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

[Ye, MingjinX]

> -----Original Message-----
> From: Richardson, Bruce <bruce.richardson at intel.com>
> Sent: Tuesday, June 17, 2025 7:34 PM
> To: Ye, MingjinX <mingjinx.ye at intel.com>
> Cc: dev at dpdk.org; stable at dpdk.org; Burakov, Anatoly
> <anatoly.burakov at intel.com>
> Subject: Re: [PATCH] net/ice: fix DCF RSS hash update
> 
> 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 at dpdk.org
> >
> > Signed-off-by: Mingjin Ye <mingjinx.ye at 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?
No logic was changed. There is a difference in behavior. Previously, when the rss_key is null, noting will happen. But now it continues to perform the next steps. This patch makes the behavior of PF and VF consistent.

> 
> > @@ -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?
It is okay to split the patch as these two are for separate purpose.  
> 
> >  	if (!rss_conf->rss_key)
> >  		return 0;
> > --
> > 2.25.1
> >