Re: [dpdk-dev] [PATCH v3 5/6] ixgbe: Config VF RSS

["Ouyang, Changchun" <changchun.ouyang@intel.com>]

Hi Steve,

> -----Original Message-----
> From: Liang, Cunming
> Sent: Sunday, January 4, 2015 10:11 AM
> To: Ouyang, Changchun; dev@dpdk.org
> Cc: Cao, Waterman
> Subject: RE: [PATCH v3 5/6] ixgbe: Config VF RSS
> 
> 
> 
> > -----Original Message-----
> > From: Ouyang, Changchun
> > Sent: Wednesday, December 24, 2014 1:23 PM
> > To: dev@dpdk.org
> > Cc: Liang, Cunming; Cao, Waterman; Ouyang, Changchun
> > Subject: [PATCH v3 5/6] ixgbe: Config VF RSS
> >
> > It needs config RSS and IXGBE_MRQC and IXGBE_VFPSRTYPE to enable VF
> RSS.
> >
> > The psrtype will determine how many queues the received packets will
> > distribute to, and the value of psrtype should depends on both facet:
> > max VF rxq number which has been negotiated with PF, and the number of
> > rxq specified in config on guest.
> >
> > Signed-off-by: Changchun Ouyang <changchun.ouyang@intel.com>
> > ---
> >  lib/librte_pmd_ixgbe/ixgbe_pf.c   | 15 +++++++
> >  lib/librte_pmd_ixgbe/ixgbe_rxtx.c | 92
> > ++++++++++++++++++++++++++++++++++-----
> >  2 files changed, 97 insertions(+), 10 deletions(-)
> >
> > diff --git a/lib/librte_pmd_ixgbe/ixgbe_pf.c
> > b/lib/librte_pmd_ixgbe/ixgbe_pf.c index cbb0145..9c9dad8 100644
> > --- a/lib/librte_pmd_ixgbe/ixgbe_pf.c
> > +++ b/lib/librte_pmd_ixgbe/ixgbe_pf.c
> > @@ -187,6 +187,21 @@ int ixgbe_pf_host_configure(struct rte_eth_dev
> > *eth_dev)
> >  	IXGBE_WRITE_REG(hw, IXGBE_MPSAR_LO(hw-
> >mac.num_rar_entries),
> > 0);
> >  	IXGBE_WRITE_REG(hw, IXGBE_MPSAR_HI(hw-
> >mac.num_rar_entries),
> > 0);
> >
> > +	/*
> > +	 * VF RSS can support at most 4 queues for each VF, even if
> > +	 * 8 queues are available for each VF, it need refine to 4
> > +	 * queues here due to this limitation, otherwise no queue
> > +	 * will receive any packet even RSS is enabled.
> > +	 */
> > +	if (eth_dev->data->dev_conf.rxmode.mq_mode ==
> > ETH_MQ_RX_VMDQ_RSS) {
> > +		if (RTE_ETH_DEV_SRIOV(eth_dev).nb_q_per_pool == 8) {
> > +			RTE_ETH_DEV_SRIOV(eth_dev).active =
> ETH_32_POOLS;
> > +			RTE_ETH_DEV_SRIOV(eth_dev).nb_q_per_pool = 4;
> > +			RTE_ETH_DEV_SRIOV(eth_dev).def_pool_q_idx =
> > +				dev_num_vf(eth_dev) * 4;
> > +		}
> > +	}
> > +
> >  	/* set VMDq map to default PF pool */
> >  	hw->mac.ops.set_vmdq(hw, 0,
> > RTE_ETH_DEV_SRIOV(eth_dev).def_vmdq_idx);
> >
> > diff --git a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
> > b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
> > index f69abda..a7c17a4 100644
> > --- a/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
> > +++ b/lib/librte_pmd_ixgbe/ixgbe_rxtx.c
> > @@ -3327,6 +3327,39 @@ ixgbe_alloc_rx_queue_mbufs(struct
> igb_rx_queue
> > *rxq)
> >  }
> >
> >  static int
> > +ixgbe_config_vf_rss(struct rte_eth_dev *dev) {
> > +	struct ixgbe_hw *hw;
> > +	uint32_t mrqc;
> > +
> > +	ixgbe_rss_configure(dev);
> > +
> > +	hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);
> > +
> > +	/* MRQC: enable VF RSS */
> > +	mrqc = IXGBE_READ_REG(hw, IXGBE_MRQC);
> > +	mrqc &= ~IXGBE_MRQC_MRQE_MASK;
> > +	switch (RTE_ETH_DEV_SRIOV(dev).active) {
> > +	case ETH_64_POOLS:
> > +		mrqc |= IXGBE_MRQC_VMDQRSS64EN;
> > +		break;
> > +
> > +	case ETH_32_POOLS:
> > +	case ETH_16_POOLS:
> > +		mrqc |= IXGBE_MRQC_VMDQRSS32EN;
> > +		break;
> > +
> > +	default:
> > +		PMD_INIT_LOG(ERR, "Invalid pool number in IOV mode");
> > +		return -EINVAL;
> > +	}
> > +
> > +	IXGBE_WRITE_REG(hw, IXGBE_MRQC, mrqc);
> > +
> > +	return 0;
> > +}
> > +
> > +static int
> >  ixgbe_dev_mq_rx_configure(struct rte_eth_dev *dev)  {
> >  	struct ixgbe_hw *hw =
> > @@ -3358,24 +3391,38 @@ ixgbe_dev_mq_rx_configure(struct
> rte_eth_dev
> > *dev)
> >  			default: ixgbe_rss_disable(dev);
> >  		}
> >  	} else {
> > -		switch (RTE_ETH_DEV_SRIOV(dev).active) {
> >  		/*
> >  		 * SRIOV active scheme
> >  		 * FIXME if support DCB/RSS together with VMDq & SRIOV
> >  		 */
> > -		case ETH_64_POOLS:
> > -			IXGBE_WRITE_REG(hw, IXGBE_MRQC,
> > IXGBE_MRQC_VMDQEN);
> > +		switch (dev->data->dev_conf.rxmode.mq_mode) {
> > +		case ETH_MQ_RX_RSS:
> > +		case ETH_MQ_RX_VMDQ_RSS:
> > +			ixgbe_config_vf_rss(dev);
> >  			break;
> >
> > -		case ETH_32_POOLS:
> > -			IXGBE_WRITE_REG(hw, IXGBE_MRQC,
> > IXGBE_MRQC_VMDQRT4TCEN);
> > -			break;
> > +		default:
> > +			switch (RTE_ETH_DEV_SRIOV(dev).active) {
> [Liang, Cunming]  Just a minor comments. To avoid a switch branch inside
> another switch, we can have a  ixgbe_config_vf_default(), which process all
> the things if no RSS/DCB required in multi-queue setting.
> Then we can put all the 'switch(SRIOV(dev).active){...}'  in it.

Yes, will resolve it in v4 patch.

> > +			case ETH_64_POOLS:
> > +				IXGBE_WRITE_REG(hw, IXGBE_MRQC,
> > +					IXGBE_MRQC_VMDQEN);
> > +				break;
> >
> > -		case ETH_16_POOLS:
> > -			IXGBE_WRITE_REG(hw, IXGBE_MRQC,
> > IXGBE_MRQC_VMDQRT8TCEN);
> > +			case ETH_32_POOLS:
> > +				IXGBE_WRITE_REG(hw, IXGBE_MRQC,
> > +					IXGBE_MRQC_VMDQRT4TCEN);
> > +				break;
> > +
> > +			case ETH_16_POOLS:
> > +				IXGBE_WRITE_REG(hw, IXGBE_MRQC,
> > +					IXGBE_MRQC_VMDQRT8TCEN);
> > +				break;
> > +			default:
> > +				PMD_INIT_LOG(ERR,
> > +					"invalid pool number in IOV mode");
> > +				break;
> > +			}
> >  			break;
> > -		default:
> > -			PMD_INIT_LOG(ERR, "invalid pool number in IOV
> mode");
> >  		}
> >  	}
> >
> > @@ -3989,10 +4036,32 @@ ixgbevf_dev_rx_init(struct rte_eth_dev *dev)
> >  	uint16_t buf_size;
> >  	uint16_t i;
> >  	int ret;
> > +	uint16_t valid_rxq_num;
> >
> >  	PMD_INIT_FUNC_TRACE();
> >  	hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);
> >
> > +	valid_rxq_num = RTE_MIN(dev->data->nb_rx_queues, hw-
> > >mac.max_rx_queues);
> > +
> > +	/*
> > +	 * VMDq RSS can't support 3 queues, so config it into 4 queues,
> > +	 * and give user a hint that some packets may loss if it doesn't
> > +	 * poll the queue where those packets are distributed to.
> > +	 */
> > +	if (valid_rxq_num == 3)
> [Liang, Cunming] According to the inline comment, it makes more sense to
> use 'if (valid_rxq_num >= 3)'.
> In case, the value returned by max_rx_queues is not less equal than 4.

This will be resolved in v4 patch.
Thanks
Changchun