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

[Maxime Coquelin <maxime.coquelin@redhat.com>]

On 02/09/2018 09:59 AM, Maxime Coquelin wrote:
> Hi Zhihong,
> 
> On 02/09/2018 06:44 AM, Wang, Zhihong wrote:
>> 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
>> Thanks
>> -Zhihong
>>
>>> -----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 <qian.q.xu@intel.com>
>>> Cc: Yao, Lei A <lei.a.yao@intel.com>; dev@dpdk.org; 
>>> yliu@fridaylinux.org;
>>> maxime.coquelin@redhat.com; Thomas Monjalon <thomas@monjalon.net>;
>>> 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:
>>>> Any update, Olivier?
>>>> We are near to release, and the bug-fix is important for the virtio 
>>>> vector
>>> path usage. Thanks.
>>>>
>>>>> -----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 <lei.a.yao@intel.com>
>>>>> Cc: dev@dpdk.org; yliu@fridaylinux.org; maxime.coquelin@redhat.com;
>>>>> Thomas Monjalon <thomas@monjalon.net>; stable@dpdk.org
>>>>> Subject: Re: [dpdk-dev] [PATCH v2 06/10] net/virtio: fix queue setup
>>> consistency
>>>>>
>>>>> 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:
>>>>>> 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
>>>>> vector path:
>>>>>> 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!
>>>>>>
>>>>>> BRs
>>>>>> Lei
>>>>>>> -----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
>>>>>>> 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 <olivier.matz@6wind.com>
>>>>>>> ---
>>>>>>>   drivers/net/virtio/virtio_ethdev.c | 13 +++++++++++++
>>>>>>> drivers/net/virtio/virtio_ethdev.h |  6 ++++++
>>>>>>>   drivers/net/virtio/virtio_rxtx.c   | 40
>>> ++++++++++++++++++++++++++++++-
>>>>>>> -------
>>>>>>>   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,
>>>>>>>           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,
>>>>>>>       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
>>>>>>> *dev,
>>>>>>>       }
>>>>>>>       dev->data->rx_queues[queue_idx] = rxvq;
>>>>>>>
>>>>>>> +    return 0;
>>>>>>> +}
>>>>>>> +
>>>>>>> +int
>>>>>>> +virtio_dev_rx_queue_setup_finish(struct rte_eth_dev *dev,
>>> uint16_t
>>>>>>> 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
>>>>> +545,6
>>>>>>> @@ 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
>>>>>>> *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
>>>>>>> *dev,
>>>>>>>
>>>>>>>       VIRTQUEUE_DUMP(vq);
>>>>>>>
>>>>>>> -    dev->data->tx_queues[queue_idx] = txvq;
>>>>>>>       return 0;
>>>>>>>   }
>>>>>>>
>>>>>>> -- 
>>>>>>> 2.11.0
>>>>>>