xsk: Add xdp statistics to xsk_diag

Add xdp statistics to the information dumped through the xsk_diag interface
Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200708072835.4427-4-ciara.loftus@intel.com

include/uapi/linux/xdp_diag.h

@@ -30,6 +30,7 @@ struct xdp_diag_msg {
 #define XDP_SHOW_RING_CFG	(1 << 1)
 #define XDP_SHOW_UMEM		(1 << 2)
 #define XDP_SHOW_MEMINFO	(1 << 3)
+#define XDP_SHOW_STATS		(1 << 4)
 
 enum {
 	XDP_DIAG_NONE,
@@ -41,6 +42,7 @@ enum {
 	XDP_DIAG_UMEM_FILL_RING,
 	XDP_DIAG_UMEM_COMPLETION_RING,
 	XDP_DIAG_MEMINFO,
+	XDP_DIAG_STATS,
 	__XDP_DIAG_MAX,
 };
 
@@ -69,4 +71,13 @@ struct xdp_diag_umem {
 	__u32	refs;
 };
 
+struct xdp_diag_stats {
+	__u64	n_rx_dropped;
+	__u64	n_rx_invalid;
+	__u64	n_rx_full;
+	__u64	n_fill_ring_empty;
+	__u64	n_tx_invalid;
+	__u64	n_tx_ring_empty;
+};
+
 #endif /* _LINUX_XDP_DIAG_H */

net/xdp/xsk_diag.c

@@ -76,6 +76,19 @@ static int xsk_diag_put_umem(const struct xdp_sock *xs, struct sk_buff *nlskb)
 	return err;
 }
 
+static int xsk_diag_put_stats(const struct xdp_sock *xs, struct sk_buff *nlskb)
+{
+	struct xdp_diag_stats du = {};
+
+	du.n_rx_dropped = xs->rx_dropped;
+	du.n_rx_invalid = xskq_nb_invalid_descs(xs->rx);
+	du.n_rx_full = xs->rx_queue_full;
+	du.n_fill_ring_empty = xs->umem ? xskq_nb_queue_empty_descs(xs->umem->fq) : 0;
+	du.n_tx_invalid = xskq_nb_invalid_descs(xs->tx);
+	du.n_tx_ring_empty = xskq_nb_queue_empty_descs(xs->tx);
+	return nla_put(nlskb, XDP_DIAG_STATS, sizeof(du), &du);
+}
+
 static int xsk_diag_fill(struct sock *sk, struct sk_buff *nlskb,
 			 struct xdp_diag_req *req,
 			 struct user_namespace *user_ns,
@@ -118,6 +131,10 @@ static int xsk_diag_fill(struct sock *sk, struct sk_buff *nlskb,
 	    sock_diag_put_meminfo(sk, nlskb, XDP_DIAG_MEMINFO))
 		goto out_nlmsg_trim;
 
+	if ((req->xdiag_show & XDP_SHOW_STATS) &&
+	    xsk_diag_put_stats(xs, nlskb))
+		goto out_nlmsg_trim;
+
 	mutex_unlock(&xs->mutex);
 	nlmsg_end(nlskb, nlh);
 	return 0;