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Message-ID: <d950f4f6-6581-a99f-3375-c0359d45c9f5@gmail.com>
Date:   Tue, 25 Jul 2023 12:59:32 +0300
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Subject: Re: [net 2/2] net/mlx5: Fix flowhash key set/get for custom RSS
Content-Language: en-US
To:     Joe Damato <jdamato@fastly.com>, netdev@vger.kernel.org,
        saeedm@nvidia.com, ecree@solarflare.com, andrew@lunn.ch,
        kuba@kernel.org, davem@davemloft.net, leon@kernel.org,
        pabeni@redhat.com, bhutchings@solarflare.com, arnd@arndb.de
Cc:     linux-kernel@vger.kernel.org, Tariq Toukan <tariqt@nvidia.com>
References: <20230723150658.241597-1-jdamato@fastly.com>
 <20230723150658.241597-3-jdamato@fastly.com>
From:   Tariq Toukan <ttoukan.linux@gmail.com>
In-Reply-To: <20230723150658.241597-3-jdamato@fastly.com>
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Precedence: bulk


On 23/07/2023 18:06, Joe Damato wrote:
> mlx5 flow hash field retrieval and set only worked on the default
> RSS context, not custom RSS contexts.
> 
> For example, before this patch attempting to retrieve the flow hash fields
> for RSS context 1 fails:
> 

Hi,

You are adding new driver functionality, please take it through net-next.

> $ sudo ethtool -u eth1 rx-flow-hash tcp4 context 1
> Cannot get RX network flow hashing options: Invalid argument
> 
> This patch fixes getting and setting the flow hash fields for contexts
> other than the default context.
> 
> Getting the flow hash fields for RSS context 1:
> 
> sudo ethtool -u eth1 rx-flow-hash tcp4 context 1
> For RSS context 1:
> TCP over IPV4 flows use these fields for computing Hash flow key:
> IP DA
> 
> Now, setting the flash hash fields to a custom value:
> 
> sudo ethtool -U eth1 rx-flow-hash tcp4 sdfn context 1
> 
> And retrieving them again:
> 
> sudo ethtool -u eth1 rx-flow-hash tcp4 context 1
> For RSS context 1:
> TCP over IPV4 flows use these fields for computing Hash flow key:
> IP SA
> IP DA
> L4 bytes 0 & 1 [TCP/UDP src port]
> L4 bytes 2 & 3 [TCP/UDP dst port]
> 
> Fixes: f01cc58c18d6 ("net/mlx5e: Support multiple RSS contexts")
> Signed-off-by: Joe Damato <jdamato@fastly.com>
> ---
>   .../ethernet/mellanox/mlx5/core/en/rx_res.c   | 23 ++++++++++---
>   .../ethernet/mellanox/mlx5/core/en/rx_res.h   |  5 +--
>   .../mellanox/mlx5/core/en_fs_ethtool.c        | 33 ++++++++++++++-----
>   3 files changed, 46 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/rx_res.c b/drivers/net/ethernet/mellanox/mlx5/core/en/rx_res.c
> index e1095bc36543..bb189c92e4c0 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/en/rx_res.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/en/rx_res.c
> @@ -218,17 +218,32 @@ int mlx5e_rx_res_rss_set_rxfh(struct mlx5e_rx_res *res, u32 rss_idx,
>   	return mlx5e_rss_set_rxfh(rss, indir, key, hfunc, res->rss_rqns, res->rss_nch);
>   }
>   
> -u8 mlx5e_rx_res_rss_get_hash_fields(struct mlx5e_rx_res *res, enum mlx5_traffic_types tt)
> +int mlx5e_rx_res_rss_get_hash_fields(struct mlx5e_rx_res *res, enum mlx5_traffic_types tt,
> +				     u32 rss_idx)

For consistency with other functions, please keep the rss_idx next to 
the res argument.

>   {
> -	struct mlx5e_rss *rss = res->rss[0];
> +	struct mlx5e_rss *rss;
> +
> +	if (rss_idx >= MLX5E_MAX_NUM_RSS)
> +		return -EINVAL;
> +
> +	rss = res->rss[rss_idx];
> +	if (!rss)
> +		return -EINVAL;

return -ENOENT; in this case.

>   
>   	return mlx5e_rss_get_hash_fields(rss, tt);
>   }
>   
>   int mlx5e_rx_res_rss_set_hash_fields(struct mlx5e_rx_res *res, enum mlx5_traffic_types tt,
> -				     u8 rx_hash_fields)
> +				     u8 rx_hash_fields, u32 rss_idx)

Same. let rss_idx come as second argument.
>   {
> -	struct mlx5e_rss *rss = res->rss[0];
> +	struct mlx5e_rss *rss;
> +
> +	if (rss_idx >= MLX5E_MAX_NUM_RSS)
> +		return -EINVAL;
> +
> +	rss = res->rss[rss_idx];
> +	if (!rss)
> +		return -EINVAL;

ENOENT

>   
>   	return mlx5e_rss_set_hash_fields(rss, tt, rx_hash_fields);
>   }
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/rx_res.h b/drivers/net/ethernet/mellanox/mlx5/core/en/rx_res.h
> index 5d5f64fab60f..8ac9d67a9603 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/en/rx_res.h
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/en/rx_res.h
> @@ -48,9 +48,10 @@ int mlx5e_rx_res_rss_get_rxfh(struct mlx5e_rx_res *res, u32 rss_idx,
>   int mlx5e_rx_res_rss_set_rxfh(struct mlx5e_rx_res *res, u32 rss_idx,
>   			      const u32 *indir, const u8 *key, const u8 *hfunc);
>   
> -u8 mlx5e_rx_res_rss_get_hash_fields(struct mlx5e_rx_res *res, enum mlx5_traffic_types tt);
> +int mlx5e_rx_res_rss_get_hash_fields(struct mlx5e_rx_res *res, enum mlx5_traffic_types tt,
> +				     u32 rss_idx);
>   int mlx5e_rx_res_rss_set_hash_fields(struct mlx5e_rx_res *res, enum mlx5_traffic_types tt,
> -				     u8 rx_hash_fields);
> +				     u8 rx_hash_fields, u32 rss_idx);
>   int mlx5e_rx_res_packet_merge_set_param(struct mlx5e_rx_res *res,
>   					struct mlx5e_packet_merge_param *pkt_merge_param);
>   
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_fs_ethtool.c b/drivers/net/ethernet/mellanox/mlx5/core/en_fs_ethtool.c
> index aac32e505c14..50b8f3da4db1 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/en_fs_ethtool.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_fs_ethtool.c
> @@ -902,8 +902,14 @@ static int mlx5e_set_rss_hash_opt(struct mlx5e_priv *priv,
>   	u8 rx_hash_field = 0;
>   	int err;
>   	int tt;
> +	u32 flow_type = 0;
> +	u32 rss_idx = 0;
>   
> -	tt = flow_type_to_traffic_type(nfc->flow_type);
> +	if (nfc->flow_type & FLOW_RSS)
> +		rss_idx = nfc->rss_context;
> +
> +	flow_type = flow_type_mask(nfc->flow_type);
> +	tt = flow_type_to_traffic_type(flow_type);
>   	if (tt < 0)
>   		return tt;
>   
> @@ -911,10 +917,10 @@ static int mlx5e_set_rss_hash_opt(struct mlx5e_priv *priv,
>   	 *  on src IP, dest IP, TCP/UDP src port and TCP/UDP dest
>   	 *  port.
>   	 */
> -	if (nfc->flow_type != TCP_V4_FLOW &&
> -	    nfc->flow_type != TCP_V6_FLOW &&
> -	    nfc->flow_type != UDP_V4_FLOW &&
> -	    nfc->flow_type != UDP_V6_FLOW)
> +	if (flow_type != TCP_V4_FLOW &&
> +	    flow_type != TCP_V6_FLOW &&
> +	    flow_type != UDP_V4_FLOW &&
> +	    flow_type != UDP_V6_FLOW)
>   		return -EOPNOTSUPP;
>   
>   	if (nfc->data & ~(RXH_IP_SRC | RXH_IP_DST |
> @@ -931,7 +937,7 @@ static int mlx5e_set_rss_hash_opt(struct mlx5e_priv *priv,
>   		rx_hash_field |= MLX5_HASH_FIELD_SEL_L4_DPORT;
>   
>   	mutex_lock(&priv->state_lock);
> -	err = mlx5e_rx_res_rss_set_hash_fields(priv->rx_res, tt, rx_hash_field);
> +	err = mlx5e_rx_res_rss_set_hash_fields(priv->rx_res, tt, rx_hash_field, rss_idx);
>   	mutex_unlock(&priv->state_lock);
>   
>   	return err;
> @@ -940,14 +946,23 @@ static int mlx5e_set_rss_hash_opt(struct mlx5e_priv *priv,
>   static int mlx5e_get_rss_hash_opt(struct mlx5e_priv *priv,
>   				  struct ethtool_rxnfc *nfc)
>   {
> -	u32 hash_field = 0;
> +	int hash_field = 0;
>   	int tt;
> +	u32 flow_type = 0;
> +	u32 rss_idx = 0;

Please maintain the reversed Christmas tree.

> +
> +	if (nfc->flow_type & FLOW_RSS)
> +		rss_idx = nfc->rss_context;
>   
> -	tt = flow_type_to_traffic_type(nfc->flow_type);
> +	flow_type = flow_type_mask(nfc->flow_type);
> +	tt = flow_type_to_traffic_type(flow_type);
>   	if (tt < 0)
>   		return tt;
>   
> -	hash_field = mlx5e_rx_res_rss_get_hash_fields(priv->rx_res, tt);
> +	hash_field = mlx5e_rx_res_rss_get_hash_fields(priv->rx_res, tt, rss_idx);
> +	if (hash_field < 0)
> +		return hash_field;
> +
>   	nfc->data = 0;
>   
>   	if (hash_field & MLX5_HASH_FIELD_SEL_SRC_IP)