Merge branch 'bpf-event-output-offload'

Jakub Kicinski says:

====================
This series centres on NFP offload of bpf_event_output().  The
first patch allows perf event arrays to be used by offloaded
programs.  Next patch makes the nfp driver keep track of such
arrays to be able to filter FW events referring to maps.
Perf event arrays are not device bound.  Having driver
reimplement and manage the perf array seems brittle and unnecessary.

Patch 4 moves slightly the verifier step which replaces map fds
with map pointers.  This is useful for nfp JIT since we can then
easily replace host pointers with NFP table ids (patch 6).  This
allows us to lift the limitation on map helpers having to be used
with the same map pointer on all paths.  Second use of replacing
fds with real host map pointers is that we can use the host map
pointer as a key for FW events in perf event array offload.

Patch 5 adds perf event output offload support for the NFP.

There are some differences between bpf_event_output() offloaded
and non-offloaded version.  The FW messages which carry events
may get dropped and reordered relatively easily.  The return codes
from the helper are also not guaranteed to match the host.  Users
are warned about some of those discrepancies with a one time
warning message to kernel logs.

bpftool gains an ability to dump perf ring events in a very simple
format.  This was very useful for testing and simple debug, maybe
it will be useful to others?

Last patch is a trivial comment fix.
====================

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

1 files changed, 76 insertions, 1 deletions

diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c
index 465995281dcd..32f9e397a6c0 100644
--- a/tools/bpf/bpftool/common.c
+++ b/tools/bpf/bpftool/common.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2017 Netronome Systems, Inc.
+ * Copyright (C) 2017-2018 Netronome Systems, Inc.
  *
  * This software is dual licensed under the GNU General License Version 2,
  * June 1991 as shown in the file COPYING in the top-level directory of this
@@ -33,6 +33,7 @@
 
 /* Author: Jakub Kicinski <kubakici@wp.pl> */
 
+#include <ctype.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <fts.h>
@@ -330,6 +331,16 @@ char *get_fdinfo(int fd, const char *key)
 	return NULL;
 }
 
+void print_data_json(uint8_t *data, size_t len)
+{
+	unsigned int i;
+
+	jsonw_start_array(json_wtr);
+	for (i = 0; i < len; i++)
+		jsonw_printf(json_wtr, "%d", data[i]);
+	jsonw_end_array(json_wtr);
+}
+
 void print_hex_data_json(uint8_t *data, size_t len)
 {
 	unsigned int i;
@@ -420,6 +431,70 @@ void delete_pinned_obj_table(struct pinned_obj_table *tab)
 	}
 }
 
+unsigned int get_page_size(void)
+{
+	static int result;
+
+	if (!result)
+		result = getpagesize();
+	return result;
+}
+
+unsigned int get_possible_cpus(void)
+{
+	static unsigned int result;
+	char buf[128];
+	long int n;
+	char *ptr;
+	int fd;
+
+	if (result)
+		return result;
+
+	fd = open("/sys/devices/system/cpu/possible", O_RDONLY);
+	if (fd < 0) {
+		p_err("can't open sysfs possible cpus");
+		exit(-1);
+	}
+
+	n = read(fd, buf, sizeof(buf));
+	if (n < 2) {
+		p_err("can't read sysfs possible cpus");
+		exit(-1);
+	}
+	close(fd);
+
+	if (n == sizeof(buf)) {
+		p_err("read sysfs possible cpus overflow");
+		exit(-1);
+	}
+
+	ptr = buf;
+	n = 0;
+	while (*ptr && *ptr != '\n') {
+		unsigned int a, b;
+
+		if (sscanf(ptr, "%u-%u", &a, &b) == 2) {
+			n += b - a + 1;
+
+			ptr = strchr(ptr, '-') + 1;
+		} else if (sscanf(ptr, "%u", &a) == 1) {
+			n++;
+		} else {
+			assert(0);
+		}
+
+		while (isdigit(*ptr))
+			ptr++;
+		if (*ptr == ',')
+			ptr++;
+	}
+
+	result = n;
+
+	return result;
+}
+
 static char *
 ifindex_to_name_ns(__u32 ifindex, __u32 ns_dev, __u32 ns_ino, char *buf)
 {