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

["Zhang, Qi Z" <qi.z.zhang@intel.com>]

> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of Yang, Qiming
> Sent: Thursday, July 23, 2020 9:57 AM
> To: Wang, ShougangX <shougangx.wang@intel.com>; 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: Re: [dpdk-dev] [PATCH v3] net/i40e: fix incorrect hash look up table
> 
> 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)

I agree with Qiming, if we move this check into i40e_pf_config_rss, dose that looks we don't need to create a new function?

> >  		ret = i40e_pf_config_rss(pf);
> > --
> > 2.17.1