Re: [Intel-wired-lan] [PATCH iwl-net v4 1/2] ice: skip per-VLAN promisc rules when default VSI Rx rule is set

[Marcin Szycik]

On 08/07/2026 14:57, Petr Oros wrote:
> When an ice port in a vlan-filtering bridge goes promiscuous (typical for
> bond slaves), the driver installs a per-VLAN ICE_SW_LKUP_PROMISC_VLAN rule
> for every VID on top of the broad ICE_SW_LKUP_DFLT VSI Rx rule. Each rule
> consumes one of the ~32K Flow Lookup Unit (FLU) entries the device shares
> across PFs, so a wide trunk (vid 2-4094) over several PFs overruns the
> pool: firmware rejects further Add Switch Rules with ENOSPC (AQ 0x10) and
> the DFLT Rx rule itself fails to install:
> 
>   ice 0000:5c:00.1: Failed to set VSI 14 as the default forwarding
>                     VSI, error -5
>   ice 0000:5c:00.1 ens1f1: Error -5 setting default VSI 14 Rx rule
> 
> Once a switch context is overrun the retries can also come back as ENOENT
> (AQ 0x2), which has misled triage toward a perceived recipe binding defect
> rather than a capacity issue.
> 
> The DFLT rule already catches every packet on the port regardless of VLAN
> tag, so the per-VLAN promisc expansion is redundant while it is installed.
> Skip it at the two sites that drive it, ice_set_promisc() and
> ice_vlan_rx_add_vid(), keyed on ice_is_vsi_dflt_vsi() rather than the
> netdev IFF_PROMISC flag so a failed or LAG-suppressed DFLT install still
> falls back to the per-VLAN rules.
> 
> IFF_ALLMULTI and IFF_PROMISC can reach ice_vsi_sync_fltr() in separate
> passes (a bridge join sets them through separate calls), so the allmulti
> pass may expand the per-VID rules before the DFLT rule exists. Drop those
> now-redundant rules right after ice_set_dflt_vsi() installs the DFLT rule;
> ice_vsi_exit_dflt_promisc() reinstates them when promisc is cleared.
> 
> ice_vsi_sync_fltr() subscribed multicast promiscuity only inside the
> "default VSI not yet in use" branch, so a promiscuous VSI that finds the
> default VSI rule already present (owned by another VSI, or preserved
> across a switchdev session) ended up in unicast promisc with no multicast
> subscription. Issue ice_set_promisc(ICE_MCAST_PROMISC_BITS) whenever the
> netdev is promiscuous; it is idempotent and returns 0 if the rule is
> already present.
> 
> Fixes: 1273f89578f2 ("ice: Fix broken IFF_ALLMULTI handling")
> Signed-off-by: Petr Oros <poros@xxxxxxxxxx>

LGTM
Reviewed-by: Marcin Szycik <marcin.szycik@xxxxxxxxxxxxxxx>
> ---
> v4 (review comments from Marcin Szycik):
> - Reworded the ice_clear_promisc() and the per-VID cleanup comments.
> - Flipped the ice_vsi_clear_vlan_mc_promisc() guard to an early return to
>   reduce indentation, and noted that the clear is best-effort.
> No functional change.
> 
> v3: https://lore.kernel.org/all/20260701133601.2118382-2-poros@xxxxxxxxxx/
> v2: https://lore.kernel.org/all/20260622113428.2565255-2-poros@xxxxxxxxxx/
> v1: https://lore.kernel.org/all/89efbea9831175e6f57e9fe8557f7a0e48e050b7.1781786935.git.poros@xxxxxxxxxx/
> ---
>  drivers/net/ethernet/intel/ice/ice_main.c | 109 +++++++++++++++++-----
>  1 file changed, 88 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
> index b43d420ece99ca..f1fef26eeadac9 100644
> --- a/drivers/net/ethernet/intel/ice/ice_main.c
> +++ b/drivers/net/ethernet/intel/ice/ice_main.c
> @@ -274,7 +274,8 @@ static int ice_set_promisc(struct ice_vsi *vsi, u8 promisc_m)
>  	if (vsi->type != ICE_VSI_PF)
>  		return 0;
>  
> -	if (ice_vsi_has_non_zero_vlans(vsi)) {
> +	/* skip per-VID expansion; the DFLT Rx rule already covers every VID */
> +	if (ice_vsi_has_non_zero_vlans(vsi) && !ice_is_vsi_dflt_vsi(vsi)) {
>  		promisc_m |= (ICE_PROMISC_VLAN_RX | ICE_PROMISC_VLAN_TX);
>  		status = ice_fltr_set_vlan_vsi_promisc(&vsi->back->hw, vsi,
>  						       promisc_m);
> @@ -304,9 +305,20 @@ static int ice_clear_promisc(struct ice_vsi *vsi, u8 promisc_m)
>  		return 0;
>  
>  	if (ice_vsi_has_non_zero_vlans(vsi)) {
> -		promisc_m |= (ICE_PROMISC_VLAN_RX | ICE_PROMISC_VLAN_TX);
> +		u8 vlan_promisc_m = promisc_m | ICE_PROMISC_VLAN_RX |
> +				    ICE_PROMISC_VLAN_TX;
> +		int vid0_status;
> +
> +		/* the vid=0 rule may be in either recipe (the recipe used to
> +		 * set it is not recorded), so clear both; clearing an absent
> +		 * rule returns 0
> +		 */
>  		status = ice_fltr_clear_vlan_vsi_promisc(&vsi->back->hw, vsi,
> -							 promisc_m);
> +							 vlan_promisc_m);
> +		vid0_status = ice_fltr_clear_vsi_promisc(&vsi->back->hw,
> +							 vsi->idx, promisc_m, 0);
> +		if (!status)
> +			status = vid0_status;
>  	} else {
>  		status = ice_fltr_clear_vsi_promisc(&vsi->back->hw, vsi->idx,
>  						    promisc_m, 0);
> @@ -317,6 +329,61 @@ static int ice_clear_promisc(struct ice_vsi *vsi, u8 promisc_m)
>  	return status;
>  }
>  
> +/**
> + * ice_vsi_exit_dflt_promisc - drop the default VSI Rx rule on promisc off
> + * @vsi: the VSI leaving promiscuous mode
> + *
> + * For an IFF_ALLMULTI VSI with VLANs the per-VID multicast rules are
> + * reinstated before the default rule is cleared so coverage never lapses;
> + * the then redundant vid=0 rule is dropped best-effort. The callees log
> + * their own failures, so error returns are not re-logged here.
> + *
> + * Return: 0 on success, negative on error with the default rule left in place.
> + */
> +static int ice_vsi_exit_dflt_promisc(struct ice_vsi *vsi)
> +{
> +	struct ice_vsi_vlan_ops *vlan_ops = ice_get_compat_vsi_vlan_ops(vsi);
> +	struct net_device *netdev = vsi->netdev;
> +	struct ice_hw *hw = &vsi->back->hw;
> +	bool restore_mc;
> +	int err;
> +
> +	restore_mc = (vsi->current_netdev_flags & IFF_ALLMULTI) &&
> +		     ice_vsi_has_non_zero_vlans(vsi);
> +
> +	if (restore_mc) {
> +		err = ice_fltr_set_vlan_vsi_promisc(hw, vsi,
> +						    ICE_MCAST_VLAN_PROMISC_BITS);
> +		if (err && err != -EEXIST)
> +			return err;
> +	}
> +
> +	err = ice_clear_dflt_vsi(vsi);
> +	if (err)
> +		return err;
> +
> +	if (netdev->features & NETIF_F_HW_VLAN_CTAG_FILTER)
> +		vlan_ops->ena_rx_filtering(vsi);
> +
> +	if (restore_mc)
> +		ice_fltr_clear_vsi_promisc(hw, vsi->idx, ICE_MCAST_PROMISC_BITS,
> +					   0);
> +
> +	return 0;
> +}
> +
> +/* Drop the per-VID multicast promisc rules made redundant by the default
> + * VSI Rx rule; best-effort, a leftover is harmless while that rule stands.
> + */
> +static void ice_vsi_clear_vlan_mc_promisc(struct ice_vsi *vsi)
> +{
> +	if (!ice_vsi_has_non_zero_vlans(vsi))
> +		return;
> +
> +	ice_fltr_clear_vlan_vsi_promisc(&vsi->back->hw, vsi,
> +					ICE_MCAST_VLAN_PROMISC_BITS);
> +}
> +
>  /**
>   * ice_vsi_sync_fltr - Update the VSI filter list to the HW
>   * @vsi: ptr to the VSI
> @@ -429,30 +496,31 @@ static int ice_vsi_sync_fltr(struct ice_vsi *vsi)
>  				err = 0;
>  				vlan_ops->dis_rx_filtering(vsi);
>  
> -				/* promiscuous mode implies allmulticast so
> -				 * that VSIs that are in promiscuous mode are
> -				 * subscribed to multicast packets coming to
> -				 * the port
> +				/* a prior allmulti pass may have added per-VID
> +				 * rules now covered by the DFLT rule
>  				 */
> -				err = ice_set_promisc(vsi,
> -						      ICE_MCAST_PROMISC_BITS);
> -				if (err)
> -					goto out_promisc;
> +				ice_vsi_clear_vlan_mc_promisc(vsi);
>  			}
> +
> +			/* Promiscuous mode implies allmulticast. Subscribe
> +			 * the VSI to all multicast even when the default VSI
> +			 * rule is already in use and the block above is
> +			 * skipped (it may be owned by another VSI, or
> +			 * preserved across a switchdev session); the unicast
> +			 * catch-all does not cover the multicast subscription.
> +			 */
> +			err = ice_set_promisc(vsi, ICE_MCAST_PROMISC_BITS);
> +			if (err)
> +				goto out_promisc;
>  		} else {
>  			/* Clear Rx filter to remove traffic from wire */
>  			if (ice_is_vsi_dflt_vsi(vsi)) {
> -				err = ice_clear_dflt_vsi(vsi);
> +				err = ice_vsi_exit_dflt_promisc(vsi);
>  				if (err) {
> -					netdev_err(netdev, "Error %d clearing default VSI %i Rx rule\n",
> -						   err, vsi->vsi_num);
>  					vsi->current_netdev_flags |=
>  						IFF_PROMISC;
>  					goto out_promisc;
>  				}
> -				if (vsi->netdev->features &
> -				    NETIF_F_HW_VLAN_CTAG_FILTER)
> -					vlan_ops->ena_rx_filtering(vsi);
>  			}
>  
>  			/* disable allmulti here, but only if allmulti is not
> @@ -3676,10 +3744,9 @@ int ice_vlan_rx_add_vid(struct net_device *netdev, __be16 proto, u16 vid)
>  	while (test_and_set_bit(ICE_CFG_BUSY, vsi->state))
>  		usleep_range(1000, 2000);
>  
> -	/* Add multicast promisc rule for the VLAN ID to be added if
> -	 * all-multicast is currently enabled.
> -	 */
> -	if (vsi->current_netdev_flags & IFF_ALLMULTI) {
> +	/* skip the per-VID rule when the DFLT Rx rule already covers this VID */
> +	if ((vsi->current_netdev_flags & IFF_ALLMULTI) &&
> +	    !ice_is_vsi_dflt_vsi(vsi)) {
>  		ret = ice_fltr_set_vsi_promisc(&vsi->back->hw, vsi->idx,
>  					       ICE_MCAST_VLAN_PROMISC_BITS,
>  					       vid);