Re: [dpdk-dev] [PATCH v2] app/testpmd: fix set Rx offloads RSS hash off

["Wang, Jie1X" <jie1x.wang@intel.com>]

> -----Original Message-----
> From: Yigit, Ferruh <ferruh.yigit@intel.com>
> Sent: Saturday, November 6, 2021 12:24 AM
> To: Wang, Jie1X <jie1x.wang@intel.com>; dev@dpdk.org
> Cc: Zhang, Yuying <yuying.zhang@intel.com>; Li, Xiaoyun
> <xiaoyun.li@intel.com>; Yang, SteveX <stevex.yang@intel.com>; Guo, Junfeng
> <junfeng.guo@intel.com>; Zhang, Qi Z <qi.z.zhang@intel.com>
> Subject: Re: [dpdk-dev] [PATCH v2] app/testpmd: fix set Rx offloads RSS hash off
> 
> On 11/4/2021 9:29 AM, Jie Wang wrote:
> > When we set Rx offloads RSS hash off in cmdline, then we start port,
> > if dev->data->dev_conf.rxmode.mq_mode RSS enable(multiple queues
> > mode), it will load RSS hash in driver and sync to port.
> >
> > After setting Rx offloads RSS hash off, this patch removes
> > RTE_ETH_MQ_RX_RSS in port->dev_conf.rxmode.mq_mode to fix this issue.
> >
> > And after setting Rx offloads RSS hash on, this patch also adds
> > RTE_ETH_MQ_RX_RSS in port->dev_conf.rxmode.mq_mode.
> >
> > Fixes: c73a9071877a ("app/testpmd: add commands to test new offload
> > API")
> >
> > Signed-off-by: Jie Wang <jie1x.wang@intel.com>
> > ---
> >   app/test-pmd/cmdline.c | 6 ++++++
> >   1 file changed, 6 insertions(+)
> >
> > diff --git a/app/test-pmd/cmdline.c b/app/test-pmd/cmdline.c index
> > d08a1c9777..f8277e4443 100644
> > --- a/app/test-pmd/cmdline.c
> > +++ b/app/test-pmd/cmdline.c
> > @@ -16176,10 +16176,16 @@ cmd_config_per_port_rx_offload_parsed(void
> *parsed_result,
> >   		port->dev_conf.rxmode.offloads |= single_offload;
> >   		for (q = 0; q < nb_rx_queues; q++)
> >   			port->rx_conf[q].offloads |= single_offload;
> > +
> > +		if (single_offload & 0x80000)
> 
> I don't why you used immediate value, but you mean
> 'RTE_ETH_RX_OFFLOAD_RSS_HASH' here.
> 

I will update it in next version.

> > +			port->dev_conf.rxmode.mq_mode |=
> RTE_ETH_MQ_RX_RSS;
> 
> Why enabling RSS when 'RSS HASH' offload is enabled? In this case if RSS is
> disabled I think it should fail.
> 
> Can you please describe again what problem you are solving?
> 

If 'RSS HASH' offload is disabled in the first, the mq_mode RSS is disabled.
Then 'RSS HASH' offload is enabled in the second, so that we should enable RSS here.

> >   	} else {
> >   		port->dev_conf.rxmode.offloads &= ~single_offload;
> >   		for (q = 0; q < nb_rx_queues; q++)
> >   			port->rx_conf[q].offloads &= ~single_offload;
> > +
> > +		if (single_offload & 0x80000)
> > +			port->dev_conf.rxmode.mq_mode &=
> ~RTE_ETH_MQ_RX_RSS;

When 'RSS HASH' offload is disabled, that mq_mode RSS should be disabled too. So that it will not enable 'RSS HASH' offload in driver.

> >   	}
> >
> >   	cmd_reconfig_device_queue(port_id, 1, 1);
> >