Re: [dpdk-dev] [PATCH] net/ixgbevf: remove MTU setting limitation

["Zhao1, Wei" <wei.zhao1@intel.com>]

Hi, 

> -----Original Message-----
> From: David Harton (dharton) [mailto:dharton@cisco.com]
> Sent: Wednesday, April 3, 2019 8:36 PM
> To: Zhao1, Wei <wei.zhao1@intel.com>; dev@dpdk.org
> Cc: Lu, Wenzhuo <wenzhuo.lu@intel.com>; Ananyev, Konstantin
> <konstantin.ananyev@intel.com>; Zhang, Qi Z <qi.z.zhang@intel.com>
> Subject: RE: [dpdk-dev] [PATCH] net/ixgbevf: remove MTU setting limitation
> 
> Hi,
> 
> > -----Original Message-----
> > From: Zhao1, Wei <wei.zhao1@intel.com>
> > Sent: Tuesday, April 02, 2019 10:26 PM
> > To: David Harton (dharton) <dharton@cisco.com>; dev@dpdk.org
> > Cc: Lu, Wenzhuo <wenzhuo.lu@intel.com>; Ananyev, Konstantin
> > <konstantin.ananyev@intel.com>; Zhang, Qi Z <qi.z.zhang@intel.com>
> > Subject: RE: [dpdk-dev] [PATCH] net/ixgbevf: remove MTU setting
> > limitation
> >
> > HI,
> >
> > Why not add some more code
> > "
> > 	if (rx_conf->offloads & DEV_RX_OFFLOAD_SCATTER)
> > 		dev->data->scattered_rx = 1;
> > "
> >
> > Into ixgbevf_dev_rx_init() to enable scatter mode when start device?
> 
> I don't think it's necessary is it?
> 
> Doesn't this code in ixgbevf_dev_rx_init() handle it?


Sorry, miss that code.

> 
>         if (rxmode->offloads & DEV_RX_OFFLOAD_SCATTER ||
>             /* It adds dual VLAN length for supporting dual VLAN */
>             (rxmode->max_rx_pkt_len +
>                 2 * IXGBE_VLAN_TAG_SIZE) > buf_size) {
>             if (!dev->data->scattered_rx)
>                 PMD_INIT_LOG(DEBUG, "forcing scatter mode");
>             dev->data->scattered_rx = 1;
>         }
> 
> Regards,
> Dave
> 
> >
> >
> > Reviewed-by: Wei Zhao <wei.zhao1@intel.com>
> >
> >
> > > -----Original Message-----
> > > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of David Harton
> > > Sent: Wednesday, April 3, 2019 9:19 AM
> > > To: dev@dpdk.org
> > > Cc: Lu, Wenzhuo <wenzhuo.lu@intel.com>; Ananyev, Konstantin
> > > <konstantin.ananyev@intel.com>; David Harton <dharton@cisco.com>
> > > Subject: [dpdk-dev] [PATCH] net/ixgbevf: remove MTU setting
> > > limitation
> > >
> > > Currently, if requested MTU is bigger than mbuf size and scattered
> > > receive is not enabled, setting MTU to that value fails.
> > >
> > > This patch allows setting this special MTU when device is stopped,
> > > because scattered_rx will be re-configured during next port start
> > > and driver may enable scattered receive according new MTU value.
> > >
> > > After this patch, driver may select different receive function
> > > automatically after MTU set, according MTU values selected.
> > >
> > > Signed-off-by: David Harton <dharton@cisco.com>
> > > ---
> > >  drivers/net/ixgbe/ixgbe_ethdev.c | 12 +++++++-----
> > >  1 file changed, 7 insertions(+), 5 deletions(-)
> > >
> > > diff --git a/drivers/net/ixgbe/ixgbe_ethdev.c
> > > b/drivers/net/ixgbe/ixgbe_ethdev.c
> > > index feec85634..0b962c8db 100644
> > > --- a/drivers/net/ixgbe/ixgbe_ethdev.c
> > > +++ b/drivers/net/ixgbe/ixgbe_ethdev.c
> > > @@ -6346,20 +6346,22 @@ ixgbevf_dev_set_mtu(struct rte_eth_dev
> *dev,
> > > uint16_t mtu)  {
> > >  	struct ixgbe_hw *hw;
> > >  	uint32_t max_frame = mtu + IXGBE_ETH_OVERHEAD;
> > > -	struct rte_eth_rxmode *rx_conf = &dev->data->dev_conf.rxmode;
> > > +	struct rte_eth_dev_data *dev_data = dev->data;
> > >
> > >  	hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);
> > >
> > >  	if ((mtu < ETHER_MIN_MTU) || (max_frame >
> > > ETHER_MAX_JUMBO_FRAME_LEN))
> > >  		return -EINVAL;
> > >
> > > -	/* refuse mtu that requires the support of scattered packets when
> > > this
> > > -	 * feature has not been enabled before.
> > > +	/* If device is started, refuse mtu that requires the support of
> > > +	 * scattered packets when this feature has not been enabled before.
> > >  	 */
> > > -	if (!(rx_conf->offloads & DEV_RX_OFFLOAD_SCATTER) &&
> > > +	if (dev_data->dev_started && !dev_data->scattered_rx &&
> > >  	    (max_frame + 2 * IXGBE_VLAN_TAG_SIZE >
> > > -	     dev->data->min_rx_buf_size - RTE_PKTMBUF_HEADROOM))
> > > +	     dev->data->min_rx_buf_size - RTE_PKTMBUF_HEADROOM)) {
> > > +		PMD_INIT_LOG(ERR, "Stop port first.");
> > >  		return -EINVAL;
> > > +	}
> > >
> > >  	/*
> > >  	 * When supported by the underlying PF driver, use the
> > > IXGBE_VF_SET_MTU
> > > --
> > > 2.19.1