RE: [PATCH v3 2/2] net/ice: fix scalar Tx path segment

["Ye, MingjinX" <mingjinx.ye@intel.com>]

> -----Original Message-----
> From: Zhang, Qi Z <qi.z.zhang@intel.com>
> Sent: 2022年11月11日 13:09
> To: Ye, MingjinX <mingjinx.ye@intel.com>; dev@dpdk.org
> Cc: Yang, Qiming <qiming.yang@intel.com>; stable@dpdk.org; Zhou, YidingX
> <yidingx.zhou@intel.com>; Wu, Jingjing <jingjing.wu@intel.com>; Lu,
> Wenzhuo <wenzhuo.lu@intel.com>; Ferruh Yigit <ferruh.yigit@intel.com>; Li,
> Xiaoyun <xiaoyun.li@intel.com>; Liu, KevinX <kevinx.liu@intel.com>
> Subject: RE: [PATCH v3 2/2] net/ice: fix scalar Tx path segment
> 
> 
> 
> > -----Original Message-----
> > From: Ye, MingjinX <mingjinx.ye@intel.com>
> > Sent: Friday, November 11, 2022 8:04 PM
> > To: dev@dpdk.org
> > Cc: Yang, Qiming <qiming.yang@intel.com>; stable@dpdk.org; Zhou,
> > YidingX <yidingx.zhou@intel.com>; Ye, MingjinX
> > <mingjinx.ye@intel.com>; Zhang, Qi Z <qi.z.zhang@intel.com>; Wu,
> > Jingjing <jingjing.wu@intel.com>; Lu, Wenzhuo <wenzhuo.lu@intel.com>;
> > Ferruh Yigit <ferruh.yigit@intel.com>; Li, Xiaoyun
> > <xiaoyun.li@intel.com>; Liu, KevinX <kevinx.liu@intel.com>
> > Subject: [PATCH v3 2/2] net/ice: fix scalar Tx path segment
> >
> > The scalar Tx path would send empty buffer that causes the Tx queue to
> > overflow.
> >
> > This patch adds the last buffer length judgment in tx_prepare to fix
> > this issue, rte_errno will be set to EINVAL and returned if the last buffer is
> empty.
> >
> > Fixes: 17c7d0f9d6a4 ("net/ice: support basic Rx/Tx")
> > Fixes: ccf33dccf7aa ("net/ice: check illegal packet sizes")
> > Cc: stable@dpdk.org
> >
> > Signed-off-by: Mingjin Ye <mingjinx.ye@intel.com>
> > ---
> >  drivers/net/ice/ice_rxtx.c | 24 ++++++++++++++++++++++++
> >  1 file changed, 24 insertions(+)
> >
> > diff --git a/drivers/net/ice/ice_rxtx.c b/drivers/net/ice/ice_rxtx.c
> > index e6ddd2513d..69358f6a3a 100644
> > --- a/drivers/net/ice/ice_rxtx.c
> > +++ b/drivers/net/ice/ice_rxtx.c
> > @@ -3643,6 +3643,22 @@ ice_set_tx_function_flag(struct rte_eth_dev
> > *dev, struct ice_tx_queue *txq)
> >  #define ICE_MIN_TSO_MSS            64
> >  #define ICE_MAX_TSO_MSS            9728
> >  #define ICE_MAX_TSO_FRAME_SIZE     262144
> > +
> > +/*Check for invalid mbuf*/
> > +static inline uint16_t
> > +ice_check_mbuf(struct rte_mbuf *tx_pkt) {
> 
> Better to name the function to exactly match what it does.
> e.g.: ice_check_emtpy_mbuf
> and also declare it as inline.
will optimize.
> 
> > +	struct rte_mbuf *txd = tx_pkt;
> > +
> > +	while (txd != NULL) {
> > +		if (txd->data_len == 0)
> > +			return -1;
> > +		txd = txd->next;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> >  uint16_t
> >  ice_prep_pkts(__rte_unused void *tx_queue, struct rte_mbuf **tx_pkts,
> >  	      uint16_t nb_pkts)
> > @@ -3653,6 +3669,7 @@ ice_prep_pkts(__rte_unused void *tx_queue,
> > struct rte_mbuf **tx_pkts,
> >  	struct ice_tx_queue *txq = tx_queue;
> >  	struct rte_eth_dev *dev = &rte_eth_devices[txq->port_id];
> >  	uint16_t max_frame_size = dev->data->mtu + ICE_ETH_OVERHEAD;
> > +	uint16_t nb_used;
> >
> >  	for (i = 0; i < nb_pkts; i++) {
> >  		m = tx_pkts[i];
> > @@ -3689,6 +3706,13 @@ ice_prep_pkts(__rte_unused void *tx_queue,
> > struct rte_mbuf **tx_pkts,
> >  			rte_errno = -ret;
> >  			return i;
> >  		}
> > +
> > +		if (!(ol_flags & RTE_MBUF_F_TX_TCP_SEG) &&
> > +			ice_check_mbuf(m)) {
> 
> Why "!(ol_flags & RTE_MBUF_F_TX_TCP_SEG)" is needed here?
> A empty mbuf with TSO enabled is still acceptable?
Should not be expected to be implemented in test-pmd, should detect.
> 
> > +			rte_errno = EINVAL;
> > +			PMD_DRV_LOG(ERR, "INVALID mbuf:	last mbuf
> > data_len=[0]");
> > +			return i;
> > +		}
> >  	}
> >  	return i;
> >  }
> > --
> > 2.34.1