tcg: Move qemu_tcg_mttcg_enabled() to 'system/tcg.h'

qemu_tcg_mttcg_enabled() is specific to 1/ TCG and
2/ system emulation. Move the prototype declaration
to "system/tcg.h", reducing 'mttcg_enabled' variable
scope.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20250403220420.78937-17-philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

accel/tcg/tcg-all.c

@@ -38,6 +38,7 @@
 #include "hw/qdev-core.h"
 #else
 #include "hw/boards.h"
+#include "system/tcg.h"
 #endif
 #include "internal-common.h"
 #include "cpu-param.h"
@@ -58,6 +59,17 @@ typedef struct TCGState TCGState;
 DECLARE_INSTANCE_CHECKER(TCGState, TCG_STATE,
                          TYPE_TCG_ACCEL)
 
+#ifndef CONFIG_USER_ONLY
+
+static bool mttcg_enabled;
+
+bool qemu_tcg_mttcg_enabled(void)
+{
+    return mttcg_enabled;
+}
+
+#endif /* !CONFIG_USER_ONLY */
+
 /*
  * We default to false if we know other options have been enabled
  * which are currently incompatible with MTTCG. Otherwise when each
@@ -97,7 +109,6 @@ static void tcg_accel_instance_init(Object *obj)
 #endif
 }
 
-bool mttcg_enabled;
 bool one_insn_per_tb;
 
 static int tcg_init_machine(MachineState *ms)
@@ -106,14 +117,14 @@ static int tcg_init_machine(MachineState *ms)
     unsigned max_threads = 1;
 
     tcg_allowed = true;
-    mttcg_enabled = s->mttcg_enabled;
 
     page_init();
     tb_htable_init();
 
 #ifndef CONFIG_USER_ONLY
-    if (mttcg_enabled) {
+    if (s->mttcg_enabled) {
         max_threads = ms->smp.max_cpus;
+        mttcg_enabled = true;
     }
 #endif
     tcg_init(s->tb_size * MiB, s->splitwx_enabled, max_threads);

include/hw/core/cpu.h

@@ -594,15 +594,6 @@ extern CPUTailQ cpus_queue;
 
 extern __thread CPUState *current_cpu;
 
-/**
- * qemu_tcg_mttcg_enabled:
- * Check whether we are running MultiThread TCG or not.
- *
- * Returns: %true if we are in MTTCG mode %false otherwise.
- */
-extern bool mttcg_enabled;
-#define qemu_tcg_mttcg_enabled() (mttcg_enabled)
-
 /**
  * cpu_paging_enabled:
  * @cpu: The CPU whose state is to be inspected.

include/system/tcg.h

@@ -17,4 +17,12 @@ extern bool tcg_allowed;
 #define tcg_enabled() 0
 #endif
 
+/**
+ * qemu_tcg_mttcg_enabled:
+ * Check whether we are running MultiThread TCG or not.
+ *
+ * Returns: %true if we are in MTTCG mode %false otherwise.
+ */
+bool qemu_tcg_mttcg_enabled(void);
+
 #endif

target/riscv/tcg/tcg-cpu.c

@@ -36,6 +36,7 @@
 #include "tcg/tcg.h"
 #ifndef CONFIG_USER_ONLY
 #include "hw/boards.h"
+#include "system/tcg.h"
 #endif
 
 /* Hash that stores user set extensions */