Re: [PATCH v2 06/10] net/virtio: fix queue setup consistency

From: Maxime Coquelin <hidden>
Date: 2018-02-09 09:40:39


On 02/09/2018 09:59 AM, Maxime Coquelin wrote:

Hi Zhihong,

On 02/09/2018 06:44 AM, Wang, Zhihong wrote:

quoted

Hi Olivier,

Given the situation that the vec path can be selected silently now once
condition is met. So theoretically speaking this issue impacts the whole
virtio pmd. If you plan to fix it in the next release, do you want to do
a temporary workaround to disable the vec path selection till then?

That may be the less worse solution if we don't fix it quickly.
Reverting the patch isn't trivial, so this is not an option.

I'm trying to reproduce it now, I'll let you know if I find something.

Hmm, I reproduced Tiwei instructions, and in my case, Vhost's testpmd
crashes because Virtio-user makes it doing an out of bound access.

Could you provide a patch to disable vector path selection? I'll
continue to debug, but we can start reviewing it so that it is ready if
we need it.

Thanks,
Maxime

Cheers,
Maxime

quoted

Thanks
-Zhihong

quoted

-----Original Message-----
From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Olivier Matz
Sent: Thursday, February 8, 2018 6:01 AM
To: Xu, Qian Q <redacted>
Cc: Yao, Lei A <redacted>; dev@dpdk.org; 
yliu@fridaylinux.org;
maxime.coquelin@redhat.com; Thomas Monjalon [off-list ref];
stable@dpdk.org
Subject: Re: [dpdk-dev] [PATCH v2 06/10] net/virtio: fix queue setup
consistency

Hi,

It's in my short plans, but unfortunately some other high priority tasks
were inserted before. Honnestly, I'm not sure I'll be able to make it
for the release, but I'll do my best.

Olivier



On Wed, Feb 07, 2018 at 08:31:07AM +0000, Xu, Qian Q wrote:

quoted

Any update, Olivier?
We are near to release, and the bug-fix is important for the virtio 
vector

path usage. Thanks.

quoted

-----Original Message-----
From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Olivier Matz
Sent: Thursday, February 1, 2018 4:28 PM
To: Yao, Lei A <redacted>
Cc: dev@dpdk.org; yliu@fridaylinux.org; maxime.coquelin@redhat.com;
Thomas Monjalon [off-list ref]; stable@dpdk.org
Subject: Re: [dpdk-dev] [PATCH v2 06/10] net/virtio: fix queue setup

consistency

quoted

Hi Lei,

It's on my todo list, I'll check this as soon as possible.

Olivier


On Thu, Feb 01, 2018 at 03:14:15AM +0000, Yao, Lei A wrote:

quoted

Hi, Olivier

This is Lei from DPDK validation team in Intel. During our DPDK
18.02-rc1 test, I find the following patch will cause one serious 
issue

with virtio

quoted

vector path:

quoted

the traffic can't resume after stop/start the virtio device.

The step like following:
1. Launch vhost-user port using testpmd at Host 2. Launch VM with
virtio device, mergeable is off 3. Bind the virtio device to pmd
driver, launch testpmd, let the tx/rx use vector path
     virtio_xmit_pkts_simple
     virtio_recv_pkts_vec
4. Send traffic to virtio device from vhost side, then stop the 
virtio
device 5. Start the virtio device again After step 5, the traffic
can't resume.

Could you help check this and give a fix? This issue will impact the
virtio pmd user experience heavily. By the way, this patch is already
included into V17.11. Looks like we need give a patch to this LTS 
version.

Thanks a lot!

quoted

BRs
Lei

quoted

-----Original Message-----
From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Olivier Matz
Sent: Thursday, September 7, 2017 8:14 PM
To: dev@dpdk.org; yliu@fridaylinux.org;

maxime.coquelin@redhat.com

quoted

Cc: stephen@networkplumber.org; stable@dpdk.org
Subject: [dpdk-dev] [PATCH v2 06/10] net/virtio: fix queue setup
consistency

In rx/tx queue setup functions, some code is executed only if
use_simple_rxtx == 1. The value of this variable can change
depending on the offload flags or sse support. If Rx queue setup is
called before Tx queue setup, it can result in an invalid 
configuration:

- dev_configure is called: use_simple_rxtx is initialized to 0
- rx queue setup is called: queues are initialized without simple 
path
   support
- tx queue setup is called: use_simple_rxtx switch to 1, and simple
   Rx/Tx handlers are selected

Fix this by postponing a part of Rx/Tx queue initialization in
dev_start(), as it was the case in the initial implementation.

Fixes: 48cec290a3d2 ("net/virtio: move queue configure code to
proper
place")
Cc: stable@dpdk.org

Signed-off-by: Olivier Matz <redacted>
---
  drivers/net/virtio/virtio_ethdev.c | 13 +++++++++++++
drivers/net/virtio/virtio_ethdev.h |  6 ++++++
  drivers/net/virtio/virtio_rxtx.c   | 40

++++++++++++++++++++++++++++++-

quoted

-------
  3 files changed, 51 insertions(+), 8 deletions(-)

diff --git a/drivers/net/virtio/virtio_ethdev.c

b/drivers/net/virtio/virtio_ethdev.c
index 8eee3ff80..c7888f103 100644

--- a/drivers/net/virtio/virtio_ethdev.c
+++ b/drivers/net/virtio/virtio_ethdev.c

@@ -1737,6 +1737,19 @@ virtio_dev_start(struct rte_eth_dev *dev)

      struct virtnet_rx *rxvq;
      struct virtnet_tx *txvq __rte_unused;
      struct virtio_hw *hw = dev->data->dev_private;
+    int ret;
+
+    /* Finish the initialization of the queues */
+    for (i = 0; i < dev->data->nb_rx_queues; i++) {
+        ret = virtio_dev_rx_queue_setup_finish(dev, i);
+        if (ret < 0)
+            return ret;
+    }
+    for (i = 0; i < dev->data->nb_tx_queues; i++) {
+        ret = virtio_dev_tx_queue_setup_finish(dev, i);
+        if (ret < 0)
+            return ret;
+    }

      /* check if lsc interrupt feature is enabled */
      if (dev->data->dev_conf.intr_conf.lsc) { diff --git
a/drivers/net/virtio/virtio_ethdev.h
b/drivers/net/virtio/virtio_ethdev.h
index c3413c6d9..2039bc547 100644

--- a/drivers/net/virtio/virtio_ethdev.h
+++ b/drivers/net/virtio/virtio_ethdev.h

@@ -92,10 +92,16 @@ int  virtio_dev_rx_queue_setup(struct

rte_eth_dev *dev, uint16_t rx_queue_id,
          const struct rte_eth_rxconf *rx_conf,
          struct rte_mempool *mb_pool);

+int virtio_dev_rx_queue_setup_finish(struct rte_eth_dev *dev,
+                uint16_t rx_queue_id);
+
  int  virtio_dev_tx_queue_setup(struct rte_eth_dev *dev, uint16_t
tx_queue_id,
          uint16_t nb_tx_desc, unsigned int socket_id,
          const struct rte_eth_txconf *tx_conf);

+int virtio_dev_tx_queue_setup_finish(struct rte_eth_dev *dev,
+                uint16_t tx_queue_id);
+
  uint16_t virtio_recv_pkts(void *rx_queue, struct rte_mbuf

**rx_pkts,

quoted

          uint16_t nb_pkts);

diff --git a/drivers/net/virtio/virtio_rxtx.c

b/drivers/net/virtio/virtio_rxtx.c
index e30377c51..a32e3229f 100644

--- a/drivers/net/virtio/virtio_rxtx.c
+++ b/drivers/net/virtio/virtio_rxtx.c

@@ -421,9 +421,6 @@ virtio_dev_rx_queue_setup(struct

rte_eth_dev *dev,

quoted

      struct virtio_hw *hw = dev->data->dev_private;
      struct virtqueue *vq = hw->vqs[vtpci_queue_idx];
      struct virtnet_rx *rxvq;
-    int error, nbufs;
-    struct rte_mbuf *m;
-    uint16_t desc_idx;

      PMD_INIT_FUNC_TRACE();

@@ -440,10 +437,24 @@ virtio_dev_rx_queue_setup(struct

rte_eth_dev

quoted

*dev,
      }
      dev->data->rx_queues[queue_idx] = rxvq;

+    return 0;
+}
+
+int
+virtio_dev_rx_queue_setup_finish(struct rte_eth_dev *dev,

uint16_t

quoted

queue_idx)
+{
+    uint16_t vtpci_queue_idx = 2 * queue_idx +
VTNET_SQ_RQ_QUEUE_IDX;
+    struct virtio_hw *hw = dev->data->dev_private;
+    struct virtqueue *vq = hw->vqs[vtpci_queue_idx];
+    struct virtnet_rx *rxvq = &vq->rxq;
+    struct rte_mbuf *m;
+    uint16_t desc_idx;
+    int error, nbufs;
+
+    PMD_INIT_FUNC_TRACE();

      /* Allocate blank mbufs for the each rx descriptor */
      nbufs = 0;
-    error = ENOSPC;

      if (hw->use_simple_rxtx) {
          for (desc_idx = 0; desc_idx < vq->vq_nentries; @@ -

534,7

quoted

+545,6

quoted

@@ virtio_dev_tx_queue_setup(struct rte_eth_dev *dev,

      struct virtqueue *vq = hw->vqs[vtpci_queue_idx];
      struct virtnet_tx *txvq;
      uint16_t tx_free_thresh;
-    uint16_t desc_idx;

      PMD_INIT_FUNC_TRACE();

@@ -563,9 +573,24 @@ virtio_dev_tx_queue_setup(struct

rte_eth_dev

quoted

*dev,

      vq->vq_free_thresh = tx_free_thresh;

-    if (hw->use_simple_rxtx) {
-        uint16_t mid_idx  = vq->vq_nentries >> 1;
+    dev->data->tx_queues[queue_idx] = txvq;
+    return 0;
+}
+
+int
+virtio_dev_tx_queue_setup_finish(struct rte_eth_dev *dev,
+                uint16_t queue_idx)
+{
+    uint8_t vtpci_queue_idx = 2 * queue_idx +
VTNET_SQ_TQ_QUEUE_IDX;
+    struct virtio_hw *hw = dev->data->dev_private;
+    struct virtqueue *vq = hw->vqs[vtpci_queue_idx];
+    uint16_t mid_idx = vq->vq_nentries >> 1;
+    struct virtnet_tx *txvq = &vq->txq;
+    uint16_t desc_idx;

+    PMD_INIT_FUNC_TRACE();
+
+    if (hw->use_simple_rxtx) {
          for (desc_idx = 0; desc_idx < mid_idx; desc_idx++) {
              vq->vq_ring.avail->ring[desc_idx] =
                  desc_idx + mid_idx;

@@ -587,7 +612,6 @@ virtio_dev_tx_queue_setup(struct

rte_eth_dev

quoted

*dev,

      VIRTQUEUE_DUMP(vq);

-    dev->data->tx_queues[queue_idx] = txvq;
      return 0;
  }

-- 
2.11.0

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