failover: should_be_hidden() should take a bool

We didn't use at all the -1 value, and we don't really care.  It was
only used for the cases when this is not the device that we are
searching for.  And in that case we should not hide the device.

Once there, simplify virtio-Snet_primary_should_be_hidden.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20201118083748.1328-16-quintela@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/core/qdev.c

@@ -214,26 +214,17 @@ void device_listener_unregister(DeviceListener *listener)
 
 bool qdev_should_hide_device(QemuOpts *opts)
 {
-    int rc = -1;
     DeviceListener *listener;
 
     QTAILQ_FOREACH(listener, &device_listeners, link) {
-       if (listener->should_be_hidden) {
-            /*
-             * should_be_hidden_will return
-             *  1 if device matches opts and it should be hidden
-             *  0 if device matches opts and should not be hidden
-             *  -1 if device doesn't match ops
-             */
-            rc = listener->should_be_hidden(listener, opts);
-        }
-
-        if (rc > 0) {
-            break;
+        if (listener->should_be_hidden) {
+            if (listener->should_be_hidden(listener, opts)) {
+                return true;
+            }
         }
     }
 
-    return rc > 0;
+    return false;
 }
 
 void qdev_set_legacy_instance_id(DeviceState *dev, int alias_id,

hw/net/virtio-net.c

@@ -3161,24 +3161,19 @@ static void virtio_net_migration_state_notifier(Notifier *notifier, void *data)
     virtio_net_handle_migration_primary(n, s);
 }
 
-static int virtio_net_primary_should_be_hidden(DeviceListener *listener,
-                                               QemuOpts *device_opts)
+static bool virtio_net_primary_should_be_hidden(DeviceListener *listener,
+                                                QemuOpts *device_opts)
 {
     VirtIONet *n = container_of(listener, VirtIONet, primary_listener);
-    bool match_found = false;
-    bool hide = false;
+    bool hide;
     const char *standby_id;
 
     if (!device_opts) {
-        return -1;
+        return false;
     }
     standby_id = qemu_opt_get(device_opts, "failover_pair_id");
-    if (g_strcmp0(standby_id, n->netclient_name) == 0) {
-        match_found = true;
-    } else {
-        match_found = false;
-        hide = false;
-        goto out;
+    if (g_strcmp0(standby_id, n->netclient_name) != 0) {
+        return false;
     }
 
     /* failover_primary_hidden is set during feature negotiation */
@@ -3188,15 +3183,7 @@ static int virtio_net_primary_should_be_hidden(DeviceListener *listener,
     if (!n->primary_device_id) {
         warn_report("primary_device_id not set");
     }
-
-out:
-    if (match_found && hide) {
-        return 1;
-    } else if (match_found && !hide) {
-        return 0;
-    } else {
-        return -1;
-    }
+    return hide;
 }
 
 static void virtio_net_device_realize(DeviceState *dev, Error **errp)

include/hw/qdev-core.h

@@ -200,7 +200,7 @@ struct DeviceListener {
      * inform qdev that a device should be hidden, depending on the device
      * opts, for example, to hide a standby device.
      */
-    int (*should_be_hidden)(DeviceListener *listener, QemuOpts *device_opts);
+    bool (*should_be_hidden)(DeviceListener *listener, QemuOpts *device_opts);
     QTAILQ_ENTRY(DeviceListener) link;
 };