Merge remote-tracking branch 'remotes/stefanha-gitlab/tags/tracing-pull-request' into staging

Pull request

# gpg: Signature made Mon 12 Jul 2021 17:49:46 BST
# gpg:                using RSA key 8695A8BFD3F97CDAAC35775A9CA4ABB381AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>" [full]
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>" [full]
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35  775A 9CA4 ABB3 81AB 73C8

* remotes/stefanha-gitlab/tags/tracing-pull-request:
  trace, lttng: require .pc files
  trace/simple: add st_init_group
  trace/simple: pass iter to st_write_event_mapping
  trace: add trace_event_iter_init_group
  trace: iter init tweaks
  qemu-trace-stap: changing SYSTEMTAP_TAPSET considered harmful.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 17 insertions, 5 deletions

diff --git a/trace/simple.c b/trace/simple.c
index 9cd2ed1fb3..ac499edee0 100644
--- a/trace/simple.c
+++ b/trace/simple.c
@@ -280,14 +280,12 @@ void trace_record_finish(TraceBufferRecord *rec)
     }
 }
 
-static int st_write_event_mapping(void)
+static int st_write_event_mapping(TraceEventIter *iter)
 {
     uint64_t type = TRACE_RECORD_TYPE_MAPPING;
-    TraceEventIter iter;
     TraceEvent *ev;
 
-    trace_event_iter_init(&iter, NULL);
-    while ((ev = trace_event_iter_next(&iter)) != NULL) {
+    while ((ev = trace_event_iter_next(iter)) != NULL) {
         uint64_t id = trace_event_get_id(ev);
         const char *name = trace_event_get_name(ev);
         uint32_t len = strlen(name);
@@ -309,6 +307,7 @@ static int st_write_event_mapping(void)
  */
 bool st_set_trace_file_enabled(bool enable)
 {
+    TraceEventIter iter;
     bool was_enabled = trace_fp;
 
     if (enable == !!trace_fp) {
@@ -333,8 +332,9 @@ bool st_set_trace_file_enabled(bool enable)
             return was_enabled;
         }
 
+        trace_event_iter_init_all(&iter);
         if (fwrite(&header, sizeof header, 1, trace_fp) != 1 ||
-            st_write_event_mapping() < 0) {
+            st_write_event_mapping(&iter) < 0) {
             fclose(trace_fp);
             trace_fp = NULL;
             return was_enabled;
@@ -422,3 +422,15 @@ bool st_init(void)
     atexit(st_flush_trace_buffer);
     return true;
 }
+
+void st_init_group(size_t group)
+{
+    TraceEventIter iter;
+
+    if (!trace_writeout_enabled) {
+        return;
+    }
+
+    trace_event_iter_init_group(&iter, group);
+    st_write_event_mapping(&iter);
+}