perf parse-events: Set exclude_guest=1 for user-space counting

Currently if we run 'perf record -e cycles:u', exclude_guest=0.

But it doesn't make sense in most cases that we request for
user-space counting but we also get the guest report.

Of course, we also need to consider 'perf kvm' usage case that
authorized perf users on the host may only want to count guest user
space events. For example,

  # perf kvm --guest record -e cycles:u

When we have 'exclude_guest=1' for 'perf kvm' usage, we may get nothing
from guest events.

To keep perf semantics consistent and clear, this patch sets
exclude_guest=1 for user-space counting but except for 'perf kvm' usage.

Before:

  perf record -e cycles:u ./div
  perf evlist -v
  cycles:u: ..., exclude_kernel: 1, exclude_hv: 1, ...

After:
  perf record -e cycles:u ./div
  perf evlist -v
  cycles:u: ..., exclude_kernel: 1, exclude_hv: 1,  exclude_guest: 1, ...

Before:
  perf kvm --guest record -e cycles:u -vvv

perf_event_attr:

  size                             120
  { sample_period, sample_freq }   4000
  sample_type                      IP|TID|TIME|ID|CPU|PERIOD
  read_format                      ID
  disabled                         1
  inherit                          1
  exclude_kernel                   1
  exclude_hv                       1
  freq                             1
  sample_id_all                    1

After:

  perf kvm --guest record -e cycles:u -vvv

perf_event_attr:
  size                             120
  { sample_period, sample_freq }   4000
  sample_type                      IP|TID|TIME|ID|CPU|PERIOD
  read_format                      ID
  disabled                         1
  inherit                          1
  exclude_kernel                   1
  exclude_hv                       1
  freq                             1
  sample_id_all                    1

For Before/After, exclude_guest are both 0 for perf kvm usage.

perf test 6

 6: Parse event definition strings             : Ok

Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Tested-by: Like Xu <like.xu@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20200814012120.16647-1-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/tests/parse-events.c

@@ -719,7 +719,7 @@ static int test__group2(struct evlist *evlist)
 	TEST_ASSERT_VAL("wrong exclude_user", !evsel->core.attr.exclude_user);
 	TEST_ASSERT_VAL("wrong exclude_kernel", !evsel->core.attr.exclude_kernel);
 	TEST_ASSERT_VAL("wrong exclude_hv", evsel->core.attr.exclude_hv);
-	TEST_ASSERT_VAL("wrong exclude guest", !evsel->core.attr.exclude_guest);
+	TEST_ASSERT_VAL("wrong exclude guest", evsel->core.attr.exclude_guest);
 	TEST_ASSERT_VAL("wrong exclude host", !evsel->core.attr.exclude_host);
 	TEST_ASSERT_VAL("wrong precise_ip", !evsel->core.attr.precise_ip);
 	TEST_ASSERT_VAL("wrong leader", evsel__is_group_leader(evsel));
@@ -842,7 +842,7 @@ static int test__group3(struct evlist *evlist __maybe_unused)
 	TEST_ASSERT_VAL("wrong exclude_user", !evsel->core.attr.exclude_user);
 	TEST_ASSERT_VAL("wrong exclude_kernel", evsel->core.attr.exclude_kernel);
 	TEST_ASSERT_VAL("wrong exclude_hv", evsel->core.attr.exclude_hv);
-	TEST_ASSERT_VAL("wrong exclude guest", !evsel->core.attr.exclude_guest);
+	TEST_ASSERT_VAL("wrong exclude guest", evsel->core.attr.exclude_guest);
 	TEST_ASSERT_VAL("wrong exclude host", !evsel->core.attr.exclude_host);
 	TEST_ASSERT_VAL("wrong precise_ip", !evsel->core.attr.precise_ip);
 	TEST_ASSERT_VAL("wrong leader", evsel__is_group_leader(evsel));

tools/perf/util/parse-events.c

@@ -37,6 +37,7 @@
 #include "util/evsel_config.h"
 #include "util/event.h"
 #include "util/pfm.h"
+#include "perf.h"
 
 #define MAX_NAME_LEN 100
 
@@ -1794,6 +1795,8 @@ static int get_event_modifier(struct event_modifier *mod, char *str,
 		if (*str == 'u') {
 			if (!exclude)
 				exclude = eu = ek = eh = 1;
+			if (!exclude_GH && !perf_guest)
+				eG = 1;
 			eu = 0;
 		} else if (*str == 'k') {
 			if (!exclude)