1 | /* |
2 | * replay.c |
3 | * |
4 | * Copyright (c) 2010-2015 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 "qemu/timer.h" |
18 | #include "qemu/main-loop.h" |
19 | #include "qemu/option.h" |
20 | #include "sysemu/cpus.h" |
21 | #include "qemu/error-report.h" |
22 | |
23 | /* Current version of the replay mechanism. |
24 | Increase it when file format changes. */ |
25 | #define REPLAY_VERSION 0xe02008 |
26 | /* Size of replay log header */ |
27 | #define (sizeof(uint32_t) + sizeof(uint64_t)) |
28 | |
29 | ReplayMode replay_mode = REPLAY_MODE_NONE; |
30 | char *replay_snapshot; |
31 | |
32 | /* Name of replay file */ |
33 | static char *replay_filename; |
34 | ReplayState replay_state; |
35 | static GSList *replay_blockers; |
36 | |
37 | bool replay_next_event_is(int event) |
38 | { |
39 | bool res = false; |
40 | |
41 | /* nothing to skip - not all instructions used */ |
42 | if (replay_state.instruction_count != 0) { |
43 | assert(replay_state.data_kind == EVENT_INSTRUCTION); |
44 | return event == EVENT_INSTRUCTION; |
45 | } |
46 | |
47 | while (true) { |
48 | unsigned int data_kind = replay_state.data_kind; |
49 | if (event == data_kind) { |
50 | res = true; |
51 | } |
52 | switch (data_kind) { |
53 | case EVENT_SHUTDOWN ... EVENT_SHUTDOWN_LAST: |
54 | replay_finish_event(); |
55 | qemu_system_shutdown_request(data_kind - EVENT_SHUTDOWN); |
56 | break; |
57 | default: |
58 | /* clock, time_t, checkpoint and other events */ |
59 | return res; |
60 | } |
61 | } |
62 | return res; |
63 | } |
64 | |
65 | uint64_t replay_get_current_icount(void) |
66 | { |
67 | return cpu_get_icount_raw(); |
68 | } |
69 | |
70 | int replay_get_instructions(void) |
71 | { |
72 | int res = 0; |
73 | replay_mutex_lock(); |
74 | if (replay_next_event_is(EVENT_INSTRUCTION)) { |
75 | res = replay_state.instruction_count; |
76 | } |
77 | replay_mutex_unlock(); |
78 | return res; |
79 | } |
80 | |
81 | void replay_account_executed_instructions(void) |
82 | { |
83 | if (replay_mode == REPLAY_MODE_PLAY) { |
84 | g_assert(replay_mutex_locked()); |
85 | if (replay_state.instruction_count > 0) { |
86 | int count = (int)(replay_get_current_icount() |
87 | - replay_state.current_icount); |
88 | |
89 | /* Time can only go forward */ |
90 | assert(count >= 0); |
91 | |
92 | replay_state.instruction_count -= count; |
93 | replay_state.current_icount += count; |
94 | if (replay_state.instruction_count == 0) { |
95 | assert(replay_state.data_kind == EVENT_INSTRUCTION); |
96 | replay_finish_event(); |
97 | /* Wake up iothread. This is required because |
98 | timers will not expire until clock counters |
99 | will be read from the log. */ |
100 | qemu_notify_event(); |
101 | } |
102 | } |
103 | } |
104 | } |
105 | |
106 | bool replay_exception(void) |
107 | { |
108 | |
109 | if (replay_mode == REPLAY_MODE_RECORD) { |
110 | g_assert(replay_mutex_locked()); |
111 | replay_save_instructions(); |
112 | replay_put_event(EVENT_EXCEPTION); |
113 | return true; |
114 | } else if (replay_mode == REPLAY_MODE_PLAY) { |
115 | g_assert(replay_mutex_locked()); |
116 | bool res = replay_has_exception(); |
117 | if (res) { |
118 | replay_finish_event(); |
119 | } |
120 | return res; |
121 | } |
122 | |
123 | return true; |
124 | } |
125 | |
126 | bool replay_has_exception(void) |
127 | { |
128 | bool res = false; |
129 | if (replay_mode == REPLAY_MODE_PLAY) { |
130 | g_assert(replay_mutex_locked()); |
131 | replay_account_executed_instructions(); |
132 | res = replay_next_event_is(EVENT_EXCEPTION); |
133 | } |
134 | |
135 | return res; |
136 | } |
137 | |
138 | bool replay_interrupt(void) |
139 | { |
140 | if (replay_mode == REPLAY_MODE_RECORD) { |
141 | g_assert(replay_mutex_locked()); |
142 | replay_save_instructions(); |
143 | replay_put_event(EVENT_INTERRUPT); |
144 | return true; |
145 | } else if (replay_mode == REPLAY_MODE_PLAY) { |
146 | g_assert(replay_mutex_locked()); |
147 | bool res = replay_has_interrupt(); |
148 | if (res) { |
149 | replay_finish_event(); |
150 | } |
151 | return res; |
152 | } |
153 | |
154 | return true; |
155 | } |
156 | |
157 | bool replay_has_interrupt(void) |
158 | { |
159 | bool res = false; |
160 | if (replay_mode == REPLAY_MODE_PLAY) { |
161 | g_assert(replay_mutex_locked()); |
162 | replay_account_executed_instructions(); |
163 | res = replay_next_event_is(EVENT_INTERRUPT); |
164 | } |
165 | return res; |
166 | } |
167 | |
168 | void replay_shutdown_request(ShutdownCause cause) |
169 | { |
170 | if (replay_mode == REPLAY_MODE_RECORD) { |
171 | g_assert(replay_mutex_locked()); |
172 | replay_put_event(EVENT_SHUTDOWN + cause); |
173 | } |
174 | } |
175 | |
176 | bool replay_checkpoint(ReplayCheckpoint checkpoint) |
177 | { |
178 | bool res = false; |
179 | static bool in_checkpoint; |
180 | assert(EVENT_CHECKPOINT + checkpoint <= EVENT_CHECKPOINT_LAST); |
181 | |
182 | if (!replay_file) { |
183 | return true; |
184 | } |
185 | |
186 | if (in_checkpoint) { |
187 | /* If we are already in checkpoint, then there is no need |
188 | for additional synchronization. |
189 | Recursion occurs when HW event modifies timers. |
190 | Timer modification may invoke the checkpoint and |
191 | proceed to recursion. */ |
192 | return true; |
193 | } |
194 | in_checkpoint = true; |
195 | |
196 | replay_save_instructions(); |
197 | |
198 | if (replay_mode == REPLAY_MODE_PLAY) { |
199 | g_assert(replay_mutex_locked()); |
200 | if (replay_next_event_is(EVENT_CHECKPOINT + checkpoint)) { |
201 | replay_finish_event(); |
202 | } else if (replay_state.data_kind != EVENT_ASYNC) { |
203 | res = false; |
204 | goto out; |
205 | } |
206 | replay_read_events(checkpoint); |
207 | /* replay_read_events may leave some unread events. |
208 | Return false if not all of the events associated with |
209 | checkpoint were processed */ |
210 | res = replay_state.data_kind != EVENT_ASYNC; |
211 | } else if (replay_mode == REPLAY_MODE_RECORD) { |
212 | g_assert(replay_mutex_locked()); |
213 | replay_put_event(EVENT_CHECKPOINT + checkpoint); |
214 | /* This checkpoint belongs to several threads. |
215 | Processing events from different threads is |
216 | non-deterministic */ |
217 | if (checkpoint != CHECKPOINT_CLOCK_WARP_START |
218 | /* FIXME: this is temporary fix, other checkpoints |
219 | may also be invoked from the different threads someday. |
220 | Asynchronous event processing should be refactored |
221 | to create additional replay event kind which is |
222 | nailed to the one of the threads and which processes |
223 | the event queue. */ |
224 | && checkpoint != CHECKPOINT_CLOCK_VIRTUAL) { |
225 | replay_save_events(checkpoint); |
226 | } |
227 | res = true; |
228 | } |
229 | out: |
230 | in_checkpoint = false; |
231 | return res; |
232 | } |
233 | |
234 | bool replay_has_checkpoint(void) |
235 | { |
236 | bool res = false; |
237 | if (replay_mode == REPLAY_MODE_PLAY) { |
238 | g_assert(replay_mutex_locked()); |
239 | replay_account_executed_instructions(); |
240 | res = EVENT_CHECKPOINT <= replay_state.data_kind |
241 | && replay_state.data_kind <= EVENT_CHECKPOINT_LAST; |
242 | } |
243 | return res; |
244 | } |
245 | |
246 | static void replay_enable(const char *fname, int mode) |
247 | { |
248 | const char *fmode = NULL; |
249 | assert(!replay_file); |
250 | |
251 | switch (mode) { |
252 | case REPLAY_MODE_RECORD: |
253 | fmode = "wb" ; |
254 | break; |
255 | case REPLAY_MODE_PLAY: |
256 | fmode = "rb" ; |
257 | break; |
258 | default: |
259 | fprintf(stderr, "Replay: internal error: invalid replay mode\n" ); |
260 | exit(1); |
261 | } |
262 | |
263 | atexit(replay_finish); |
264 | |
265 | replay_file = fopen(fname, fmode); |
266 | if (replay_file == NULL) { |
267 | fprintf(stderr, "Replay: open %s: %s\n" , fname, strerror(errno)); |
268 | exit(1); |
269 | } |
270 | |
271 | replay_filename = g_strdup(fname); |
272 | replay_mode = mode; |
273 | replay_mutex_init(); |
274 | |
275 | replay_state.data_kind = -1; |
276 | replay_state.instruction_count = 0; |
277 | replay_state.current_icount = 0; |
278 | replay_state.has_unread_data = 0; |
279 | |
280 | /* skip file header for RECORD and check it for PLAY */ |
281 | if (replay_mode == REPLAY_MODE_RECORD) { |
282 | fseek(replay_file, HEADER_SIZE, SEEK_SET); |
283 | } else if (replay_mode == REPLAY_MODE_PLAY) { |
284 | unsigned int version = replay_get_dword(); |
285 | if (version != REPLAY_VERSION) { |
286 | fprintf(stderr, "Replay: invalid input log file version\n" ); |
287 | exit(1); |
288 | } |
289 | /* go to the beginning */ |
290 | fseek(replay_file, HEADER_SIZE, SEEK_SET); |
291 | replay_fetch_data_kind(); |
292 | } |
293 | |
294 | replay_init_events(); |
295 | } |
296 | |
297 | void replay_configure(QemuOpts *opts) |
298 | { |
299 | const char *fname; |
300 | const char *rr; |
301 | ReplayMode mode = REPLAY_MODE_NONE; |
302 | Location loc; |
303 | |
304 | if (!opts) { |
305 | return; |
306 | } |
307 | |
308 | loc_push_none(&loc); |
309 | qemu_opts_loc_restore(opts); |
310 | |
311 | rr = qemu_opt_get(opts, "rr" ); |
312 | if (!rr) { |
313 | /* Just enabling icount */ |
314 | goto out; |
315 | } else if (!strcmp(rr, "record" )) { |
316 | mode = REPLAY_MODE_RECORD; |
317 | } else if (!strcmp(rr, "replay" )) { |
318 | mode = REPLAY_MODE_PLAY; |
319 | } else { |
320 | error_report("Invalid icount rr option: %s" , rr); |
321 | exit(1); |
322 | } |
323 | |
324 | fname = qemu_opt_get(opts, "rrfile" ); |
325 | if (!fname) { |
326 | error_report("File name not specified for replay" ); |
327 | exit(1); |
328 | } |
329 | |
330 | replay_snapshot = g_strdup(qemu_opt_get(opts, "rrsnapshot" )); |
331 | replay_vmstate_register(); |
332 | replay_enable(fname, mode); |
333 | |
334 | out: |
335 | loc_pop(&loc); |
336 | } |
337 | |
338 | void replay_start(void) |
339 | { |
340 | if (replay_mode == REPLAY_MODE_NONE) { |
341 | return; |
342 | } |
343 | |
344 | if (replay_blockers) { |
345 | error_reportf_err(replay_blockers->data, "Record/replay: " ); |
346 | exit(1); |
347 | } |
348 | if (!use_icount) { |
349 | error_report("Please enable icount to use record/replay" ); |
350 | exit(1); |
351 | } |
352 | |
353 | /* Timer for snapshotting will be set up here. */ |
354 | |
355 | replay_enable_events(); |
356 | } |
357 | |
358 | void replay_finish(void) |
359 | { |
360 | if (replay_mode == REPLAY_MODE_NONE) { |
361 | return; |
362 | } |
363 | |
364 | replay_save_instructions(); |
365 | |
366 | /* finalize the file */ |
367 | if (replay_file) { |
368 | if (replay_mode == REPLAY_MODE_RECORD) { |
369 | /* write end event */ |
370 | replay_put_event(EVENT_END); |
371 | |
372 | /* write header */ |
373 | fseek(replay_file, 0, SEEK_SET); |
374 | replay_put_dword(REPLAY_VERSION); |
375 | } |
376 | |
377 | fclose(replay_file); |
378 | replay_file = NULL; |
379 | } |
380 | if (replay_filename) { |
381 | g_free(replay_filename); |
382 | replay_filename = NULL; |
383 | } |
384 | |
385 | g_free(replay_snapshot); |
386 | replay_snapshot = NULL; |
387 | |
388 | replay_finish_events(); |
389 | } |
390 | |
391 | void replay_add_blocker(Error *reason) |
392 | { |
393 | replay_blockers = g_slist_prepend(replay_blockers, reason); |
394 | } |
395 | |