From mboxrd@z Thu Jan 1 00:00:00 1970
Return-Path: <ktraynor@redhat.com>
Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28])
by dpdk.org (Postfix) with ESMTP id 4F9AB200;
Thu, 7 Dec 2017 17:01:11 +0100 (CET)
Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com
[10.5.11.12])
(using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits))
(No client certificate requested)
by mx1.redhat.com (Postfix) with ESMTPS id 89D647EBD6;
Thu, 7 Dec 2017 16:01:10 +0000 (UTC)
Received: from ktraynor.remote.csb (ovpn-116-183.ams2.redhat.com
[10.36.116.183])
by smtp.corp.redhat.com (Postfix) with ESMTP id D6F986EE5B;
Thu, 7 Dec 2017 16:00:58 +0000 (UTC)
To: Tiwei Bie <tiwei.bie@intel.com>, yliu@fridaylinux.org,
maxime.coquelin@redhat.com, dev@dpdk.org
Cc: antonio.fischetti@intel.com, stable@dpdk.org,
"Kavanagh, Mark B" <mark.b.kavanagh@intel.com>
References: <20171207053059.19487-1-tiwei.bie@intel.com>
<20171207053059.19487-2-tiwei.bie@intel.com>
From: Kevin Traynor <ktraynor@redhat.com>
Organization: Red Hat
Message-ID: <9407e2ce-8b2b-9a9d-a493-1757609184a9@redhat.com>
Date: Thu, 7 Dec 2017 16:00:57 +0000
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
Thunderbird/52.2.0
MIME-Version: 1.0
In-Reply-To: <20171207053059.19487-2-tiwei.bie@intel.com>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12
X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16
(mx1.redhat.com [10.5.110.27]); Thu, 07 Dec 2017 16:01:10 +0000 (UTC)
Subject: Re: [dpdk-dev] [PATCH 1/5] net/virtio: fix vector Rx break caused
by rxq flushing
X-BeenThere: dev@dpdk.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: DPDK patches and discussions <dev.dpdk.org>
List-Unsubscribe: <http://dpdk.org/ml/options/dev>,
<mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://dpdk.org/ml/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <http://dpdk.org/ml/listinfo/dev>,
<mailto:dev-request@dpdk.org?subject=subscribe>
X-List-Received-Date: Thu, 07 Dec 2017 16:01:11 -0000
On 12/07/2017 05:30 AM, Tiwei Bie wrote:
> The vector Rx will be broken if backend has consumed all
> the descs in the avail ring before the device is started.
> Because in current implementation, vector Rx will return
> immediately without refilling the avail ring if the used
> ring is empty. So we have to refill the avail ring after
> flushing the elements in the used ring for vector Rx.
>
> Besides, vector Rx has a different ring layout assumption
> and mbuf management. So we need to handle it differently.
>
Hi Tiwei, does the issue only occur with the vector rx? How about if the
simple rx is used because VIRTIO_NET_F_MRG_RXBUF is set?
Kevin.
> Fixes: d8227497ec5c ("net/virtio: flush Rx queues on start")
> Cc: stable@dpdk.org
>
> Reported-by: Antonio Fischetti <antonio.fischetti@intel.com>
> Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
> ---
> drivers/net/virtio/virtio_ethdev.c | 2 +-
> drivers/net/virtio/virtqueue.c | 31 ++++++++++++++++++++++++-------
> drivers/net/virtio/virtqueue.h | 2 +-
> 3 files changed, 26 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/net/virtio/virtio_ethdev.c b/drivers/net/virtio/virtio_ethdev.c
> index e0328f61d..64a0cc608 100644
> --- a/drivers/net/virtio/virtio_ethdev.c
> +++ b/drivers/net/virtio/virtio_ethdev.c
> @@ -1860,7 +1860,7 @@ virtio_dev_start(struct rte_eth_dev *dev)
> for (i = 0; i < dev->data->nb_rx_queues; i++) {
> rxvq = dev->data->rx_queues[i];
> /* Flush the old packets */
> - virtqueue_flush(rxvq->vq);
> + virtqueue_rxvq_flush(rxvq->vq);
> virtqueue_notify(rxvq->vq);
> }
>
> diff --git a/drivers/net/virtio/virtqueue.c b/drivers/net/virtio/virtqueue.c
> index c3a536f8a..696d0e4a4 100644
> --- a/drivers/net/virtio/virtqueue.c
> +++ b/drivers/net/virtio/virtqueue.c
> @@ -37,6 +37,7 @@
> #include "virtqueue.h"
> #include "virtio_logs.h"
> #include "virtio_pci.h"
> +#include "virtio_rxtx_simple.h"
>
> /*
> * Two types of mbuf to be cleaned:
> @@ -62,8 +63,10 @@ virtqueue_detatch_unused(struct virtqueue *vq)
>
> /* Flush the elements in the used ring. */
> void
> -virtqueue_flush(struct virtqueue *vq)
> +virtqueue_rxvq_flush(struct virtqueue *vq)
> {
> + struct virtnet_rx *rxq = &vq->rxq;
> + struct virtio_hw *hw = vq->hw;
> struct vring_used_elem *uep;
> struct vq_desc_extra *dxp;
> uint16_t used_idx, desc_idx;
> @@ -74,13 +77,27 @@ virtqueue_flush(struct virtqueue *vq)
> for (i = 0; i < nb_used; i++) {
> used_idx = vq->vq_used_cons_idx & (vq->vq_nentries - 1);
> uep = &vq->vq_ring.used->ring[used_idx];
> - desc_idx = (uint16_t)uep->id;
> - dxp = &vq->vq_descx[desc_idx];
> - if (dxp->cookie != NULL) {
> - rte_pktmbuf_free(dxp->cookie);
> - dxp->cookie = NULL;
> + if (hw->use_simple_rx) {
> + desc_idx = used_idx;
> + rte_pktmbuf_free(vq->sw_ring[desc_idx]);
> + vq->vq_free_cnt++;
> + } else {
> + desc_idx = (uint16_t)uep->id;
> + dxp = &vq->vq_descx[desc_idx];
> + if (dxp->cookie != NULL) {
> + rte_pktmbuf_free(dxp->cookie);
> + dxp->cookie = NULL;
> + }
> + vq_ring_free_chain(vq, desc_idx);
> }
> vq->vq_used_cons_idx++;
> - vq_ring_free_chain(vq, desc_idx);
> + }
> +
> + if (hw->use_simple_rx) {
> + while (vq->vq_free_cnt >= RTE_VIRTIO_VPMD_RX_REARM_THRESH) {
> + virtio_rxq_rearm_vec(rxq);
> + if (virtqueue_kick_prepare(vq))
> + virtqueue_notify(vq);
> + }
> }
> }
> diff --git a/drivers/net/virtio/virtqueue.h b/drivers/net/virtio/virtqueue.h
> index 2305d91a4..ab466c2db 100644
> --- a/drivers/net/virtio/virtqueue.h
> +++ b/drivers/net/virtio/virtqueue.h
> @@ -304,7 +304,7 @@ void virtqueue_dump(struct virtqueue *vq);
> struct rte_mbuf *virtqueue_detatch_unused(struct virtqueue *vq);
>
> /* Flush the elements in the used ring. */
> -void virtqueue_flush(struct virtqueue *vq);
> +void virtqueue_rxvq_flush(struct virtqueue *vq);
>
> static inline int
> virtqueue_full(const struct virtqueue *vq)
>