Re: [dpdk-dev] [PATCH] app/testpmd: fix DCB config issue on ixgbe

["Iremonger, Bernard" <bernard.iremonger@intel.com>]

Hi Wenzhuo,

<snip>

> > Subject: [dpdk-dev] [PATCH] app/testpmd: fix DCB config issue on ixgbe
> >
> > An issue is found that DCB cannot be configured on ixgbe NICs. It's
> > said the TX queue number is not right.
> > On ixgbe the max TX queue number is not fixed, it depends on the
> > multi- queue mode.
> >
> > This patch adds the device configuration before getting info in the
> > DCB configuration process. So the right info can be got depending on
> > the configuration.
> >
> > Fixes: 96c0450dff86 (ixgbe: fix dropping packets from unsupported Tx
> > queues)

As the fix in this patch is to testpmd, I don't think the fixes line is correct.

> > Signed-off-by: Wenzhuo Lu <wenzhuo.lu@intel.com>
> > ---
> >  app/test-pmd/testpmd.c | 39 +++++++++++++++++++++------------------
> >  1 file changed, 21 insertions(+), 18 deletions(-)
> >
> > diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c index
> > 1428974..ba41bea 100644
> > --- a/app/test-pmd/testpmd.c
> > +++ b/app/test-pmd/testpmd.c
> > @@ -1962,17 +1962,30 @@ init_port_dcb_config(portid_t pid,
> >  		     uint8_t pfc_en)
> >  {
> >  	struct rte_eth_conf port_conf;
> > -	struct rte_eth_dev_info dev_info;
> >  	struct rte_port *rte_port;
> >  	int retval;
> >  	uint16_t i;
> >
> > -	rte_eth_dev_info_get(pid, &dev_info);
> > +	rte_port = &ports[pid];
> > +
> > +	memset(&port_conf, 0, sizeof(struct rte_eth_conf));
> > +	/* Enter DCB configuration status */
> > +	dcb_config = 1;
> > +
> > +	/*set configuration of DCB in vt mode and DCB in non-vt mode*/
> > +	retval = get_eth_dcb_conf(&port_conf, dcb_mode, num_tcs,
> > pfc_en);
> > +	if (retval < 0)
> > +		return retval;
> > +	port_conf.rxmode.hw_vlan_filter = 1;
> > +
> > +	(void)rte_eth_dev_configure(pid, 0, 0, &port_conf);
> 
> The return value of rte_eth_dev_configure() should be checked.
> Calling rte_eth_dev_configure() with  parameters nb_rx_q and nb_tx_q
> equal to 0 returns -EINVAL, and does nothing.
> Should the values of nb_rx_q and nb_tx_q be non zero?

The call to rte_eth_dev_configure() may not be necessary, as it is also called when the port is started.
 
> > +	rte_eth_dev_info_get(pid, &rte_port->dev_info);
> >
> >  	/* If dev_info.vmdq_pool_base is greater than 0,
> >  	 * the queue id of vmdq pools is started after pf queues.
> >  	 */
> > -	if (dcb_mode == DCB_VT_ENABLED && dev_info.vmdq_pool_base >
> > 0) {
> > +	if (dcb_mode == DCB_VT_ENABLED &&
> > +	    rte_port->dev_info.vmdq_pool_base > 0) {
> >  		printf("VMDQ_DCB multi-queue mode is nonsensical"
> >  			" for port %d.", pid);
> >  		return -1;
> > @@ -1982,13 +1995,13 @@ init_port_dcb_config(portid_t pid,
> >  	 * and has the same number of rxq and txq in dcb mode
> >  	 */
> >  	if (dcb_mode == DCB_VT_ENABLED) {
> > -		nb_rxq = dev_info.max_rx_queues;
> > -		nb_txq = dev_info.max_tx_queues;
> > +		nb_rxq = rte_port->dev_info.max_rx_queues;
> > +		nb_txq = rte_port->dev_info.max_tx_queues;

If nb_rxq and nb_txq are set to max_rx_queues and max_tx_queues respectively, there is a failure when the port is started in ixgbe_check_mq_mode() at line 1990 in ixgbe_ethdev.c.
SRIOV is active, nb_rx_q=128 nb_tx_q=128 queue number must be less than or equal to 1.

nb_rxq and nb_txq are equal to 1 at this point, if they are not changed, port start completes successfully.
 

> >  	} else {
> >  		/*if vt is disabled, use all pf queues */
> > -		if (dev_info.vmdq_pool_base == 0) {
> > -			nb_rxq = dev_info.max_rx_queues;
> > -			nb_txq = dev_info.max_tx_queues;
> > +		if (rte_port->dev_info.vmdq_pool_base == 0) {
> > +			nb_rxq = rte_port->dev_info.max_rx_queues;
> > +			nb_txq = rte_port->dev_info.max_tx_queues;
> >  		} else {
> >  			nb_rxq = (queueid_t)num_tcs;
> >  			nb_txq = (queueid_t)num_tcs;
> > @@ -1997,16 +2010,6 @@ init_port_dcb_config(portid_t pid,
> >  	}
> >  	rx_free_thresh = 64;
> >
> > -	memset(&port_conf, 0, sizeof(struct rte_eth_conf));
> > -	/* Enter DCB configuration status */
> > -	dcb_config = 1;
> > -
> > -	/*set configuration of DCB in vt mode and DCB in non-vt mode*/
> > -	retval = get_eth_dcb_conf(&port_conf, dcb_mode, num_tcs,
> > pfc_en);
> > -	if (retval < 0)
> > -		return retval;
> > -
> > -	rte_port = &ports[pid];
> >  	memcpy(&rte_port->dev_conf, &port_conf, sizeof(struct
> > rte_eth_conf));
> >
> >  	rxtx_port_config(rte_port);
> > --
> > 1.9.3
Regards,

Bernard