The E810 switch gives drop rules absolute precedence over forwarding rules regardless of recipe priority (verified on E810 in every combination of installation order and match specificity). TC however requires filters to be evaluated in priority order, so when a higher priority filter stays software-only because its match or action cannot be offloaded while a lower priority drop filter is offloaded, the hardware drops packets the higher priority filter should have seen: tc filter add dev $pf ingress prio 1 protocol ip flower \ ip_proto l2tp action pass tc filter add dev $pf ingress prio 2 protocol ip flower action drop The pass filter is rejected (unsupported action), the drop filter is offloaded and the hardware drops all IPv4 traffic including the L2TP packets the prio 1 filter should accept. Track filters that were presented to the driver but not offloaded and refuse to offload a drop filter when a higher priority filter on the same device block and direction is software-only or is offloaded with a forwarding action, which the hardware drop would equally override. The refused drop filter keeps working in software. Filters are compared only within one device block since TC priorities are not ordered across blocks. Filters with skip_sw bypass the check because the user explicitly requested hardware-only operation and refusing would fail the filter add entirely, and the tracking applies to the legacy switch mode only, switchdev pipelines manage rule priorities themselves. The check does not analyze match overlap, so it is conservative, and it runs only at drop offload time. A conflicting filter installed after a drop filter was already offloaded cannot un-offload it, and filters the driver never saw (added while hw-tc-offload was off) are invisible to it. Installing filters in priority order with offload enabled avoids both. Fixes: 0d08a441fb1a ("ice: ndo_setup_tc implementation for PF") Signed-off-by: Petr Oros --- drivers/net/ethernet/intel/ice/ice.h | 1 + drivers/net/ethernet/intel/ice/ice_tc_lib.c | 150 +++++++++++++++++++- drivers/net/ethernet/intel/ice/ice_tc_lib.h | 21 +++ 3 files changed, 166 insertions(+), 6 deletions(-) diff --git a/drivers/net/ethernet/intel/ice/ice.h b/drivers/net/ethernet/intel/ice/ice.h index db3c7015c56c43..6c596e5a315175 100644 --- a/drivers/net/ethernet/intel/ice/ice.h +++ b/drivers/net/ethernet/intel/ice/ice.h @@ -643,6 +643,7 @@ struct ice_pf { */ u16 num_dmac_chnl_fltrs; struct hlist_head tc_flower_fltr_list; + struct hlist_head tc_sw_fltr_list; u64 supported_rxdids; diff --git a/drivers/net/ethernet/intel/ice/ice_tc_lib.c b/drivers/net/ethernet/intel/ice/ice_tc_lib.c index fbd8cbad150a98..7cfc8941b7ba57 100644 --- a/drivers/net/ethernet/intel/ice/ice_tc_lib.c +++ b/drivers/net/ethernet/intel/ice/ice_tc_lib.c @@ -2269,6 +2269,112 @@ ice_find_tc_flower_fltr(struct ice_pf *pf, unsigned long cookie) return NULL; } +/** + * ice_tc_fltr_is_drop - check if a filter carries a drop action + * @cls_flower: offload request describing the filter + * + * Return: true if any action of the filter is a drop, false otherwise. + */ +static bool ice_tc_fltr_is_drop(struct flow_cls_offload *cls_flower) +{ + struct flow_rule *rule = flow_cls_offload_flow_rule(cls_flower); + struct flow_action_entry *act; + int i; + + if (cls_flower->classid) + return false; + + flow_action_for_each(i, act, &rule->action) + if (act->id == FLOW_ACTION_DROP) + return true; + + return false; +} + +/** + * ice_tc_untrack_sw_fltr - forget a tracked software-only filter + * @pf: pointer to PF structure + * @cookie: unique filter identifier from the offload request + * + * Return: true if the filter was tracked, false otherwise. + */ +static bool ice_tc_untrack_sw_fltr(struct ice_pf *pf, unsigned long cookie) +{ + struct ice_tc_sw_fltr *sw_fltr; + + hlist_for_each_entry(sw_fltr, &pf->tc_sw_fltr_list, node) { + if (sw_fltr->cookie != cookie) + continue; + + hlist_del(&sw_fltr->node); + kfree(sw_fltr); + return true; + } + + return false; +} + +/** + * ice_tc_track_sw_fltr - remember a filter that was not offloaded + * @pf: pointer to PF structure + * @filter_dev: device the filter was requested on + * @cls_flower: offload request describing the filter + * @direction: block direction the filter was requested for + */ +static void ice_tc_track_sw_fltr(struct ice_pf *pf, + struct net_device *filter_dev, + struct flow_cls_offload *cls_flower, + enum ice_eswitch_fltr_direction direction) +{ + struct ice_tc_sw_fltr *sw_fltr; + + hlist_for_each_entry(sw_fltr, &pf->tc_sw_fltr_list, node) + if (sw_fltr->cookie == cls_flower->cookie) + return; + + sw_fltr = kzalloc_obj(*sw_fltr); + if (!sw_fltr) + return; + + sw_fltr->cookie = cls_flower->cookie; + sw_fltr->filter_dev = filter_dev; + sw_fltr->prio = cls_flower->common.prio; + sw_fltr->direction = direction; + sw_fltr->is_drop = ice_tc_fltr_is_drop(cls_flower); + hlist_add_head(&sw_fltr->node, &pf->tc_sw_fltr_list); +} + +/** + * ice_tc_drop_bypasses_fltr - check if a drop rule would bypass a filter + * @pf: pointer to PF structure + * @filter_dev: device the drop filter is requested on + * @prio: TC priority of the drop filter + * @direction: block direction of the drop filter + * + * Return: true if such a filter exists, false otherwise. + */ +static bool +ice_tc_drop_bypasses_fltr(struct ice_pf *pf, struct net_device *filter_dev, + u32 prio, enum ice_eswitch_fltr_direction direction) +{ + struct ice_tc_flower_fltr *fltr; + struct ice_tc_sw_fltr *sw_fltr; + + hlist_for_each_entry(sw_fltr, &pf->tc_sw_fltr_list, node) + if (sw_fltr->filter_dev == filter_dev && + sw_fltr->direction == direction && sw_fltr->prio < prio && + !sw_fltr->is_drop) + return true; + + hlist_for_each_entry(fltr, &pf->tc_flower_fltr_list, tc_flower_node) + if (fltr->filter_dev == filter_dev && + fltr->direction == direction && fltr->prio < prio && + fltr->action.fltr_act != ICE_DROP_PACKET) + return true; + + return false; +} + /** * ice_add_cls_flower - add TC flower filters * @netdev: Pointer to filter device @@ -2284,14 +2390,24 @@ int ice_add_cls_flower(struct net_device *netdev, struct ice_vsi *vsi, { struct netlink_ext_ack *extack = cls_flower->common.extack; struct net_device *vsi_netdev = vsi->netdev; + enum ice_eswitch_fltr_direction direction; struct ice_tc_flower_fltr *fltr; struct ice_pf *pf = vsi->back; + bool track_sw_fltrs; int err; - if (ice_is_reset_in_progress(pf->state)) - return -EBUSY; - if (test_bit(ICE_FLAG_FW_LLDP_AGENT, pf->flags)) - return -EINVAL; + direction = ingress ? ICE_ESWITCH_FLTR_INGRESS : + ICE_ESWITCH_FLTR_EGRESS; + track_sw_fltrs = !ice_is_eswitch_mode_switchdev(pf); + + if (ice_is_reset_in_progress(pf->state)) { + err = -EBUSY; + goto track_sw; + } + if (test_bit(ICE_FLAG_FW_LLDP_AGENT, pf->flags)) { + err = -EINVAL; + goto track_sw; + } if (ice_is_port_repr_netdev(netdev)) vsi_netdev = netdev; @@ -2304,7 +2420,8 @@ int ice_add_cls_flower(struct net_device *netdev, struct ice_vsi *vsi, */ if (netdev == vsi_netdev) NL_SET_ERR_MSG_MOD(extack, "can't apply TC flower filters, turn ON hw-tc-offload and try again"); - return -EINVAL; + err = -EINVAL; + goto track_sw; } /* avoid duplicate entries, if exists - return error */ @@ -2314,14 +2431,32 @@ int ice_add_cls_flower(struct net_device *netdev, struct ice_vsi *vsi, return -EEXIST; } + if (track_sw_fltrs && !cls_flower->common.skip_sw && + ice_tc_fltr_is_drop(cls_flower) && + ice_tc_drop_bypasses_fltr(pf, netdev, cls_flower->common.prio, + direction)) { + NL_SET_ERR_MSG_MOD(extack, + "Drop filter not offloaded because it would bypass a higher priority filter"); + err = -EOPNOTSUPP; + goto track_sw; + } + /* prep and add TC-flower filter in HW */ err = ice_add_tc_fltr(netdev, vsi, cls_flower, &fltr, ingress); if (err) - return err; + goto track_sw; + + fltr->filter_dev = netdev; + fltr->prio = cls_flower->common.prio; /* add filter into an ordered list */ hlist_add_head(&fltr->tc_flower_node, &pf->tc_flower_fltr_list); return 0; + +track_sw: + if (track_sw_fltrs && !cls_flower->common.skip_sw) + ice_tc_track_sw_fltr(pf, netdev, cls_flower, direction); + return err; } /** @@ -2336,6 +2471,9 @@ ice_del_cls_flower(struct ice_vsi *vsi, struct flow_cls_offload *cls_flower) struct ice_pf *pf = vsi->back; int err; + if (ice_tc_untrack_sw_fltr(pf, cls_flower->cookie)) + return 0; + /* find filter */ fltr = ice_find_tc_flower_fltr(pf, cls_flower->cookie); if (!fltr) { diff --git a/drivers/net/ethernet/intel/ice/ice_tc_lib.h b/drivers/net/ethernet/intel/ice/ice_tc_lib.h index 752af65e70b7bf..37d6f4100ecfbc 100644 --- a/drivers/net/ethernet/intel/ice/ice_tc_lib.h +++ b/drivers/net/ethernet/intel/ice/ice_tc_lib.h @@ -139,12 +139,33 @@ enum ice_eswitch_fltr_direction { ICE_ESWITCH_FLTR_EGRESS, }; +/** + * struct ice_tc_sw_fltr - filter presented to the driver but not offloaded + * @node: node in the pf->tc_sw_fltr_list + * @cookie: unique filter identifier from the offload request + * @filter_dev: device the filter was requested on + * @prio: TC priority, lower value is evaluated first + * @direction: block direction the filter was requested for + * @is_drop: the filter carries a drop action + */ +struct ice_tc_sw_fltr { + struct hlist_node node; + unsigned long cookie; + struct net_device *filter_dev; + u32 prio; + enum ice_eswitch_fltr_direction direction; + bool is_drop; +}; + struct ice_tc_flower_fltr { struct hlist_node tc_flower_node; /* cookie becomes filter_rule_id if rule is added successfully */ unsigned long cookie; + struct net_device *filter_dev; + u32 prio; + /* add_adv_rule returns information like recipe ID, rule_id. Store * those values since they are needed to remove advanced rule */ -- 2.55.0