qemu

cpus.c (18854B)

---

 /*
  * QEMU System Emulator
  *
  * Copyright (c) 2003-2008 Fabrice Bellard
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
 
 #include "qemu/osdep.h"
 #include "monitor/monitor.h"
 #include "qemu/coroutine-tls.h"
 #include "qapi/error.h"
 #include "qapi/qapi-commands-machine.h"
 #include "qapi/qapi-commands-misc.h"
 #include "qapi/qapi-events-run-state.h"
 #include "qapi/qmp/qerror.h"
 #include "exec/gdbstub.h"
 #include "sysemu/hw_accel.h"
 #include "exec/cpu-common.h"
 #include "qemu/thread.h"
 #include "qemu/plugin.h"
 #include "sysemu/cpus.h"
 #include "qemu/guest-random.h"
 #include "hw/nmi.h"
 #include "sysemu/replay.h"
 #include "sysemu/runstate.h"
 #include "sysemu/cpu-timers.h"
 #include "sysemu/whpx.h"
 #include "hw/boards.h"
 #include "hw/hw.h"
 #include "trace.h"
 
 #ifdef CONFIG_LINUX
 
 #include <sys/prctl.h>
 
 #ifndef PR_MCE_KILL
 #define PR_MCE_KILL 33
 #endif
 
 #ifndef PR_MCE_KILL_SET
 #define PR_MCE_KILL_SET 1
 #endif
 
 #ifndef PR_MCE_KILL_EARLY
 #define PR_MCE_KILL_EARLY 1
 #endif
 
 #endif /* CONFIG_LINUX */
 
 static QemuMutex qemu_global_mutex;
 
 /*
  * The chosen accelerator is supposed to register this.
  */
 static const AccelOpsClass *cpus_accel;
 
 bool cpu_is_stopped(CPUState *cpu)
 {
     return cpu->stopped || !runstate_is_running();
 }
 
 bool cpu_work_list_empty(CPUState *cpu)
 {
     return QSIMPLEQ_EMPTY_ATOMIC(&cpu->work_list);
 }
 
 bool cpu_thread_is_idle(CPUState *cpu)
 {
     if (cpu->stop || !cpu_work_list_empty(cpu)) {
         return false;
     }
     if (cpu_is_stopped(cpu)) {
         return true;
     }
     if (!cpu->halted || cpu_has_work(cpu)) {
         return false;
     }
     if (cpus_accel->cpu_thread_is_idle) {
         return cpus_accel->cpu_thread_is_idle(cpu);
     }
     return true;
 }
 
 bool all_cpu_threads_idle(void)
 {
     CPUState *cpu;
 
     CPU_FOREACH(cpu) {
         if (!cpu_thread_is_idle(cpu)) {
             return false;
         }
     }
     return true;
 }
 
 /***********************************************************/
 void hw_error(const char *fmt, ...)
 {
     va_list ap;
     CPUState *cpu;
 
     va_start(ap, fmt);
     fprintf(stderr, "qemu: hardware error: ");
     vfprintf(stderr, fmt, ap);
     fprintf(stderr, "\n");
     CPU_FOREACH(cpu) {
         fprintf(stderr, "CPU #%d:\n", cpu->cpu_index);
         cpu_dump_state(cpu, stderr, CPU_DUMP_FPU);
     }
     va_end(ap);
     abort();
 }
 
 void cpu_synchronize_all_states(void)
 {
     CPUState *cpu;
 
     CPU_FOREACH(cpu) {
         cpu_synchronize_state(cpu);
     }
 }
 
 void cpu_synchronize_all_post_reset(void)
 {
     CPUState *cpu;
 
     CPU_FOREACH(cpu) {
         cpu_synchronize_post_reset(cpu);
     }
 }
 
 void cpu_synchronize_all_post_init(void)
 {
     CPUState *cpu;
 
     CPU_FOREACH(cpu) {
         cpu_synchronize_post_init(cpu);
     }
 }
 
 void cpu_synchronize_all_pre_loadvm(void)
 {
     CPUState *cpu;
 
     CPU_FOREACH(cpu) {
         cpu_synchronize_pre_loadvm(cpu);
     }
 }
 
 void cpu_synchronize_state(CPUState *cpu)
 {
     if (cpus_accel->synchronize_state) {
         cpus_accel->synchronize_state(cpu);
     }
 }
 
 void cpu_synchronize_post_reset(CPUState *cpu)
 {
     if (cpus_accel->synchronize_post_reset) {
         cpus_accel->synchronize_post_reset(cpu);
     }
 }
 
 void cpu_synchronize_post_init(CPUState *cpu)
 {
     if (cpus_accel->synchronize_post_init) {
         cpus_accel->synchronize_post_init(cpu);
     }
 }
 
 void cpu_synchronize_pre_loadvm(CPUState *cpu)
 {
     if (cpus_accel->synchronize_pre_loadvm) {
         cpus_accel->synchronize_pre_loadvm(cpu);
     }
 }
 
 bool cpus_are_resettable(void)
 {
     if (cpus_accel->cpus_are_resettable) {
         return cpus_accel->cpus_are_resettable();
     }
     return true;
 }
 
 int64_t cpus_get_virtual_clock(void)
 {
     /*
      * XXX
      *
      * need to check that cpus_accel is not NULL, because qcow2 calls
      * qemu_get_clock_ns(CLOCK_VIRTUAL) without any accel initialized and
      * with ticks disabled in some io-tests:
      * 030 040 041 060 099 120 127 140 156 161 172 181 191 192 195 203 229 249 256 267
      *
      * is this expected?
      *
      * XXX
      */
     if (cpus_accel && cpus_accel->get_virtual_clock) {
         return cpus_accel->get_virtual_clock();
     }
     return cpu_get_clock();
 }
 
 /*
  * return the time elapsed in VM between vm_start and vm_stop.  Unless
  * icount is active, cpus_get_elapsed_ticks() uses units of the host CPU cycle
  * counter.
  */
 int64_t cpus_get_elapsed_ticks(void)
 {
     if (cpus_accel->get_elapsed_ticks) {
         return cpus_accel->get_elapsed_ticks();
     }
     return cpu_get_ticks();
 }
 
 static void generic_handle_interrupt(CPUState *cpu, int mask)
 {
     cpu->interrupt_request |= mask;
 
     if (!qemu_cpu_is_self(cpu)) {
         qemu_cpu_kick(cpu);
     }
 }
 
 void cpu_interrupt(CPUState *cpu, int mask)
 {
     if (cpus_accel->handle_interrupt) {
         cpus_accel->handle_interrupt(cpu, mask);
     } else {
         generic_handle_interrupt(cpu, mask);
     }
 }
 
 static int do_vm_stop(RunState state, bool send_stop)
 {
     int ret = 0;
 
     if (runstate_is_running()) {
         runstate_set(state);
         cpu_disable_ticks();
         pause_all_vcpus();
         vm_state_notify(0, state);
         if (send_stop) {
             qapi_event_send_stop();
         }
     }
 
     bdrv_drain_all();
     ret = bdrv_flush_all();
     trace_vm_stop_flush_all(ret);
 
     return ret;
 }
 
 /* Special vm_stop() variant for terminating the process.  Historically clients
  * did not expect a QMP STOP event and so we need to retain compatibility.
  */
 int vm_shutdown(void)
 {
     return do_vm_stop(RUN_STATE_SHUTDOWN, false);
 }
 
 bool cpu_can_run(CPUState *cpu)
 {
     if (cpu->stop) {
         return false;
     }
     if (cpu_is_stopped(cpu)) {
         return false;
     }
     return true;
 }
 
 void cpu_handle_guest_debug(CPUState *cpu)
 {
     if (replay_running_debug()) {
         if (!cpu->singlestep_enabled) {
             /*
              * Report about the breakpoint and
              * make a single step to skip it
              */
             replay_breakpoint();
             cpu_single_step(cpu, SSTEP_ENABLE);
         } else {
             cpu_single_step(cpu, 0);
         }
     } else {
         gdb_set_stop_cpu(cpu);
         qemu_system_debug_request();
         cpu->stopped = true;
     }
 }
 
 #ifdef CONFIG_LINUX
 static void sigbus_reraise(void)
 {
     sigset_t set;
     struct sigaction action;
 
     memset(&action, 0, sizeof(action));
     action.sa_handler = SIG_DFL;
     if (!sigaction(SIGBUS, &action, NULL)) {
         raise(SIGBUS);
         sigemptyset(&set);
         sigaddset(&set, SIGBUS);
         pthread_sigmask(SIG_UNBLOCK, &set, NULL);
     }
     perror("Failed to re-raise SIGBUS!");
     abort();
 }
 
 static void sigbus_handler(int n, siginfo_t *siginfo, void *ctx)
 {
     if (siginfo->si_code != BUS_MCEERR_AO && siginfo->si_code != BUS_MCEERR_AR) {
         sigbus_reraise();
     }
 
     if (current_cpu) {
         /* Called asynchronously in VCPU thread.  */
         if (kvm_on_sigbus_vcpu(current_cpu, siginfo->si_code, siginfo->si_addr)) {
             sigbus_reraise();
         }
     } else {
         /* Called synchronously (via signalfd) in main thread.  */
         if (kvm_on_sigbus(siginfo->si_code, siginfo->si_addr)) {
             sigbus_reraise();
         }
     }
 }
 
 static void qemu_init_sigbus(void)
 {
     struct sigaction action;
 
     /*
      * ALERT: when modifying this, take care that SIGBUS forwarding in
      * qemu_prealloc_mem() will continue working as expected.
      */
     memset(&action, 0, sizeof(action));
     action.sa_flags = SA_SIGINFO;
     action.sa_sigaction = sigbus_handler;
     sigaction(SIGBUS, &action, NULL);
 
     prctl(PR_MCE_KILL, PR_MCE_KILL_SET, PR_MCE_KILL_EARLY, 0, 0);
 }
 #else /* !CONFIG_LINUX */
 static void qemu_init_sigbus(void)
 {
 }
 #endif /* !CONFIG_LINUX */
 
 static QemuThread io_thread;
 
 /* cpu creation */
 static QemuCond qemu_cpu_cond;
 /* system init */
 static QemuCond qemu_pause_cond;
 
 void qemu_init_cpu_loop(void)
 {
     qemu_init_sigbus();
     qemu_cond_init(&qemu_cpu_cond);
     qemu_cond_init(&qemu_pause_cond);
     qemu_mutex_init(&qemu_global_mutex);
 
     qemu_thread_get_self(&io_thread);
 }
 
 void run_on_cpu(CPUState *cpu, run_on_cpu_func func, run_on_cpu_data data)
 {
     do_run_on_cpu(cpu, func, data, &qemu_global_mutex);
 }
 
 static void qemu_cpu_stop(CPUState *cpu, bool exit)
 {
     g_assert(qemu_cpu_is_self(cpu));
     cpu->stop = false;
     cpu->stopped = true;
     if (exit) {
         cpu_exit(cpu);
     }
     qemu_cond_broadcast(&qemu_pause_cond);
 }
 
 void qemu_wait_io_event_common(CPUState *cpu)
 {
     qatomic_mb_set(&cpu->thread_kicked, false);
     if (cpu->stop) {
         qemu_cpu_stop(cpu, false);
     }
     process_queued_cpu_work(cpu);
 }
 
 void qemu_wait_io_event(CPUState *cpu)
 {
     bool slept = false;
 
     while (cpu_thread_is_idle(cpu)) {
         if (!slept) {
             slept = true;
             qemu_plugin_vcpu_idle_cb(cpu);
         }
         qemu_cond_wait(cpu->halt_cond, &qemu_global_mutex);
     }
     if (slept) {
         qemu_plugin_vcpu_resume_cb(cpu);
     }
 
 #ifdef _WIN32
     /* Eat dummy APC queued by cpus_kick_thread. */
     if (hax_enabled()) {
         SleepEx(0, TRUE);
     }
 #endif
     qemu_wait_io_event_common(cpu);
 }
 
 void cpus_kick_thread(CPUState *cpu)
 {
     if (cpu->thread_kicked) {
         return;
     }
     cpu->thread_kicked = true;
 
 #ifndef _WIN32
     int err = pthread_kill(cpu->thread->thread, SIG_IPI);
     if (err && err != ESRCH) {
         fprintf(stderr, "qemu:%s: %s", __func__, strerror(err));
         exit(1);
     }
 #else
     qemu_sem_post(&cpu->sem);
 #endif
 }
 
 void qemu_cpu_kick(CPUState *cpu)
 {
     qemu_cond_broadcast(cpu->halt_cond);
     if (cpus_accel->kick_vcpu_thread) {
         cpus_accel->kick_vcpu_thread(cpu);
     } else { /* default */
         cpus_kick_thread(cpu);
     }
 }
 
 void qemu_cpu_kick_self(void)
 {
     assert(current_cpu);
     cpus_kick_thread(current_cpu);
 }
 
 bool qemu_cpu_is_self(CPUState *cpu)
 {
     return qemu_thread_is_self(cpu->thread);
 }
 
 bool qemu_in_vcpu_thread(void)
 {
     return current_cpu && qemu_cpu_is_self(current_cpu);
 }
 
 QEMU_DEFINE_STATIC_CO_TLS(bool, iothread_locked)
 
 bool qemu_mutex_iothread_locked(void)
 {
     return get_iothread_locked();
 }
 
 bool qemu_in_main_thread(void)
 {
     return qemu_mutex_iothread_locked();
 }
 
 /*
  * The BQL is taken from so many places that it is worth profiling the
  * callers directly, instead of funneling them all through a single function.
  */
 void qemu_mutex_lock_iothread_impl(const char *file, int line)
 {
     QemuMutexLockFunc bql_lock = qatomic_read(&qemu_bql_mutex_lock_func);
 
     g_assert(!qemu_mutex_iothread_locked());
     bql_lock(&qemu_global_mutex, file, line);
     set_iothread_locked(true);
 }
 
 void qemu_mutex_unlock_iothread(void)
 {
     g_assert(qemu_mutex_iothread_locked());
     set_iothread_locked(false);
     qemu_mutex_unlock(&qemu_global_mutex);
 }
 
 void qemu_cond_wait_iothread(QemuCond *cond)
 {
     qemu_cond_wait(cond, &qemu_global_mutex);
 }
 
 void qemu_cond_timedwait_iothread(QemuCond *cond, int ms)
 {
     qemu_cond_timedwait(cond, &qemu_global_mutex, ms);
 }
 
 /* signal CPU creation */
 void cpu_thread_signal_created(CPUState *cpu)
 {
     cpu->created = true;
     qemu_cond_signal(&qemu_cpu_cond);
 }
 
 /* signal CPU destruction */
 void cpu_thread_signal_destroyed(CPUState *cpu)
 {
     cpu->created = false;
     qemu_cond_signal(&qemu_cpu_cond);
 }
 
 
 static bool all_vcpus_paused(void)
 {
     CPUState *cpu;
 
     CPU_FOREACH(cpu) {
         if (!cpu->stopped) {
             return false;
         }
     }
 
     return true;
 }
 
 void pause_all_vcpus(void)
 {
     CPUState *cpu;
 
     qemu_clock_enable(QEMU_CLOCK_VIRTUAL, false);
     CPU_FOREACH(cpu) {
         if (qemu_cpu_is_self(cpu)) {
             qemu_cpu_stop(cpu, true);
         } else {
             cpu->stop = true;
             qemu_cpu_kick(cpu);
         }
     }
 
     /* We need to drop the replay_lock so any vCPU threads woken up
      * can finish their replay tasks
      */
     replay_mutex_unlock();
 
     while (!all_vcpus_paused()) {
         qemu_cond_wait(&qemu_pause_cond, &qemu_global_mutex);
         CPU_FOREACH(cpu) {
             qemu_cpu_kick(cpu);
         }
     }
 
     qemu_mutex_unlock_iothread();
     replay_mutex_lock();
     qemu_mutex_lock_iothread();
 }
 
 void cpu_resume(CPUState *cpu)
 {
     cpu->stop = false;
     cpu->stopped = false;
     qemu_cpu_kick(cpu);
 }
 
 void resume_all_vcpus(void)
 {
     CPUState *cpu;
 
     if (!runstate_is_running()) {
         return;
     }
 
     qemu_clock_enable(QEMU_CLOCK_VIRTUAL, true);
     CPU_FOREACH(cpu) {
         cpu_resume(cpu);
     }
 }
 
 void cpu_remove_sync(CPUState *cpu)
 {
     cpu->stop = true;
     cpu->unplug = true;
     qemu_cpu_kick(cpu);
     qemu_mutex_unlock_iothread();
     qemu_thread_join(cpu->thread);
     qemu_mutex_lock_iothread();
 }
 
 void cpus_register_accel(const AccelOpsClass *ops)
 {
     assert(ops != NULL);
     assert(ops->create_vcpu_thread != NULL); /* mandatory */
     cpus_accel = ops;
 }
 
 const AccelOpsClass *cpus_get_accel(void)
 {
     /* broken if we call this early */
     assert(cpus_accel);
     return cpus_accel;
 }
 
 void qemu_init_vcpu(CPUState *cpu)
 {
     MachineState *ms = MACHINE(qdev_get_machine());
 
     cpu->nr_cores = ms->smp.cores;
     cpu->nr_threads =  ms->smp.threads;
     cpu->stopped = true;
     cpu->random_seed = qemu_guest_random_seed_thread_part1();
 
     if (!cpu->as) {
         /* If the target cpu hasn't set up any address spaces itself,
          * give it the default one.
          */
         cpu->num_ases = 1;
         cpu_address_space_init(cpu, 0, "cpu-memory", cpu->memory);
     }
 
     /* accelerators all implement the AccelOpsClass */
     g_assert(cpus_accel != NULL && cpus_accel->create_vcpu_thread != NULL);
     cpus_accel->create_vcpu_thread(cpu);
 
     while (!cpu->created) {
         qemu_cond_wait(&qemu_cpu_cond, &qemu_global_mutex);
     }
 }
 
 void cpu_stop_current(void)
 {
     if (current_cpu) {
         current_cpu->stop = true;
         cpu_exit(current_cpu);
     }
 }
 
 int vm_stop(RunState state)
 {
     if (qemu_in_vcpu_thread()) {
         qemu_system_vmstop_request_prepare();
         qemu_system_vmstop_request(state);
         /*
          * FIXME: should not return to device code in case
          * vm_stop() has been requested.
          */
         cpu_stop_current();
         return 0;
     }
 
     return do_vm_stop(state, true);
 }
 
 /**
  * Prepare for (re)starting the VM.
  * Returns -1 if the vCPUs are not to be restarted (e.g. if they are already
  * running or in case of an error condition), 0 otherwise.
  */
 int vm_prepare_start(bool step_pending)
 {
     RunState requested;
 
     qemu_vmstop_requested(&requested);
     if (runstate_is_running() && requested == RUN_STATE__MAX) {
         return -1;
     }
 
     /* Ensure that a STOP/RESUME pair of events is emitted if a
      * vmstop request was pending.  The BLOCK_IO_ERROR event, for
      * example, according to documentation is always followed by
      * the STOP event.
      */
     if (runstate_is_running()) {
         qapi_event_send_stop();
         qapi_event_send_resume();
         return -1;
     }
 
     /*
      * WHPX accelerator needs to know whether we are going to step
      * any CPUs, before starting the first one.
      */
     if (cpus_accel->synchronize_pre_resume) {
         cpus_accel->synchronize_pre_resume(step_pending);
     }
 
     /* We are sending this now, but the CPUs will be resumed shortly later */
     qapi_event_send_resume();
 
     cpu_enable_ticks();
     runstate_set(RUN_STATE_RUNNING);
     vm_state_notify(1, RUN_STATE_RUNNING);
     return 0;
 }
 
 void vm_start(void)
 {
     if (!vm_prepare_start(false)) {
         resume_all_vcpus();
     }
 }
 
 /* does a state transition even if the VM is already stopped,
    current state is forgotten forever */
 int vm_stop_force_state(RunState state)
 {
     if (runstate_is_running()) {
         return vm_stop(state);
     } else {
         int ret;
         runstate_set(state);
 
         bdrv_drain_all();
         /* Make sure to return an error if the flush in a previous vm_stop()
          * failed. */
         ret = bdrv_flush_all();
         trace_vm_stop_flush_all(ret);
         return ret;
     }
 }
 
 void qmp_memsave(int64_t addr, int64_t size, const char *filename,
                  bool has_cpu, int64_t cpu_index, Error **errp)
 {
     FILE *f;
     uint32_t l;
     CPUState *cpu;
     uint8_t buf[1024];
     int64_t orig_addr = addr, orig_size = size;
 
     if (!has_cpu) {
         cpu_index = 0;
     }
 
     cpu = qemu_get_cpu(cpu_index);
     if (cpu == NULL) {
         error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cpu-index",
                    "a CPU number");
         return;
     }
 
     f = fopen(filename, "wb");
     if (!f) {
         error_setg_file_open(errp, errno, filename);
         return;
     }
 
     while (size != 0) {
         l = sizeof(buf);
         if (l > size)
             l = size;
         if (cpu_memory_rw_debug(cpu, addr, buf, l, 0) != 0) {
             error_setg(errp, "Invalid addr 0x%016" PRIx64 "/size %" PRId64
                              " specified", orig_addr, orig_size);
             goto exit;
         }
         if (fwrite(buf, 1, l, f) != l) {
             error_setg(errp, QERR_IO_ERROR);
             goto exit;
         }
         addr += l;
         size -= l;
     }
 
 exit:
     fclose(f);
 }
 
 void qmp_pmemsave(int64_t addr, int64_t size, const char *filename,
                   Error **errp)
 {
     FILE *f;
     uint32_t l;
     uint8_t buf[1024];
 
     f = fopen(filename, "wb");
     if (!f) {
         error_setg_file_open(errp, errno, filename);
         return;
     }
 
     while (size != 0) {
         l = sizeof(buf);
         if (l > size)
             l = size;
         cpu_physical_memory_read(addr, buf, l);
         if (fwrite(buf, 1, l, f) != l) {
             error_setg(errp, QERR_IO_ERROR);
             goto exit;
         }
         addr += l;
         size -= l;
     }
 
 exit:
     fclose(f);
 }
 
 void qmp_inject_nmi(Error **errp)
 {
     nmi_monitor_handle(monitor_get_cpu_index(monitor_cur()), errp);
 }