migration: Drop migration_is_idle()

Now with the current migration_is_running(), it will report exactly the
opposite of what will be reported by migration_is_idle().

Drop migration_is_idle(), instead use "!migration_is_running()" which
should be identical on functionality.

In reality, most of the idle check is inverted, so it's even easier to
write with "migrate_is_running()" check.

Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Link: https://lore.kernel.org/r/20241024213056.1395400-6-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>

hw/virtio/virtio-mem.c

@@ -188,7 +188,7 @@ static bool virtio_mem_is_busy(void)
      * after plugging them) until we're running on the destination (as we didn't
      * migrate these blocks when they were unplugged).
      */
-    return migration_in_incoming_postcopy() || !migration_is_idle();
+    return migration_in_incoming_postcopy() || migration_is_running();
 }
 
 typedef int (*virtio_mem_range_cb)(VirtIOMEM *vmem, void *arg,

include/migration/misc.h

@@ -53,7 +53,6 @@ void dump_vmstate_json_to_file(FILE *out_fp);
 void migration_object_init(void);
 void migration_shutdown(void);
 
-bool migration_is_idle(void);
 bool migration_is_active(void);
 bool migration_is_device(void);
 bool migration_is_running(void);

migration/migration.c

@@ -1633,25 +1633,6 @@ bool migration_in_bg_snapshot(void)
     return migrate_background_snapshot() && migration_is_running();
 }
 
-bool migration_is_idle(void)
-{
-    MigrationState *s = current_migration;
-
-    if (!s) {
-        return true;
-    }
-
-    switch (s->state) {
-    case MIGRATION_STATUS_NONE:
-    case MIGRATION_STATUS_CANCELLED:
-    case MIGRATION_STATUS_COMPLETED:
-    case MIGRATION_STATUS_FAILED:
-        return true;
-    default:
-        return false;
-    }
-}
-
 bool migration_is_active(void)
 {
     MigrationState *s = current_migration;
@@ -1730,7 +1711,7 @@ static bool is_busy(Error **reasonp, Error **errp)
     ERRP_GUARD();
 
     /* Snapshots are similar to migrations, so check RUN_STATE_SAVE_VM too. */
-    if (runstate_check(RUN_STATE_SAVE_VM) || !migration_is_idle()) {
+    if (runstate_check(RUN_STATE_SAVE_VM) || migration_is_running()) {
         error_propagate_prepend(errp, *reasonp,
                                 "disallowing migration blocker "
                                 "(migration/snapshot in progress) for: ");

migration/ram.c

@@ -4498,7 +4498,7 @@ static void ram_mig_ram_block_resized(RAMBlockNotifier *n, void *host,
         return;
     }
 
-    if (!migration_is_idle()) {
+    if (migration_is_running()) {
         /*
          * Precopy code on the source cannot deal with the size of RAM blocks
          * changing at random points in time - especially after sending the

system/qdev-monitor.c

@@ -679,7 +679,7 @@ DeviceState *qdev_device_add_from_qdict(const QDict *opts,
         return NULL;
     }
 
-    if (!migration_is_idle()) {
+    if (migration_is_running()) {
         error_setg(errp, "device_add not allowed while migrating");
         return NULL;
     }
@@ -928,7 +928,7 @@ void qdev_unplug(DeviceState *dev, Error **errp)
         return;
     }
 
-    if (!migration_is_idle() && !dev->allow_unplug_during_migration) {
+    if (migration_is_running() && !dev->allow_unplug_during_migration) {
         error_setg(errp, "device_del not allowed while migrating");
         return;
     }