Re: [PATCH] net/ice: fix DCF RSS hash update

[Bruce Richardson <bruce.richardson@intel.com>]

On Wed, Jun 11, 2025 at 09:50:57AM +0000, Mingjin Ye wrote:
> Get rss hash configuration, rss_hf is always the default value.
> The driver does nothing if the rss key is invalid during the rss
> hash update.
> 
> This patch is get the current configuration of rss_hf. Extract
> the update rss key code from ice_dcf_dev_rss_hash_update to
> ice_dcf_set_rss_key and make it consistent with the pf behaviour.
> 
> Fixes: c223cadc9e5f ("net/ice: support RSS hash configuration in DCF mode")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Mingjin Ye <mingjinx.ye@intel.com>

Hi,

some comments inline below.

/Bruce

> ---
>  drivers/net/intel/ice/ice_dcf_ethdev.c | 38 +++++++++++++++-----------
>  1 file changed, 22 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/net/intel/ice/ice_dcf_ethdev.c b/drivers/net/intel/ice/ice_dcf_ethdev.c
> index efff76afa8..accabd0ab9 100644
> --- a/drivers/net/intel/ice/ice_dcf_ethdev.c
> +++ b/drivers/net/intel/ice/ice_dcf_ethdev.c
> @@ -1394,31 +1394,38 @@ ice_dcf_dev_rss_reta_query(struct rte_eth_dev *dev,
>  }
>  
>  static int
> -ice_dcf_dev_rss_hash_update(struct rte_eth_dev *dev,
> -			struct rte_eth_rss_conf *rss_conf)
> +ice_dcf_set_rss_key(struct ice_dcf_hw *hw, uint8_t *key, uint8_t key_len)
>  {
> -	struct ice_dcf_adapter *adapter = dev->data->dev_private;
> -	struct ice_dcf_hw *hw = &adapter->real_hw;
> -	int ret;
> -
> -	if (!(hw->vf_res->vf_cap_flags & VIRTCHNL_VF_OFFLOAD_RSS_PF))
> -		return -ENOTSUP;
> -
>  	/* HENA setting, it is enabled by default, no change */
> -	if (!rss_conf->rss_key || rss_conf->rss_key_len == 0) {
> +	if (!key || key_len == 0) {
>  		PMD_DRV_LOG(DEBUG, "No key to be configured");
>  		return 0;
> -	} else if (rss_conf->rss_key_len != hw->vf_res->rss_key_size) {
> +	} else if (key_len != hw->vf_res->rss_key_size) {
>  		PMD_DRV_LOG(ERR, "The size of hash key configured "
>  			"(%d) doesn't match the size of hardware can "
> -			"support (%d)", rss_conf->rss_key_len,
> +			"support (%d)", key_len,
>  			hw->vf_res->rss_key_size);
>  		return -EINVAL;
>  	}
>  
> -	rte_memcpy(hw->rss_key, rss_conf->rss_key, rss_conf->rss_key_len);
> +	rte_memcpy(hw->rss_key, key, key_len);
> +
> +	return ice_dcf_configure_rss_key(hw);
> +}
> +
> +static int
> +ice_dcf_dev_rss_hash_update(struct rte_eth_dev *dev,
> +			struct rte_eth_rss_conf *rss_conf)
> +{
> +	struct ice_dcf_adapter *adapter = dev->data->dev_private;
> +	struct ice_dcf_hw *hw = &adapter->real_hw;
> +	int ret;
> +
> +	if (!(hw->vf_res->vf_cap_flags & VIRTCHNL_VF_OFFLOAD_RSS_PF))
> +		return -ENOTSUP;
>  
> -	ret = ice_dcf_configure_rss_key(hw);
> +	/* set hash key */
> +	ret = ice_dcf_set_rss_key(hw, rss_conf->rss_key, rss_conf->rss_key_len);
>  	if (ret)
>  		return ret;
>  

This part of the diff (from start of the patch to here) is just extracting
the existing code into a new function, right? There is no change to
behaviour here?

> @@ -1452,8 +1459,7 @@ ice_dcf_dev_rss_hash_conf_get(struct rte_eth_dev *dev,
>  	if (!(hw->vf_res->vf_cap_flags & VIRTCHNL_VF_OFFLOAD_RSS_PF))
>  		return -ENOTSUP;
>  
> -	/* Just set it to default value now. */
> -	rss_conf->rss_hf = ICE_RSS_OFFLOAD_ALL;
> +	rss_conf->rss_hf = dev->data->dev_conf.rx_adv_conf.rss_conf.rss_hf;
>  

This line seems to be the main fix in this patch. Is it worth splitting the
patch in two - having this fix and the code refactor above in separate
patches?

>  	if (!rss_conf->rss_key)
>  		return 0;
> -- 
> 2.25.1
>