@@ -129,6 +129,9 @@ This functionality is also provided through monitor commands:
* trace-event NAME on|off
Enable/disable a given trace event.
+The "-trace events=<file>" command line argument can be used to enable the
+events listed in <file> from the very beginning of the program.
+
== Trace backends ==
The "tracetool" script automates tedious trace event code generation and also
@@ -302,6 +302,9 @@ static QemuOptsList qemu_trace_opts = {
.head = QTAILQ_HEAD_INITIALIZER(qemu_trace_opts.head),
.desc = {
{
+ .name = "events",
+ .type = QEMU_OPT_STRING,
+ },{
.name = "file",
.type = QEMU_OPT_STRING,
},
@@ -2394,17 +2394,29 @@ Normally QEMU loads a configuration file from @var{sysconfdir}/qemu.conf and
option will prevent QEMU from loading these configuration files at startup.
ETEXI
DEF("trace", HAS_ARG, QEMU_OPTION_trace,
- "-trace\n"
- " Specify a trace file to log traces to\n",
+ "-trace [events=<file>][,file=<file>]\n"
+ " specify tracing options\n",
QEMU_ARCH_ALL)
STEXI
-HXCOMM This line is not accurate, as the option is backend-specific but HX does
-HXCOMM not support conditional compilation of text.
-@item -trace
+HXCOMM This line is not accurate, as some sub-options are backend-specific but
+HXCOMM HX does not support conditional compilation of text.
+@item -trace [events=@var{file}][,file=@var{file}]
@findex -trace
-Specify a trace file to log output traces to.
+
+Specify tracing options.
+
+@table @option
+@item events=@var{file}
+Immediately enable events listed in @var{file}.
+The file must contain one event name (as listed in the @var{trace-events} file)
+per line.
+
+This option is not available when using the @var{nop} tracing backend.
+@item file=@var{file}
+Log output traces to @var{file}.
This option is available only when using the @var{simple} tracing backend.
+@end table
ETEXI
HXCOMM This is the last statement. Insert new options before this line!
@@ -34,3 +34,33 @@ bool trace_event_set_state (const char *name, bool state)
#endif
return false;
}
+
+void trace_config_event_set_state (const char *fname)
+{
+ if (fname == NULL) {
+ return;
+ }
+
+ FILE *fp = fopen(fname, "r");
+ if (!fp) {
+ fprintf(stderr, "could not open trace events file '%s': %s\n",
+ fname, strerror(errno));
+ exit(1);
+ }
+ char line_buf[1024];
+ while (fgets(line_buf, sizeof(line_buf), fp)) {
+ size_t len = strlen(line_buf);
+ if (len > 1) { /* skip empty lines */
+ line_buf[len - 1] = '\0';
+ if (!trace_event_set_state(line_buf, true)) {
+ fprintf(stderr, "qemu: error: trace event '%s' does not exist\n", line_buf);
+ exit(1);
+ }
+ }
+ }
+ if (fclose(fp) != 0) {
+ fprintf(stderr, "qemu: error: closing file '%s': %s\n",
+ fname, strerror(errno));
+ exit(1);
+ }
+}
@@ -11,4 +11,6 @@
void trace_print_events (FILE *stream, fprintf_function stream_printf);
bool trace_event_set_state (const char *name, bool state);
+void trace_config_event_set_state (const char *fname);
+
#endif /* TRACE_CONTROL_H */
@@ -156,6 +156,7 @@ int main(int argc, char **argv)
#include "slirp/libslirp.h"
#include "trace.h"
+#include "trace/control.h"
#include "trace/simple.h"
#include "qemu-queue.h"
#include "cpus.h"
@@ -2870,6 +2871,7 @@ int main(int argc, char **argv, char **envp)
fprintf(stderr, "qemu: option \"-%s\" is not supported by this tracing backend\n", popt->name);
exit(1);
#endif
+ trace_config_event_set_state(qemu_opt_get(opts, "events"));
trace_file = qemu_opt_get(opts, "file");
#if !defined(CONFIG_SIMPLE_TRACE)
if (trace_file) {
The "-trace events" argument can be used to provide a file with a list of trace event names that will be enabled prior to starting execution, thus providing early tracing. This saves the user from manually toggling event states through the monitor interface or whichever backend-specific interface. Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu> --- docs/tracing.txt | 3 +++ qemu-config.c | 3 +++ qemu-options.hx | 24 ++++++++++++++++++------ trace/control.c | 30 ++++++++++++++++++++++++++++++ trace/control.h | 2 ++ vl.c | 2 ++ 6 files changed, 58 insertions(+), 6 deletions(-)