qemu-img: add support for rate limit in qemu-img commit
[qemu.git] / replay / replay-debugging.c
1 /*
2 * replay-debugging.c
3 *
4 * Copyright (c) 2010-2020 Institute for System Programming
5 * of the Russian Academy of Sciences.
6 *
7 * This work is licensed under the terms of the GNU GPL, version 2 or later.
8 * See the COPYING file in the top-level directory.
9 *
10 */
11
12 #include "qemu/osdep.h"
13 #include "qapi/error.h"
14 #include "sysemu/replay.h"
15 #include "sysemu/runstate.h"
16 #include "replay-internal.h"
17 #include "monitor/hmp.h"
18 #include "monitor/monitor.h"
19 #include "qapi/qapi-commands-replay.h"
20 #include "qapi/qmp/qdict.h"
21 #include "qemu/timer.h"
22 #include "block/snapshot.h"
23 #include "migration/snapshot.h"
24
25 static bool replay_is_debugging;
26 static int64_t replay_last_breakpoint;
27 static int64_t replay_last_snapshot;
28
29 bool replay_running_debug(void)
30 {
31 return replay_is_debugging;
32 }
33
34 void hmp_info_replay(Monitor *mon, const QDict *qdict)
35 {
36 if (replay_mode == REPLAY_MODE_NONE) {
37 monitor_printf(mon, "Record/replay is not active\n");
38 } else {
39 monitor_printf(mon,
40 "%s execution '%s': instruction count = %"PRId64"\n",
41 replay_mode == REPLAY_MODE_RECORD ? "Recording" : "Replaying",
42 replay_get_filename(), replay_get_current_icount());
43 }
44 }
45
46 ReplayInfo *qmp_query_replay(Error **errp)
47 {
48 ReplayInfo *retval = g_new0(ReplayInfo, 1);
49
50 retval->mode = replay_mode;
51 if (replay_get_filename()) {
52 retval->filename = g_strdup(replay_get_filename());
53 retval->has_filename = true;
54 }
55 retval->icount = replay_get_current_icount();
56 return retval;
57 }
58
59 static void replay_break(uint64_t icount, QEMUTimerCB callback, void *opaque)
60 {
61 assert(replay_mode == REPLAY_MODE_PLAY);
62 assert(replay_mutex_locked());
63 assert(replay_break_icount >= replay_get_current_icount());
64 assert(callback);
65
66 replay_break_icount = icount;
67
68 if (replay_break_timer) {
69 timer_del(replay_break_timer);
70 }
71 replay_break_timer = timer_new_ns(QEMU_CLOCK_REALTIME,
72 callback, opaque);
73 }
74
75 static void replay_delete_break(void)
76 {
77 assert(replay_mode == REPLAY_MODE_PLAY);
78 assert(replay_mutex_locked());
79
80 if (replay_break_timer) {
81 timer_del(replay_break_timer);
82 timer_free(replay_break_timer);
83 replay_break_timer = NULL;
84 }
85 replay_break_icount = -1ULL;
86 }
87
88 static void replay_stop_vm(void *opaque)
89 {
90 vm_stop(RUN_STATE_PAUSED);
91 replay_delete_break();
92 }
93
94 void qmp_replay_break(int64_t icount, Error **errp)
95 {
96 if (replay_mode == REPLAY_MODE_PLAY) {
97 if (icount >= replay_get_current_icount()) {
98 replay_break(icount, replay_stop_vm, NULL);
99 } else {
100 error_setg(errp,
101 "cannot set breakpoint at the instruction in the past");
102 }
103 } else {
104 error_setg(errp, "setting the breakpoint is allowed only in play mode");
105 }
106 }
107
108 void hmp_replay_break(Monitor *mon, const QDict *qdict)
109 {
110 int64_t icount = qdict_get_try_int(qdict, "icount", -1LL);
111 Error *err = NULL;
112
113 qmp_replay_break(icount, &err);
114 if (err) {
115 error_report_err(err);
116 return;
117 }
118 }
119
120 void qmp_replay_delete_break(Error **errp)
121 {
122 if (replay_mode == REPLAY_MODE_PLAY) {
123 replay_delete_break();
124 } else {
125 error_setg(errp, "replay breakpoints are allowed only in play mode");
126 }
127 }
128
129 void hmp_replay_delete_break(Monitor *mon, const QDict *qdict)
130 {
131 Error *err = NULL;
132
133 qmp_replay_delete_break(&err);
134 if (err) {
135 error_report_err(err);
136 return;
137 }
138 }
139
140 static char *replay_find_nearest_snapshot(int64_t icount,
141 int64_t *snapshot_icount)
142 {
143 BlockDriverState *bs;
144 QEMUSnapshotInfo *sn_tab;
145 QEMUSnapshotInfo *nearest = NULL;
146 char *ret = NULL;
147 int nb_sns, i;
148 AioContext *aio_context;
149
150 *snapshot_icount = -1;
151
152 bs = bdrv_all_find_vmstate_bs();
153 if (!bs) {
154 goto fail;
155 }
156 aio_context = bdrv_get_aio_context(bs);
157
158 aio_context_acquire(aio_context);
159 nb_sns = bdrv_snapshot_list(bs, &sn_tab);
160 aio_context_release(aio_context);
161
162 for (i = 0; i < nb_sns; i++) {
163 if (bdrv_all_find_snapshot(sn_tab[i].name, &bs) == 0) {
164 if (sn_tab[i].icount != -1ULL
165 && sn_tab[i].icount <= icount
166 && (!nearest || nearest->icount < sn_tab[i].icount)) {
167 nearest = &sn_tab[i];
168 }
169 }
170 }
171 if (nearest) {
172 ret = g_strdup(nearest->name);
173 *snapshot_icount = nearest->icount;
174 }
175 g_free(sn_tab);
176
177 fail:
178 return ret;
179 }
180
181 static void replay_seek(int64_t icount, QEMUTimerCB callback, Error **errp)
182 {
183 char *snapshot = NULL;
184 int64_t snapshot_icount;
185
186 if (replay_mode != REPLAY_MODE_PLAY) {
187 error_setg(errp, "replay must be enabled to seek");
188 return;
189 }
190
191 snapshot = replay_find_nearest_snapshot(icount, &snapshot_icount);
192 if (snapshot) {
193 if (icount < replay_get_current_icount()
194 || replay_get_current_icount() < snapshot_icount) {
195 vm_stop(RUN_STATE_RESTORE_VM);
196 load_snapshot(snapshot, errp);
197 }
198 g_free(snapshot);
199 }
200 if (replay_get_current_icount() <= icount) {
201 replay_break(icount, callback, NULL);
202 vm_start();
203 } else {
204 error_setg(errp, "cannot seek to the specified instruction count");
205 }
206 }
207
208 void qmp_replay_seek(int64_t icount, Error **errp)
209 {
210 replay_seek(icount, replay_stop_vm, errp);
211 }
212
213 void hmp_replay_seek(Monitor *mon, const QDict *qdict)
214 {
215 int64_t icount = qdict_get_try_int(qdict, "icount", -1LL);
216 Error *err = NULL;
217
218 qmp_replay_seek(icount, &err);
219 if (err) {
220 error_report_err(err);
221 return;
222 }
223 }
224
225 static void replay_stop_vm_debug(void *opaque)
226 {
227 replay_is_debugging = false;
228 vm_stop(RUN_STATE_DEBUG);
229 replay_delete_break();
230 }
231
232 bool replay_reverse_step(void)
233 {
234 Error *err = NULL;
235
236 assert(replay_mode == REPLAY_MODE_PLAY);
237
238 if (replay_get_current_icount() != 0) {
239 replay_seek(replay_get_current_icount() - 1,
240 replay_stop_vm_debug, &err);
241 if (err) {
242 error_free(err);
243 return false;
244 }
245 replay_is_debugging = true;
246 return true;
247 }
248
249 return false;
250 }
251
252 static void replay_continue_end(void)
253 {
254 replay_is_debugging = false;
255 vm_stop(RUN_STATE_DEBUG);
256 replay_delete_break();
257 }
258
259 static void replay_continue_stop(void *opaque)
260 {
261 Error *err = NULL;
262 if (replay_last_breakpoint != -1LL) {
263 replay_seek(replay_last_breakpoint, replay_stop_vm_debug, &err);
264 if (err) {
265 error_free(err);
266 replay_continue_end();
267 }
268 return;
269 }
270 /*
271 * No breakpoints since the last snapshot.
272 * Find previous snapshot and try again.
273 */
274 if (replay_last_snapshot != 0) {
275 replay_seek(replay_last_snapshot - 1, replay_continue_stop, &err);
276 if (err) {
277 error_free(err);
278 replay_continue_end();
279 }
280 replay_last_snapshot = replay_get_current_icount();
281 return;
282 } else {
283 /* Seek to the very first step */
284 replay_seek(0, replay_stop_vm_debug, &err);
285 if (err) {
286 error_free(err);
287 replay_continue_end();
288 }
289 return;
290 }
291 replay_continue_end();
292 }
293
294 bool replay_reverse_continue(void)
295 {
296 Error *err = NULL;
297
298 assert(replay_mode == REPLAY_MODE_PLAY);
299
300 if (replay_get_current_icount() != 0) {
301 replay_seek(replay_get_current_icount() - 1,
302 replay_continue_stop, &err);
303 if (err) {
304 error_free(err);
305 return false;
306 }
307 replay_last_breakpoint = -1LL;
308 replay_is_debugging = true;
309 replay_last_snapshot = replay_get_current_icount();
310 return true;
311 }
312
313 return false;
314 }
315
316 void replay_breakpoint(void)
317 {
318 assert(replay_mode == REPLAY_MODE_PLAY);
319 replay_last_breakpoint = replay_get_current_icount();
320 }
321
322 void replay_gdb_attached(void)
323 {
324 /*
325 * Create VM snapshot on temporary overlay to allow reverse
326 * debugging even if snapshots were not enabled.
327 */
328 if (replay_mode == REPLAY_MODE_PLAY
329 && !replay_snapshot) {
330 if (save_snapshot("start_debugging", NULL) != 0) {
331 /* Can't create the snapshot. Continue conventional debugging. */
332 }
333 }
334 }