[v2] net/mlx5: check the reg available for metadata action

  From: Tonghao Zhang <xiangxia.m.yue@gmail.com>

If user don't set the dv_xmeta_en to 1 or 2,
in the flow_dv_convert_action_set_meta function:
* flow_dv_get_metadata_reg may return the REG_NONE,
  when MLX5_METADATA_FDB enabled for metadata set
  action.
* reg_to_field(REG_NONE) return MLX5_MODI_OUT_NONE
  which is invalid.

The rdma-core calltrace:
  dr_action_create_modify_action
  dr_actions_convert_modify_header
  dr_action_modify_sw_to_hw
  dr_action_modify_sw_to_hw_set
  dr_ste_get_modify_hdr_hw_field

sw_field [MLX5_MODI_OUT_NONE 4095]
should not > ste_ctx->modify_hdr_field_arr_sz [92]

As doc[1] says:
| dv_xmeta_en 0, this is default value, defines the legacy mode,
| the MARK and META related actions and items operate only within
| NIC Tx and NIC Rx steering domains, no MARK and META information
| crosses the domain boundaries.

This patch add check for that case to warn that not supported.

[1] - http://doc.dpdk.org/guides-20.02/nics/mlx5.html
Fixes: fcc8d2f716fd ("net/mlx5: extend flow metadata support")
Cc: stable@dpdk.org

Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
---
 drivers/net/mlx5/mlx5_flow_dv.c | 31 +++++++++++++++++++------------
 1 file changed, 19 insertions(+), 12 deletions(-)
  

Hi, Tonghao

Thank you for the patch,  and a lot of my apologizes - I mixed up your patch with other
fix and thought we did not need it. Now I reviwed it again - we fixed flow_dv_validate_item_meta()
(in other way - with explicit register check) but flow_dv_validate_action_set_meta() still needs the fix.
Would you like to rebase your patch and send v3 or prefer to let us do it?

With best regards, Slava

> -----Original Message-----
> From: xiangxia.m.yue@gmail.com <xiangxia.m.yue@gmail.com>
> Sent: Sunday, May 24, 2020 14:07
> To: Slava Ovsiienko <viacheslavo@mellanox.com>
> Cc: dev@dpdk.org; Tonghao Zhang <xiangxia.m.yue@gmail.com>;
> stable@dpdk.org
> Subject: [PATCH dpdk-dev v2] net/mlx5: check the reg available for metadata
> action
> 
> From: Tonghao Zhang <xiangxia.m.yue@gmail.com>
> 
> If user don't set the dv_xmeta_en to 1 or 2, in the
> flow_dv_convert_action_set_meta function:
> * flow_dv_get_metadata_reg may return the REG_NONE,
>   when MLX5_METADATA_FDB enabled for metadata set
>   action.
> * reg_to_field(REG_NONE) return MLX5_MODI_OUT_NONE
>   which is invalid.
> 
> The rdma-core calltrace:
>   dr_action_create_modify_action
>   dr_actions_convert_modify_header
>   dr_action_modify_sw_to_hw
>   dr_action_modify_sw_to_hw_set
>   dr_ste_get_modify_hdr_hw_field
> 
> sw_field [MLX5_MODI_OUT_NONE 4095]
> should not > ste_ctx->modify_hdr_field_arr_sz [92]
> 
> As doc[1] says:
> | dv_xmeta_en 0, this is default value, defines the legacy mode, the
> | MARK and META related actions and items operate only within NIC Tx and
> | NIC Rx steering domains, no MARK and META information crosses the
> | domain boundaries.
> 
> This patch add check for that case to warn that not supported.
> 
> [1] -
> https://eur03.safelinks.protection.outlook.com/?url=http%3A%2F%2Fdoc.dp
> dk.org%2Fguides-
> 20.02%2Fnics%2Fmlx5.html&amp;data=02%7C01%7Cviacheslavo%40mellan
> ox.com%7Ce55c7bccccd14490af4208d7ffd29c78%7Ca652971c7d2e4d9ba6a
> 4d149256f461b%7C0%7C0%7C637259152350270223&amp;sdata=PiDsa8dD
> 4bJrGL2FGHWUOybIAMD5pxq8p5vxmtlS9lc%3D&amp;reserved=0
> Fixes: fcc8d2f716fd ("net/mlx5: extend flow metadata support")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>
> ---
>  drivers/net/mlx5/mlx5_flow_dv.c | 31 +++++++++++++++++++------------
>  1 file changed, 19 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/net/mlx5/mlx5_flow_dv.c
> b/drivers/net/mlx5/mlx5_flow_dv.c index e4818319507c..c77835270d60
> 100644
> --- a/drivers/net/mlx5/mlx5_flow_dv.c
> +++ b/drivers/net/mlx5/mlx5_flow_dv.c
> @@ -1251,6 +1251,7 @@ flow_dv_convert_action_set_meta
> 
>  	if (reg < 0)
>  		return reg;
> +	MLX5_ASSERT(reg != REG_NONE);
>  	/*
>  	 * In datapath code there is no endianness
>  	 * coversions for perfromance reasons, all @@ -1449,7 +1450,6 @@
> flow_dv_validate_item_meta(struct rte_eth_dev *dev __rte_unused,
>  			   struct rte_flow_error *error)
>  {
>  	struct mlx5_priv *priv = dev->data->dev_private;
> -	struct mlx5_dev_config *config = &priv->config;
>  	const struct rte_flow_item_meta *spec = item->spec;
>  	const struct rte_flow_item_meta *mask = item->mask;
>  	struct rte_flow_item_meta nic_mask = { @@ -1463,23 +1463,25
> @@ flow_dv_validate_item_meta(struct rte_eth_dev *dev __rte_unused,
> 
> RTE_FLOW_ERROR_TYPE_ITEM_SPEC,
>  					  item->spec,
>  					  "data cannot be empty");
> -	if (config->dv_xmeta_en != MLX5_XMETA_MODE_LEGACY) {
> -		if (!mlx5_flow_ext_mreg_supported(dev))
> -			return rte_flow_error_set(error, ENOTSUP,
> +	if (!mlx5_flow_ext_mreg_supported(dev))
> +		return rte_flow_error_set(error, ENOTSUP,
>  					  RTE_FLOW_ERROR_TYPE_ITEM,
> item,
>  					  "extended metadata register"
>  					  " isn't supported");
> -		reg = flow_dv_get_metadata_reg(dev, attr, error);
> -		if (reg < 0)
> -			return reg;
> -		if (reg == REG_B)
> -			return rte_flow_error_set(error, ENOTSUP,
> +	reg = flow_dv_get_metadata_reg(dev, attr, error);
> +	if (reg < 0)
> +		return reg;
> +	if (reg == REG_NONE)
> +		return rte_flow_error_set(error, ENOTSUP,
> +					  RTE_FLOW_ERROR_TYPE_ITEM,
> item,
> +					  "unavailable metadata register");
> +	if (reg == REG_B)
> +		return rte_flow_error_set(error, ENOTSUP,
>  					  RTE_FLOW_ERROR_TYPE_ITEM,
> item,
>  					  "match on reg_b "
>  					  "isn't supported");
> -		if (reg != REG_A)
> -			nic_mask.data = priv->sh->dv_meta_mask;
> -	}
> +	if (reg != REG_A)
> +		nic_mask.data = priv->sh->dv_meta_mask;
>  	if (!mask)
>  		mask = &rte_flow_item_meta_mask;
>  	if (!mask->data)
> @@ -2244,6 +2246,11 @@ flow_dv_validate_action_set_meta(struct
> rte_eth_dev *dev,
>  	reg = flow_dv_get_metadata_reg(dev, attr, error);
>  	if (reg < 0)
>  		return reg;
> +	if (reg == REG_NONE)
> +		return rte_flow_error_set(error, ENOTSUP,
> +					  RTE_FLOW_ERROR_TYPE_ACTION,
> +					  action, "unavailable "
> +					  "metadata register");
>  	if (reg != REG_A && reg != REG_B) {
>  		struct mlx5_priv *priv = dev->data->dev_private;
> 
> --
> 2.26.1