virtio: Clarify MR transaction optimization
[qemu/kevin.git] / softmmu / cpus.c
blobc3caaeb26ec13f4b393de8a731c58389570223c3
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-machine.h"
30 #include "qapi/qapi-commands-misc.h"
31 #include "qapi/qapi-events-run-state.h"
32 #include "qapi/qmp/qerror.h"
33 #include "exec/gdbstub.h"
34 #include "sysemu/hw_accel.h"
35 #include "exec/exec-all.h"
36 #include "qemu/thread.h"
37 #include "qemu/plugin.h"
38 #include "sysemu/cpus.h"
39 #include "qemu/guest-random.h"
40 #include "hw/nmi.h"
41 #include "sysemu/replay.h"
42 #include "sysemu/runstate.h"
43 #include "sysemu/cpu-timers.h"
44 #include "sysemu/whpx.h"
45 #include "hw/boards.h"
46 #include "hw/hw.h"
47 #include "trace.h"
49 #ifdef CONFIG_LINUX
51 #include <sys/prctl.h>
53 #ifndef PR_MCE_KILL
54 #define PR_MCE_KILL 33
55 #endif
57 #ifndef PR_MCE_KILL_SET
58 #define PR_MCE_KILL_SET 1
59 #endif
61 #ifndef PR_MCE_KILL_EARLY
62 #define PR_MCE_KILL_EARLY 1
63 #endif
65 #endif /* CONFIG_LINUX */
67 static QemuMutex qemu_global_mutex;
69 bool cpu_is_stopped(CPUState *cpu)
71 return cpu->stopped || !runstate_is_running();
74 bool cpu_work_list_empty(CPUState *cpu)
76 bool ret;
78 qemu_mutex_lock(&cpu->work_mutex);
79 ret = QSIMPLEQ_EMPTY(&cpu->work_list);
80 qemu_mutex_unlock(&cpu->work_mutex);
81 return ret;
84 bool cpu_thread_is_idle(CPUState *cpu)
86 if (cpu->stop || !cpu_work_list_empty(cpu)) {
87 return false;
89 if (cpu_is_stopped(cpu)) {
90 return true;
92 if (!cpu->halted || cpu_has_work(cpu) ||
93 kvm_halt_in_kernel() || whpx_apic_in_platform()) {
94 return false;
96 return true;
99 bool all_cpu_threads_idle(void)
101 CPUState *cpu;
103 CPU_FOREACH(cpu) {
104 if (!cpu_thread_is_idle(cpu)) {
105 return false;
108 return true;
111 /***********************************************************/
112 void hw_error(const char *fmt, ...)
114 va_list ap;
115 CPUState *cpu;
117 va_start(ap, fmt);
118 fprintf(stderr, "qemu: hardware error: ");
119 vfprintf(stderr, fmt, ap);
120 fprintf(stderr, "\n");
121 CPU_FOREACH(cpu) {
122 fprintf(stderr, "CPU #%d:\n", cpu->cpu_index);
123 cpu_dump_state(cpu, stderr, CPU_DUMP_FPU);
125 va_end(ap);
126 abort();
130 * The chosen accelerator is supposed to register this.
132 static const AccelOpsClass *cpus_accel;
134 void cpu_synchronize_all_states(void)
136 CPUState *cpu;
138 CPU_FOREACH(cpu) {
139 cpu_synchronize_state(cpu);
143 void cpu_synchronize_all_post_reset(void)
145 CPUState *cpu;
147 CPU_FOREACH(cpu) {
148 cpu_synchronize_post_reset(cpu);
152 void cpu_synchronize_all_post_init(void)
154 CPUState *cpu;
156 CPU_FOREACH(cpu) {
157 cpu_synchronize_post_init(cpu);
161 void cpu_synchronize_all_pre_loadvm(void)
163 CPUState *cpu;
165 CPU_FOREACH(cpu) {
166 cpu_synchronize_pre_loadvm(cpu);
170 void cpu_synchronize_state(CPUState *cpu)
172 if (cpus_accel->synchronize_state) {
173 cpus_accel->synchronize_state(cpu);
177 void cpu_synchronize_post_reset(CPUState *cpu)
179 if (cpus_accel->synchronize_post_reset) {
180 cpus_accel->synchronize_post_reset(cpu);
184 void cpu_synchronize_post_init(CPUState *cpu)
186 if (cpus_accel->synchronize_post_init) {
187 cpus_accel->synchronize_post_init(cpu);
191 void cpu_synchronize_pre_loadvm(CPUState *cpu)
193 if (cpus_accel->synchronize_pre_loadvm) {
194 cpus_accel->synchronize_pre_loadvm(cpu);
198 bool cpus_are_resettable(void)
200 return cpu_check_are_resettable();
203 int64_t cpus_get_virtual_clock(void)
206 * XXX
208 * need to check that cpus_accel is not NULL, because qcow2 calls
209 * qemu_get_clock_ns(CLOCK_VIRTUAL) without any accel initialized and
210 * with ticks disabled in some io-tests:
211 * 030 040 041 060 099 120 127 140 156 161 172 181 191 192 195 203 229 249 256 267
213 * is this expected?
215 * XXX
217 if (cpus_accel && cpus_accel->get_virtual_clock) {
218 return cpus_accel->get_virtual_clock();
220 return cpu_get_clock();
224 * return the time elapsed in VM between vm_start and vm_stop. Unless
225 * icount is active, cpus_get_elapsed_ticks() uses units of the host CPU cycle
226 * counter.
228 int64_t cpus_get_elapsed_ticks(void)
230 if (cpus_accel->get_elapsed_ticks) {
231 return cpus_accel->get_elapsed_ticks();
233 return cpu_get_ticks();
236 static void generic_handle_interrupt(CPUState *cpu, int mask)
238 cpu->interrupt_request |= mask;
240 if (!qemu_cpu_is_self(cpu)) {
241 qemu_cpu_kick(cpu);
245 void cpu_interrupt(CPUState *cpu, int mask)
247 if (cpus_accel->handle_interrupt) {
248 cpus_accel->handle_interrupt(cpu, mask);
249 } else {
250 generic_handle_interrupt(cpu, mask);
254 static int do_vm_stop(RunState state, bool send_stop)
256 int ret = 0;
258 if (runstate_is_running()) {
259 runstate_set(state);
260 cpu_disable_ticks();
261 pause_all_vcpus();
262 vm_state_notify(0, state);
263 if (send_stop) {
264 qapi_event_send_stop();
268 bdrv_drain_all();
269 ret = bdrv_flush_all();
270 trace_vm_stop_flush_all(ret);
272 return ret;
275 /* Special vm_stop() variant for terminating the process. Historically clients
276 * did not expect a QMP STOP event and so we need to retain compatibility.
278 int vm_shutdown(void)
280 return do_vm_stop(RUN_STATE_SHUTDOWN, false);
283 bool cpu_can_run(CPUState *cpu)
285 if (cpu->stop) {
286 return false;
288 if (cpu_is_stopped(cpu)) {
289 return false;
291 return true;
294 void cpu_handle_guest_debug(CPUState *cpu)
296 if (replay_running_debug()) {
297 if (!cpu->singlestep_enabled) {
299 * Report about the breakpoint and
300 * make a single step to skip it
302 replay_breakpoint();
303 cpu_single_step(cpu, SSTEP_ENABLE);
304 } else {
305 cpu_single_step(cpu, 0);
307 } else {
308 gdb_set_stop_cpu(cpu);
309 qemu_system_debug_request();
310 cpu->stopped = true;
314 #ifdef CONFIG_LINUX
315 static void sigbus_reraise(void)
317 sigset_t set;
318 struct sigaction action;
320 memset(&action, 0, sizeof(action));
321 action.sa_handler = SIG_DFL;
322 if (!sigaction(SIGBUS, &action, NULL)) {
323 raise(SIGBUS);
324 sigemptyset(&set);
325 sigaddset(&set, SIGBUS);
326 pthread_sigmask(SIG_UNBLOCK, &set, NULL);
328 perror("Failed to re-raise SIGBUS!\n");
329 abort();
332 static void sigbus_handler(int n, siginfo_t *siginfo, void *ctx)
334 if (siginfo->si_code != BUS_MCEERR_AO && siginfo->si_code != BUS_MCEERR_AR) {
335 sigbus_reraise();
338 if (current_cpu) {
339 /* Called asynchronously in VCPU thread. */
340 if (kvm_on_sigbus_vcpu(current_cpu, siginfo->si_code, siginfo->si_addr)) {
341 sigbus_reraise();
343 } else {
344 /* Called synchronously (via signalfd) in main thread. */
345 if (kvm_on_sigbus(siginfo->si_code, siginfo->si_addr)) {
346 sigbus_reraise();
351 static void qemu_init_sigbus(void)
353 struct sigaction action;
355 memset(&action, 0, sizeof(action));
356 action.sa_flags = SA_SIGINFO;
357 action.sa_sigaction = sigbus_handler;
358 sigaction(SIGBUS, &action, NULL);
360 prctl(PR_MCE_KILL, PR_MCE_KILL_SET, PR_MCE_KILL_EARLY, 0, 0);
362 #else /* !CONFIG_LINUX */
363 static void qemu_init_sigbus(void)
366 #endif /* !CONFIG_LINUX */
368 static QemuThread io_thread;
370 /* cpu creation */
371 static QemuCond qemu_cpu_cond;
372 /* system init */
373 static QemuCond qemu_pause_cond;
375 void qemu_init_cpu_loop(void)
377 qemu_init_sigbus();
378 qemu_cond_init(&qemu_cpu_cond);
379 qemu_cond_init(&qemu_pause_cond);
380 qemu_mutex_init(&qemu_global_mutex);
382 qemu_thread_get_self(&io_thread);
385 void run_on_cpu(CPUState *cpu, run_on_cpu_func func, run_on_cpu_data data)
387 do_run_on_cpu(cpu, func, data, &qemu_global_mutex);
390 static void qemu_cpu_stop(CPUState *cpu, bool exit)
392 g_assert(qemu_cpu_is_self(cpu));
393 cpu->stop = false;
394 cpu->stopped = true;
395 if (exit) {
396 cpu_exit(cpu);
398 qemu_cond_broadcast(&qemu_pause_cond);
401 void qemu_wait_io_event_common(CPUState *cpu)
403 qatomic_mb_set(&cpu->thread_kicked, false);
404 if (cpu->stop) {
405 qemu_cpu_stop(cpu, false);
407 process_queued_cpu_work(cpu);
410 void qemu_wait_io_event(CPUState *cpu)
412 bool slept = false;
414 while (cpu_thread_is_idle(cpu)) {
415 if (!slept) {
416 slept = true;
417 qemu_plugin_vcpu_idle_cb(cpu);
419 qemu_cond_wait(cpu->halt_cond, &qemu_global_mutex);
421 if (slept) {
422 qemu_plugin_vcpu_resume_cb(cpu);
425 #ifdef _WIN32
426 /* Eat dummy APC queued by cpus_kick_thread. */
427 if (hax_enabled()) {
428 SleepEx(0, TRUE);
430 #endif
431 qemu_wait_io_event_common(cpu);
434 void cpus_kick_thread(CPUState *cpu)
436 #ifndef _WIN32
437 int err;
439 if (cpu->thread_kicked) {
440 return;
442 cpu->thread_kicked = true;
443 err = pthread_kill(cpu->thread->thread, SIG_IPI);
444 if (err && err != ESRCH) {
445 fprintf(stderr, "qemu:%s: %s", __func__, strerror(err));
446 exit(1);
448 #endif
451 void qemu_cpu_kick(CPUState *cpu)
453 qemu_cond_broadcast(cpu->halt_cond);
454 if (cpus_accel->kick_vcpu_thread) {
455 cpus_accel->kick_vcpu_thread(cpu);
456 } else { /* default */
457 cpus_kick_thread(cpu);
461 void qemu_cpu_kick_self(void)
463 assert(current_cpu);
464 cpus_kick_thread(current_cpu);
467 bool qemu_cpu_is_self(CPUState *cpu)
469 return qemu_thread_is_self(cpu->thread);
472 bool qemu_in_vcpu_thread(void)
474 return current_cpu && qemu_cpu_is_self(current_cpu);
477 static __thread bool iothread_locked = false;
479 bool qemu_mutex_iothread_locked(void)
481 return iothread_locked;
485 * The BQL is taken from so many places that it is worth profiling the
486 * callers directly, instead of funneling them all through a single function.
488 void qemu_mutex_lock_iothread_impl(const char *file, int line)
490 QemuMutexLockFunc bql_lock = qatomic_read(&qemu_bql_mutex_lock_func);
492 g_assert(!qemu_mutex_iothread_locked());
493 bql_lock(&qemu_global_mutex, file, line);
494 iothread_locked = true;
497 void qemu_mutex_unlock_iothread(void)
499 g_assert(qemu_mutex_iothread_locked());
500 iothread_locked = false;
501 qemu_mutex_unlock(&qemu_global_mutex);
504 void qemu_cond_wait_iothread(QemuCond *cond)
506 qemu_cond_wait(cond, &qemu_global_mutex);
509 void qemu_cond_timedwait_iothread(QemuCond *cond, int ms)
511 qemu_cond_timedwait(cond, &qemu_global_mutex, ms);
514 /* signal CPU creation */
515 void cpu_thread_signal_created(CPUState *cpu)
517 cpu->created = true;
518 qemu_cond_signal(&qemu_cpu_cond);
521 /* signal CPU destruction */
522 void cpu_thread_signal_destroyed(CPUState *cpu)
524 cpu->created = false;
525 qemu_cond_signal(&qemu_cpu_cond);
529 static bool all_vcpus_paused(void)
531 CPUState *cpu;
533 CPU_FOREACH(cpu) {
534 if (!cpu->stopped) {
535 return false;
539 return true;
542 void pause_all_vcpus(void)
544 CPUState *cpu;
546 qemu_clock_enable(QEMU_CLOCK_VIRTUAL, false);
547 CPU_FOREACH(cpu) {
548 if (qemu_cpu_is_self(cpu)) {
549 qemu_cpu_stop(cpu, true);
550 } else {
551 cpu->stop = true;
552 qemu_cpu_kick(cpu);
556 /* We need to drop the replay_lock so any vCPU threads woken up
557 * can finish their replay tasks
559 replay_mutex_unlock();
561 while (!all_vcpus_paused()) {
562 qemu_cond_wait(&qemu_pause_cond, &qemu_global_mutex);
563 CPU_FOREACH(cpu) {
564 qemu_cpu_kick(cpu);
568 qemu_mutex_unlock_iothread();
569 replay_mutex_lock();
570 qemu_mutex_lock_iothread();
573 void cpu_resume(CPUState *cpu)
575 cpu->stop = false;
576 cpu->stopped = false;
577 qemu_cpu_kick(cpu);
580 void resume_all_vcpus(void)
582 CPUState *cpu;
584 if (!runstate_is_running()) {
585 return;
588 qemu_clock_enable(QEMU_CLOCK_VIRTUAL, true);
589 CPU_FOREACH(cpu) {
590 cpu_resume(cpu);
594 void cpu_remove_sync(CPUState *cpu)
596 cpu->stop = true;
597 cpu->unplug = true;
598 qemu_cpu_kick(cpu);
599 qemu_mutex_unlock_iothread();
600 qemu_thread_join(cpu->thread);
601 qemu_mutex_lock_iothread();
604 void cpus_register_accel(const AccelOpsClass *ops)
606 assert(ops != NULL);
607 assert(ops->create_vcpu_thread != NULL); /* mandatory */
608 cpus_accel = ops;
611 void qemu_init_vcpu(CPUState *cpu)
613 MachineState *ms = MACHINE(qdev_get_machine());
615 cpu->nr_cores = ms->smp.cores;
616 cpu->nr_threads = ms->smp.threads;
617 cpu->stopped = true;
618 cpu->random_seed = qemu_guest_random_seed_thread_part1();
620 if (!cpu->as) {
621 /* If the target cpu hasn't set up any address spaces itself,
622 * give it the default one.
624 cpu->num_ases = 1;
625 cpu_address_space_init(cpu, 0, "cpu-memory", cpu->memory);
628 /* accelerators all implement the AccelOpsClass */
629 g_assert(cpus_accel != NULL && cpus_accel->create_vcpu_thread != NULL);
630 cpus_accel->create_vcpu_thread(cpu);
632 while (!cpu->created) {
633 qemu_cond_wait(&qemu_cpu_cond, &qemu_global_mutex);
637 void cpu_stop_current(void)
639 if (current_cpu) {
640 current_cpu->stop = true;
641 cpu_exit(current_cpu);
645 int vm_stop(RunState state)
647 if (qemu_in_vcpu_thread()) {
648 qemu_system_vmstop_request_prepare();
649 qemu_system_vmstop_request(state);
651 * FIXME: should not return to device code in case
652 * vm_stop() has been requested.
654 cpu_stop_current();
655 return 0;
658 return do_vm_stop(state, true);
662 * Prepare for (re)starting the VM.
663 * Returns -1 if the vCPUs are not to be restarted (e.g. if they are already
664 * running or in case of an error condition), 0 otherwise.
666 int vm_prepare_start(void)
668 RunState requested;
670 qemu_vmstop_requested(&requested);
671 if (runstate_is_running() && requested == RUN_STATE__MAX) {
672 return -1;
675 /* Ensure that a STOP/RESUME pair of events is emitted if a
676 * vmstop request was pending. The BLOCK_IO_ERROR event, for
677 * example, according to documentation is always followed by
678 * the STOP event.
680 if (runstate_is_running()) {
681 qapi_event_send_stop();
682 qapi_event_send_resume();
683 return -1;
686 /* We are sending this now, but the CPUs will be resumed shortly later */
687 qapi_event_send_resume();
689 cpu_enable_ticks();
690 runstate_set(RUN_STATE_RUNNING);
691 vm_state_notify(1, RUN_STATE_RUNNING);
692 return 0;
695 void vm_start(void)
697 if (!vm_prepare_start()) {
698 resume_all_vcpus();
702 /* does a state transition even if the VM is already stopped,
703 current state is forgotten forever */
704 int vm_stop_force_state(RunState state)
706 if (runstate_is_running()) {
707 return vm_stop(state);
708 } else {
709 int ret;
710 runstate_set(state);
712 bdrv_drain_all();
713 /* Make sure to return an error if the flush in a previous vm_stop()
714 * failed. */
715 ret = bdrv_flush_all();
716 trace_vm_stop_flush_all(ret);
717 return ret;
721 void list_cpus(const char *optarg)
723 /* XXX: implement xxx_cpu_list for targets that still miss it */
724 #if defined(cpu_list)
725 cpu_list();
726 #endif
729 void qmp_memsave(int64_t addr, int64_t size, const char *filename,
730 bool has_cpu, int64_t cpu_index, Error **errp)
732 FILE *f;
733 uint32_t l;
734 CPUState *cpu;
735 uint8_t buf[1024];
736 int64_t orig_addr = addr, orig_size = size;
738 if (!has_cpu) {
739 cpu_index = 0;
742 cpu = qemu_get_cpu(cpu_index);
743 if (cpu == NULL) {
744 error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cpu-index",
745 "a CPU number");
746 return;
749 f = fopen(filename, "wb");
750 if (!f) {
751 error_setg_file_open(errp, errno, filename);
752 return;
755 while (size != 0) {
756 l = sizeof(buf);
757 if (l > size)
758 l = size;
759 if (cpu_memory_rw_debug(cpu, addr, buf, l, 0) != 0) {
760 error_setg(errp, "Invalid addr 0x%016" PRIx64 "/size %" PRId64
761 " specified", orig_addr, orig_size);
762 goto exit;
764 if (fwrite(buf, 1, l, f) != l) {
765 error_setg(errp, QERR_IO_ERROR);
766 goto exit;
768 addr += l;
769 size -= l;
772 exit:
773 fclose(f);
776 void qmp_pmemsave(int64_t addr, int64_t size, const char *filename,
777 Error **errp)
779 FILE *f;
780 uint32_t l;
781 uint8_t buf[1024];
783 f = fopen(filename, "wb");
784 if (!f) {
785 error_setg_file_open(errp, errno, filename);
786 return;
789 while (size != 0) {
790 l = sizeof(buf);
791 if (l > size)
792 l = size;
793 cpu_physical_memory_read(addr, buf, l);
794 if (fwrite(buf, 1, l, f) != l) {
795 error_setg(errp, QERR_IO_ERROR);
796 goto exit;
798 addr += l;
799 size -= l;
802 exit:
803 fclose(f);
806 void qmp_inject_nmi(Error **errp)
808 nmi_monitor_handle(monitor_get_cpu_index(monitor_cur()), errp);