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, 13 insertions, 67 deletions

diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c
index a6cdb640a0d7..af6766e956ba 100644
--- a/tools/bpf/bpftool/map.c
+++ b/tools/bpf/bpftool/map.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
@@ -34,7 +34,6 @@
 /* Author: Jakub Kicinski <kubakici@wp.pl> */
 
 #include <assert.h>
-#include <ctype.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <stdbool.h>
@@ -69,61 +68,6 @@ static const char * const map_type_name[] = {
 	[BPF_MAP_TYPE_CPUMAP]		= "cpumap",
 };
 
-static 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 bool map_is_per_cpu(__u32 type)
 {
 	return type == BPF_MAP_TYPE_PERCPU_HASH ||
@@ -186,8 +130,7 @@ static int map_parse_fd(int *argc, char ***argv)
 	return -1;
 }
 
-static int
-map_parse_fd_and_info(int *argc, char ***argv, void *info, __u32 *info_len)
+int map_parse_fd_and_info(int *argc, char ***argv, void *info, __u32 *info_len)
 {
 	int err;
 	int fd;
@@ -873,23 +816,25 @@ static int do_help(int argc, char **argv)
 
 	fprintf(stderr,
 		"Usage: %s %s { show | list }   [MAP]\n"
-		"       %s %s dump    MAP\n"
-		"       %s %s update  MAP  key [hex] BYTES value [hex] VALUE [UPDATE_FLAGS]\n"
-		"       %s %s lookup  MAP  key [hex] BYTES\n"
-		"       %s %s getnext MAP [key [hex] BYTES]\n"
-		"       %s %s delete  MAP  key [hex] BYTES\n"
-		"       %s %s pin     MAP  FILE\n"
+		"       %s %s dump       MAP\n"
+		"       %s %s update     MAP  key DATA value VALUE [UPDATE_FLAGS]\n"
+		"       %s %s lookup     MAP  key DATA\n"
+		"       %s %s getnext    MAP [key DATA]\n"
+		"       %s %s delete     MAP  key DATA\n"
+		"       %s %s pin        MAP  FILE\n"
+		"       %s %s event_pipe MAP [cpu N index M]\n"
 		"       %s %s help\n"
 		"\n"
 		"       MAP := { id MAP_ID | pinned FILE }\n"
+		"       DATA := { [hex] BYTES }\n"
 		"       " HELP_SPEC_PROGRAM "\n"
-		"       VALUE := { BYTES | MAP | PROG }\n"
+		"       VALUE := { DATA | MAP | PROG }\n"
 		"       UPDATE_FLAGS := { any | exist | noexist }\n"
 		"       " HELP_SPEC_OPTIONS "\n"
 		"",
 		bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
 		bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2],
-		bin_name, argv[-2], bin_name, argv[-2]);
+		bin_name, argv[-2], bin_name, argv[-2], bin_name, argv[-2]);
 
 	return 0;
 }
@@ -904,6 +849,7 @@ static const struct cmd cmds[] = {
 	{ "getnext",	do_getnext },
 	{ "delete",	do_delete },
 	{ "pin",	do_pin },
+	{ "event_pipe",	do_event_pipe },
 	{ 0 }
 };