xref: /openbmc/qemu/accel/dummy-cpus.c (revision 1f9d714e9a92d382f5f7c054de647d3dde4ba803)
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  
25      rcu_register_thread();
26  
27      qemu_mutex_lock_iothread();
28      qemu_thread_get_self(cpu->thread);
29      cpu->thread_id = qemu_get_thread_id();
30      cpu->neg.can_do_io = true;
31      current_cpu = cpu;
32  
33  #ifndef _WIN32
34      sigset_t waitset;
35      int r;
36  
37      sigemptyset(&waitset);
38      sigaddset(&waitset, SIG_IPI);
39  #endif
40  
41      /* signal CPU creation */
42      cpu_thread_signal_created(cpu);
43      qemu_guest_random_seed_thread_part2(cpu->random_seed);
44  
45      do {
46          qemu_mutex_unlock_iothread();
47  #ifndef _WIN32
48          do {
49              int sig;
50              r = sigwait(&waitset, &sig);
51          } while (r == -1 && (errno == EAGAIN || errno == EINTR));
52          if (r == -1) {
53              perror("sigwait");
54              exit(1);
55          }
56  #else
57          qemu_sem_wait(&cpu->sem);
58  #endif
59          qemu_mutex_lock_iothread();
60          qemu_wait_io_event(cpu);
61      } while (!cpu->unplug);
62  
63      qemu_mutex_unlock_iothread();
64      rcu_unregister_thread();
65      return NULL;
66  }
67  
68  void dummy_start_vcpu_thread(CPUState *cpu)
69  {
70      char thread_name[VCPU_THREAD_NAME_SIZE];
71  
72      cpu->thread = g_malloc0(sizeof(QemuThread));
73      cpu->halt_cond = g_malloc0(sizeof(QemuCond));
74      qemu_cond_init(cpu->halt_cond);
75      snprintf(thread_name, VCPU_THREAD_NAME_SIZE, "CPU %d/DUMMY",
76               cpu->cpu_index);
77      qemu_thread_create(cpu->thread, thread_name, dummy_cpu_thread_fn, cpu,
78                         QEMU_THREAD_JOINABLE);
79  #ifdef _WIN32
80      qemu_sem_init(&cpu->sem, 0);
81  #endif
82  }
83