2 * Interface for configuring and controlling the state of tracing events.
4 * Copyright (C) 2011-2016 LluĂs Vilanova <vilanova@ac.upc.edu>
6 * This work is licensed under the terms of the GNU GPL, version 2 or later.
7 * See the COPYING file in the top-level directory.
10 #include "qemu/osdep.h"
11 #include "trace/control.h"
12 #include "qemu/help_option.h"
13 #include "qemu/option.h"
14 #ifdef CONFIG_TRACE_SIMPLE
15 #include "trace/simple.h"
17 #ifdef CONFIG_TRACE_FTRACE
18 #include "trace/ftrace.h"
20 #ifdef CONFIG_TRACE_LOG
23 #ifdef CONFIG_TRACE_SYSLOG
26 #include "qapi/error.h"
27 #include "qemu/error-report.h"
28 #include "qemu/config-file.h"
29 #include "monitor/monitor.h"
30 #include "trace/trace-root.h"
32 int trace_events_enabled_count;
34 typedef struct TraceEventGroup {
38 static TraceEventGroup *event_groups;
39 static size_t nevent_groups;
40 static uint32_t next_id;
41 static uint32_t next_vcpu_id;
42 static bool init_trace_on_startup;
43 static char *trace_opts_file;
45 QemuOptsList qemu_trace_opts = {
47 .implied_opt_name = "enable",
48 .head = QTAILQ_HEAD_INITIALIZER(qemu_trace_opts.head),
52 .type = QEMU_OPT_STRING,
56 .type = QEMU_OPT_STRING,
59 .type = QEMU_OPT_STRING,
66 void trace_event_register_group(TraceEvent **events)
69 for (i = 0; events[i] != NULL; i++) {
70 events[i]->id = next_id++;
71 if (events[i]->vcpu_id == TRACE_VCPU_EVENT_NONE) {
75 if (likely(next_vcpu_id < CPU_TRACE_DSTATE_MAX_EVENTS)) {
76 events[i]->vcpu_id = next_vcpu_id++;
78 warn_report("too many vcpu trace events; dropping '%s'",
82 event_groups = g_renew(TraceEventGroup, event_groups, nevent_groups + 1);
83 event_groups[nevent_groups].events = events;
86 #ifdef CONFIG_TRACE_SIMPLE
87 st_init_group(nevent_groups - 1);
92 TraceEvent *trace_event_name(const char *name)
98 trace_event_iter_init_all(&iter);
99 while ((ev = trace_event_iter_next(&iter)) != NULL) {
100 if (strcmp(trace_event_get_name(ev), name) == 0) {
107 void trace_event_iter_init_all(TraceEventIter *iter)
112 iter->pattern = NULL;
115 void trace_event_iter_init_pattern(TraceEventIter *iter, const char *pattern)
117 trace_event_iter_init_all(iter);
118 iter->pattern = pattern;
121 void trace_event_iter_init_group(TraceEventIter *iter, size_t group_id)
123 trace_event_iter_init_all(iter);
124 iter->group_id = group_id;
127 TraceEvent *trace_event_iter_next(TraceEventIter *iter)
129 while (iter->group < nevent_groups &&
130 event_groups[iter->group].events[iter->event] != NULL) {
131 TraceEvent *ev = event_groups[iter->group].events[iter->event];
132 size_t group = iter->group;
134 if (event_groups[iter->group].events[iter->event] == NULL) {
139 !g_pattern_match_simple(iter->pattern, trace_event_get_name(ev))) {
142 if (iter->group_id != -1 &&
143 iter->group_id != group) {
152 void trace_list_events(FILE *f)
156 trace_event_iter_init_all(&iter);
157 while ((ev = trace_event_iter_next(&iter)) != NULL) {
158 fprintf(f, "%s\n", trace_event_get_name(ev));
160 #ifdef CONFIG_TRACE_DTRACE
161 fprintf(f, "This list of names of trace points may be incomplete "
162 "when using the DTrace/SystemTap backends.\n"
163 "Run 'qemu-trace-stap list %s' to print the full list.\n",
164 error_get_progname());
168 static void do_trace_enable_events(const char *line_buf)
170 const bool enable = ('-' != line_buf[0]);
171 const char *line_ptr = enable ? line_buf : line_buf + 1;
174 bool is_pattern = trace_event_is_pattern(line_ptr);
176 trace_event_iter_init_pattern(&iter, line_ptr);
177 while ((ev = trace_event_iter_next(&iter)) != NULL) {
178 if (!trace_event_get_state_static(ev)) {
180 warn_report("trace event '%s' is not traceable",
188 trace_event_set_state_dynamic(ev, enable);
195 warn_report("trace event '%s' does not exist",
200 void trace_enable_events(const char *line_buf)
202 if (is_help_option(line_buf)) {
203 trace_list_events(stdout);
204 if (monitor_cur() == NULL) {
208 do_trace_enable_events(line_buf);
212 static void trace_init_events(const char *fname)
224 loc_set_file(fname, 0);
225 fp = fopen(fname, "r");
227 error_report("%s", strerror(errno));
230 while (fgets(line_buf, sizeof(line_buf), fp)) {
231 loc_set_file(fname, ++line_idx);
232 size_t len = strlen(line_buf);
233 if (len > 1) { /* skip empty lines */
234 line_buf[len - 1] = '\0';
235 if ('#' == line_buf[0]) { /* skip commented lines */
238 trace_enable_events(line_buf);
241 if (fclose(fp) != 0) {
242 loc_set_file(fname, 0);
243 error_report("%s", strerror(errno));
249 void trace_init_file(void)
251 #ifdef CONFIG_TRACE_SIMPLE
252 st_set_trace_file(trace_opts_file);
253 if (init_trace_on_startup) {
254 st_set_trace_file_enabled(true);
256 #elif defined CONFIG_TRACE_LOG
258 * If both the simple and the log backends are enabled, "--trace file"
259 * only applies to the simple backend; use "-D" for the log
260 * backend. However we should only override -D if we actually have
261 * something to override it with.
263 if (trace_opts_file) {
264 qemu_set_log_filename(trace_opts_file, &error_fatal);
267 if (trace_opts_file) {
268 fprintf(stderr, "error: --trace file=...: "
269 "option not supported by the selected tracing backends\n");
275 void trace_fini_vcpu(CPUState *vcpu)
280 trace_guest_cpu_exit(vcpu);
282 trace_event_iter_init_all(&iter);
283 while ((ev = trace_event_iter_next(&iter)) != NULL) {
284 if (trace_event_is_vcpu(ev) &&
285 trace_event_get_state_static(ev) &&
286 trace_event_get_vcpu_state_dynamic(vcpu, ev)) {
287 /* must disable to affect the global counter */
288 trace_event_set_vcpu_state_dynamic(vcpu, ev, false);
293 bool trace_init_backends(void)
295 #ifdef CONFIG_TRACE_SIMPLE
297 fprintf(stderr, "failed to initialize simple tracing backend.\n");
302 #ifdef CONFIG_TRACE_FTRACE
303 if (!ftrace_init()) {
304 fprintf(stderr, "failed to initialize ftrace backend.\n");
309 #ifdef CONFIG_TRACE_SYSLOG
310 openlog(NULL, LOG_PID, LOG_DAEMON);
316 void trace_opt_parse(const char *optarg)
318 QemuOpts *opts = qemu_opts_parse_noisily(qemu_find_opts("trace"),
323 if (qemu_opt_get(opts, "enable")) {
324 trace_enable_events(qemu_opt_get(opts, "enable"));
326 trace_init_events(qemu_opt_get(opts, "events"));
327 init_trace_on_startup = true;
328 g_free(trace_opts_file);
329 trace_opts_file = g_strdup(qemu_opt_get(opts, "file"));
333 uint32_t trace_get_vcpu_event_count(void)