Re: [dpdk-dev] [PATCH v2 05/15] net/mlx5: support tunnel inner checksum offloads

["Xueming(Steven) Li" <xuemingl@mellanox.com>]

Hi Nelio,

> -----Original Message-----
> From: Nélio Laranjeiro <nelio.laranjeiro@6wind.com>
> Sent: Tuesday, April 10, 2018 11:28 PM
> To: Xueming(Steven) Li <xuemingl@mellanox.com>
> Cc: Shahaf Shuler <shahafs@mellanox.com>; dev@dpdk.org
> Subject: Re: [PATCH v2 05/15] net/mlx5: support tunnel inner checksum
> offloads
> 
> On Tue, Apr 10, 2018 at 09:34:05PM +0800, Xueming Li wrote:
> > This patch support tunnel inner checksum offloads. By creating tunnel
> > flow, once tunnel packet type(RTE_PTYPE_TUNNEL_xxx) identified,
> 
> Where is the code creating the tunnel flow?

Literal issue, I'll remove "By creating tunnel flow". Also, this patch set
actually a cleanup of tunnel checksum, I'll update.

> 
> > PKT_RX_IP_CKSUM_XXX and PKT_RX_L4_CKSUM_XXX represent checksum result
> > of inner headers, outer L3 and L4 header checksum are always valid as
> > soon as tunnel identified. If no tunnel identified,
> > PKT_RX_IP_CKSUM_XXX and PKT_RX_L4_CKSUM_XXX represent checksum result
> > of outer L3 and L4 headers.
> >
> > Signed-off-by: Xueming Li <xuemingl@mellanox.com>
> > ---
> >  drivers/net/mlx5/mlx5_flow.c |  7 +++++--
> > drivers/net/mlx5/mlx5_rxq.c  |  2 --  drivers/net/mlx5/mlx5_rxtx.c |
> > 18 ++++--------------  drivers/net/mlx5/mlx5_rxtx.h |  1 -
> >  4 files changed, 9 insertions(+), 19 deletions(-)
> >
> > diff --git a/drivers/net/mlx5/mlx5_flow.c
> > b/drivers/net/mlx5/mlx5_flow.c index 65d7a9b62..b3ad6dc85 100644
> > --- a/drivers/net/mlx5/mlx5_flow.c
> > +++ b/drivers/net/mlx5/mlx5_flow.c
> > @@ -829,6 +829,8 @@ mlx5_flow_convert_actions(struct rte_eth_dev *dev,
> >  /**
> >   * Validate items.
> >   *
> > + * @param dev
> > + *   Pointer to Ethernet device.
> >   * @param[in] items
> >   *   Pattern specification (list terminated by the END pattern item).
> >   * @param[out] error
> > @@ -840,7 +842,8 @@ mlx5_flow_convert_actions(struct rte_eth_dev *dev,
> >   *   0 on success, a negative errno value otherwise and rte_errno is
> set.
> >   */
> >  static int
> > -mlx5_flow_convert_items_validate(const struct rte_flow_item items[],
> > +mlx5_flow_convert_items_validate(struct rte_eth_dev *dev __rte_unused,
> > +				 const struct rte_flow_item items[],
> >  				 struct rte_flow_error *error,
> >  				 struct mlx5_flow_parse *parser)
> >  {
> > @@ -1146,7 +1149,7 @@ mlx5_flow_convert(struct rte_eth_dev *dev,
> >  	ret = mlx5_flow_convert_actions(dev, actions, error, parser);
> >  	if (ret)
> >  		return ret;
> > -	ret = mlx5_flow_convert_items_validate(items, error, parser);
> > +	ret = mlx5_flow_convert_items_validate(dev, items, error, parser);
> >  	if (ret)
> >  		return ret;
> >  	mlx5_flow_convert_finalise(parser);
> 
> I don't understand the necessity of the two hunks above.
> 
> > diff --git a/drivers/net/mlx5/mlx5_rxq.c b/drivers/net/mlx5/mlx5_rxq.c
> > index 351acfc0f..073732e16 100644
> > --- a/drivers/net/mlx5/mlx5_rxq.c
> > +++ b/drivers/net/mlx5/mlx5_rxq.c
> > @@ -1045,8 +1045,6 @@ mlx5_rxq_new(struct rte_eth_dev *dev, uint16_t idx,
> uint16_t desc,
> >  	}
> >  	/* Toggle RX checksum offload if hardware supports it. */
> >  	tmpl->rxq.csum = !!(conf->offloads & DEV_RX_OFFLOAD_CHECKSUM);
> > -	tmpl->rxq.csum_l2tun = (!!(conf->offloads & DEV_RX_OFFLOAD_CHECKSUM)
> &&
> > -				priv->config.tunnel_en);
> >  	tmpl->rxq.hw_timestamp = !!(conf->offloads &
> DEV_RX_OFFLOAD_TIMESTAMP);
> >  	/* Configure VLAN stripping. */
> >  	tmpl->rxq.vlan_strip = !!(conf->offloads &
> > DEV_RX_OFFLOAD_VLAN_STRIP); diff --git a/drivers/net/mlx5/mlx5_rxtx.c
> > b/drivers/net/mlx5/mlx5_rxtx.c index d061dfc8a..285b2dbf0 100644
> > --- a/drivers/net/mlx5/mlx5_rxtx.c
> > +++ b/drivers/net/mlx5/mlx5_rxtx.c
> > @@ -41,7 +41,7 @@ mlx5_rx_poll_len(struct mlx5_rxq_data *rxq, volatile
> struct mlx5_cqe *cqe,
> >  		 uint16_t cqe_cnt, uint32_t *rss_hash);
> >
> >  static __rte_always_inline uint32_t
> > -rxq_cq_to_ol_flags(struct mlx5_rxq_data *rxq, volatile struct
> > mlx5_cqe *cqe);
> > +rxq_cq_to_ol_flags(volatile struct mlx5_cqe *cqe);
> >
> >  uint32_t mlx5_ptype_table[] __rte_cache_aligned = {
> >  	[0xff] = RTE_PTYPE_ALL_MASK, /* Last entry for errored packet. */ @@
> > -1728,8 +1728,6 @@ mlx5_rx_poll_len(struct mlx5_rxq_data *rxq,
> > volatile struct mlx5_cqe *cqe,
> >  /**
> >   * Translate RX completion flags to offload flags.
> >   *
> > - * @param[in] rxq
> > - *   Pointer to RX queue structure.
> >   * @param[in] cqe
> >   *   Pointer to CQE.
> >   *
> > @@ -1737,7 +1735,7 @@ mlx5_rx_poll_len(struct mlx5_rxq_data *rxq,
> volatile struct mlx5_cqe *cqe,
> >   *   Offload flags (ol_flags) for struct rte_mbuf.
> >   */
> >  static inline uint32_t
> > -rxq_cq_to_ol_flags(struct mlx5_rxq_data *rxq, volatile struct
> > mlx5_cqe *cqe)
> > +rxq_cq_to_ol_flags(volatile struct mlx5_cqe *cqe)
> >  {
> >  	uint32_t ol_flags = 0;
> >  	uint16_t flags = rte_be_to_cpu_16(cqe->hdr_type_etc);
> > @@ -1749,14 +1747,6 @@ rxq_cq_to_ol_flags(struct mlx5_rxq_data *rxq,
> volatile struct mlx5_cqe *cqe)
> >  		TRANSPOSE(flags,
> >  			  MLX5_CQE_RX_L4_HDR_VALID,
> >  			  PKT_RX_L4_CKSUM_GOOD);
> > -	if ((cqe->pkt_info & MLX5_CQE_RX_TUNNEL_PACKET) && (rxq->csum_l2tun))
> > -		ol_flags |=
> > -			TRANSPOSE(flags,
> > -				  MLX5_CQE_RX_L3_HDR_VALID,
> > -				  PKT_RX_IP_CKSUM_GOOD) |
> > -			TRANSPOSE(flags,
> > -				  MLX5_CQE_RX_L4_HDR_VALID,
> > -				  PKT_RX_L4_CKSUM_GOOD);
> >  	return ol_flags;
> >  }
> >
> > @@ -1855,8 +1845,8 @@ mlx5_rx_burst(void *dpdk_rxq, struct rte_mbuf
> **pkts, uint16_t pkts_n)
> >  						mlx5_flow_mark_get(mark);
> >  				}
> >  			}
> > -			if (rxq->csum | rxq->csum_l2tun)
> > -				pkt->ol_flags |= rxq_cq_to_ol_flags(rxq, cqe);
> > +			if (rxq->csum)
> > +				pkt->ol_flags |= rxq_cq_to_ol_flags(cqe);
> >  			if (rxq->vlan_strip &&
> >  			    (cqe->hdr_type_etc &
> >  			     rte_cpu_to_be_16(MLX5_CQE_VLAN_STRIPPED))) { diff -
> -git
> > a/drivers/net/mlx5/mlx5_rxtx.h b/drivers/net/mlx5/mlx5_rxtx.h index
> > 6866f6818..d35605b55 100644
> > --- a/drivers/net/mlx5/mlx5_rxtx.h
> > +++ b/drivers/net/mlx5/mlx5_rxtx.h
> > @@ -77,7 +77,6 @@ struct rxq_zip {
> >  /* RX queue descriptor. */
> >  struct mlx5_rxq_data {
> >  	unsigned int csum:1; /* Enable checksum offloading. */
> > -	unsigned int csum_l2tun:1; /* Same for L2 tunnels. */
> >  	unsigned int hw_timestamp:1; /* Enable HW timestamp. */
> >  	unsigned int vlan_strip:1; /* Enable VLAN stripping. */
> >  	unsigned int crc_present:1; /* CRC must be subtracted. */
> > --
> > 2.13.3
> 
> This last part seems to introduce a regression by removing the support for
> the tunnel checksum offload.

Csum_l2tun is unused, checksum for tunnel and normal packet can't be enabled
separately, so only leave csum field. The code that using csum_l2tun is 
duplicated code, that's why I removed it in rxq_cq_to_ol_flags().

> 
> Seems this patch is incomplete or wrongly explained.
> 
> --
> Nélio Laranjeiro
> 6WIND