accel/dummy-cpus.c

   1 /*
   2  * Dummy cpu thread code
   3  *
   4  * Copyright IBM, Corp. 2011
   5  *
   6  * Authors:
   7  *  Anthony Liguori   <aliguori@us.ibm.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  10  * See the COPYING file in the top-level directory.
  11  *
  12  */
  13
  14 #include "qemu/osdep.h"
  15 #include "qemu/rcu.h"
  16 #include "sysemu/cpus.h"
  17 #include "qemu/guest-random.h"
  18 #include "qemu/main-loop.h"
  19 #include "hw/core/cpu.h"
  20
  21 static void *dummy_cpu_thread_fn(void *arg)
  22 {
  23     CPUState *cpu = arg;
  24     sigset_t waitset;
  25     int r;
  26
  27     rcu_register_thread();
  28
  29     qemu_mutex_lock_iothread();
  30     qemu_thread_get_self(cpu->thread);
  31     cpu->thread_id = qemu_get_thread_id();
  32     cpu->can_do_io = 1;
  33     current_cpu = cpu;
  34
  35     sigemptyset(&waitset);
  36     sigaddset(&waitset, SIG_IPI);
  37
  38     /* signal CPU creation */
  39     cpu_thread_signal_created(cpu);
  40     qemu_guest_random_seed_thread_part2(cpu->random_seed);
  41
  42     do {
  43         qemu_mutex_unlock_iothread();
  44         do {
  45             int sig;
  46             r = sigwait(&waitset, &sig);
  47         } while (r == -1 && (errno == EAGAIN || errno == EINTR));
  48         if (r == -1) {
  49             perror("sigwait");
  50             exit(1);
  51         }
  52         qemu_mutex_lock_iothread();
  53         qemu_wait_io_event(cpu);
  54     } while (!cpu->unplug);
  55
  56     qemu_mutex_unlock_iothread();
  57     rcu_unregister_thread();
  58     return NULL;
  59 }
  60
  61 void dummy_start_vcpu_thread(CPUState *cpu)
  62 {
  63     char thread_name[VCPU_THREAD_NAME_SIZE];
  64
  65     cpu->thread = g_malloc0(sizeof(QemuThread));
  66     cpu->halt_cond = g_malloc0(sizeof(QemuCond));
  67     qemu_cond_init(cpu->halt_cond);
  68     snprintf(thread_name, VCPU_THREAD_NAME_SIZE, "CPU %d/DUMMY",
  69              cpu->cpu_index);
  70     qemu_thread_create(cpu->thread, thread_name, dummy_cpu_thread_fn, cpu,
  71                        QEMU_THREAD_JOINABLE);
  72 }