Re: [PATCH] [PATCH v8 net-next] net: openvswitch: Add support to count upcall packets

[Jiri Pirko]

Tue, Dec 06, 2022 at 10:29:05AM CET, wangchuanlei@xxxxxxxxxx wrote:
>Add support to count upall packets, when kmod of openvswitch
>upcall to userspace , here count the number of packets for

s/userspace , here/userspace, here/

>upcall succeed and failed, which is a better way to see how
>many packets upcalled to userspace(ovs-vswitchd) on every
>interfaces.
>
>Here modify format of code used by comments of v7.
>
>Changes since v4 - v7:
>- optimize the function used by comments
>
>Changes since v3:
>- use nested NLA_NESTED attribute in netlink message
>
>Changes since v2:
>- add count of upcall failed packets
>
>Changes since v1:
>- add count of upcall succeed packets
>
>Signed-off-by: wangchuanlei <wangchuanlei@xxxxxxxxxx>
>---
> include/uapi/linux/openvswitch.h | 14 +++++++++
> net/openvswitch/datapath.c       | 41 ++++++++++++++++++++++++++
> net/openvswitch/vport.c          | 50 ++++++++++++++++++++++++++++++++
> net/openvswitch/vport.h          | 16 ++++++++++
> 4 files changed, 121 insertions(+)
>
>diff --git a/include/uapi/linux/openvswitch.h b/include/uapi/linux/openvswitch.h
>index 94066f87e9ee..8422ebf6885b 100644
>--- a/include/uapi/linux/openvswitch.h
>+++ b/include/uapi/linux/openvswitch.h
>@@ -277,11 +277,25 @@ enum ovs_vport_attr {
> 	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_SUCCESS,
>+	OVS_VPORT_UPCALL_FAIL,

Should be OVS_VPORT_UPCALL_ATTR_*


>+	__OVS_VPORT_UPCALL_MAX
>+};
>+
>+#define OVS_VPORT_UPCALL_MAX (__OVS_VPORT_UPCALL_MAX - 1)
>+
> enum {
> 	OVS_VXLAN_EXT_UNSPEC,
> 	OVS_VXLAN_EXT_GBP,	/* Flag or __u32 */
>diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
>index c8a9075ddd0a..1d379d943e00 100644
>--- a/net/openvswitch/datapath.c
>+++ b/net/openvswitch/datapath.c
>@@ -209,6 +209,26 @@ static struct vport *new_vport(const struct vport_parms *parms)
> 	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();
>@@ -216,6 +236,9 @@ void ovs_dp_detach_port(struct vport *p)
> 	/* 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);
> }
>@@ -305,6 +328,8 @@ int ovs_dp_upcall(struct datapath *dp, struct sk_buff *skb,
> 		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;
> 
>@@ -1825,6 +1850,12 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct genl_info *info)
> 		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);
>@@ -2097,6 +2128,9 @@ static int ovs_vport_cmd_fill_info(struct vport *vport, struct sk_buff *skb,
> 			  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;
> 
>@@ -2278,6 +2312,12 @@ static int ovs_vport_cmd_new(struct sk_buff *skb, struct genl_info *info)
> 		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;
>+	}
>+
> 	err = ovs_vport_cmd_fill_info(vport, reply, genl_info_net(info),
> 				      info->snd_portid, info->snd_seq, 0,
> 				      OVS_VPORT_CMD_NEW, GFP_KERNEL);
>@@ -2507,6 +2547,7 @@ static const struct nla_policy vport_policy[OVS_VPORT_ATTR_MAX + 1] = {
> 	[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 },

Why do you need this?


> };
> 
> static const struct genl_small_ops dp_vport_genl_ops[] = {
>diff --git a/net/openvswitch/vport.c b/net/openvswitch/vport.c
>index 82a74f998966..cdc649dae12c 100644
>--- a/net/openvswitch/vport.c
>+++ b/net/openvswitch/vport.c
>@@ -284,6 +284,56 @@ void ovs_vport_get_stats(struct vport *vport, struct ovs_vport_stats *stats)
> 	stats->tx_packets = dev_stats->tx_packets;
> }
> 
>+/**
>+ *	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_SUCCESS, tx_success,
>+			      OVS_VPORT_ATTR_PAD)) {
>+		nla_nest_cancel(skb, nla);
>+		return -EMSGSIZE;
>+	}
>+
>+	if (nla_put_u64_64bit(skb, OVS_VPORT_UPCALL_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
>  *
>diff --git a/net/openvswitch/vport.h b/net/openvswitch/vport.h
>index 7d276f60c000..3af18b5faa95 100644
>--- a/net/openvswitch/vport.h
>+++ b/net/openvswitch/vport.h
>@@ -32,6 +32,8 @@ struct vport *ovs_vport_locate(const struct net *net, const char *name);
> 
> 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 *);
> 
>@@ -65,6 +67,7 @@ struct vport_portids {
>  * @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.
>  */
>@@ -78,6 +81,7 @@ struct vport {
> 	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;
>@@ -137,6 +141,18 @@ struct vport_ops {
> 	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 *,
> 			      const struct vport_parms *);
> void ovs_vport_free(struct vport *);
>-- 
>2.27.0
>