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 D9F341E34; Thu, 28 Feb 2019 18:57:10 +0100 (CET) Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 47E4F307CB30; Thu, 28 Feb 2019 17:57:10 +0000 (UTC) Received: from localhost.localdomain (ovpn-112-64.ams2.redhat.com [10.36.112.64]) by smtp.corp.redhat.com (Postfix) with ESMTP id DF4FB1001938; Thu, 28 Feb 2019 17:57:06 +0000 (UTC) From: Maxime Coquelin To: tiwei.bie@intel.com, dev@dpdk.org Cc: Maxime Coquelin , stable@dpdk.org Date: Thu, 28 Feb 2019 18:57:04 +0100 Message-Id: <20190228175704.27948-1-maxime.coquelin@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.42]); Thu, 28 Feb 2019 17:57:10 +0000 (UTC) Subject: [dpdk-stable] [PATCH v2] vhost: prevent disabled rings to be processed with zero-copy X-BeenThere: stable@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches for DPDK stable branches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 28 Feb 2019 17:57:11 -0000 The vhost-user spec says that once the vring is disabled, the client has to stop processing it. But it can happen when dequeue zero-copy is enabled if outstanding descriptors buffers are still being processed by an external NIC or another guest. The fix consists in draining the zmbufs list to ensure no more descriptors buffers are in the wild. Note that this fix is only working in the case REPLY_ACK protocol feature is enabled, which is not the case by default for now (it is only enabled when IOMMU feature is enabled in the vhost library). Fixes: b0a985d1f340 ("vhost: add dequeue zero copy") Cc: stable@dpdk.org Reviewed-by: Tiwei Bie Signed-off-by: Maxime Coquelin --- lib/librte_vhost/vhost_user.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c index 36c0c676d..555d09ad9 100644 --- a/lib/librte_vhost/vhost_user.c +++ b/lib/librte_vhost/vhost_user.c @@ -1345,6 +1345,10 @@ vhost_user_set_vring_enable(struct virtio_net **pdev, dev->notify_ops->vring_state_changed(dev->vid, index, enable); + /* On disable, rings have to be stopped being processed. */ + if (!enable && dev->dequeue_zero_copy) + drain_zmbuf_list(dev->virtqueue[index]); + dev->virtqueue[index]->enabled = enable; return RTE_VHOST_MSG_RESULT_OK; -- 2.20.1