perf kvm: Add stat support on s390

On s390, the vmexit event has a tree-like structure: between
exit_event_begin and exit_event_end several other events may happen and
with each of them refining the previous ones.

This patch adds a decoder for such events to the generic code and also
the files <asm/kvm_perf.h> and kvm-stat.c for s390.

Commands 'perf kvm stat record', 'report' and 'live' are supported.

Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Alexander Yarygin <yarygin@linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1404397747-20939-5-git-send-email-yarygin@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 48 insertions, 4 deletions

diff --git a/tools/perf/builtin-kvm.c b/tools/perf/builtin-kvm.c
index fc2d63d3e791..43367eb00510 100644
--- a/tools/perf/builtin-kvm.c
+++ b/tools/perf/builtin-kvm.c
@@ -88,7 +88,7 @@ void exit_event_decode_key(struct perf_kvm_stat *kvm,
                            struct event_key *key,
                            char *decode)
 {
-        const char *exit_reason = get_exit_reason(kvm, kvm->exit_reasons,
+        const char *exit_reason = get_exit_reason(kvm, key->exit_reasons,
                                                   key->key);
 
         scnprintf(decode, DECODE_STR_LEN, "%s", exit_reason);
@@ -261,6 +261,43 @@ static bool update_kvm_event(struct kvm_event *event, int vcpu_id,
         return true;
 }
 
+static bool is_child_event(struct perf_kvm_stat *kvm,
+                           struct perf_evsel *evsel,
+                           struct perf_sample *sample,
+                           struct event_key *key)
+{
+        struct child_event_ops *child_ops;
+
+        child_ops = kvm->events_ops->child_ops;
+
+        if (!child_ops)
+                return false;
+
+        for (; child_ops->name; child_ops++) {
+                if (!strcmp(evsel->name, child_ops->name)) {
+                        child_ops->get_key(evsel, sample, key);
+                        return true;
+                }
+        }
+
+        return false;
+}
+
+static bool handle_child_event(struct perf_kvm_stat *kvm,
+                               struct vcpu_event_record *vcpu_record,
+                               struct event_key *key,
+                               struct perf_sample *sample __maybe_unused)
+{
+        struct kvm_event *event = NULL;
+
+        if (key->key != INVALID_KEY)
+                event = find_create_kvm_event(kvm, key);
+
+        vcpu_record->last_event = event;
+
+        return true;
+}
+
 static bool skip_event(const char *event)
 {
         const char * const *skip_events;
@@ -361,7 +398,8 @@ static bool handle_kvm_event(struct perf_kvm_stat *kvm,
                              struct perf_sample *sample)
 {
         struct vcpu_event_record *vcpu_record;
-        struct event_key key = {.key = INVALID_KEY};
+        struct event_key key = { .key = INVALID_KEY,
+                                 .exit_reasons = kvm->exit_reasons };
 
         vcpu_record = per_vcpu_record(thread, evsel, sample);
         if (!vcpu_record)
@@ -375,6 +413,9 @@ static bool handle_kvm_event(struct perf_kvm_stat *kvm,
         if (kvm->events_ops->is_begin_event(evsel, sample, &key))
                 return handle_begin_event(kvm, vcpu_record, &key, sample->time);
 
+        if (is_child_event(kvm, evsel, sample, &key))
+                return handle_child_event(kvm, vcpu_record, &key, sample);
+
         if (kvm->events_ops->is_end_event(evsel, sample, &key))
                 return handle_end_event(kvm, vcpu_record, &key, sample);
 
@@ -1143,7 +1184,8 @@ kvm_events_report(struct perf_kvm_stat *kvm, int argc, const char **argv)
 {
         const struct option kvm_events_report_options[] = {
                 OPT_STRING(0, "event", &kvm->report_event, "report event",
-                            "event for reporting: vmexit, mmio, ioport"),
+                           "event for reporting: vmexit, "
+                           "mmio (x86 only), ioport (x86 only)"),
                 OPT_INTEGER(0, "vcpu", &kvm->trace_vcpu,
                             "vcpu id to report"),
                 OPT_STRING('k', "key", &kvm->sort_key, "sort-key",
@@ -1249,7 +1291,9 @@ static int kvm_events_live(struct perf_kvm_stat *kvm,
                         "key for sorting: sample(sort by samples number)"
                         " time (sort by avg time)"),
                 OPT_U64(0, "duration", &kvm->duration,
-                    "show events other than HALT that take longer than duration usecs"),
+                        "show events other than"
+                        " HLT (x86 only) or Wait state (s390 only)"
+                        " that take longer than duration usecs"),
                 OPT_END()
         };
         const char * const live_usage[] = {