iavf: add support for offloading tc U32 cls filters

Add support for offloading cls U32 filters. Only "skbedit queue_mapping"
and "drop" actions are supported. Also, only "ip" and "802_3" tc
protocols are allowed. The PF must advertise the VIRTCHNL_VF_OFFLOAD_TC_U32
capability flag.

Since the filters will be enabled via the FD stage at the PF, a new type
of FDIR filters is added and the existing list and state machine are used.

The new filters can be used to configure flow directors based on raw
(binary) pattern in the rx packet.

Examples:

0. # tc qdisc add dev enp175s0v0 ingress

1. Redirect UDP from src IP 192.168.2.1 to queue 12:

# tc filter add dev <dev> protocol ip ingress u32 \
match u32 0x45000000 0xff000000 at 0 \
match u32 0x00110000 0x00ff0000 at 8 \
match u32 0xC0A80201 0xffffffff at 12 \
match u32 0x00000000 0x00000000 at 24 \
action skbedit queue_mapping 12 skip_sw

2. Drop all ICMP:

# tc filter add dev <dev> protocol ip ingress u32 \
match u32 0x45000000 0xff000000 at 0 \
match u32 0x00010000 0x00ff0000 at 8 \
match u32 0x00000000 0x00000000 at 24 \
action drop skip_sw

3. Redirect ICMP traffic from MAC 3c:fd:fe:a5:47:e0 to queue 7
(note proto: 802_3):

# tc filter add dev <dev> protocol 802_3 ingress u32 \
match u32 0x00003CFD 0x0000ffff at 4 \
match u32 0xFEA547E0 0xffffffff at 8 \
match u32 0x08004500 0xffffff00 at 12 \
match u32 0x00000001 0x000000ff at 20 \
match u32 0x0000 0x0000 at 40 \
action skbedit queue_mapping 7 skip_sw

Notes on matches:
1 - All intermediate fields that are needed to parse the correct PTYPE
must be provided (in e.g. 3: Ethernet Type 0x0800 in MAC, IP version
and IP length: 0x45 and protocol: 0x01 (ICMP)).
2 - The last match must provide an offset that guarantees all required
headers are accounted for, even if the last header is not matched.
For example, in #2, the last match is 4 bytes at offset 24 starting
from IP header, so the total is 14 (MAC) + 24 + 4 = 42, which is the
sum of MAC+IP+ICMP headers.

Reviewed-by: Sridhar Samudrala <[e-mail]>
Reviewed-by: Marcin Szycik <[e-mail]>
Signed-off-by: Ahmed Zaki <[e-mail]>
Tested-by: Rafal Romanowski <[e-mail]>
Reviewed-by: Simon Horman <[e-mail]>
Signed-off-by: Tony Nguyen <[e-mail]>

drivers/net/ethernet/intel/iavf/iavf.h

···
 #include <net/udp.h>
 #include <net/tc_act/tc_gact.h>
 #include <net/tc_act/tc_mirred.h>
+#include <net/tc_act/tc_skbedit.h>
 
 #include "iavf_type.h"
 #include <linux/avf/virtchnl.h>
···
 			     VIRTCHNL_VF_OFFLOAD_VLAN_V2)
 #define CRC_OFFLOAD_ALLOWED(_a) ((_a)->vf_res->vf_cap_flags & \
 				 VIRTCHNL_VF_OFFLOAD_CRC)
+#define TC_U32_SUPPORT(_a) ((_a)->vf_res->vf_cap_flags & \
+			    VIRTCHNL_VF_OFFLOAD_TC_U32)
 #define VLAN_V2_FILTERING_ALLOWED(_a) \
 	(VLAN_V2_ALLOWED((_a)) && \
 	 ((_a)->vlan_v2_caps.filtering.filtering_support.outer || \
···
 
 #define IAVF_MAX_FDIR_FILTERS 128	/* max allowed Flow Director filters */
 	u16 fdir_active_fltr;
+	u16 raw_fdir_active_fltr;
 	struct list_head fdir_list_head;
 	spinlock_t fdir_fltr_lock;	/* protect the Flow Director filter list */
 
···
 /* Must be called with fdir_fltr_lock lock held */
 static inline bool iavf_fdir_max_reached(struct iavf_adapter *adapter)
 {
-	return adapter->fdir_active_fltr >= IAVF_MAX_FDIR_FILTERS;
+	return adapter->fdir_active_fltr + adapter->raw_fdir_active_fltr >=
+			IAVF_MAX_FDIR_FILTERS;
+}
+
+static inline void
+iavf_inc_fdir_active_fltr(struct iavf_adapter *adapter,
+			  struct iavf_fdir_fltr *fltr)
+{
+	if (iavf_is_raw_fdir(fltr))
+		adapter->raw_fdir_active_fltr++;
+	else
+		adapter->fdir_active_fltr++;
+}
+
+static inline void
+iavf_dec_fdir_active_fltr(struct iavf_adapter *adapter,
+			  struct iavf_fdir_fltr *fltr)
+{
+	if (iavf_is_raw_fdir(fltr))
+		adapter->raw_fdir_active_fltr--;
+	else
+		adapter->fdir_active_fltr--;
 }
 
 /* Ethtool Private Flags */

drivers/net/ethernet/intel/iavf/iavf_ethtool.c

···
 
 	spin_lock_bh(&adapter->fdir_fltr_lock);
 
-	rule = iavf_find_fdir_fltr(adapter, fsp->location);
+	rule = iavf_find_fdir_fltr(adapter, false, fsp->location);
 	if (!rule) {
 		ret = -EINVAL;
 		goto release_lock;
···
 	spin_lock_bh(&adapter->fdir_fltr_lock);
 
 	list_for_each_entry(fltr, &adapter->fdir_list_head, list) {
+		if (iavf_is_raw_fdir(fltr))
+			continue;
+
 		if (cnt == cmd->rule_cnt) {
 			val = -EMSGSIZE;
 			goto release_lock;
···
 		return -EINVAL;
 
 	spin_lock_bh(&adapter->fdir_fltr_lock);
-	if (iavf_find_fdir_fltr(adapter, fsp->location)) {
+	if (iavf_find_fdir_fltr(adapter, false, fsp->location)) {
 		dev_err(&adapter->pdev->dev, "Failed to add Flow Director filter, it already exists\n");
 		spin_unlock_bh(&adapter->fdir_fltr_lock);
 		return -EEXIST;
···
 	if (!(adapter->flags & IAVF_FLAG_FDIR_ENABLED))
 		return -EOPNOTSUPP;
 
-	return iavf_fdir_del_fltr(adapter, fsp->location);
+	return iavf_fdir_del_fltr(adapter, false, fsp->location);
 }
 
 /**

drivers/net/ethernet/intel/iavf/iavf_fdir.c

···
 
 	spin_lock_bh(&adapter->fdir_fltr_lock);
 	list_for_each_entry(tmp, &adapter->fdir_list_head, list) {
+		if (iavf_is_raw_fdir(fltr))
+			continue;
+
 		if (tmp->flow_type != fltr->flow_type)
 			continue;
 
···
 /**
  * iavf_find_fdir_fltr - find FDIR filter
  * @adapter: pointer to the VF adapter structure
- * @loc: location to find.
+ * @is_raw: filter type, is raw (tc u32) or not (ethtool)
+ * @data: data to ID the filter, type dependent
  *
  * Returns: pointer to Flow Director filter if found or NULL. Lock must be held.
  */
 struct iavf_fdir_fltr *iavf_find_fdir_fltr(struct iavf_adapter *adapter,
-					   u32 loc)
+					   bool is_raw, u32 data)
 {
 	struct iavf_fdir_fltr *rule;
 
-	list_for_each_entry(rule, &adapter->fdir_list_head, list)
-		if (rule->loc == loc)
+	list_for_each_entry(rule, &adapter->fdir_list_head, list) {
+		if ((is_raw && rule->cls_u32_handle == data) ||
+		    (!is_raw && rule->loc == data))
 			return rule;
+	}
 
 	return NULL;
 }
···
 	}
 
 	list_for_each_entry(rule, &adapter->fdir_list_head, list) {
+		if (iavf_is_raw_fdir(fltr))
+			break;
+
 		if (rule->loc >= fltr->loc)
 			break;
 		parent = rule;
···
 		list_add(&fltr->list, &parent->list);
 	else
 		list_add(&fltr->list, &adapter->fdir_list_head);
-	adapter->fdir_active_fltr++;
+
+	iavf_inc_fdir_active_fltr(adapter, fltr);
 
 	if (adapter->link_up)
 		fltr->state = IAVF_FDIR_FLTR_ADD_REQUEST;
···
 /**
  * iavf_fdir_del_fltr - delete a flow director filter from the list
  * @adapter: pointer to the VF adapter structure
- * @loc: location to delete.
+ * @is_raw: filter type, is raw (tc u32) or not (ethtool)
+ * @data: data to ID the filter, type dependent
  *
  * Return: 0 on success or negative errno on failure.
  */
-int iavf_fdir_del_fltr(struct iavf_adapter *adapter, u32 loc)
+int iavf_fdir_del_fltr(struct iavf_adapter *adapter, bool is_raw, u32 data)
 {
 	struct iavf_fdir_fltr *fltr = NULL;
 	int err = 0;
 
 	spin_lock_bh(&adapter->fdir_fltr_lock);
-	fltr = iavf_find_fdir_fltr(adapter, loc);
+	fltr = iavf_find_fdir_fltr(adapter, is_raw, data);
 
 	if (fltr) {
 		if (fltr->state == IAVF_FDIR_FLTR_ACTIVE) {
 			fltr->state = IAVF_FDIR_FLTR_DEL_REQUEST;
 		} else if (fltr->state == IAVF_FDIR_FLTR_INACTIVE) {
 			list_del(&fltr->list);
+			iavf_dec_fdir_active_fltr(adapter, fltr);
 			kfree(fltr);
-			adapter->fdir_active_fltr--;
 			fltr = NULL;
 		} else {
 			err = -EBUSY;

drivers/net/ethernet/intel/iavf/iavf_fdir.h

···
 
 	u32 flow_id;
 
+	u32 cls_u32_handle; /* for FDIR added via tc u32 */
 	u32 loc;	/* Rule location inside the flow table */
 	u32 q_index;
 
 	struct virtchnl_fdir_add vc_add_msg;
 };
+
+static inline bool iavf_is_raw_fdir(struct iavf_fdir_fltr *fltr)
+{
+	return !fltr->vc_add_msg.rule_cfg.proto_hdrs.count;
+}
 
 int iavf_validate_fdir_fltr_masks(struct iavf_adapter *adapter,
 				  struct iavf_fdir_fltr *fltr);
···
 bool iavf_fdir_is_dup_fltr(struct iavf_adapter *adapter, struct iavf_fdir_fltr *fltr);
 int iavf_fdir_add_fltr(struct iavf_adapter *adapter,
 		       struct iavf_fdir_fltr *fltr);
-int iavf_fdir_del_fltr(struct iavf_adapter *adapter, u32 loc);
+int iavf_fdir_del_fltr(struct iavf_adapter *adapter, bool is_raw, u32 data);
 struct iavf_fdir_fltr *iavf_find_fdir_fltr(struct iavf_adapter *adapter,
-					   u32 loc);
+					   bool is_raw, u32 data);
 #endif /* _IAVF_FDIR_H_ */

drivers/net/ethernet/intel/iavf/iavf_main.c

···
 
 /**
  * iavf_setup_tc_cls_flower - flower classifier offloads
- * @adapter: board private structure
+ * @adapter: pointer to iavf adapter structure
  * @cls_flower: pointer to flow_cls_offload struct with flow info
  */
 static int iavf_setup_tc_cls_flower(struct iavf_adapter *adapter,
···
 		return iavf_delete_clsflower(adapter, cls_flower);
 	case FLOW_CLS_STATS:
 		return -EOPNOTSUPP;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+/**
+ * iavf_add_cls_u32 - Add U32 classifier offloads
+ * @adapter: pointer to iavf adapter structure
+ * @cls_u32: pointer to tc_cls_u32_offload struct with flow info
+ *
+ * Return: 0 on success or negative errno on failure.
+ */
+static int iavf_add_cls_u32(struct iavf_adapter *adapter,
+			    struct tc_cls_u32_offload *cls_u32)
+{
+	struct netlink_ext_ack *extack = cls_u32->common.extack;
+	struct virtchnl_fdir_rule *rule_cfg;
+	struct virtchnl_filter_action *vact;
+	struct virtchnl_proto_hdrs *hdrs;
+	struct ethhdr *spec_h, *mask_h;
+	const struct tc_action *act;
+	struct iavf_fdir_fltr *fltr;
+	struct tcf_exts *exts;
+	unsigned int q_index;
+	int i, status = 0;
+	int off_base = 0;
+
+	if (cls_u32->knode.link_handle) {
+		NL_SET_ERR_MSG_MOD(extack, "Linking not supported");
+		return -EOPNOTSUPP;
+	}
+
+	fltr = kzalloc(sizeof(*fltr), GFP_KERNEL);
+	if (!fltr)
+		return -ENOMEM;
+
+	rule_cfg = &fltr->vc_add_msg.rule_cfg;
+	hdrs = &rule_cfg->proto_hdrs;
+	hdrs->count = 0;
+
+	/* The parser lib at the PF expects the packet starting with MAC hdr */
+	switch (ntohs(cls_u32->common.protocol)) {
+	case ETH_P_802_3:
+		break;
+	case ETH_P_IP:
+		spec_h = (struct ethhdr *)hdrs->raw.spec;
+		mask_h = (struct ethhdr *)hdrs->raw.mask;
+		spec_h->h_proto = htons(ETH_P_IP);
+		mask_h->h_proto = htons(0xFFFF);
+		off_base += ETH_HLEN;
+		break;
+	default:
+		NL_SET_ERR_MSG_MOD(extack, "Only 802_3 and ip filter protocols are supported");
+		status = -EOPNOTSUPP;
+		goto free_alloc;
+	}
+
+	for (i = 0; i < cls_u32->knode.sel->nkeys; i++) {
+		__be32 val, mask;
+		int off;
+
+		off = off_base + cls_u32->knode.sel->keys[i].off;
+		val = cls_u32->knode.sel->keys[i].val;
+		mask = cls_u32->knode.sel->keys[i].mask;
+
+		if (off >= sizeof(hdrs->raw.spec)) {
+			NL_SET_ERR_MSG_MOD(extack, "Input exceeds maximum allowed.");
+			status = -EINVAL;
+			goto free_alloc;
+		}
+
+		memcpy(&hdrs->raw.spec[off], &val, sizeof(val));
+		memcpy(&hdrs->raw.mask[off], &mask, sizeof(mask));
+		hdrs->raw.pkt_len = off + sizeof(val);
+	}
+
+	/* Only one action is allowed */
+	rule_cfg->action_set.count = 1;
+	vact = &rule_cfg->action_set.actions[0];
+	exts = cls_u32->knode.exts;
+
+	tcf_exts_for_each_action(i, act, exts) {
+		/* FDIR queue */
+		if (is_tcf_skbedit_rx_queue_mapping(act)) {
+			q_index = tcf_skbedit_rx_queue_mapping(act);
+			if (q_index >= adapter->num_active_queues) {
+				status = -EINVAL;
+				goto free_alloc;
+			}
+
+			vact->type = VIRTCHNL_ACTION_QUEUE;
+			vact->act_conf.queue.index = q_index;
+			break;
+		}
+
+		/* Drop */
+		if (is_tcf_gact_shot(act)) {
+			vact->type = VIRTCHNL_ACTION_DROP;
+			break;
+		}
+
+		/* Unsupported action */
+		NL_SET_ERR_MSG_MOD(extack, "Unsupported action.");
+		status = -EOPNOTSUPP;
+		goto free_alloc;
+	}
+
+	fltr->vc_add_msg.vsi_id = adapter->vsi.id;
+	fltr->cls_u32_handle = cls_u32->knode.handle;
+	return iavf_fdir_add_fltr(adapter, fltr);
+
+free_alloc:
+	kfree(fltr);
+	return status;
+}
+
+/**
+ * iavf_del_cls_u32 - Delete U32 classifier offloads
+ * @adapter: pointer to iavf adapter structure
+ * @cls_u32: pointer to tc_cls_u32_offload struct with flow info
+ *
+ * Return: 0 on success or negative errno on failure.
+ */
+static int iavf_del_cls_u32(struct iavf_adapter *adapter,
+			    struct tc_cls_u32_offload *cls_u32)
+{
+	return iavf_fdir_del_fltr(adapter, true, cls_u32->knode.handle);
+}
+
+/**
+ * iavf_setup_tc_cls_u32 - U32 filter offloads
+ * @adapter: pointer to iavf adapter structure
+ * @cls_u32: pointer to tc_cls_u32_offload struct with flow info
+ *
+ * Return: 0 on success or negative errno on failure.
+ */
+static int iavf_setup_tc_cls_u32(struct iavf_adapter *adapter,
+				 struct tc_cls_u32_offload *cls_u32)
+{
+	if (!TC_U32_SUPPORT(adapter) || !FDIR_FLTR_SUPPORT(adapter))
+		return -EOPNOTSUPP;
+
+	switch (cls_u32->command) {
+	case TC_CLSU32_NEW_KNODE:
+	case TC_CLSU32_REPLACE_KNODE:
+		return iavf_add_cls_u32(adapter, cls_u32);
+	case TC_CLSU32_DELETE_KNODE:
+		return iavf_del_cls_u32(adapter, cls_u32);
 	default:
 		return -EOPNOTSUPP;
 	}
···
 	switch (type) {
 	case TC_SETUP_CLSFLOWER:
 		return iavf_setup_tc_cls_flower(cb_priv, type_data);
+	case TC_SETUP_CLSU32:
+		return iavf_setup_tc_cls_u32(cb_priv, type_data);
 	default:
 		return -EOPNOTSUPP;
 	}
···
 		    fdir->state == IAVF_FDIR_FLTR_INACTIVE) {
 			/* Delete filters not registered in PF */
 			list_del(&fdir->list);
+			iavf_dec_fdir_active_fltr(adapter, fdir);
 			kfree(fdir);
-			adapter->fdir_active_fltr--;
 		} else if (fdir->state == IAVF_FDIR_FLTR_ADD_PENDING ||
 			   fdir->state == IAVF_FDIR_FLTR_DIS_REQUEST ||
 			   fdir->state == IAVF_FDIR_FLTR_ACTIVE) {
···
 	/* get HW VLAN features that can be toggled */
 	hw_vlan_features = iavf_get_netdev_vlan_hw_features(adapter);
 
-	/* Enable cloud filter if ADQ is supported */
-	if (vfres->vf_cap_flags & VIRTCHNL_VF_OFFLOAD_ADQ)
+	/* Enable HW TC offload if ADQ or tc U32 is supported */
+	if (vfres->vf_cap_flags & VIRTCHNL_VF_OFFLOAD_ADQ ||
+	    TC_U32_SUPPORT(adapter))
 		hw_features |= NETIF_F_HW_TC;
+
 	if (vfres->vf_cap_flags & VIRTCHNL_VF_OFFLOAD_USO)
 		hw_features |= NETIF_F_GSO_UDP_L4;
 

drivers/net/ethernet/intel/iavf/iavf_virtchnl.c

···
 	       VIRTCHNL_VF_OFFLOAD_WB_ON_ITR |
 	       VIRTCHNL_VF_OFFLOAD_RSS_PCTYPE_V2 |
 	       VIRTCHNL_VF_OFFLOAD_ENCAP |
+	       VIRTCHNL_VF_OFFLOAD_TC_U32 |
 	       VIRTCHNL_VF_OFFLOAD_VLAN_V2 |
 	       VIRTCHNL_VF_OFFLOAD_CRC |
 	       VIRTCHNL_VF_OFFLOAD_ENCAP_CSUM |
···
 			 * list on PF is already cleared after a reset
 			 */
 			list_del(&f->list);
+			iavf_dec_fdir_active_fltr(adapter, f);
 			kfree(f);
-			adapter->fdir_active_fltr--;
 		}
 	}
 	spin_unlock_bh(&adapter->fdir_fltr_lock);
···
 						dev_err(&adapter->pdev->dev,
 							"%s\n", msg);
 					list_del(&fdir->list);
+					iavf_dec_fdir_active_fltr(adapter, fdir);
 					kfree(fdir);
-					adapter->fdir_active_fltr--;
 				}
 			}
 			spin_unlock_bh(&adapter->fdir_fltr_lock);
···
 					 list) {
 			if (fdir->state == IAVF_FDIR_FLTR_ADD_PENDING) {
 				if (add_fltr->status == VIRTCHNL_FDIR_SUCCESS) {
-					dev_info(&adapter->pdev->dev, "Flow Director filter with location %u is added\n",
-						 fdir->loc);
+					if (!iavf_is_raw_fdir(fdir))
+						dev_info(&adapter->pdev->dev, "Flow Director filter with location %u is added\n",
+							 fdir->loc);
+					else
+						dev_info(&adapter->pdev->dev, "Flow Director filter (raw) for TC handle %x is added\n",
+							 TC_U32_USERHTID(fdir->cls_u32_handle));
 					fdir->state = IAVF_FDIR_FLTR_ACTIVE;
 					fdir->flow_id = add_fltr->flow_id;
 				} else {
···
 						 add_fltr->status);
 					iavf_print_fdir_fltr(adapter, fdir);
 					list_del(&fdir->list);
+					iavf_dec_fdir_active_fltr(adapter, fdir);
 					kfree(fdir);
-					adapter->fdir_active_fltr--;
 				}
 			}
 		}
···
 				if (del_fltr->status == VIRTCHNL_FDIR_SUCCESS ||
 				    del_fltr->status ==
 				    VIRTCHNL_FDIR_FAILURE_RULE_NONEXIST) {
-					dev_info(&adapter->pdev->dev, "Flow Director filter with location %u is deleted\n",
-						 fdir->loc);
+					if (!iavf_is_raw_fdir(fdir))
+						dev_info(&adapter->pdev->dev, "Flow Director filter with location %u is deleted\n",
+							 fdir->loc);
+					else
+						dev_info(&adapter->pdev->dev, "Flow Director filter (raw) for TC handle %x is deleted\n",
+							 TC_U32_USERHTID(fdir->cls_u32_handle));
 					list_del(&fdir->list);
+					iavf_dec_fdir_active_fltr(adapter, fdir);
 					kfree(fdir);
-					adapter->fdir_active_fltr--;
 				} else {
 					fdir->state = IAVF_FDIR_FLTR_ACTIVE;
 					dev_info(&adapter->pdev->dev, "Failed to delete Flow Director filter with status: %d\n",

drivers/net/ethernet/intel/ice/ice_virtchnl.c

···
 	if (vf->driver_caps & VIRTCHNL_VF_OFFLOAD_FDIR_PF)
 		vfres->vf_cap_flags |= VIRTCHNL_VF_OFFLOAD_FDIR_PF;
 
+	if (vf->driver_caps & VIRTCHNL_VF_OFFLOAD_TC_U32 &&
+	    vfres->vf_cap_flags & VIRTCHNL_VF_OFFLOAD_FDIR_PF)
+		vfres->vf_cap_flags |= VIRTCHNL_VF_OFFLOAD_TC_U32;
+
 	if (vf->driver_caps & VIRTCHNL_VF_OFFLOAD_RSS_PCTYPE_V2)
 		vfres->vf_cap_flags |= VIRTCHNL_VF_OFFLOAD_RSS_PCTYPE_V2;
 

include/linux/avf/virtchnl.h

···
 /* used to negotiate communicating link speeds in Mbps */
 #define VIRTCHNL_VF_CAP_ADV_LINK_SPEED		BIT(7)
 #define  VIRTCHNL_VF_OFFLOAD_CRC		BIT(10)
+#define VIRTCHNL_VF_OFFLOAD_TC_U32		BIT(11)
 #define VIRTCHNL_VF_OFFLOAD_VLAN_V2		BIT(15)
 #define VIRTCHNL_VF_OFFLOAD_VLAN		BIT(16)
 #define VIRTCHNL_VF_OFFLOAD_RX_POLLING		BIT(17)