Re: [dpdk-dev] [PATCH v2 07/15] net/mlx5: support tunnel RSS level

["Nélio Laranjeiro" <nelio.laranjeiro@6wind.com>]

On Sat, Apr 14, 2018 at 12:25:12PM +0000, Xueming(Steven) Li wrote:
>[...]
> > > @@ -1211,23 +1322,23 @@ mlx5_flow_convert(struct rte_eth_dev *dev,
> > >  		if (ret)
> > >  			goto exit_free;
> > >  	}
> > > -	if (parser->mark)
> > > -		mlx5_flow_create_flag_mark(parser, parser->mark_id);
> > > -	if (parser->count && parser->create) {
> > > -		mlx5_flow_create_count(dev, parser);
> > > -		if (!parser->cs)
> > > -			goto exit_count_error;
> > > -	}
> > >  	/*
> > >  	 * Last step. Complete missing specification to reach the RSS
> > >  	 * configuration.
> > >  	 */
> > >  	if (!parser->drop)
> > > -		ret = mlx5_flow_convert_rss(parser);
> > > +		ret = mlx5_flow_convert_rss(dev, parser);
> > >  		if (ret)
> > >  			goto exit_free;
> > >  		mlx5_flow_convert_finalise(parser);
> > >  	mlx5_flow_update_priority(dev, parser, attr);
> > > +	if (parser->mark)
> > > +		mlx5_flow_create_flag_mark(parser, parser->mark_id);
> > > +	if (parser->count && parser->create) {
> > > +		mlx5_flow_create_count(dev, parser);
> > > +		if (!parser->cs)
> > > +			goto exit_count_error;
> > > +	}
> > 
> > Why do you need to move this code?
> 
> To avoid counter resource missing if anything wrong in function 
> mlx5_flow_convert_rss().

Why this modification is addressed in this patch, why should it it be in
the patch introducing the mlx5_flow_convert_rss()?

>[...]
> > > @@ -1386,6 +1386,8 @@ mlx5_ind_table_ibv_verify(struct rte_eth_dev *dev)
> > >   *   Number of queues.
> > >   * @param tunnel
> > >   *   Tunnel type.
> > > + * @param rss_level
> > > + *   RSS hash on tunnel level.
> > >   *
> > >   * @return
> > >   *   The Verbs object initialised, NULL otherwise and rte_errno is set.
> > > @@ -1394,13 +1396,17 @@ struct mlx5_hrxq *  mlx5_hrxq_new(struct
> > > rte_eth_dev *dev,
> > >  	      const uint8_t *rss_key, uint32_t rss_key_len,
> > >  	      uint64_t hash_fields,
> > > -	      const uint16_t *queues, uint32_t queues_n, uint32_t tunnel)
> > > +	      const uint16_t *queues, uint32_t queues_n,
> > > +	      uint32_t tunnel, uint32_t rss_level)
> > 
> > tunnel and rss_level seems to be redundant here.
> > 
> > rss_level > 1 is equivalent to tunnel, there is no need to have both.
> 
> There is a case of tunnel and outer rss(1).

Why cannot it be handled by a regular Hash Rx queue, i.e. what is the
benefit of creating a tunnel hash Rx queue to make the same job as a
legacy one?

See below,

> > >  {
> > >  	struct priv *priv = dev->data->dev_private;
> > >  	struct mlx5_hrxq *hrxq;
> > >  	struct mlx5_ind_table_ibv *ind_tbl;
> > >  	struct ibv_qp *qp;
> > >  	int err;
> > > +#ifdef HAVE_IBV_DEVICE_TUNNEL_SUPPORT
> > > +	struct mlx5dv_qp_init_attr qp_init_attr = {0}; #endif
> > >
> > >  	queues_n = hash_fields ? queues_n : 1;
> > >  	ind_tbl = mlx5_ind_table_ibv_get(dev, queues, queues_n); @@ -1410,6
> > > +1416,33 @@ mlx5_hrxq_new(struct rte_eth_dev *dev,
> > >  		rte_errno = ENOMEM;
> > >  		return NULL;
> > >  	}
> > > +#ifdef HAVE_IBV_DEVICE_TUNNEL_SUPPORT
> > > +	if (tunnel) {

Why not: if (rss_level > 1) ?

> > > +		qp_init_attr.comp_mask =
> > > +				MLX5DV_QP_INIT_ATTR_MASK_QP_CREATE_FLAGS;
> > > +		qp_init_attr.create_flags = MLX5DV_QP_CREATE_TUNNEL_OFFLOADS;
> > > +	}
> > > +	qp = mlx5_glue->dv_create_qp(
> > > +		priv->ctx,
> > > +		&(struct ibv_qp_init_attr_ex){
> > > +			.qp_type = IBV_QPT_RAW_PACKET,
> > > +			.comp_mask =
> > > +				IBV_QP_INIT_ATTR_PD |
> > > +				IBV_QP_INIT_ATTR_IND_TABLE |
> > > +				IBV_QP_INIT_ATTR_RX_HASH,
> > > +			.rx_hash_conf = (struct ibv_rx_hash_conf){
> > > +				.rx_hash_function = IBV_RX_HASH_FUNC_TOEPLITZ,
> > > +				.rx_hash_key_len = rss_key_len,
> > > +				.rx_hash_key = (void *)(uintptr_t)rss_key,
> > > +				.rx_hash_fields_mask = hash_fields |
> > > +					(tunnel && rss_level ?
> > > +					(uint32_t)IBV_RX_HASH_INNER : 0),
>[...]

 .rx_hash_fields_mask = hash_fields |
 (rss_level > 1) ?
 (uint32_t)IBV_RX_HASH_INNER : 0),

Thanks,

-- 
Nélio Laranjeiro
6WIND