From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by dpdk.org (Postfix) with ESMTP id 79A142B9F; Mon, 5 Sep 2016 07:12:53 +0200 (CEST) Received: from orsmga003.jf.intel.com ([10.7.209.27]) by orsmga105.jf.intel.com with ESMTP; 04 Sep 2016 22:12:51 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.30,285,1470726000"; d="scan'208";a="875120395" Received: from yliu-dev.sh.intel.com (HELO yliu-dev) ([10.239.67.162]) by orsmga003.jf.intel.com with ESMTP; 04 Sep 2016 22:12:51 -0700 Date: Mon, 5 Sep 2016 13:24:46 +0800 From: Yuanhan Liu To: Zhihong Wang Cc: dev@dpdk.org, maxime.coquelin@redhat.com, yuanhan.liu@linux.intel.com, thomas.monjalon@6wind.com, stable@dpdk.org Message-ID: <20160905052446.GP7328@yliu-dev.sh.intel.com> References: <1471319402-112998-1-git-send-email-zhihong.wang@intel.com> <1472528164-54296-1-git-send-email-zhihong.wang@intel.com> <1472528164-54296-2-git-send-email-zhihong.wang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1472528164-54296-2-git-send-email-zhihong.wang@intel.com> User-Agent: Mutt/1.5.23 (2014-03-12) Subject: Re: [dpdk-dev] [dpdk-stable] [PATCH v4 1/6] vhost: fix windows vm hang 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: Mon, 05 Sep 2016 05:12:54 -0000 On Mon, Aug 29, 2016 at 11:35:59PM -0400, Zhihong Wang wrote: > This patch fixes a Windows VM compatibility issue in DPDK 16.07 vhost code, > which causes the guest to hang once any packets are enqueued when mrg_rxbuf > is turned on. This commit log lacks two important pieces: why does the hang happen and how does your patch fix it. > How to test? > > 1. Start testpmd in the host with a vhost port. > > 2. Start a Windows VM image with qemu and connect to the vhost port. > > 3. Start io forwarding with tx_first in host testpmd. > > For 16.07 code, the Windows VM will hang once any packets are enqueued. > > Cc: > Signed-off-by: Zhihong Wang > --- > lib/librte_vhost/vhost_rxtx.c | 17 ++++++++++++----- > 1 file changed, 12 insertions(+), 5 deletions(-) > > diff --git a/lib/librte_vhost/vhost_rxtx.c b/lib/librte_vhost/vhost_rxtx.c > index 08a73fd..5806f99 100644 > --- a/lib/librte_vhost/vhost_rxtx.c > +++ b/lib/librte_vhost/vhost_rxtx.c > @@ -384,6 +384,8 @@ copy_mbuf_to_desc_mergeable(struct virtio_net *dev, struct vhost_virtqueue *vq, > uint16_t start_idx = vq->last_used_idx; > uint16_t cur_idx = start_idx; > uint64_t desc_addr; > + uint32_t desc_chain_head; > + uint32_t desc_chain_len; What's the point of introducing "desc_chain_len"? It has the same value of desc_offset. --yliu