Re: [dpdk-dev] [PATCH v3] net/i40e: fix incorrect hash look up table

["Yang, Qiming" <qiming.yang@intel.com>]

I don't understand why you add new function and new function mostly do the same thing.
Why don't add fix in original code.

> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of Shougang Wang
> Sent: Wednesday, July 22, 2020 16:16
> To: dev@dpdk.org
> Cc: Xing, Beilei <beilei.xing@intel.com>; Guo, Jia <jia.guo@intel.com>; Wang,
> ShougangX <shougangx.wang@intel.com>; stable@dpdk.org
> Subject: [dpdk-dev] [PATCH v3] net/i40e: fix incorrect hash look up table
> 
> The hash look up table (LUT) is managed by global register but it is not
> initialized when RSS is disabled. Once user wants to enable RSS during
> runtime, the LUT will not be initialized.
> This patch fixes the issue by initializing the LUT whether RSS enabled or not.
> 
> Fixes: feaae285b342 ("net/i40e: support hash configuration in RSS flow")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Shougang Wang <shougangx.wang@intel.com>
> ---
> v3:
> -Updated the time of initializing the look up table
> ---
>  drivers/net/i40e/i40e_ethdev.c | 85 ++++++++++++++++++++--------------
>  1 file changed, 49 insertions(+), 36 deletions(-)
> 
> diff --git a/drivers/net/i40e/i40e_ethdev.c b/drivers/net/i40e/i40e_ethdev.c
> index 05d5f2861..e35590d96 100644
> --- a/drivers/net/i40e/i40e_ethdev.c
> +++ b/drivers/net/i40e/i40e_ethdev.c
> @@ -8984,42 +8984,7 @@ i40e_pf_calc_configured_queues_num(struct
> i40e_pf *pf)  static int  i40e_pf_config_rss(struct i40e_pf *pf)  {
> -	struct i40e_hw *hw = I40E_PF_TO_HW(pf);
>  	struct rte_eth_rss_conf rss_conf;
> -	uint32_t i, lut = 0;
> -	uint16_t j, num;
> -
> -	/*
> -	 * 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, I40E_MAX_Q_PER_TC);
> -	PMD_INIT_LOG(INFO, "Max of contiguous %u PF queues are
> configured",
> -			num);
> -
> -	if (num == 0) {
> -		PMD_INIT_LOG(ERR,
> -			"No PF queues are configured to enable RSS for port
> %u",
> -			pf->dev_data->port_id);
> -		return -ENOTSUP;
> -	}
> -
> -	if (pf->adapter->rss_reta_updated == 0) {
> -		for (i = 0, j = 0; i < hw->func_caps.rss_table_size; i++, j++) {
> -			if (j == num)
> -				j = 0;
> -			lut = (lut << 8) | (j & ((0x1 <<
> -				hw->func_caps.rss_table_entry_width) - 1));
> -			if ((i & 3) == 3)
> -				I40E_WRITE_REG(hw, I40E_PFQF_HLUT(i >>
> 2),
> -					       rte_bswap32(lut));
> -		}
> -	}
> 
>  	rss_conf = pf->dev_data->dev_conf.rx_adv_conf.rss_conf;
>  	if ((rss_conf.rss_hf & pf->adapter->flow_types_mask) == 0) { @@ -
> 9195,12 +9160,60 @@ i40e_tunnel_filter_handle(struct rte_eth_dev *dev,
>  	return ret;
>  }
> 
> +/* Initialize the hash look up table */ static int
> +i40e_pf_init_rss_lut(struct i40e_pf *pf) {
> +	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, I40E_MAX_Q_PER_TC);
> +	PMD_INIT_LOG(INFO, "Max of contiguous %u PF queues are
> configured",
> +		     num);
> +
> +	if (num == 0) {
> +		PMD_INIT_LOG(ERR,
> +			"No PF queues are configured to enable RSS for port
> %u",
> +			pf->dev_data->port_id);
> +		return -ENOTSUP;
> +	}
> +
> +	if (pf->adapter->rss_reta_updated == 0) {
> +		for (i = 0, j = 0; i < hw->func_caps.rss_table_size; i++, j++) {
> +			if (j == num)
> +				j = 0;
> +			lut = (lut << 8) | (j & ((0x1 <<
> +				hw->func_caps.rss_table_entry_width) - 1));
> +			if ((i & 3) == 3)
> +				I40E_WRITE_REG(hw, I40E_PFQF_HLUT(i >>
> 2),
> +					       rte_bswap32(lut));
> +		}
> +	}
> +
> +	return 0;
> +}
> +
>  static int
>  i40e_pf_config_mq_rx(struct i40e_pf *pf)  {
> -	int ret = 0;
> +	int ret;
>  	enum rte_eth_rx_mq_mode mq_mode = pf->dev_data-
> >dev_conf.rxmode.mq_mode;
> 
> +	/* Initialize hash look up table */
> +	ret = i40e_pf_init_rss_lut(pf);
> +	if (ret)
> +		return ret;
> +
>  	/* RSS setup */
>  	if (mq_mode & ETH_MQ_RX_RSS_FLAG)
>  		ret = i40e_pf_config_rss(pf);
> --
> 2.17.1