Re: [dpdk-dev] [PATCH] net/mlx5: fix E-Switch flow without port item

[Yongseok Koh <yskoh@mellanox.com>]

On Tue, Apr 23, 2019 at 11:19:16AM +0000, Ori Kam wrote:
> When creating a flow rule without the port_id pattern item, always the
> PF was selected.
> 
> This commit fixes this issue, if no port_id pattern item is available
> then we use the port that the flow was created on as source port.
> 
> Fixes: 822fb3195348 ("net/mlx5: add port id item to Direct Verbs")
> 
> Signed-off-by: Ori Kam <orika@mellanox.com>
> ---
>  drivers/net/mlx5/mlx5_flow_dv.c | 30 +++++++++++++++---------------
>  1 file changed, 15 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/net/mlx5/mlx5_flow_dv.c b/drivers/net/mlx5/mlx5_flow_dv.c
> index c2a2fc6..d17adbe 100644
> --- a/drivers/net/mlx5/mlx5_flow_dv.c
> +++ b/drivers/net/mlx5/mlx5_flow_dv.c
> @@ -3623,6 +3623,8 @@ struct field_modify_info modify_tcp[] = {
>  	union flow_dv_attr flow_attr = { .attr = 0 };
>  	struct mlx5_flow_dv_tag_resource tag_resource;
>  	uint32_t modify_action_position = UINT32_MAX;
> +	void *match_mask = matcher.mask.buf;
> +	void *match_value = dev_flow->dv.value.buf;
>  
>  	flow->group = attr->group;
>  	if (attr->transfer)
> @@ -3895,23 +3897,8 @@ struct field_modify_info modify_tcp[] = {
>  	}
>  	dev_flow->dv.actions_n = actions_n;
>  	flow->actions = action_flags;
> -	if (attr->ingress && !attr->transfer &&
> -	    (priv->representor || priv->master)) {
> -		/* It was validated - we support unidirection flows only. */
> -		assert(!attr->egress);
> -		/*
> -		 * Add matching on source vport index only
> -		 * for ingress rules in E-Switch configurations.
> -		 */
> -		flow_dv_translate_item_source_vport(matcher.mask.buf,
> -						    dev_flow->dv.value.buf,
> -						    priv->vport_id,
> -						    0xffff);
> -	}
>  	for (; items->type != RTE_FLOW_ITEM_TYPE_END; items++) {
>  		int tunnel = !!(item_flags & MLX5_FLOW_LAYER_TUNNEL);
> -		void *match_mask = matcher.mask.buf;
> -		void *match_value = dev_flow->dv.value.buf;
>  
>  		switch (items->type) {
>  		case RTE_FLOW_ITEM_TYPE_PORT_ID:
> @@ -4018,6 +4005,19 @@ struct field_modify_info modify_tcp[] = {
>  		}
>  		item_flags |= last_item;
>  	}
> +	if (((attr->ingress && !attr->transfer) ||
> +	     (attr->transfer && !(item_flags & MLX5_FLOW_ITEM_PORT_ID))) &&
> +	    (priv->representor || priv->master)) {

From the validations, I could figure out
- Either ingress (I) or egress (E) must be specified
- Transfer (T) can't be egress
- Port ID (P) is valid only if transfer (T) is specified.

(!T and I) or (T and !P)
= (I - T) + (T - P)
= I - P

So, this condition is equivalent to 
	if (attr->ingress && !!(item_flags & MLX5_FLOW_ITEM_PORT_ID) &&
	    (priv->representor || priv->master)) {
		...
	}

Right?

If agreed, please add comment properly.

> +		/* It was validated - we support unidirection flows only. */
> +		assert(!attr->egress);

This comment and assert are there to mention ingress and egress are exclusive.
Is it still relevant? Did you also test the patch with enabling DEBUG?

> +		/*
> +		 * Add matching on source vport index only
> +		 * for ingress rules in E-Switch configurations.
> +		 */

Please make this comment appropriate as well.

Thanks,
Yongseok

> +		if (flow_dv_translate_item_port_id(dev, match_mask,
> +						   match_value, NULL))
> +			return -rte_errno;
> +	}
>  	assert(!flow_dv_check_valid_spec(matcher.mask.buf,
>  					 dev_flow->dv.value.buf));
>  	dev_flow->layers = item_flags;
> -- 
> 1.8.3.1
>