throttle: Make throttle_is_valid() set errp

The caller does not need to set it, and this will allow us to refactor
this function later.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

blockdev.c

@@ -349,9 +349,7 @@ static bool check_throttle_config(ThrottleConfig *cfg, Error **errp)
         return false;
     }
 
-    if (!throttle_is_valid(cfg)) {
-        error_setg(errp, "bps/iops/max values must be within [0, %lld]",
-                   THROTTLE_VALUE_MAX);
+    if (!throttle_is_valid(cfg, errp)) {
         return false;
     }
 

include/qemu/throttle.h

@@ -108,7 +108,7 @@ bool throttle_enabled(ThrottleConfig *cfg);
 
 bool throttle_conflicting(ThrottleConfig *cfg, Error **errp);
 
-bool throttle_is_valid(ThrottleConfig *cfg);
+bool throttle_is_valid(ThrottleConfig *cfg, Error **errp);
 
 bool throttle_max_is_missing_limit(ThrottleConfig *cfg, Error **errp);
 

tests/test-throttle.c

@@ -315,7 +315,7 @@ static void test_is_valid_for_value(int value, bool should_be_valid)
         for (index = 0; index < BUCKETS_COUNT; index++) {
             memset(&cfg, 0, sizeof(cfg));
             set_cfg_value(is_max, index, value);
-            g_assert(throttle_is_valid(&cfg) == should_be_valid);
+            g_assert(throttle_is_valid(&cfg, NULL) == should_be_valid);
         }
     }
 }

util/throttle.c

@@ -287,8 +287,9 @@ bool throttle_conflicting(ThrottleConfig *cfg, Error **errp)
 /* check if a throttling configuration is valid
  * @cfg: the throttling configuration to inspect
  * @ret: true if valid else false
+ * @errp: error object
  */
-bool throttle_is_valid(ThrottleConfig *cfg)
+bool throttle_is_valid(ThrottleConfig *cfg, Error **errp)
 {
     int i;
 
@@ -297,6 +298,8 @@ bool throttle_is_valid(ThrottleConfig *cfg)
             cfg->buckets[i].max < 0 ||
             cfg->buckets[i].avg > THROTTLE_VALUE_MAX ||
             cfg->buckets[i].max > THROTTLE_VALUE_MAX) {
+            error_setg(errp, "bps/iops/max values must be within [0, %lld]",
+                       THROTTLE_VALUE_MAX);
             return false;
         }
     }