Re: [dpdk-dev] [PATCH v7 02/14] ethdev: add support for hairpin queue

[Andrew Rybchenko <arybchenko@solarflare.com>]

On 11/5/19 2:36 PM, Ori Kam wrote:
> 
> 
>> -----Original Message-----
>> From: Ferruh Yigit <ferruh.yigit@intel.com>
>> Sent: Tuesday, November 5, 2019 1:25 PM
>> To: Ori Kam <orika@mellanox.com>; John McNamara
>> <john.mcnamara@intel.com>; Marko Kovacevic
>> <marko.kovacevic@intel.com>; Thomas Monjalon <thomas@monjalon.net>;
>> Andrew Rybchenko <arybchenko@solarflare.com>
>> Cc: dev@dpdk.org; jingjing.wu@intel.com; stephen@networkplumber.org; Jerin
>> Jacob <jerin.jacob@caviumnetworks.com>
>> Subject: Re: [PATCH v7 02/14] ethdev: add support for hairpin queue
>>
>> On 10/30/2019 11:53 PM, Ori Kam wrote:
>>> This commit introduce hairpin queue type.
>>>
>>> The hairpin queue in build from Rx queue binded to Tx queue.
>>> It is used to offload traffic coming from the wire and redirect it back
>>> to the wire.
>>>
>>> There are 3 new functions:
>>> - rte_eth_dev_hairpin_capability_get
>>> - rte_eth_rx_hairpin_queue_setup
>>> - rte_eth_tx_hairpin_queue_setup
>>>
>>> In order to use the queue, there is a need to create rte_flow
>>> with queue / RSS action that targets one or more of the Rx queues.
>>>
>>> Signed-off-by: Ori Kam <orika@mellanox.com>
>>> Reviewed-by: Andrew Rybchenko <arybchenko@solarflare.com>
>>
>> <...>
>>
>>>  #include <rte_ethdev_core.h>
>>>
>>>  /**
>>> + * @internal
>>> + * Check if the selected Rx queue is hairpin queue.
>>> + *
>>> + * @param dev
>>> + *  Pointer to the selected device.
>>> + * @param queue_id
>>> + *  The selected queue.
>>> + *
>>> + * @return
>>> + *   - (1) if the queue is hairpin queue, 0 otherwise.
>>> + */
>>> +int
>>> +rte_eth_dev_is_rx_hairpin_queue(struct rte_eth_dev *dev, uint16_t
>> queue_id);
>>> +
>>> +/**
>>> + * @internal
>>> + * Check if the selected Tx queue is hairpin queue.
>>> + *
>>> + * @param dev
>>> + *  Pointer to the selected device.
>>> + * @param queue_id
>>> + *  The selected queue.
>>> + *
>>> + * @return
>>> + *   - (1) if the queue is hairpin queue, 0 otherwise.
>>> + */
>>> +int
>>> +rte_eth_dev_is_tx_hairpin_queue(struct rte_eth_dev *dev, uint16_t
>> queue_id);
>>> +
>>> +/**
>>
>> If these functions are internal why there are in 'rte_ethdev.h' ?
>>
>>>   *
>>>   * Retrieve a burst of input packets from a receive queue of an Ethernet
>>>   * device. The retrieved packets are stored in *rte_mbuf* structures whose
>>> @@ -4251,6 +4400,11 @@ int rte_eth_dev_adjust_nb_rx_tx_desc(uint16_t
>> port_id,
>>>  		RTE_ETHDEV_LOG(ERR, "Invalid RX queue_id=%u\n",
>> queue_id);
>>>  		return 0;
>>>  	}
>>> +	if (rte_eth_dev_is_rx_hairpin_queue(dev, queue_id)) {
>>> +		RTE_ETHDEV_LOG(ERR, "Rx burst failed, queue_id=%u is
>> hairpin queue\n",
>>> +			       queue_id);
>>> +		return 0;
>>> +	}
>>>  #endif
>>>  	nb_rx = (*dev->rx_pkt_burst)(dev->data->rx_queues[queue_id],
>>>  				     rx_pkts, nb_pkts);
>>> @@ -4517,6 +4671,11 @@ static inline int
>> rte_eth_tx_descriptor_status(uint16_t port_id,
>>>  		RTE_ETHDEV_LOG(ERR, "Invalid TX queue_id=%u\n",
>> queue_id);
>>>  		return 0;
>>>  	}
>>> +	if (rte_eth_dev_is_tx_hairpin_queue(dev, queue_id)) {
>>> +		RTE_ETHDEV_LOG(ERR, "Tx burst failed, queue_id=%u is
>> hairpin queue\n",
>>> +			       queue_id);
>>> +		return 0;
>>> +	}
>>>  #endif
>>
>> Hi Ori,
>>
>> These are causing build error, thanks Jerin for catching, because they are
>> internal and called by a public static inline API, so whoever calls
>> 'rte_eth_rx/tx_burst()' APIs in the shared build, can't find
>> 'rte_eth_dev_is_rx/tx_hairpin_queue()' functions [1],
>>
>> as far as I can see there are two options:
>> 1) Remove these checks
>> 2) Make 'rte_eth_dev_is_rx/tx_hairpin_queue()' public API instead of internal
>>
>> If there is a value to make 'rte_eth_dev_is_rx/tx_hairpin_queue()' public API
>> we
>> should go with (2) else (1).
>>
> 
> I think we can skip the tests,
> But it was Andrew request so we must get is response.
> It was also his empathies that they should be internal.

It is important for me to keep rte_eth_dev_state internal and
few patches ago rte_eth_dev_is_rx_hairpin_queue() was inline.
I'm OK to make the function experimental or keep it internal
(no API/ABI stability requirements) but externally visible (in .map).

>> [1]
>> /usr/bin/ld: rte_event_eth_rx_adapter.o: in function `rxa_eth_rx':
>> rte_event_eth_rx_adapter.c:(.text+0x1728): undefined reference to
>> `rte_eth_dev_is_rx_hairpin_queue'
>> /usr/bin/ld: rte_event_eth_rx_adapter.o: in function `rxa_service_func':
>> rte_event_eth_rx_adapter.c:(.text+0x22ab): undefined reference to
>> `rte_eth_dev_is_rx_hairpin_queue'
>> /usr/bin/ld: rte_event_eth_tx_adapter.o: in function `txa_service_buffer_retry':
>> rte_event_eth_tx_adapter.c:(.text+0xa43): undefined reference to
>> `rte_eth_dev_is_tx_hairpin_queue'
>> /usr/bin/ld: rte_event_eth_tx_adapter.o: in function `txa_service_func':
>> rte_event_eth_tx_adapter.c:(.text+0xe7d): undefined reference to
>> `rte_eth_dev_is_tx_hairpin_queue'
>> /usr/bin/ld: rte_event_eth_tx_adapter.c:(.text+0x1155): undefined reference to
>> `rte_eth_dev_is_tx_hairpin_queue'
>> collect2: error: ld returned 1 exit status