and content reads is enforced. Fixes: 2f3225a7d69b ("vhost: add vector filling support for packed ring") Cc: stable@dpdk.org Reported-by: Jason Wang Signed-off-by: Maxime Coquelin Acked-by: Ilya Maximets --- lib/librte_vhost/virtio_net.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c index f11ebb54f..68b72e7a5 100644 --- a/lib/librte_vhost/virtio_net.c +++ b/lib/librte_vhost/virtio_net.c @@ -520,6 +520,12 @@ fill_vec_buf_packed(struct virtio_net *dev, struct vhost_virtqueue *vq, if (unlikely(!desc_is_avail(&descs[avail_idx], wrap_counter))) return -1; + /* + * The ordering between desc flags and desc + * content reads need to be enforced. + */ + rte_smp_rmb(); + *desc_count = 0; *len = 0;