static void *migration_thread(void *opaque) { MigrationState *s = opaque; int64_t initial_time = qemu_get_clock_ms(rt_clock); int64_t initial_bytes = 0; int64_t max_size = 0; int64_t start_time = initial_time; bool old_vm_running = false; DPRINTF("beginning savevm\n"); qemu_savevm_state_begin(s->file, &s->params); while (s->state == MIG_STATE_ACTIVE) { int64_t current_time; uint64_t pending_size; if (!qemu_file_rate_limit(s->file)) { DPRINTF("iterate\n"); pending_size = qemu_savevm_state_pending(s->file, max_size); DPRINTF("pending size %lu max %lu\n", pending_size, max_size); if (pending_size && pending_size >= max_size) { qemu_savevm_state_iterate(s->file); } else { int ret; DPRINTF("done iterating\n"); qemu_mutex_lock_iothread(); start_time = qemu_get_clock_ms(rt_clock); qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER); old_vm_running = runstate_is_running(); ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE); if (ret >= 0) { qemu_file_set_rate_limit(s->file, INT_MAX); qemu_savevm_state_complete(s->file); } qemu_mutex_unlock_iothread(); if (ret < 0) { migrate_finish_set_state(s, MIG_STATE_ERROR); break; } if (!qemu_file_get_error(s->file)) { migrate_finish_set_state(s, MIG_STATE_COMPLETED); break; } } } if (qemu_file_get_error(s->file)) { migrate_finish_set_state(s, MIG_STATE_ERROR); break; } current_time = qemu_get_clock_ms(rt_clock); if (current_time >= initial_time + BUFFER_DELAY) { uint64_t transferred_bytes = qemu_ftell(s->file) - initial_bytes; uint64_t time_spent = current_time - initial_time; double bandwidth = transferred_bytes / time_spent; max_size = bandwidth * migrate_max_downtime() / 1000000; s->mbps = time_spent ? (((double) transferred_bytes * 8.0) / ((double) time_spent / 1000.0)) / 1000.0 / 1000.0 : -1; DPRINTF("transferred %" PRIu64 " time_spent %" PRIu64 " bandwidth %g max_size %" PRId64 "\n", transferred_bytes, time_spent, bandwidth, max_size); /* if we haven't sent anything, we don't want to recalculate 10000 is a small enough number for our purposes */ if (s->dirty_bytes_rate && transferred_bytes > 10000) { s->expected_downtime = s->dirty_bytes_rate / bandwidth; } qemu_file_reset_rate_limit(s->file); initial_time = current_time; initial_bytes = qemu_ftell(s->file); } if (qemu_file_rate_limit(s->file)) { /* usleep expects microseconds */ g_usleep((initial_time + BUFFER_DELAY - current_time)*1000); } } qemu_mutex_lock_iothread(); if (s->state == MIG_STATE_COMPLETED) { int64_t end_time = qemu_get_clock_ms(rt_clock); s->total_time = end_time - s->total_time; s->downtime = end_time - start_time; runstate_set(RUN_STATE_POSTMIGRATE); } else { if (old_vm_running) { vm_start(); } } qemu_bh_schedule(s->cleanup_bh); qemu_mutex_unlock_iothread(); return NULL; }