[dpdk-dev] [PATCH v2] net/i40e: fix incorrect hash look up table

[Zhang, Qi Z]

> -----Original Message-----
> From: dev <dev-bounces at dpdk.org> On Behalf Of Shougang Wang
> Sent: Tuesday, July 21, 2020 1:49 PM
> To: dev at dpdk.org
> Cc: Xing, Beilei <beilei.xing at intel.com>; Guo, Jia <jia.guo at intel.com>; Wang,
> ShougangX <shougangx.wang at intel.com>; stable at dpdk.org
> Subject: [dpdk-dev] [PATCH v2] net/i40e: fix incorrect hash look up table
> 
> The hash look up table(LUT) will not be initializing when starting testpmd with
> --disable-rss. So that some invalid queue indexes may still in the LUT. When
> enable RSS by creating RSS rule, some packets will not be into the valid queues.
> This patch fixes this issue by initializing the LUT when creating an RSS rule.

Could you explain why you only initialize the LUT when creating an RSS rule but not at dev_init or dev_start?
What if user configure LUT table before create a RSS rule? Does that mean the LUT table will be flushed?

> 
> Fixes: feaae285b342 ("net/i40e: support hash configuration in RSS flow")
> Cc: stable at dpdk.org
> 
> Signed-off-by: Shougang Wang <shougangx.wang at intel.com>
> ---
>  drivers/net/i40e/i40e_ethdev.c | 134 ++++++++++++++++-----------------
>  1 file changed, 63 insertions(+), 71 deletions(-)
> 
> diff --git a/drivers/net/i40e/i40e_ethdev.c b/drivers/net/i40e/i40e_ethdev.c
> index 393b5320f..e56543393 100644
> --- a/drivers/net/i40e/i40e_ethdev.c
> +++ b/drivers/net/i40e/i40e_ethdev.c
> @@ -13070,6 +13070,55 @@ i40e_rss_conf_init(struct i40e_rte_flow_rss_conf
> *out,
>  	return 0;
>  }
> 
> +/* If conf is NULL, function will init hash LUT with default
> +configration*/ static int i40e_rss_set_lut(struct i40e_pf *pf,
> +		 struct i40e_rte_flow_rss_conf *conf) {
> +	struct i40e_hw *hw = I40E_PF_TO_HW(pf);
> +	uint32_t lut = 0;
> +	uint16_t j, num;
> +	uint32_t i;
> +
> +	/* If both VMDQ and RSS enabled, not all of PF queues are configured.
> +	 * It's necessary to calculate the actual PF queues that are configured.
> +	 */
> +	if (pf->dev_data->dev_conf.rxmode.mq_mode &
> ETH_MQ_RX_VMDQ_FLAG)
> +		num = i40e_pf_calc_configured_queues_num(pf);
> +	else
> +		num = pf->dev_data->nb_rx_queues;
> +
> +	if (conf == NULL)
> +		num = RTE_MIN(num, I40E_MAX_Q_PER_TC);
> +	else
> +		num = RTE_MIN(num, conf->conf.queue_num);
> +	PMD_DRV_LOG(INFO, "Max of contiguous %u PF queues are configured",
> +			num);
> +
> +	if (num == 0) {
> +		PMD_DRV_LOG(ERR,
> +			"No PF queues are configured to enable RSS for port %u",
> +			pf->dev_data->port_id);
> +		return -ENOTSUP;
> +	}
> +
> +	/* Fill in redirection table */
> +	for (i = 0, j = 0; i < hw->func_caps.rss_table_size; i++, j++) {
> +		if (j == num)
> +			j = 0;
> +		if (conf == NULL)
> +			lut = (lut << 8) | (j & ((0x1 <<
> +				hw->func_caps.rss_table_entry_width) - 1));
> +		else
> +			lut = (lut << 8) | (conf->conf.queue[j] & ((0x1 <<
> +			hw->func_caps.rss_table_entry_width) - 1));
> +		if ((i & 3) == 3)
> +			I40E_WRITE_REG(hw, I40E_PFQF_HLUT(i >> 2), lut);
> +	}
> +
> +	return 0;
> +}
> +
>  /* Write HENA register to enable hash */  static int
> i40e_rss_hash_set(struct i40e_pf *pf, struct i40e_rte_flow_rss_conf *rss_conf)
> @@ -13318,12 +13367,24 @@ static int  i40e_rss_enable_hash(struct i40e_pf
> *pf,
>  		struct i40e_rte_flow_rss_conf *conf)
>  {
> +	enum rte_eth_rx_mq_mode mq_mode =
> +pf->dev_data->dev_conf.rxmode.mq_mode;
>  	struct i40e_rte_flow_rss_conf *rss_info = &pf->rss_info;
>  	struct i40e_rte_flow_rss_conf rss_conf;
> +	int ret;
> 
>  	if (!(conf->conf.types & pf->adapter->flow_types_mask))
>  		return -ENOTSUP;
> 
> +	/* If the RSS is disabled before this, the LUT is uninitialized.
> +	 * So it is necessary to initialize it here.
> +	 */
> +	if (!(mq_mode & ETH_MQ_RX_RSS_FLAG)
> && !pf->rss_info.conf.queue_num &&
> +	    !pf->adapter->rss_reta_updated) {
> +		ret = i40e_rss_set_lut(pf, NULL);
> +		if (ret)
> +			return ret;
> +	}
> +
>  	memset(&rss_conf, 0, sizeof(rss_conf));
>  	rte_memcpy(&rss_conf, conf, sizeof(rss_conf));
> 
> @@ -13362,39 +13423,7 @@ static int
>  i40e_rss_config_queue_region(struct i40e_pf *pf,
>  		struct i40e_rte_flow_rss_conf *conf)
>  {
> -	struct i40e_hw *hw = I40E_PF_TO_HW(pf);
> -	uint32_t lut = 0;
> -	uint16_t j, num;
> -	uint32_t i;
> -
> -	/* If both VMDQ and RSS enabled, not all of PF queues are configured.
> -	 * It's necessary to calculate the actual PF queues that are configured.
> -	 */
> -	if (pf->dev_data->dev_conf.rxmode.mq_mode &
> ETH_MQ_RX_VMDQ_FLAG)
> -		num = i40e_pf_calc_configured_queues_num(pf);
> -	else
> -		num = pf->dev_data->nb_rx_queues;
> -
> -	num = RTE_MIN(num, conf->conf.queue_num);
> -	PMD_DRV_LOG(INFO, "Max of contiguous %u PF queues are configured",
> -			num);
> -
> -	if (num == 0) {
> -		PMD_DRV_LOG(ERR,
> -			"No PF queues are configured to enable RSS for port %u",
> -			pf->dev_data->port_id);
> -		return -ENOTSUP;
> -	}
> -
> -	/* Fill in redirection table */
> -	for (i = 0, j = 0; i < hw->func_caps.rss_table_size; i++, j++) {
> -		if (j == num)
> -			j = 0;
> -		lut = (lut << 8) | (conf->conf.queue[j] & ((0x1 <<
> -			hw->func_caps.rss_table_entry_width) - 1));
> -		if ((i & 3) == 3)
> -			I40E_WRITE_REG(hw, I40E_PFQF_HLUT(i >> 2), lut);
> -	}
> +	i40e_rss_set_lut(pf, conf);
> 
>  	i40e_rss_mark_invalid_rule(pf, conf);
> 
> @@ -13491,46 +13520,9 @@ i40e_rss_disable_hash(struct i40e_pf *pf,  static
> int  i40e_rss_clear_queue_region(struct i40e_pf *pf)  {
> -	struct i40e_hw *hw = I40E_PF_TO_HW(pf);
>  	struct i40e_rte_flow_rss_conf *rss_info = &pf->rss_info;
> -	uint16_t queue[I40E_MAX_Q_PER_TC];
> -	uint32_t num_rxq, i;
> -	uint32_t lut = 0;
> -	uint16_t j, num;
> -
> -	num_rxq = RTE_MIN(pf->dev_data->nb_rx_queues,
> I40E_MAX_Q_PER_TC);
> 
> -	for (j = 0; j < num_rxq; j++)
> -		queue[j] = j;
> -
> -	/* If both VMDQ and RSS enabled, not all of PF queues are configured.
> -	 * It's necessary to calculate the actual PF queues that are configured.
> -	 */
> -	if (pf->dev_data->dev_conf.rxmode.mq_mode &
> ETH_MQ_RX_VMDQ_FLAG)
> -		num = i40e_pf_calc_configured_queues_num(pf);
> -	else
> -		num = pf->dev_data->nb_rx_queues;
> -
> -	num = RTE_MIN(num, num_rxq);
> -	PMD_DRV_LOG(INFO, "Max of contiguous %u PF queues are configured",
> -			num);
> -
> -	if (num == 0) {
> -		PMD_DRV_LOG(ERR,
> -			"No PF queues are configured to enable RSS for port %u",
> -			pf->dev_data->port_id);
> -		return -ENOTSUP;
> -	}
> -
> -	/* Fill in redirection table */
> -	for (i = 0, j = 0; i < hw->func_caps.rss_table_size; i++, j++) {
> -		if (j == num)
> -			j = 0;
> -		lut = (lut << 8) | (queue[j] & ((0x1 <<
> -			hw->func_caps.rss_table_entry_width) - 1));
> -		if ((i & 3) == 3)
> -			I40E_WRITE_REG(hw, I40E_PFQF_HLUT(i >> 2), lut);
> -	}
> +	i40e_rss_set_lut(pf, NULL);
> 
>  	rss_info->conf.queue_num = 0;
>  	memset(&rss_info->conf.queue, 0, sizeof(uint16_t));
> --
> 2.17.1