[RFC PATCH 1/2] cpus: Introduce const_cpu_env() and const_env_archcpu()

[Philippe Mathieu-Daudé]

const_cpu_env() is similar to cpu_env() but return a const
CPU 'env' state.
Same for const_env_archcpu() w.r.t. env_archcpu().

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 include/exec/cpu-common.h | 5 +++++
 include/hw/core/cpu.h     | 6 ++++++
 2 files changed, 11 insertions(+)

diff --git a/include/exec/cpu-common.h b/include/exec/cpu-common.h
index b1d76d69850..f765e97a973 100644
--- a/include/exec/cpu-common.h
+++ b/include/exec/cpu-common.h
@@ -250,6 +250,11 @@ static inline ArchCPU *env_archcpu(CPUArchState *env)
     return (void *)env - sizeof(CPUState);
 }
 
+static inline const ArchCPU *const_env_archcpu(const CPUArchState *env)
+{
+    return (const void *)env - sizeof(CPUState);
+}
+
 /**
  * env_cpu_const(env)
  * @env: The architecture environment
diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
index c3ca0babcb3..ecb31221b26 100644
--- a/include/hw/core/cpu.h
+++ b/include/hw/core/cpu.h
@@ -588,6 +588,12 @@ static inline CPUArchState *cpu_env(CPUState *cpu)
     return (CPUArchState *)(cpu + 1);
 }
 
+static inline const CPUArchState *const_cpu_env(const CPUState *cpu)
+{
+    /* We validate that CPUArchState follows CPUState in cpu-all.h. */
+    return (const CPUArchState *)(cpu + 1);
+}
+
 typedef QTAILQ_HEAD(CPUTailQ, CPUState) CPUTailQ;
 extern CPUTailQ cpus_queue;
 
-- 
2.47.1