Re: [PATCH] vhost PMD: Fix wrong handling of maximum value of rx/tx queues

[Tetsuya Mukawa <mukawa@igel.co.jp>]

On 2016/03/23 2:17, Loftus, Ciara wrote:
>> Currently, the maximum value of rx/tx queueus are kept by EAL. But,
>> the value are used like below different meanings in vhost PMD.
>>  - The maximum value of current enabled queues.
>>  - The maximum value of current supported queues.
>>
>> This wrong double meaning will cause an issue like below steps.
>>
>> * Invoke application with below option.
>>   --vdev 'eth_vhost0,iface=<socket path>,queues=4'
>> * Configure queues like below.
>>   rte_eth_dev_configure(portid, 2, 2, ...);
>> * Configure queues again like below.
>>   rte_eth_dev_configure(portid, 4, 4, ...);
>>
>> The second rte_eth_dev_configure() will be failed because both
>> the maximum value of current enabled queues and supported queues
>> will be '2' after calling first rte_eth_dev_configure().
>>
>> To fix the issue, the patch prepare one more variable to keep the
>> number of maximum supported queues in vhost PMD.
>>
>> Signed-off-by: Tetsuya Mukawa <mukawa@igel.co.jp>
>> ---
>>  drivers/net/vhost/rte_eth_vhost.c | 14 ++++++++++++--
>>  1 file changed, 12 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/net/vhost/rte_eth_vhost.c
>> b/drivers/net/vhost/rte_eth_vhost.c
>> index 6b9d287..5fd8c70 100644
>> --- a/drivers/net/vhost/rte_eth_vhost.c
>> +++ b/drivers/net/vhost/rte_eth_vhost.c
>> @@ -88,6 +88,7 @@ struct vhost_queue {
>>  struct pmd_internal {
>>  	char *dev_name;
>>  	char *iface_name;
>> +	uint16_t max_queues;
>>
>>  	volatile uint16_t once;
>>  };
>> @@ -555,11 +556,19 @@ static void
>>  eth_dev_info(struct rte_eth_dev *dev,
>>  	     struct rte_eth_dev_info *dev_info)
>>  {
>> +	struct pmd_internal *internal;
>> +
>> +	internal = dev->data->dev_private;
>> +	if (internal == NULL) {
>> +		RTE_LOG(ERR, PMD, "Invalid device specified\n");
>> +		return;
>> +	}
>> +
>>  	dev_info->driver_name = drivername;
>>  	dev_info->max_mac_addrs = 1;
>>  	dev_info->max_rx_pktlen = (uint32_t)-1;
>> -	dev_info->max_rx_queues = dev->data->nb_rx_queues;
>> -	dev_info->max_tx_queues = dev->data->nb_tx_queues;
>> +	dev_info->max_rx_queues = internal->max_queues;
>> +	dev_info->max_tx_queues = internal->max_queues;
>>  	dev_info->min_rx_bufsize = 0;
>>  }
>>
>> @@ -751,6 +760,7 @@ eth_dev_vhost_create(const char *name, char
>> *iface_name, int16_t queues,
>>  	memmove(data->name, eth_dev->data->name, sizeof(data-
>>> name));
>>  	data->nb_rx_queues = queues;
>>  	data->nb_tx_queues = queues;
>> +	internal->max_queues = queues;
>>  	data->dev_link = pmd_link;
>>  	data->mac_addrs = eth_addr;
>>
>> --
>> 2.1.4
> Hi Tetsuya,
>
> Thanks again for the patch.
>
> Acked-by: Ciara Loftus <ciara.loftus@intel.com>
>
> Thanks,
> Ciara
>

I appreciate your reviewing and testing.

Thanks,
Tetsuya