Hi Bernard,
> -----Original Message-----
> From: Iremonger, Bernard
> Sent: Tuesday, October 18, 2016 4:58 PM
> To: Lu, Wenzhuo; dev at dpdk.org; Shah, Rahul R
> Subject: RE: [PATCH v2] net/ixgbe: support multiqueue mode VMDq DCB with
> SRIOV
>
> Hi Wenzhuo,
>
> <snip>
>
> > > Subject: RE: [PATCH v2] net/ixgbe: support multiqueue mode VMDq DCB
> > > with SRIOV
> > >
> > > Hi Wenzhuo,
> > >
> > > > > if (hw->mac.type != ixgbe_mac_82598EB) { @@ -3339,11 +3340,17
> > > > @@
> > > > > ixgbe_dcb_tx_hw_config(struct ixgbe_hw *hw,
> > > > > if (dcb_config->vt_mode)
> > > > > reg |= IXGBE_MTQC_VT_ENA;
> > > > > IXGBE_WRITE_REG(hw, IXGBE_MTQC, reg);
> > > > > -
> > > > > - /* Disable drop for all queues */
> > > > > - for (q = 0; q < 128; q++)
> > > > > - IXGBE_WRITE_REG(hw, IXGBE_QDE,
> > > > > - (IXGBE_QDE_WRITE | (q <<
> > > > > IXGBE_QDE_IDX_SHIFT)));
> > > > > + if (RTE_ETH_DEV_SRIOV(dev).active == 0) {
> > > > > + /* Disable drop for all queues in VMDQ mode*/
> > > > > + for (q = 0; q < 128; q++)
> > > > > + IXGBE_WRITE_REG(hw, IXGBE_QDE,
> > > > > + (IXGBE_QDE_WRITE |
> (q <<
> > > > > IXGBE_QDE_IDX_SHIFT) | IXGBE_QDE_ENABLE));
This code is used to enable drop, but the comments say 'disable drop'.
> > > > > + } else {
> > > > > + /* Enable drop for all queues in SRIOV mode */
> > > > > + for (q = 0; q < 128; q++)
> > > > > + IXGBE_WRITE_REG(hw, IXGBE_QDE,
> > > > > + (IXGBE_QDE_WRITE |
> (q <<
> > > > > IXGBE_QDE_IDX_SHIFT)));
This code is used to disable drop, but the comments say 'enable drop'.
I've checked the V4, the same problem too. I think the problem is the comments,
right?
> > > > > + }
> > > > I think it has nothing to do with mq mode. Do I miss something?
> > >
> > > Behavior is different when SRIOV is enabled.
> > I don't understand why the behavior is different. To my opinion, the
> > drop has nothing to do with the mode. We can enable or disable it.
> > The old behavior is disabling it by default. Now you change it to
> > disabling it by default in NO-SRIOV mode, but enabling it in SRIOV mode.
> > What I don't get is the reason.
>
> Please refer to section 4.6.11.3.1 page 180 of the 82599-10-gbe-controller-
> datasheet.pdf
> The last paragraph on page 180 states:
>
> "Queue Drop Enable (PFQDE) - In SR-IO the QDE bit should be set to 1b in the
> PFQDE register for all queues.
> In VMDq mode, the QDE bit should be set to 0b for all queues."
Got it, thanks a lot :)
>
>
> > > > > /* Enable the Tx desc arbiter */
> > > > > reg = IXGBE_READ_REG(hw, IXGBE_RTTDCS); @@ -3378,7
> > > > > +3385,7 @@ ixgbe_vmdq_dcb_hw_tx_config(struct rte_eth_dev *dev,
> > > > > vmdq_tx_conf->nb_queue_pools == ETH_16_POOLS
> > > > ?
> > > > > 0xFFFF : 0xFFFFFFFF);
> > > > >
> > > > > /*Configure general DCB TX parameters*/
> > > > > - ixgbe_dcb_tx_hw_config(hw, dcb_config);
> > > > > + ixgbe_dcb_tx_hw_config(dev, dcb_config);
> > > > > }
> > > > >
> > > > > static void
> > > > > @@ -3661,7 +3668,7 @@ ixgbe_dcb_hw_configure(struct rte_eth_dev
> > > > *dev,
> > > > > /*get DCB TX configuration parameters from
> > > > > rte_eth_conf*/
> > > > > ixgbe_dcb_tx_config(dev, dcb_config);
> > > > > /*Configure general DCB TX parameters*/
> > > > > - ixgbe_dcb_tx_hw_config(hw, dcb_config);
> > > > > + ixgbe_dcb_tx_hw_config(dev, dcb_config);
> > > > > break;
> > > > > default:
> > > > > PMD_INIT_LOG(ERR, "Incorrect DCB TX mode
> > > > configuration"); @@
> > > > > -3810,9 +3817,6 @@ void ixgbe_configure_dcb(struct rte_eth_dev
> > *dev)
> > > > > (dev_conf->rxmode.mq_mode != ETH_MQ_RX_DCB_RSS))
> > > > > return;
> > > > >
> > > > > - if (dev->data->nb_rx_queues != ETH_DCB_NUM_QUEUES)
> > > > > - return;
> > > > I remember it's a limitation of implementation. The reason is the
> > > > resource allocation. Why could we remove it now?
> > >
> > > ETH_DCB_NUM_QUEUES is 128, nb_rx_queues may not be 128.
> > I think it's a limitation to force the queue number to be
> > ETH_DCB_NUM_QUEUES.
> > Just to confirm it, have you try to set rx queue number to something
> > different from 128, like 64, 32...
>
> In my test scenario the nb_rx_queues is 1.
Glad to know that, thanks :)
>
> Regards,
>
> Bernard
