[Qemu-devel] [PATCH RFC 7/7] target-arm: Embed CPUARMState in QOM ARMCPU

["Andreas Färber" <afaerber@suse.de>]

We g_malloc0()'ed CPUARMState ourself, and exec.c's cpu_copy() runs
through cpu_init() as well, so we are at liberty to supply the CPUState
any way we see fit. Having CPUARMState as field in the QOM CPU allows
both to access env from an ARMCPU object and to access the QOM Object
and its ObjectClass from an env pointer, in ARM code for now.

The goal is to convert all CPUs to QOM and to use CPU objects in central
places, especially once we have property support for Object.
This will then allow to have TCG AREG0 point to target-specific fields
where small immediate offsets are desired (as pointed out by rth) while
allowing for common fields at known offsets from the base class.

Having the CPUID in ARMCPUClass, we can set it from the realize function.
Same for cpu_model_str, which is now the QOM class name.

Signed-off-by: Andreas Färber <afaerber@suse.de>
Cc: Anthony Liguori <aliguori@us.ibm.com>
Cc: Paul Brook <paul@codesourcery.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Richard Henderson <rth@twiddle.net>
---
 target-arm/cpu-core.c |   13 +++++++++++++
 target-arm/cpu-core.h |    7 +++++++
 target-arm/helper.c   |   13 ++++++-------
 3 files changed, 26 insertions(+), 7 deletions(-)

diff --git a/target-arm/cpu-core.c b/target-arm/cpu-core.c
index 9761d8e..b1ac22c 100644
--- a/target-arm/cpu-core.c
+++ b/target-arm/cpu-core.c
@@ -234,12 +234,25 @@ static const struct ARMCPUDef arm_cpu_models[] = {
     { }
 };
 
+static void arm_cpu_realize(Object *obj)
+{
+    ARMCPU *cpu = ARM_CPU(obj);
+    ARMCPUClass *cpu_class = ARM_CPU_GET_CLASS(obj);
+
+    memset(&cpu->env, 0, sizeof(CPUARMState));
+    cpu_exec_init(&cpu->env);
+
+    cpu->env.cpu_model_str = object_get_typename(obj);
+    cpu->env.cp15.c0_cpuid = cpu_class->id;
+}
+
 static void cpu_register(const struct ARMCPUDef *def)
 {
     TypeInfo type = {
         .name = def->name,
         .parent = TYPE_ARM_CPU,
         .instance_size = sizeof(ARMCPU),
+        .instance_init = arm_cpu_realize,
         .class_size = sizeof(ARMCPUClass),
         .class_init = def->class_init,
     };
diff --git a/target-arm/cpu-core.h b/target-arm/cpu-core.h
index be4bbc3..08b6b2b 100644
--- a/target-arm/cpu-core.h
+++ b/target-arm/cpu-core.h
@@ -10,6 +10,7 @@
 #define QEMU_ARM_CPU_CORE_H
 
 #include "qemu/cpu.h"
+#include "cpu.h"
 
 #define TYPE_ARM_CPU "arm-cpu-core"
 #define ARM_CPU_CLASS(klass) \
@@ -27,7 +28,13 @@ typedef struct ARMCPUClass {
 
 typedef struct ARMCPU {
     CPU parent_obj;
+
+    /* TODO Inline this and split off common state */
+    CPUARMState env;
 } ARMCPU;
 
+#define ENV_GET_OBJECT(e) \
+    (Object *)((void *)(e) - offsetof(ARMCPU, env))
+
 
 #endif
diff --git a/target-arm/helper.c b/target-arm/helper.c
index ece9635..1ffd7ba 100644
--- a/target-arm/helper.c
+++ b/target-arm/helper.c
@@ -400,7 +400,7 @@ static int vfp_gdb_set_reg(CPUState *env, uint8_t *buf, int reg)
 CPUARMState *cpu_arm_init(const char *cpu_model)
 {
     ObjectClass *klass;
-    ARMCPUClass *cpu_class;
+    ARMCPU *cpu;
     CPUARMState *env;
     static int inited = 0;
 
@@ -408,16 +408,14 @@ CPUARMState *cpu_arm_init(const char *cpu_model)
     if (klass == NULL) {
         return NULL;
     }
-    cpu_class = ARM_CPU_CLASS(klass);
-    env = g_malloc0(sizeof(CPUARMState));
-    cpu_exec_init(env);
+    cpu = ARM_CPU(object_new_with_type(klass->type));
+    env = &cpu->env;
+
     if (tcg_enabled() && !inited) {
         inited = 1;
         arm_translate_init();
     }
 
-    env->cpu_model_str = cpu_model;
-    env->cp15.c0_cpuid = cpu_class->id;
     cpu_reset(env);
     if (arm_feature(env, ARM_FEATURE_NEON)) {
         gdb_register_coprocessor(env, vfp_gdb_get_reg, vfp_gdb_set_reg,
@@ -459,7 +457,8 @@ void arm_cpu_list(FILE *f, fprintf_function cpu_fprintf)
 
 void cpu_arm_close(CPUARMState *env)
 {
-    g_free(env);
+    Object *obj = ENV_GET_OBJECT(env);
+    object_delete(obj);
 }
 
 static int bad_mode_switch(CPUState *env, int mode)
-- 
1.7.7