Avoid allocating TCG resources in non-TCG mode

Do not allocate TCG-only resources like the translation buffer when
running over KVM or XEN. Saves a "few" bytes in the qemu address space
and is also conceptually cleaner.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 14 insertions, 5 deletions

diff --git a/exec.c b/exec.c
index 751fd8967b..5bc920313a 100644
--- a/exec.c
+++ b/exec.c
@@ -570,16 +570,12 @@ static void code_gen_alloc(unsigned long tb_size)
 /* Must be called before using the QEMU cpus. 'tb_size' is the size
    (in bytes) allocated to the translation buffer. Zero means default
    size. */
-void cpu_exec_init_all(unsigned long tb_size)
+void tcg_exec_init(unsigned long tb_size)
 {
     cpu_gen_init();
     code_gen_alloc(tb_size);
     code_gen_ptr = code_gen_buffer;
     page_init();
-#if !defined(CONFIG_USER_ONLY)
-    memory_map_init();
-    io_mem_init();
-#endif
 #if !defined(CONFIG_USER_ONLY) || !defined(CONFIG_USE_GUEST_BASE)
     /* There's no guest base to take into account, so go ahead and
        initialize the prologue now.  */
@@ -587,6 +583,19 @@ void cpu_exec_init_all(unsigned long tb_size)
 #endif
 }
 
+bool tcg_enabled(void)
+{
+    return code_gen_buffer != NULL;
+}
+
+void cpu_exec_init_all(void)
+{
+#if !defined(CONFIG_USER_ONLY)
+    memory_map_init();
+    io_mem_init();
+#endif
+}
+
 #if defined(CPU_SAVE_VERSION) && !defined(CONFIG_USER_ONLY)
 
 static int cpu_common_post_load(void *opaque, int version_id)