net: openvswitch: Add support to count upcall packets

Add support to count upall packets, when kmod of openvswitch
upcall to count the number of packets for upcall succeed and
failed, which is a better way to see how many packets upcalled
on every interfaces.

Signed-off-by: wangchuanlei <[e-mail]>
Acked-by: Eelco Chaudron <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

include/uapi/linux/openvswitch.h

···
 	OVS_VPORT_ATTR_PAD,
 	OVS_VPORT_ATTR_IFINDEX,
 	OVS_VPORT_ATTR_NETNSID,
+	OVS_VPORT_ATTR_UPCALL_STATS,
 	__OVS_VPORT_ATTR_MAX
 };
 
 #define OVS_VPORT_ATTR_MAX (__OVS_VPORT_ATTR_MAX - 1)
+
+/**
+ * enum ovs_vport_upcall_attr - attributes for %OVS_VPORT_UPCALL* commands
+ * @OVS_VPORT_UPCALL_SUCCESS: 64-bit upcall success packets.
+ * @OVS_VPORT_UPCALL_FAIL: 64-bit upcall fail packets.
+ */
+enum ovs_vport_upcall_attr {
+	OVS_VPORT_UPCALL_ATTR_SUCCESS,
+	OVS_VPORT_UPCALL_ATTR_FAIL,
+	__OVS_VPORT_UPCALL_ATTR_MAX
+};
+
+#define OVS_VPORT_UPCALL_ATTR_MAX (__OVS_VPORT_UPCALL_ATTR_MAX - 1)
 
 enum {
 	OVS_VXLAN_EXT_UNSPEC,

net/openvswitch/datapath.c

···
 	return vport;
 }
 
+static void ovs_vport_update_upcall_stats(struct sk_buff *skb,
+					  const struct dp_upcall_info *upcall_info,
+					  bool upcall_result)
+{
+	struct vport *p = OVS_CB(skb)->input_vport;
+	struct vport_upcall_stats_percpu *stats;
+
+	if (upcall_info->cmd != OVS_PACKET_CMD_MISS &&
+	    upcall_info->cmd != OVS_PACKET_CMD_ACTION)
+		return;
+
+	stats = this_cpu_ptr(p->upcall_stats);
+	u64_stats_update_begin(&stats->syncp);
+	if (upcall_result)
+		u64_stats_inc(&stats->n_success);
+	else
+		u64_stats_inc(&stats->n_fail);
+	u64_stats_update_end(&stats->syncp);
+}
+
 void ovs_dp_detach_port(struct vport *p)
 {
 	ASSERT_OVSL();
 
 	/* First drop references to device. */
 	hlist_del_rcu(&p->dp_hash_node);
+
+	/* Free percpu memory */
+	free_percpu(p->upcall_stats);
 
 	/* Then destroy it. */
 	ovs_vport_del(p);
···
 		err = queue_userspace_packet(dp, skb, key, upcall_info, cutlen);
 	else
 		err = queue_gso_packets(dp, skb, key, upcall_info, cutlen);
+
+	ovs_vport_update_upcall_stats(skb, upcall_info, !err);
 	if (err)
 		goto err;
 
···
 		goto err_destroy_portids;
 	}
 
+	vport->upcall_stats = netdev_alloc_pcpu_stats(struct vport_upcall_stats_percpu);
+	if (!vport->upcall_stats) {
+		err = -ENOMEM;
+		goto err_destroy_portids;
+	}
+
 	err = ovs_dp_cmd_fill_info(dp, reply, info->snd_portid,
 				   info->snd_seq, 0, OVS_DP_CMD_NEW);
 	BUG_ON(err < 0);
···
 			  OVS_VPORT_ATTR_PAD))
 		goto nla_put_failure;
 
+	if (ovs_vport_get_upcall_stats(vport, skb))
+		goto nla_put_failure;
+
 	if (ovs_vport_get_upcall_portids(vport, skb))
 		goto nla_put_failure;
 
···
 	if (IS_ERR(vport)) {
 		if (err == -EAGAIN)
 			goto restart;
+		goto exit_unlock_free;
+	}
+
+	vport->upcall_stats = netdev_alloc_pcpu_stats(struct vport_upcall_stats_percpu);
+	if (!vport->upcall_stats) {
+		err = -ENOMEM;
 		goto exit_unlock_free;
 	}
 
···
 	[OVS_VPORT_ATTR_OPTIONS] = { .type = NLA_NESTED },
 	[OVS_VPORT_ATTR_IFINDEX] = { .type = NLA_U32 },
 	[OVS_VPORT_ATTR_NETNSID] = { .type = NLA_S32 },
+	[OVS_VPORT_ATTR_UPCALL_STATS] = { .type = NLA_NESTED },
 };
 
 static const struct genl_small_ops dp_vport_genl_ops[] = {

net/openvswitch/vport.c

···
 }
 
 /**
+ *	ovs_vport_get_upcall_stats - retrieve upcall stats
+ *
+ * @vport: vport from which to retrieve the stats.
+ * @skb: sk_buff where upcall stats should be appended.
+ *
+ * Retrieves upcall stats for the given device.
+ *
+ * Must be called with ovs_mutex or rcu_read_lock.
+ */
+int ovs_vport_get_upcall_stats(struct vport *vport, struct sk_buff *skb)
+{
+	struct nlattr *nla;
+	int i;
+
+	__u64 tx_success = 0;
+	__u64 tx_fail = 0;
+
+	for_each_possible_cpu(i) {
+		const struct vport_upcall_stats_percpu *stats;
+		unsigned int start;
+
+		stats = per_cpu_ptr(vport->upcall_stats, i);
+		do {
+			start = u64_stats_fetch_begin(&stats->syncp);
+			tx_success += u64_stats_read(&stats->n_success);
+			tx_fail += u64_stats_read(&stats->n_fail);
+		} while (u64_stats_fetch_retry(&stats->syncp, start));
+	}
+
+	nla = nla_nest_start_noflag(skb, OVS_VPORT_ATTR_UPCALL_STATS);
+	if (!nla)
+		return -EMSGSIZE;
+
+	if (nla_put_u64_64bit(skb, OVS_VPORT_UPCALL_ATTR_SUCCESS, tx_success,
+			      OVS_VPORT_ATTR_PAD)) {
+		nla_nest_cancel(skb, nla);
+		return -EMSGSIZE;
+	}
+
+	if (nla_put_u64_64bit(skb, OVS_VPORT_UPCALL_ATTR_FAIL, tx_fail,
+			      OVS_VPORT_ATTR_PAD)) {
+		nla_nest_cancel(skb, nla);
+		return -EMSGSIZE;
+	}
+	nla_nest_end(skb, nla);
+
+	return 0;
+}
+
+/**
  *	ovs_vport_get_options - retrieve device options
  *
  * @vport: vport from which to retrieve the options.

net/openvswitch/vport.h

···
 
 void ovs_vport_get_stats(struct vport *, struct ovs_vport_stats *);
 
+int ovs_vport_get_upcall_stats(struct vport *vport, struct sk_buff *skb);
+
 int ovs_vport_set_options(struct vport *, struct nlattr *options);
 int ovs_vport_get_options(const struct vport *, struct sk_buff *);
 
···
  * @hash_node: Element in @dev_table hash table in vport.c.
  * @dp_hash_node: Element in @datapath->ports hash table in datapath.c.
  * @ops: Class structure.
+ * @upcall_stats: Upcall stats of every ports.
  * @detach_list: list used for detaching vport in net-exit call.
  * @rcu: RCU callback head for deferred destruction.
  */
···
 	struct hlist_node hash_node;
 	struct hlist_node dp_hash_node;
 	const struct vport_ops *ops;
+	struct vport_upcall_stats_percpu __percpu *upcall_stats;
 
 	struct list_head detach_list;
 	struct rcu_head rcu;
···
 	int (*send)(struct sk_buff *skb);
 	struct module *owner;
 	struct list_head list;
+};
+
+/**
+ * struct vport_upcall_stats_percpu - per-cpu packet upcall statistics for
+ * a given vport.
+ * @n_success: Number of packets that upcall to userspace succeed.
+ * @n_fail:    Number of packets that upcall to userspace failed.
+ */
+struct vport_upcall_stats_percpu {
+	struct u64_stats_sync syncp;
+	u64_stats_t n_success;
+	u64_stats_t n_fail;
 };
 
 struct vport *ovs_vport_alloc(int priv_size, const struct vport_ops *,