Re: [dpdk-dev] [PATCH v3] net/vhost: fix vhost invalid state

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

On 04/12/2018 09:21 AM, Tan, Jianfeng wrote:
> 
> 
> On 4/12/2018 1:02 AM, Junjie Chen wrote:
>> dev_start sets *dev_attached* after setup queues, this sets device to
>> invalid state since no frontend is attached. Also destroy_device set
>> *started* to zero which makes *allow_queuing* always zero until dev_start
>> get called again. Actually, we should not determine queues existence by
>> *dev_attached* but by queues pointers or other separated variable(s).
>>
>> Fixes: 30a701a53737 ("net/vhost: fix crash when creating vdev
>> dynamically")
>>
>> Signed-off-by: Junjie Chen <junjie.j.chen@intel.com>
>> Tested-by: Jens Freimann <jfreimann@redhat.com>
> 
> Overall, looks great to me except a nit below.
> 
> Reviewed-by: Jianfeng Tan <jianfeng.tan@intel.com>

Thanks Jianfeng, I can handle the small change while applying.

Can you confirm that it is implied that the queue are already allocated,
else we wouldn't find the internal resource and quit earlier (in case of
eth_dev_close called twice for example)?

Thanks,
Maxime

> 
>> ---
>> Changes in v3:
>> - remove useless log in queue status showing
>> Changes in v2:
>> - use started to determine vhost queues readiness
>> - revert setting started to zero in destroy_device
>>   drivers/net/vhost/rte_eth_vhost.c | 59 
>> +++++++++++++++++++--------------------
>>   1 file changed, 29 insertions(+), 30 deletions(-)
>>
>> diff --git a/drivers/net/vhost/rte_eth_vhost.c 
>> b/drivers/net/vhost/rte_eth_vhost.c
>> index 11b6076..e392d71 100644
>> --- a/drivers/net/vhost/rte_eth_vhost.c
>> +++ b/drivers/net/vhost/rte_eth_vhost.c
>> @@ -528,10 +528,11 @@ update_queuing_status(struct rte_eth_dev *dev)
>>       unsigned int i;
>>       int allow_queuing = 1;
>> -    if (rte_atomic32_read(&internal->dev_attached) == 0)
>> +    if (!dev->data->rx_queues || !dev->data->tx_queues)
>>           return;
>> -    if (rte_atomic32_read(&internal->started) == 0)
>> +    if (rte_atomic32_read(&internal->started) == 0 ||
>> +        rte_atomic32_read(&internal->dev_attached) == 0)
>>           allow_queuing = 0;
>>       /* Wait until rx/tx_pkt_burst stops accessing vhost device */
>> @@ -607,13 +608,10 @@ new_device(int vid)
>>   #endif
>>       internal->vid = vid;
>> -    if (eth_dev->data->rx_queues && eth_dev->data->tx_queues) {
>> +    if (rte_atomic32_read(&internal->started) == 1)
>>           queue_setup(eth_dev, internal);
>> -        rte_atomic32_set(&internal->dev_attached, 1);
>> -    } else {
>> -        RTE_LOG(INFO, PMD, "RX/TX queues have not setup yet\n");
>> -        rte_atomic32_set(&internal->dev_attached, 0);
>> -    }
>> +    else
>> +        RTE_LOG(INFO, PMD, "RX/TX queues not exist yet\n");
>>       for (i = 0; i < rte_vhost_get_vring_num(vid); i++)
>>           rte_vhost_enable_guest_notification(vid, i, 0);
>> @@ -622,6 +620,7 @@ new_device(int vid)
>>       eth_dev->data->dev_link.link_status = ETH_LINK_UP;
>> +    rte_atomic32_set(&internal->dev_attached, 1);
>>       update_queuing_status(eth_dev);
>>       RTE_LOG(INFO, PMD, "Vhost device %d created\n", vid);
>> @@ -651,23 +650,24 @@ destroy_device(int vid)
>>       eth_dev = list->eth_dev;
>>       internal = eth_dev->data->dev_private;
>> -    rte_atomic32_set(&internal->started, 0);
>> -    update_queuing_status(eth_dev);
>>       rte_atomic32_set(&internal->dev_attached, 0);
>> +    update_queuing_status(eth_dev);
>>       eth_dev->data->dev_link.link_status = ETH_LINK_DOWN;
>> -    for (i = 0; i < eth_dev->data->nb_rx_queues; i++) {
>> -        vq = eth_dev->data->rx_queues[i];
>> -        if (vq == NULL)
>> -            continue;
>> -        vq->vid = -1;
>> -    }
>> -    for (i = 0; i < eth_dev->data->nb_tx_queues; i++) {
>> -        vq = eth_dev->data->tx_queues[i];
>> -        if (vq == NULL)
>> -            continue;
>> -        vq->vid = -1;
>> +    if (eth_dev->data->rx_queues && eth_dev->data->tx_queues) {
>> +        for (i = 0; i < eth_dev->data->nb_rx_queues; i++) {
>> +            vq = eth_dev->data->rx_queues[i];
>> +            if (!vq)
>> +                continue;
>> +            vq->vid = -1;
>> +        }
>> +        for (i = 0; i < eth_dev->data->nb_tx_queues; i++) {
>> +            vq = eth_dev->data->tx_queues[i];
>> +            if (!vq)
>> +                continue;
>> +            vq->vid = -1;
>> +        }
>>       }
>>       state = vring_states[eth_dev->data->port_id];
>> @@ -792,11 +792,7 @@ eth_dev_start(struct rte_eth_dev *eth_dev)
>>   {
>>       struct pmd_internal *internal = eth_dev->data->dev_private;
>> -    if (unlikely(rte_atomic32_read(&internal->dev_attached) == 0)) {
>> -        queue_setup(eth_dev, internal);
>> -        rte_atomic32_set(&internal->dev_attached, 1);
>> -    }
>> -
>> +    queue_setup(eth_dev, internal);
>>       rte_atomic32_set(&internal->started, 1);
>>       update_queuing_status(eth_dev);
>> @@ -836,10 +832,13 @@ eth_dev_close(struct rte_eth_dev *dev)
>>       pthread_mutex_unlock(&internal_list_lock);
>>       rte_free(list);
>> -    for (i = 0; i < dev->data->nb_rx_queues; i++)
>> -        rte_free(dev->data->rx_queues[i]);
>> -    for (i = 0; i < dev->data->nb_tx_queues; i++)
>> -        rte_free(dev->data->tx_queues[i]);
>> +    if (dev->data->rx_queues)
> 
> This is implied that rx_queues is already allocated. So I don't think we 
> need this.
> 
>> +        for (i = 0; i < dev->data->nb_rx_queues; i++)
>> +            rte_free(dev->data->rx_queues[i]);
>> +
>> +    if (dev->data->tx_queues)
>> +        for (i = 0; i < dev->data->nb_tx_queues; i++)
>> +            rte_free(dev->data->tx_queues[i]);
>>       rte_free(dev->data->mac_addrs);
>>       free(internal->dev_name);
>