gdbstub: add reverse continue support in replay mode
[qemu/ar7.git] / softmmu / cpus.c
blob9e33416b4de396367375fc6264f44dc4bc66fc39
1 /*
2 * QEMU System Emulator
4 * Copyright (c) 2003-2008 Fabrice Bellard
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
25 #include "qemu/osdep.h"
26 #include "qemu-common.h"
27 #include "monitor/monitor.h"
28 #include "qapi/error.h"
29 #include "qapi/qapi-commands-misc.h"
30 #include "qapi/qapi-events-run-state.h"
31 #include "qapi/qmp/qerror.h"
32 #include "exec/gdbstub.h"
33 #include "sysemu/hw_accel.h"
34 #include "exec/exec-all.h"
35 #include "qemu/thread.h"
36 #include "qemu/plugin.h"
37 #include "sysemu/cpus.h"
38 #include "qemu/guest-random.h"
39 #include "hw/nmi.h"
40 #include "sysemu/replay.h"
41 #include "sysemu/runstate.h"
42 #include "sysemu/cpu-timers.h"
43 #include "hw/boards.h"
44 #include "hw/hw.h"
46 #ifdef CONFIG_LINUX
48 #include <sys/prctl.h>
50 #ifndef PR_MCE_KILL
51 #define PR_MCE_KILL 33
52 #endif
54 #ifndef PR_MCE_KILL_SET
55 #define PR_MCE_KILL_SET 1
56 #endif
58 #ifndef PR_MCE_KILL_EARLY
59 #define PR_MCE_KILL_EARLY 1
60 #endif
62 #endif /* CONFIG_LINUX */
64 static QemuMutex qemu_global_mutex;
66 bool cpu_is_stopped(CPUState *cpu)
68 return cpu->stopped || !runstate_is_running();
71 bool cpu_work_list_empty(CPUState *cpu)
73 bool ret;
75 qemu_mutex_lock(&cpu->work_mutex);
76 ret = QSIMPLEQ_EMPTY(&cpu->work_list);
77 qemu_mutex_unlock(&cpu->work_mutex);
78 return ret;
81 bool cpu_thread_is_idle(CPUState *cpu)
83 if (cpu->stop || !cpu_work_list_empty(cpu)) {
84 return false;
86 if (cpu_is_stopped(cpu)) {
87 return true;
89 if (!cpu->halted || cpu_has_work(cpu) ||
90 kvm_halt_in_kernel()) {
91 return false;
93 return true;
96 bool all_cpu_threads_idle(void)
98 CPUState *cpu;
100 CPU_FOREACH(cpu) {
101 if (!cpu_thread_is_idle(cpu)) {
102 return false;
105 return true;
108 /***********************************************************/
109 void hw_error(const char *fmt, ...)
111 va_list ap;
112 CPUState *cpu;
114 va_start(ap, fmt);
115 fprintf(stderr, "qemu: hardware error: ");
116 vfprintf(stderr, fmt, ap);
117 fprintf(stderr, "\n");
118 CPU_FOREACH(cpu) {
119 fprintf(stderr, "CPU #%d:\n", cpu->cpu_index);
120 cpu_dump_state(cpu, stderr, CPU_DUMP_FPU);
122 va_end(ap);
123 abort();
127 * The chosen accelerator is supposed to register this.
129 static const CpusAccel *cpus_accel;
131 void cpu_synchronize_all_states(void)
133 CPUState *cpu;
135 CPU_FOREACH(cpu) {
136 cpu_synchronize_state(cpu);
140 void cpu_synchronize_all_post_reset(void)
142 CPUState *cpu;
144 CPU_FOREACH(cpu) {
145 cpu_synchronize_post_reset(cpu);
149 void cpu_synchronize_all_post_init(void)
151 CPUState *cpu;
153 CPU_FOREACH(cpu) {
154 cpu_synchronize_post_init(cpu);
158 void cpu_synchronize_all_pre_loadvm(void)
160 CPUState *cpu;
162 CPU_FOREACH(cpu) {
163 cpu_synchronize_pre_loadvm(cpu);
167 void cpu_synchronize_state(CPUState *cpu)
169 if (cpus_accel->synchronize_state) {
170 cpus_accel->synchronize_state(cpu);
174 void cpu_synchronize_post_reset(CPUState *cpu)
176 if (cpus_accel->synchronize_post_reset) {
177 cpus_accel->synchronize_post_reset(cpu);
181 void cpu_synchronize_post_init(CPUState *cpu)
183 if (cpus_accel->synchronize_post_init) {
184 cpus_accel->synchronize_post_init(cpu);
188 void cpu_synchronize_pre_loadvm(CPUState *cpu)
190 if (cpus_accel->synchronize_pre_loadvm) {
191 cpus_accel->synchronize_pre_loadvm(cpu);
195 int64_t cpus_get_virtual_clock(void)
198 * XXX
200 * need to check that cpus_accel is not NULL, because qcow2 calls
201 * qemu_get_clock_ns(CLOCK_VIRTUAL) without any accel initialized and
202 * with ticks disabled in some io-tests:
203 * 030 040 041 060 099 120 127 140 156 161 172 181 191 192 195 203 229 249 256 267
205 * is this expected?
207 * XXX
209 if (cpus_accel && cpus_accel->get_virtual_clock) {
210 return cpus_accel->get_virtual_clock();
212 return cpu_get_clock();
216 * return the time elapsed in VM between vm_start and vm_stop. Unless
217 * icount is active, cpus_get_elapsed_ticks() uses units of the host CPU cycle
218 * counter.
220 int64_t cpus_get_elapsed_ticks(void)
222 if (cpus_accel->get_elapsed_ticks) {
223 return cpus_accel->get_elapsed_ticks();
225 return cpu_get_ticks();
228 static void generic_handle_interrupt(CPUState *cpu, int mask)
230 cpu->interrupt_request |= mask;
232 if (!qemu_cpu_is_self(cpu)) {
233 qemu_cpu_kick(cpu);
237 void cpu_interrupt(CPUState *cpu, int mask)
239 if (cpus_accel->handle_interrupt) {
240 cpus_accel->handle_interrupt(cpu, mask);
241 } else {
242 generic_handle_interrupt(cpu, mask);
246 static int do_vm_stop(RunState state, bool send_stop)
248 int ret = 0;
250 if (runstate_is_running()) {
251 runstate_set(state);
252 cpu_disable_ticks();
253 pause_all_vcpus();
254 vm_state_notify(0, state);
255 if (send_stop) {
256 qapi_event_send_stop();
260 bdrv_drain_all();
261 ret = bdrv_flush_all();
263 return ret;
266 /* Special vm_stop() variant for terminating the process. Historically clients
267 * did not expect a QMP STOP event and so we need to retain compatibility.
269 int vm_shutdown(void)
271 return do_vm_stop(RUN_STATE_SHUTDOWN, false);
274 bool cpu_can_run(CPUState *cpu)
276 if (cpu->stop) {
277 return false;
279 if (cpu_is_stopped(cpu)) {
280 return false;
282 return true;
285 void cpu_handle_guest_debug(CPUState *cpu)
287 if (replay_running_debug()) {
288 if (!cpu->singlestep_enabled) {
290 * Report about the breakpoint and
291 * make a single step to skip it
293 replay_breakpoint();
294 cpu_single_step(cpu, SSTEP_ENABLE);
295 } else {
296 cpu_single_step(cpu, 0);
298 } else {
299 gdb_set_stop_cpu(cpu);
300 qemu_system_debug_request();
301 cpu->stopped = true;
305 #ifdef CONFIG_LINUX
306 static void sigbus_reraise(void)
308 sigset_t set;
309 struct sigaction action;
311 memset(&action, 0, sizeof(action));
312 action.sa_handler = SIG_DFL;
313 if (!sigaction(SIGBUS, &action, NULL)) {
314 raise(SIGBUS);
315 sigemptyset(&set);
316 sigaddset(&set, SIGBUS);
317 pthread_sigmask(SIG_UNBLOCK, &set, NULL);
319 perror("Failed to re-raise SIGBUS!\n");
320 abort();
323 static void sigbus_handler(int n, siginfo_t *siginfo, void *ctx)
325 if (siginfo->si_code != BUS_MCEERR_AO && siginfo->si_code != BUS_MCEERR_AR) {
326 sigbus_reraise();
329 if (current_cpu) {
330 /* Called asynchronously in VCPU thread. */
331 if (kvm_on_sigbus_vcpu(current_cpu, siginfo->si_code, siginfo->si_addr)) {
332 sigbus_reraise();
334 } else {
335 /* Called synchronously (via signalfd) in main thread. */
336 if (kvm_on_sigbus(siginfo->si_code, siginfo->si_addr)) {
337 sigbus_reraise();
342 static void qemu_init_sigbus(void)
344 struct sigaction action;
346 memset(&action, 0, sizeof(action));
347 action.sa_flags = SA_SIGINFO;
348 action.sa_sigaction = sigbus_handler;
349 sigaction(SIGBUS, &action, NULL);
351 prctl(PR_MCE_KILL, PR_MCE_KILL_SET, PR_MCE_KILL_EARLY, 0, 0);
353 #else /* !CONFIG_LINUX */
354 static void qemu_init_sigbus(void)
357 #endif /* !CONFIG_LINUX */
359 static QemuThread io_thread;
361 /* cpu creation */
362 static QemuCond qemu_cpu_cond;
363 /* system init */
364 static QemuCond qemu_pause_cond;
366 void qemu_init_cpu_loop(void)
368 qemu_init_sigbus();
369 qemu_cond_init(&qemu_cpu_cond);
370 qemu_cond_init(&qemu_pause_cond);
371 qemu_mutex_init(&qemu_global_mutex);
373 qemu_thread_get_self(&io_thread);
376 void run_on_cpu(CPUState *cpu, run_on_cpu_func func, run_on_cpu_data data)
378 do_run_on_cpu(cpu, func, data, &qemu_global_mutex);
381 static void qemu_cpu_stop(CPUState *cpu, bool exit)
383 g_assert(qemu_cpu_is_self(cpu));
384 cpu->stop = false;
385 cpu->stopped = true;
386 if (exit) {
387 cpu_exit(cpu);
389 qemu_cond_broadcast(&qemu_pause_cond);
392 void qemu_wait_io_event_common(CPUState *cpu)
394 qatomic_mb_set(&cpu->thread_kicked, false);
395 if (cpu->stop) {
396 qemu_cpu_stop(cpu, false);
398 process_queued_cpu_work(cpu);
401 void qemu_wait_io_event(CPUState *cpu)
403 bool slept = false;
405 while (cpu_thread_is_idle(cpu)) {
406 if (!slept) {
407 slept = true;
408 qemu_plugin_vcpu_idle_cb(cpu);
410 qemu_cond_wait(cpu->halt_cond, &qemu_global_mutex);
412 if (slept) {
413 qemu_plugin_vcpu_resume_cb(cpu);
416 #ifdef _WIN32
417 /* Eat dummy APC queued by cpus_kick_thread. */
418 if (hax_enabled()) {
419 SleepEx(0, TRUE);
421 #endif
422 qemu_wait_io_event_common(cpu);
425 void cpus_kick_thread(CPUState *cpu)
427 #ifndef _WIN32
428 int err;
430 if (cpu->thread_kicked) {
431 return;
433 cpu->thread_kicked = true;
434 err = pthread_kill(cpu->thread->thread, SIG_IPI);
435 if (err && err != ESRCH) {
436 fprintf(stderr, "qemu:%s: %s", __func__, strerror(err));
437 exit(1);
439 #endif
442 void qemu_cpu_kick(CPUState *cpu)
444 qemu_cond_broadcast(cpu->halt_cond);
445 if (cpus_accel->kick_vcpu_thread) {
446 cpus_accel->kick_vcpu_thread(cpu);
447 } else { /* default */
448 cpus_kick_thread(cpu);
452 void qemu_cpu_kick_self(void)
454 assert(current_cpu);
455 cpus_kick_thread(current_cpu);
458 bool qemu_cpu_is_self(CPUState *cpu)
460 return qemu_thread_is_self(cpu->thread);
463 bool qemu_in_vcpu_thread(void)
465 return current_cpu && qemu_cpu_is_self(current_cpu);
468 static __thread bool iothread_locked = false;
470 bool qemu_mutex_iothread_locked(void)
472 return iothread_locked;
476 * The BQL is taken from so many places that it is worth profiling the
477 * callers directly, instead of funneling them all through a single function.
479 void qemu_mutex_lock_iothread_impl(const char *file, int line)
481 QemuMutexLockFunc bql_lock = qatomic_read(&qemu_bql_mutex_lock_func);
483 g_assert(!qemu_mutex_iothread_locked());
484 bql_lock(&qemu_global_mutex, file, line);
485 iothread_locked = true;
488 void qemu_mutex_unlock_iothread(void)
490 g_assert(qemu_mutex_iothread_locked());
491 iothread_locked = false;
492 qemu_mutex_unlock(&qemu_global_mutex);
495 void qemu_cond_wait_iothread(QemuCond *cond)
497 qemu_cond_wait(cond, &qemu_global_mutex);
500 void qemu_cond_timedwait_iothread(QemuCond *cond, int ms)
502 qemu_cond_timedwait(cond, &qemu_global_mutex, ms);
505 /* signal CPU creation */
506 void cpu_thread_signal_created(CPUState *cpu)
508 cpu->created = true;
509 qemu_cond_signal(&qemu_cpu_cond);
512 /* signal CPU destruction */
513 void cpu_thread_signal_destroyed(CPUState *cpu)
515 cpu->created = false;
516 qemu_cond_signal(&qemu_cpu_cond);
520 static bool all_vcpus_paused(void)
522 CPUState *cpu;
524 CPU_FOREACH(cpu) {
525 if (!cpu->stopped) {
526 return false;
530 return true;
533 void pause_all_vcpus(void)
535 CPUState *cpu;
537 qemu_clock_enable(QEMU_CLOCK_VIRTUAL, false);
538 CPU_FOREACH(cpu) {
539 if (qemu_cpu_is_self(cpu)) {
540 qemu_cpu_stop(cpu, true);
541 } else {
542 cpu->stop = true;
543 qemu_cpu_kick(cpu);
547 /* We need to drop the replay_lock so any vCPU threads woken up
548 * can finish their replay tasks
550 replay_mutex_unlock();
552 while (!all_vcpus_paused()) {
553 qemu_cond_wait(&qemu_pause_cond, &qemu_global_mutex);
554 CPU_FOREACH(cpu) {
555 qemu_cpu_kick(cpu);
559 qemu_mutex_unlock_iothread();
560 replay_mutex_lock();
561 qemu_mutex_lock_iothread();
564 void cpu_resume(CPUState *cpu)
566 cpu->stop = false;
567 cpu->stopped = false;
568 qemu_cpu_kick(cpu);
571 void resume_all_vcpus(void)
573 CPUState *cpu;
575 if (!runstate_is_running()) {
576 return;
579 qemu_clock_enable(QEMU_CLOCK_VIRTUAL, true);
580 CPU_FOREACH(cpu) {
581 cpu_resume(cpu);
585 void cpu_remove_sync(CPUState *cpu)
587 cpu->stop = true;
588 cpu->unplug = true;
589 qemu_cpu_kick(cpu);
590 qemu_mutex_unlock_iothread();
591 qemu_thread_join(cpu->thread);
592 qemu_mutex_lock_iothread();
595 void cpus_register_accel(const CpusAccel *ca)
597 assert(ca != NULL);
598 assert(ca->create_vcpu_thread != NULL); /* mandatory */
599 cpus_accel = ca;
602 void qemu_init_vcpu(CPUState *cpu)
604 MachineState *ms = MACHINE(qdev_get_machine());
606 cpu->nr_cores = ms->smp.cores;
607 cpu->nr_threads = ms->smp.threads;
608 cpu->stopped = true;
609 cpu->random_seed = qemu_guest_random_seed_thread_part1();
611 if (!cpu->as) {
612 /* If the target cpu hasn't set up any address spaces itself,
613 * give it the default one.
615 cpu->num_ases = 1;
616 cpu_address_space_init(cpu, 0, "cpu-memory", cpu->memory);
619 /* accelerators all implement the CpusAccel interface */
620 g_assert(cpus_accel != NULL && cpus_accel->create_vcpu_thread != NULL);
621 cpus_accel->create_vcpu_thread(cpu);
623 while (!cpu->created) {
624 qemu_cond_wait(&qemu_cpu_cond, &qemu_global_mutex);
628 void cpu_stop_current(void)
630 if (current_cpu) {
631 current_cpu->stop = true;
632 cpu_exit(current_cpu);
636 int vm_stop(RunState state)
638 if (qemu_in_vcpu_thread()) {
639 qemu_system_vmstop_request_prepare();
640 qemu_system_vmstop_request(state);
642 * FIXME: should not return to device code in case
643 * vm_stop() has been requested.
645 cpu_stop_current();
646 return 0;
649 return do_vm_stop(state, true);
653 * Prepare for (re)starting the VM.
654 * Returns -1 if the vCPUs are not to be restarted (e.g. if they are already
655 * running or in case of an error condition), 0 otherwise.
657 int vm_prepare_start(void)
659 RunState requested;
661 qemu_vmstop_requested(&requested);
662 if (runstate_is_running() && requested == RUN_STATE__MAX) {
663 return -1;
666 /* Ensure that a STOP/RESUME pair of events is emitted if a
667 * vmstop request was pending. The BLOCK_IO_ERROR event, for
668 * example, according to documentation is always followed by
669 * the STOP event.
671 if (runstate_is_running()) {
672 qapi_event_send_stop();
673 qapi_event_send_resume();
674 return -1;
677 /* We are sending this now, but the CPUs will be resumed shortly later */
678 qapi_event_send_resume();
680 cpu_enable_ticks();
681 runstate_set(RUN_STATE_RUNNING);
682 vm_state_notify(1, RUN_STATE_RUNNING);
683 return 0;
686 void vm_start(void)
688 if (!vm_prepare_start()) {
689 resume_all_vcpus();
693 /* does a state transition even if the VM is already stopped,
694 current state is forgotten forever */
695 int vm_stop_force_state(RunState state)
697 if (runstate_is_running()) {
698 return vm_stop(state);
699 } else {
700 runstate_set(state);
702 bdrv_drain_all();
703 /* Make sure to return an error if the flush in a previous vm_stop()
704 * failed. */
705 return bdrv_flush_all();
709 void list_cpus(const char *optarg)
711 /* XXX: implement xxx_cpu_list for targets that still miss it */
712 #if defined(cpu_list)
713 cpu_list();
714 #endif
717 void qmp_memsave(int64_t addr, int64_t size, const char *filename,
718 bool has_cpu, int64_t cpu_index, Error **errp)
720 FILE *f;
721 uint32_t l;
722 CPUState *cpu;
723 uint8_t buf[1024];
724 int64_t orig_addr = addr, orig_size = size;
726 if (!has_cpu) {
727 cpu_index = 0;
730 cpu = qemu_get_cpu(cpu_index);
731 if (cpu == NULL) {
732 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cpu-index",
733 "a CPU number");
734 return;
737 f = fopen(filename, "wb");
738 if (!f) {
739 error_setg_file_open(errp, errno, filename);
740 return;
743 while (size != 0) {
744 l = sizeof(buf);
745 if (l > size)
746 l = size;
747 if (cpu_memory_rw_debug(cpu, addr, buf, l, 0) != 0) {
748 error_setg(errp, "Invalid addr 0x%016" PRIx64 "/size %" PRId64
749 " specified", orig_addr, orig_size);
750 goto exit;
752 if (fwrite(buf, 1, l, f) != l) {
753 error_setg(errp, QERR_IO_ERROR);
754 goto exit;
756 addr += l;
757 size -= l;
760 exit:
761 fclose(f);
764 void qmp_pmemsave(int64_t addr, int64_t size, const char *filename,
765 Error **errp)
767 FILE *f;
768 uint32_t l;
769 uint8_t buf[1024];
771 f = fopen(filename, "wb");
772 if (!f) {
773 error_setg_file_open(errp, errno, filename);
774 return;
777 while (size != 0) {
778 l = sizeof(buf);
779 if (l > size)
780 l = size;
781 cpu_physical_memory_read(addr, buf, l);
782 if (fwrite(buf, 1, l, f) != l) {
783 error_setg(errp, QERR_IO_ERROR);
784 goto exit;
786 addr += l;
787 size -= l;
790 exit:
791 fclose(f);
794 void qmp_inject_nmi(Error **errp)
796 nmi_monitor_handle(monitor_get_cpu_index(), errp);