Re: [dpdk-dev] [PATCH v5 4/6] ether: Check VMDq RSS mode

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

> -----Original Message-----
> From: Vlad Zolotarov [mailto:vladz@cloudius-systems.com]
> Sent: Friday, January 9, 2015 2:49 AM
> To: Ouyang, Changchun; dev@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH v5 4/6] ether: Check VMDq RSS mode
> 
> 
> On 01/08/15 11:19, Vlad Zolotarov wrote:
> >
> > On 01/07/15 08:32, Ouyang Changchun wrote:
> >> Check mq mode for VMDq RSS, handle it correctly instead of returning
> >> an error; Also remove the limitation of per pool queue number has max
> >> value of 1, because the per pool queue number could be 2 or 4 if it
> >> is VMDq RSS mode;
> >>
> >> The number of rxq specified in config will determine the mq mode for
> >> VMDq RSS.
> >>
> >> Signed-off-by: Changchun Ouyang <changchun.ouyang@intel.com>
> >>
> >> changes in v5:
> >>    - Fix '<' issue, it should be '<=' to test rxq number;
> >>    - Extract a function to remove the embeded switch-case statement.
> >>
> >> ---
> >>   lib/librte_ether/rte_ethdev.c | 50
> >> ++++++++++++++++++++++++++++++++++++++-----
> >>   1 file changed, 45 insertions(+), 5 deletions(-)
> >>
> >> diff --git a/lib/librte_ether/rte_ethdev.c
> >> b/lib/librte_ether/rte_ethdev.c index 95f2ceb..8363e26 100644
> >> --- a/lib/librte_ether/rte_ethdev.c
> >> +++ b/lib/librte_ether/rte_ethdev.c
> >> @@ -503,6 +503,31 @@ rte_eth_dev_tx_queue_config(struct
> rte_eth_dev
> >> *dev, uint16_t nb_queues)
> >>   }
> >>     static int
> >> +rte_eth_dev_check_vf_rss_rxq_num(uint8_t port_id, uint16_t nb_rx_q)
> >> +{
> >> +    struct rte_eth_dev *dev = &rte_eth_devices[port_id];
> >> +    switch (nb_rx_q) {
> >> +    case 1:
> >> +    case 2:
> >> +        RTE_ETH_DEV_SRIOV(dev).active =
> >> +            ETH_64_POOLS;
> >> +        break;
> >> +    case 4:
> >> +        RTE_ETH_DEV_SRIOV(dev).active =
> >> +            ETH_32_POOLS;
> >> +        break;
> >> +    default:
> >> +        return -EINVAL;
> >> +    }
> >> +
> >> +    RTE_ETH_DEV_SRIOV(dev).nb_q_per_pool = nb_rx_q;
> >> +    RTE_ETH_DEV_SRIOV(dev).def_pool_q_idx =
> >> +        dev->pci_dev->max_vfs * nb_rx_q;
> >> +
> >> +    return 0;
> >> +}
> >> +
> >> +static int
> >>   rte_eth_dev_check_mq_mode(uint8_t port_id, uint16_t nb_rx_q,
> >> uint16_t nb_tx_q,
> >>                 const struct rte_eth_conf *dev_conf)
> >>   {
> >> @@ -510,8 +535,7 @@ rte_eth_dev_check_mq_mode(uint8_t port_id,
> >> uint16_t nb_rx_q, uint16_t nb_tx_q,
> >>         if (RTE_ETH_DEV_SRIOV(dev).active != 0) {
> >>           /* check multi-queue mode */
> >> -        if ((dev_conf->rxmode.mq_mode == ETH_MQ_RX_RSS) ||
> >> -            (dev_conf->rxmode.mq_mode == ETH_MQ_RX_DCB) ||
> >> +        if ((dev_conf->rxmode.mq_mode == ETH_MQ_RX_DCB) ||
> >>               (dev_conf->rxmode.mq_mode == ETH_MQ_RX_DCB_RSS) ||
> >>               (dev_conf->txmode.mq_mode == ETH_MQ_TX_DCB)) {
> >>               /* SRIOV only works in VMDq enable mode */ @@ -525,7
> >> +549,6 @@ rte_eth_dev_check_mq_mode(uint8_t port_id, uint16_t
> >> nb_rx_q, uint16_t nb_tx_q,
> >>           }
> >>             switch (dev_conf->rxmode.mq_mode) {
> >> -        case ETH_MQ_RX_VMDQ_RSS:
> >>           case ETH_MQ_RX_VMDQ_DCB:
> >>           case ETH_MQ_RX_VMDQ_DCB_RSS:
> >>               /* DCB/RSS VMDQ in SRIOV mode, not implement yet */ @@
> >> -534,6 +557,25 @@ rte_eth_dev_check_mq_mode(uint8_t port_id,
> uint16_t
> >> nb_rx_q, uint16_t nb_tx_q,
> >>                       "unsupported VMDQ mq_mode rx %u\n",
> >>                       port_id, dev_conf->rxmode.mq_mode);
> >>               return (-EINVAL);
> >> +        case ETH_MQ_RX_RSS:
> >> +            PMD_DEBUG_TRACE("ethdev port_id=%" PRIu8
> >> +                    " SRIOV active, "
> >> +                    "Rx mq mode is changed from:"
> >> +                    "mq_mode %u into VMDQ mq_mode %u\n",
> >> +                    port_id,
> >> +                    dev_conf->rxmode.mq_mode,
> >> +                    dev->data->dev_conf.rxmode.mq_mode);
> >> +        case ETH_MQ_RX_VMDQ_RSS:
> >> +            dev->data->dev_conf.rxmode.mq_mode =
> ETH_MQ_RX_VMDQ_RSS;
> >> +            if (nb_rx_q <= RTE_ETH_DEV_SRIOV(dev).nb_q_per_pool)
> >> +                if (rte_eth_dev_check_vf_rss_rxq_num(port_id,
> >> nb_rx_q) != 0) {
> >> +                    PMD_DEBUG_TRACE("ethdev port_id=%d"
> >> +                        " SRIOV active, invalid queue"
> >> +                        " number for VMDQ RSS\n",
> >> +                        port_id);
> >
> > Some nitpicking here: I'd add the allowed values descriptions to the
> > error message. Something like: "invalid queue number for VMDQ RSS.
> > Allowed values are 1, 2 or 4\n".
> >
> >> +                    return -EINVAL;
> >> +                }
> >> +            break;
> >>           default: /* ETH_MQ_RX_VMDQ_ONLY or ETH_MQ_RX_NONE */
> >>               /* if nothing mq mode configure, use default scheme */
> >>               dev->data->dev_conf.rxmode.mq_mode =
> >> ETH_MQ_RX_VMDQ_ONLY; @@ -553,8 +595,6 @@
> >> rte_eth_dev_check_mq_mode(uint8_t port_id, uint16_t nb_rx_q,
> uint16_t nb_tx_q,
> >>           default: /* ETH_MQ_TX_VMDQ_ONLY or ETH_MQ_TX_NONE */
> >>               /* if nothing mq mode configure, use default scheme */
> >>               dev->data->dev_conf.txmode.mq_mode =
> ETH_MQ_TX_VMDQ_ONLY;
> >> -            if (RTE_ETH_DEV_SRIOV(dev).nb_q_per_pool > 1)
> >> -                RTE_ETH_DEV_SRIOV(dev).nb_q_per_pool = 1;
> >
> > I'm not sure u may just remove it. These lines originally belong to a
> > different flow. Are u sure u can remove them like that? What if the
> > mq_mode is ETH_MQ_RX_NONE and nb_q_per_pool has been initialized
> to 4
> > or 8 in ixgbe_pf_host_init()?
> 
> I misread the patch - these lines belong to the txmode.mq_mode switch case.
> I think it's ok to remove these really strange lines here. And when I look at it i
> think for the similar reasons the similar lines should be removed in the Rx
> case too: consider non-RSS case with MQ DCB Tx configuration.
> 
I search code in this function, only one place has   
" if (RTE_ETH_DEV_SRIOV(dev).nb_q_per_pool > 1) 
           RTE_ETH_DEV_SRIOV(dev).nb_q_per_pool = 1;"

The only place is default branch, which is for rx_none, or vmdq_only mode,
We don't need remove this, as it should assign as 1 because it did use 1 queue per pool.