[RFC,v4,8/9] module: introduce MODULE_INIT_ACCEL_CPU

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 9ef5daf4c5..509b249f52 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -2251,8 +2251,6 @@  static int kvm_init(MachineState *ms)
         ret = ram_block_discard_disable(true);
         assert(!ret);
     }
-
-    cpus_register_accel(&kvm_cpus);
     return 0;
 
 err:
@@ -3236,3 +3234,12 @@  static void kvm_type_init(void)
 }
 
 type_init(kvm_type_init);
+
+static void kvm_accel_cpu_init(void)
+{
+    if (kvm_enabled()) {
+        cpus_register_accel(&kvm_cpus);
+    }
+}
+
+accel_cpu_init(kvm_accel_cpu_init);
diff --git a/accel/qtest/qtest.c b/accel/qtest/qtest.c
index b282cea5cf..8d14059e32 100644
--- a/accel/qtest/qtest.c
+++ b/accel/qtest/qtest.c
@@ -32,7 +32,6 @@  const CpusAccel qtest_cpus = {
 
 static int qtest_init_accel(MachineState *ms)
 {
-    cpus_register_accel(&qtest_cpus);
     return 0;
 }
 
@@ -58,3 +57,12 @@  static void qtest_type_init(void)
 }
 
 type_init(qtest_type_init);
+
+static void qtest_accel_cpu_init(void)
+{
+    if (qtest_enabled()) {
+        cpus_register_accel(&qtest_cpus);
+    }
+}
+
+accel_cpu_init(qtest_accel_cpu_init);
diff --git a/accel/tcg/tcg-all.c b/accel/tcg/tcg-all.c
index fa1208158f..9ffedc8151 100644
--- a/accel/tcg/tcg-all.c
+++ b/accel/tcg/tcg-all.c
@@ -104,8 +104,6 @@  static int tcg_init(MachineState *ms)
 
     tcg_exec_init(s->tb_size * 1024 * 1024);
     mttcg_enabled = s->mttcg_enabled;
-    cpus_register_accel(&tcg_cpus);
-
     return 0;
 }
 
@@ -201,3 +199,12 @@  static void register_accel_types(void)
 }
 
 type_init(register_accel_types);
+
+static void tcg_accel_cpu_init(void)
+{
+    if (tcg_enabled()) {
+        cpus_register_accel(&tcg_cpus);
+    }
+}
+
+accel_cpu_init(tcg_accel_cpu_init);
diff --git a/accel/xen/xen-all.c b/accel/xen/xen-all.c
index 878a4089d9..6932a9f364 100644
--- a/accel/xen/xen-all.c
+++ b/accel/xen/xen-all.c
@@ -185,9 +185,6 @@  static int xen_init(MachineState *ms)
      * opt out of system RAM being allocated by generic code
      */
     mc->default_ram_id = NULL;
-
-    cpus_register_accel(&xen_cpus);
-
     return 0;
 }
 
@@ -228,3 +225,12 @@  static void xen_type_init(void)
 }
 
 type_init(xen_type_init);
+
+static void xen_accel_cpu_init(void)
+{
+    if (xen_enabled()) {
+        cpus_register_accel(&xen_cpus);
+    }
+}
+
+accel_cpu_init(xen_accel_cpu_init);
diff --git a/include/qemu/module.h b/include/qemu/module.h
index 944d403cbd..485eda986a 100644
--- a/include/qemu/module.h
+++ b/include/qemu/module.h
@@ -44,6 +44,7 @@  typedef enum {
     MODULE_INIT_BLOCK,
     MODULE_INIT_OPTS,
     MODULE_INIT_QOM,
+    MODULE_INIT_ACCEL_CPU,
     MODULE_INIT_TRACE,
     MODULE_INIT_XEN_BACKEND,
     MODULE_INIT_LIBQOS,
@@ -54,6 +55,7 @@  typedef enum {
 #define block_init(function) module_init(function, MODULE_INIT_BLOCK)
 #define opts_init(function) module_init(function, MODULE_INIT_OPTS)
 #define type_init(function) module_init(function, MODULE_INIT_QOM)
+#define accel_cpu_init(function) module_init(function, MODULE_INIT_ACCEL_CPU)
 #define trace_init(function) module_init(function, MODULE_INIT_TRACE)
 #define xen_backend_init(function) module_init(function, \
                                                MODULE_INIT_XEN_BACKEND)
diff --git a/softmmu/vl.c b/softmmu/vl.c
index e6e0ad5a92..df4bed056a 100644
--- a/softmmu/vl.c
+++ b/softmmu/vl.c
@@ -4173,6 +4173,12 @@  void qemu_init(int argc, char **argv, char **envp)
      */
     configure_accelerators(argv[0]);
 
+    /*
+     * accelerator has been chosen and initialized, now it is time to
+     * register the cpu accel interface.
+     */
+    module_call_init(MODULE_INIT_ACCEL_CPU);
+
     /*
      * Beware, QOM objects created before this point miss global and
      * compat properties.
diff --git a/target/i386/hax/hax-all.c b/target/i386/hax/hax-all.c
index fecfe8cd6e..3bada019f5 100644
--- a/target/i386/hax/hax-all.c
+++ b/target/i386/hax/hax-all.c
@@ -364,9 +364,6 @@  static int hax_accel_init(MachineState *ms)
                 !ret ? "working" : "not working",
                 !ret ? "fast virt" : "emulation");
     }
-    if (ret == 0) {
-        cpus_register_accel(&hax_cpus);
-    }
     return ret;
 }
 
@@ -1141,3 +1138,12 @@  static void hax_type_init(void)
 }
 
 type_init(hax_type_init);
+
+static void hax_accel_cpu_init(void)
+{
+    if (hax_enabled()) {
+        cpus_register_accel(&hax_cpus);
+    }
+}
+
+accel_cpu_init(hax_accel_cpu_init);
diff --git a/target/i386/hvf/hvf.c b/target/i386/hvf/hvf.c
index ed9356565c..249b77797f 100644
--- a/target/i386/hvf/hvf.c
+++ b/target/i386/hvf/hvf.c
@@ -887,7 +887,6 @@  static int hvf_accel_init(MachineState *ms)
   
     hvf_state = s;
     memory_listener_register(&hvf_memory_listener, &address_space_memory);
-    cpus_register_accel(&hvf_cpus);
     return 0;
 }
 
@@ -911,3 +910,12 @@  static void hvf_type_init(void)
 }
 
 type_init(hvf_type_init);
+
+static void hvf_accel_cpu_init(void)
+{
+    if (hvf_enabled()) {
+        cpus_register_accel(&hvf_cpus);
+    }
+}
+
+accel_cpu_init(hvf_accel_cpu_init);
diff --git a/target/i386/whpx/whpx-all.c b/target/i386/whpx/whpx-all.c
index f4f3e33eac..2e715e2bc6 100644
--- a/target/i386/whpx/whpx-all.c
+++ b/target/i386/whpx/whpx-all.c
@@ -1642,8 +1642,6 @@  static int whpx_accel_init(MachineState *ms)
 
     whpx_memory_init();
 
-    cpus_register_accel(&whpx_cpus);
-
     printf("Windows Hypervisor Platform accelerator is operational\n");
     return 0;
 
@@ -1713,3 +1711,12 @@  error:
 }
 
 type_init(whpx_type_init);
+
+static void whpx_accel_cpu_init(void)
+{
+    if (whpx_enabled()) {
+        cpus_register_accel(&whpx_cpus);
+    }
+}
+
+accel_cpu_init(whpx_accel_cpu_init);