module: return success on module load

Let the caller know of load success.

Note that this also changes slightly the behaviour of the function to
try loading on subsequent calls if the previous ones failed.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

include/qemu/module.h

@@ -65,6 +65,6 @@ void register_module_init(void (*fn)(void), module_init_type type);
 void register_dso_module_init(void (*fn)(void), module_init_type type);
 
 void module_call_init(module_init_type type);
-void module_load_one(const char *prefix, const char *lib_name);
+bool module_load_one(const char *prefix, const char *lib_name);
 
 #endif

util/module.c

@@ -156,8 +156,10 @@ out:
 }
 #endif
 
-void module_load_one(const char *prefix, const char *lib_name)
+bool module_load_one(const char *prefix, const char *lib_name)
 {
+    bool success = false;
+
 #ifdef CONFIG_MODULES
     char *fname = NULL;
     char *exec_dir;
@@ -170,7 +172,7 @@ void module_load_one(const char *prefix, const char *lib_name)
 
     if (!g_module_supported()) {
         fprintf(stderr, "Module is not supported by system.\n");
-        return;
+        return false;
     }
 
     if (!loaded_modules) {
@@ -181,7 +183,7 @@ void module_load_one(const char *prefix, const char *lib_name)
 
     if (!g_hash_table_add(loaded_modules, module_name)) {
         g_free(module_name);
-        return;
+        return true;
     }
 
     exec_dir = qemu_get_exec_dir();
@@ -205,13 +207,19 @@ void module_load_one(const char *prefix, const char *lib_name)
         fname = NULL;
         /* Try loading until loaded a module file */
         if (!ret) {
+            success = true;
             break;
         }
     }
 
+    if (!success) {
+        g_hash_table_remove(loaded_modules, module_name);
+    }
+
     for (i = 0; i < n_dirs; i++) {
         g_free(dirs[i]);
     }
 
 #endif
+    return success;
 }