Merge branch 'XDP-redirect-tracepoints'

Jesper Dangaard Brouer says:

====================
XDP redirect tracepoints

I feel this is as far as I can take the tracepoint infrastructure to
assist XDP monitoring.

Tracepoints comes with a base overhead of 25 nanosec for an attached
bpf_prog, and 48 nanosec for using a full perf record. This is
problematic for the XDP use-case, but it is very convenient to use the
existing perf infrastructure.

From a performance perspective, the real solution would be to attach
another bpf_prog (that understand xdp_buff), but I'm not sure we want
to introduce yet another bpf attach API for this.

One thing left is to standardize the possible err return codes, to a
limited set, to allow easier (and faster) mapping into a bpf map.
====================

Signed-off-by: David S. Miller <[email protected]>

1 files changed, 82 insertions, 18 deletions

diff --git a/include/trace/events/xdp.h b/include/trace/events/xdp.h
index 27cf2ef35f5f..862575ac8da9 100644
--- a/include/trace/events/xdp.h
+++ b/include/trace/events/xdp.h
@@ -31,55 +31,119 @@ TRACE_EVENT(xdp_exception,
 	TP_ARGS(dev, xdp, act),
 
 	TP_STRUCT__entry(
-		__array(u8, prog_tag, 8)
+		__field(int, prog_id)
 		__field(u32, act)
 		__field(int, ifindex)
 	),
 
 	TP_fast_assign(
-		BUILD_BUG_ON(sizeof(__entry->prog_tag) != sizeof(xdp->tag));
-		memcpy(__entry->prog_tag, xdp->tag, sizeof(xdp->tag));
+		__entry->prog_id	= xdp->aux->id;
 		__entry->act		= act;
 		__entry->ifindex	= dev->ifindex;
 	),
 
-	TP_printk("prog=%s action=%s ifindex=%d",
-		  __print_hex_str(__entry->prog_tag, 8),
+	TP_printk("prog_id=%d action=%s ifindex=%d",
+		  __entry->prog_id,
 		  __print_symbolic(__entry->act, __XDP_ACT_SYM_TAB),
 		  __entry->ifindex)
 );
 
-TRACE_EVENT(xdp_redirect,
+DECLARE_EVENT_CLASS(xdp_redirect_template,
 
 	TP_PROTO(const struct net_device *dev,
-		 const struct bpf_prog *xdp, u32 act,
-		 int to_index, int err),
+		 const struct bpf_prog *xdp,
+		 int to_ifindex, int err,
+		 const struct bpf_map *map, u32 map_index),
 
-	TP_ARGS(dev, xdp, act, to_index, err),
+	TP_ARGS(dev, xdp, to_ifindex, err, map, map_index),
 
 	TP_STRUCT__entry(
-		__array(u8, prog_tag, 8)
+		__field(int, prog_id)
 		__field(u32, act)
 		__field(int, ifindex)
-		__field(int, to_index)
 		__field(int, err)
+		__field(int, to_ifindex)
+		__field(u32, map_id)
+		__field(int, map_index)
 	),
 
 	TP_fast_assign(
-		BUILD_BUG_ON(sizeof(__entry->prog_tag) != sizeof(xdp->tag));
-		memcpy(__entry->prog_tag, xdp->tag, sizeof(xdp->tag));
-		__entry->act		= act;
+		__entry->prog_id	= xdp->aux->id;
+		__entry->act		= XDP_REDIRECT;
 		__entry->ifindex	= dev->ifindex;
-		__entry->to_index	= to_index;
 		__entry->err		= err;
+		__entry->to_ifindex	= to_ifindex;
+		__entry->map_id		= map ? map->id : 0;
+		__entry->map_index	= map_index;
 	),
 
-	TP_printk("prog=%s action=%s ifindex=%d to_index=%d err=%d",
-		  __print_hex_str(__entry->prog_tag, 8),
+	TP_printk("prog_id=%d action=%s ifindex=%d to_ifindex=%d err=%d",
+		  __entry->prog_id,
 		  __print_symbolic(__entry->act, __XDP_ACT_SYM_TAB),
-		  __entry->ifindex, __entry->to_index,
+		  __entry->ifindex, __entry->to_ifindex,
 		  __entry->err)
 );
+
+DEFINE_EVENT(xdp_redirect_template, xdp_redirect,
+	TP_PROTO(const struct net_device *dev,
+		 const struct bpf_prog *xdp,
+		 int to_ifindex, int err,
+		 const struct bpf_map *map, u32 map_index),
+	TP_ARGS(dev, xdp, to_ifindex, err, map, map_index)
+);
+
+DEFINE_EVENT(xdp_redirect_template, xdp_redirect_err,
+	TP_PROTO(const struct net_device *dev,
+		 const struct bpf_prog *xdp,
+		 int to_ifindex, int err,
+		 const struct bpf_map *map, u32 map_index),
+	TP_ARGS(dev, xdp, to_ifindex, err, map, map_index)
+);
+
+#define _trace_xdp_redirect(dev, xdp, to)		\
+	 trace_xdp_redirect(dev, xdp, to, 0, NULL, 0);
+
+#define _trace_xdp_redirect_err(dev, xdp, to, err)	\
+	 trace_xdp_redirect_err(dev, xdp, to, err, NULL, 0);
+
+DEFINE_EVENT_PRINT(xdp_redirect_template, xdp_redirect_map,
+	TP_PROTO(const struct net_device *dev,
+		 const struct bpf_prog *xdp,
+		 int to_ifindex, int err,
+		 const struct bpf_map *map, u32 map_index),
+	TP_ARGS(dev, xdp, to_ifindex, err, map, map_index),
+	TP_printk("prog_id=%d action=%s ifindex=%d to_ifindex=%d err=%d"
+		  " map_id=%d map_index=%d",
+		  __entry->prog_id,
+		  __print_symbolic(__entry->act, __XDP_ACT_SYM_TAB),
+		  __entry->ifindex, __entry->to_ifindex,
+		  __entry->err,
+		  __entry->map_id, __entry->map_index)
+);
+
+DEFINE_EVENT_PRINT(xdp_redirect_template, xdp_redirect_map_err,
+	TP_PROTO(const struct net_device *dev,
+		 const struct bpf_prog *xdp,
+		 int to_ifindex, int err,
+		 const struct bpf_map *map, u32 map_index),
+	TP_ARGS(dev, xdp, to_ifindex, err, map, map_index),
+	TP_printk("prog_id=%d action=%s ifindex=%d to_ifindex=%d err=%d"
+		  " map_id=%d map_index=%d",
+		  __entry->prog_id,
+		  __print_symbolic(__entry->act, __XDP_ACT_SYM_TAB),
+		  __entry->ifindex, __entry->to_ifindex,
+		  __entry->err,
+		  __entry->map_id, __entry->map_index)
+);
+
+#define _trace_xdp_redirect_map(dev, xdp, fwd, map, idx)		\
+	 trace_xdp_redirect_map(dev, xdp, fwd ? fwd->ifindex : 0,	\
+				0, map, idx);
+
+#define _trace_xdp_redirect_map_err(dev, xdp, fwd, map, idx, err)	\
+	 trace_xdp_redirect_map_err(dev, xdp, fwd ? fwd->ifindex : 0,	\
+				    err, map, idx);
+
 #endif /* _TRACE_XDP_H */
 
 #include <trace/define_trace.h>