On 2026-08-20 17:21, Richard Henderson wrote:
On 8/20/26 03:47, Philippe Mathieu-Daudé wrote:
Introduce const-qualified variants of cpu_env() and
env_archcpu(), to safely access CPU architecture
state when it should not be modified.
Signed-off-by: Philippe Mathieu-Daudé <[email protected]>
---
include/exec/cpu-common.h | 11 +++++++++++
include/hw/core/cpu.h | 6 ++++++
2 files changed, 17 insertions(+)
diff --git a/include/exec/cpu-common.h b/include/exec/cpu-common.h
index 6594f7fa1be..f3a3799f451 100644
--- a/include/exec/cpu-common.h
+++ b/include/exec/cpu-common.h
@@ -79,6 +79,17 @@ static inline bool cpu_loop_exit_requested(const
CPUState *cpu)
}
#endif /* CONFIG_TCG */
+/**
+ * env_archcpu_const(env)
+ * @env: The architecture environment (const).
+ *
+ * Return the const ArchCPU associated with the environment.
+ */
+static inline const ArchCPU *env_archcpu_const(const CPUArchState *env)
+{
+ return (const void *)env - sizeof(CPUState);
+}
+
/**
* env_archcpu(env)
* @env: The architecture environment
diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
index 81af7b9ee1a..59f777f3f15 100644
--- a/include/hw/core/cpu.h
+++ b/include/hw/core/cpu.h
@@ -594,6 +594,12 @@ struct CPUState {
QEMU_BUILD_BUG_ON(offsetof(CPUState, neg) !=
sizeof(CPUState) - sizeof(CPUNegativeOffsetState));
+static inline const CPUArchState *cpu_env_const(const CPUState *cpu)
+{
+ /* We validate that CPUArchState follows CPUState in cpu-target.c */
+ return (const CPUArchState *)(cpu + 1);
+}
+
static inline CPUArchState *cpu_env(CPUState *cpu)
{
/* We validate that CPUArchState follows CPUState in cpu-
target.c */
I wonder if we can use _Generic to make this automatic, rather than have
to choose between two different function names.
Eh clever :) This seems to work:
#define env_archcpu_(p) _Generic(*(p), \
CPUArchState: (void *)p, \
const CPUArchState: (const void *)p)
