Re: [dpdk-dev] [PATCH v4] net/ixgbe: fix l3fwd start failed on VF

["Zhang, Helin" <helin.zhang@intel.com>]

> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Dai, Wei
> Sent: Friday, January 12, 2018 11:04 AM
> To: Wu, Yanglong; dev@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH v4] net/ixgbe: fix l3fwd start failed on VF
> 
> > -----Original Message-----
> > From: Wu, Yanglong
> > Sent: Friday, January 12, 2018 10:38 AM
> > To: Dai, Wei <wei.dai@intel.com>; dev@dpdk.org
> > Subject: RE: [dpdk-dev] [PATCH v4] net/ixgbe: fix l3fwd start failed
> > on VF
> >
> > Hi
> > After confirm with Daiwei and according to the data sheet,
> > RTE_ETH_DEV_SRIOV(dev).nb_q_per_pool is the Max number of queue can
> be
> > used in VF, that would be assigned as IXGBE_MAX_RX_QUEUE_NUM /
> > RTE_ETH_DEV_SRIOV(dev).active, so that assigning nb_q_per_pool  as 1
> > when PF is in ETH_MQ_RX_NONE, which will make VF can just use only 1
> > queue, is not right. So this patch is right.
> >
> > Yanglong
> >
> > -----Original Message-----
> > From: Wu, Yanglong
> > Sent: Thursday, January 11, 2018 11:29 PM
> > To: Wu, Yanglong <yanglong.wu@intel.com>; Dai, Wei
> > <wei.dai@intel.com>; dev@dpdk.org
> > Subject: RE: [dpdk-dev] [PATCH v4] net/ixgbe: fix l3fwd start failed
> > on VF
> >
> > Hi daiwei:
> >
> > After I double checked with this bug, the problem can be described as follow:
> > When we start PF using testpmd like this: testpmd -c 0x3 -n 4
> > --socket-mem=1024,1024 --file-prefix=pf -w 0000:05:00.0 -w
> > 0000:05:00.1
> > -- -i. The number of queue signed to each port would be 1 and the
> > rxmode.mq_mode of ixgbe eth_dev  would be set as  ETH_MQ_RX_NONE.
> > And this config info is make sense, so until now there is no problem, right?
> > And according to the code:
> > 		case ETH_MQ_RX_NONE:
> > >  			/* if nothing mq mode configure, use default scheme
> */
> > >  			dev->data->dev_conf.rxmode.mq_mode =
> > ETH_MQ_RX_VMDQ_ONLY;
> > > -			if (RTE_ETH_DEV_SRIOV(dev).nb_q_per_pool > 1)
> > > -				RTE_ETH_DEV_SRIOV(dev).nb_q_per_pool = 1;
> > >  			break;
> > The nb_q_per_pool of (RTE_ETH_DEV_SRIOV(dev).nb_q_per_pool  would be
> > set as 1, that means for VF the number of max queue can be used would
> > be only 1.
> >
> > And next we start VF using l3fwd:
> > l3fwd/build/l3fwd -c 0xc0000 -n 4 -w 0000:05:10.0 -w 0000:05:10.1 --
> > -p 0x3 --config '(0,0,18),(1,0,19)' --parse-ptype The number of rx_q
> > equal to 1 and there is no problem. But, in l3fwd, the number of tx_q
> > would equal to the number of core used in l3fwd, so here number of
> > tx_q equal to 2 but as described above, the max number of queue can be
> used in VF is just only 1.
> > So there is problem and l3fwd will check failed.
> >
> >
> > So there is two ways to fix this bug, the first is using this patch,
> > don't assign RTE_ETH_DEV_SRIOV(dev).nb_q_per_pool as 1 when mq_mode
> =
> > ETH_MQ_RX_VMDQ_ONLY.
> > And the second is that the number of tx_q would not assigned as the
> > number of cores used in l3fwd.
> >
> > Which one do you think is make sense?
> >
> >
> >
> >
> > Yanglong
> >
> >
> > -----Original Message-----
> > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Wu, Yanglong
> > Sent: Thursday, January 11, 2018 6:30 PM
> > To: Dai, Wei <wei.dai@intel.com>; dev@dpdk.org
> > Subject: Re: [dpdk-dev] [PATCH v4] net/ixgbe: fix l3fwd start failed
> > on VF
> >
> > Yes, this problem is caused by PF passing a wrong number of queue to
> > VF. So basically, I removed  model check of "case ETH_MQ_RX_NONE". It
> > seem right after I do that but I'am also not very sure the changing is
> > really right. So thank to your comments, I will redebug this problem.
> >
> > -----Original Message-----
> > From: Dai, Wei
> > Sent: Thursday, January 11, 2018 5:48 PM
> > To: Wu, Yanglong <yanglong.wu@intel.com>; dev@dpdk.org; Yang, Zhiyong
> > <zhiyong.yang@intel.com>
> > Cc: Wu, Yanglong <yanglong.wu@intel.com>
> > Subject: RE: [dpdk-dev] [PATCH v4] net/ixgbe: fix l3fwd start failed
> > on VF
> >
> > According to 82599 datasheet, VF working mode is controlled by its host PF.
> > If VF is working in RSS or DCB mode, it can use more than 1 queues.
> > That also means its host PF should enable RSS or DCB.
> > The PF Rx mode can be ETH_MQ_RX_VMDQ_RSS or
> ETH_MQ_RX_VMDQ_DCB.
> > So I think that DPDK app with PF cause this issue, not ixgbe PMD itself.
> >
> > By the way, you can reply your patch mail to provide more info about
> > how You reproduce this issue to easy others' reviewing and testing your
> patch.
> >
> > Thanks
> >
> > > -----Original Message-----
> > > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Yanglong Wu
> > > Sent: Tuesday, January 9, 2018 2:32 PM
> > > To: dev@dpdk.org; Yang, Zhiyong <zhiyong.yang@intel.com>
> > > Cc: Wu, Yanglong <yanglong.wu@intel.com>
> > > Subject: [dpdk-dev] [PATCH v4] net/ixgbe: fix l3fwd start failed on
> > > VF
> > >
> > > VF can't run in multi queue mode, if nb_q_per_pool was set as 1.
> > > Nb_q_per_pool is passed through to max_rx_q and max_tx_q in VF.
> > > So if nb_q_per_pool is equal to 1, max_rx_q and max_tx_q can't be
> > > more than 1 and VF multi queue mode will fail.
> > >
> > > Fixes: 27b609cbd1c6 (ethdev: move the multi-queue mode check)
> > >
> > > Signed-off-by: Yanglong Wu <yanglong.wu@intel.com>
> Acked-by: Wei Dai <wei.dai@intel.com>
Applied to dpdk-next-net-intel, with minor commit log changes. Thanks!

/Helin