avoid open coding the accesses to cpu->accel_cpu interfaces,
and instead introduce:

accel_cpu_instance_init,
accel_cpu_realizefn

to be used by the targets/ initfn code,
and by cpu_exec_realizefn respectively.

Add warnings about the use of target-specific headers.

Signed-off-by: Claudio Fontana <cfontana@suse.de>
---
 include/hw/core/accel-cpu.h | 11 +++++++----
 include/qemu/accel.h        | 13 +++++++++++++
 accel/accel-common.c        | 19 +++++++++++++++++++
 cpu.c                       |  6 +-----
 target/i386/cpu.c           |  9 ++-------
 5 files changed, 42 insertions(+), 16 deletions(-)

diff --git a/include/hw/core/accel-cpu.h b/include/hw/core/accel-cpu.h
index 246b3e2fcb..2edecd026a 100644
--- a/include/hw/core/accel-cpu.h
+++ b/include/hw/core/accel-cpu.h
@@ -1,5 +1,6 @@
 /*
  * Accelerator interface, specializes CPUClass
+ * This header is used only by target-specific code.
  *
  * Copyright 2020 SUSE LLC
  *
@@ -11,10 +12,12 @@
 #define ACCEL_CPU_H
 
 /*
- * these defines cannot be in cpu.h, because we are using
- * CPU_RESOLVING_TYPE here.
- * Use this header to define your accelerator-specific
- * cpu-specific accelerator interfaces.
+ * This header is used to define new accelerator-specific target-specific
+ * accelerator cpu subclasses.
+ * It uses CPU_RESOLVING_TYPE, so this is clearly target-specific.
+ *
+ * Do not try to use for any other purpose than the implementation of new
+ * subclasses in target/, or the accel implementation itself in accel/
  */
 
 #define TYPE_ACCEL_CPU "accel-" CPU_RESOLVING_TYPE
diff --git a/include/qemu/accel.h b/include/qemu/accel.h
index b9d6d69eb8..da0c8ab523 100644
--- a/include/qemu/accel.h
+++ b/include/qemu/accel.h
@@ -78,4 +78,17 @@ int accel_init_machine(AccelState *accel, MachineState *ms);
 void accel_setup_post(MachineState *ms);
 #endif /* !CONFIG_USER_ONLY */
 
+/**
+ * accel_cpu_instance_init:
+ * @cpu: The CPU that needs to do accel-specific object initializations.
+ */
+void accel_cpu_instance_init(CPUState *cpu);
+
+/**
+ * accel_cpu_realizefn:
+ * @cpu: The CPU that needs to call accel-specific cpu realization.
+ * @errp: currently unused.
+ */
+void accel_cpu_realizefn(CPUState *cpu, Error **errp);
+
 #endif /* QEMU_ACCEL_H */
diff --git a/accel/accel-common.c b/accel/accel-common.c
index 9901b0531c..0f6fb4fb66 100644
--- a/accel/accel-common.c
+++ b/accel/accel-common.c
@@ -89,6 +89,25 @@ void accel_init_interfaces(AccelClass *ac)
     accel_init_cpu_interfaces(ac);
 }
 
+void accel_cpu_instance_init(CPUState *cpu)
+{
+    CPUClass *cc = CPU_GET_CLASS(cpu);
+
+    if (cc->accel_cpu && cc->accel_cpu->cpu_instance_init) {
+        cc->accel_cpu->cpu_instance_init(cpu);
+    }
+}
+
+void accel_cpu_realizefn(CPUState *cpu, Error **errp)
+{
+    CPUClass *cc = CPU_GET_CLASS(cpu);
+
+    if (cc->accel_cpu && cc->accel_cpu->cpu_realizefn) {
+        /* NB: errp parameter is unused currently */
+        cc->accel_cpu->cpu_realizefn(cpu, errp);
+    }
+}
+
 static const TypeInfo accel_cpu_type = {
     .name = TYPE_ACCEL_CPU,
     .parent = TYPE_OBJECT,
diff --git a/cpu.c b/cpu.c
index ba5d272c1e..25e6fbfa2c 100644
--- a/cpu.c
+++ b/cpu.c
@@ -130,11 +130,7 @@ void cpu_exec_realizefn(CPUState *cpu, Error **errp)
     CPUClass *cc = CPU_GET_CLASS(cpu);
 
     cpu_list_add(cpu);
-
-    if (cc->accel_cpu) {
-        /* NB: errp parameter is unused currently */
-        cc->accel_cpu->cpu_realizefn(cpu, errp);
-    }
+    accel_cpu_realizefn(cpu, errp);
 
 #ifdef CONFIG_TCG
     /* NB: errp parameter is unused currently */
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 83c474e270..c79123811f 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -28,7 +28,6 @@
 #include "sysemu/kvm.h"
 #include "sysemu/reset.h"
 #include "sysemu/hvf.h"
-#include "hw/core/accel-cpu.h"
 #include "sysemu/xen.h"
 #include "sysemu/whpx.h"
 #include "kvm/kvm_i386.h"
@@ -6680,8 +6679,6 @@ static void x86_cpu_initfn(Object *obj)
 {
     X86CPU *cpu = X86_CPU(obj);
     X86CPUClass *xcc = X86_CPU_GET_CLASS(obj);
-    CPUClass *cc = CPU_CLASS(xcc);
-
     CPUX86State *env = &cpu->env;
 
     env->nr_dies = 1;
@@ -6730,10 +6727,8 @@ static void x86_cpu_initfn(Object *obj)
         x86_cpu_load_model(cpu, xcc->model);
     }
 
-    /* if required, do the accelerator-specific cpu initialization */
-    if (cc->accel_cpu) {
-        cc->accel_cpu->cpu_instance_init(CPU(obj));
-    }
+    /* if required, do accelerator-specific cpu initializations */
+    accel_cpu_instance_init(CPU(obj));
 }
 
 static int64_t x86_cpu_get_arch_id(CPUState *cs)
-- 
2.26.2