[PATCH 2/2] qdev: Let BusRealize() return a boolean value to indicate error

[Philippe Mathieu-Daudé <f4bug@xxxxxxxxx>]

Commit 9940b2cfbc0 introduced qdev_realize() and qbus_realize()
with the ability to return a boolean value if an error occured,
thus the caller does not need to check if the Error* pointer is
set.
Provide the same ability to the BusRealize type.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@xxxxxxxxx>
---
 include/hw/qdev-core.h | 14 +++++++++++++-
 hw/hyperv/vmbus.c      |  5 +++--
 hw/nubus/nubus-bus.c   |  5 +++--
 hw/pci/pci.c           | 12 +++++++++---
 hw/xen/xen-bus.c       |  5 +++--
 5 files changed, 31 insertions(+), 10 deletions(-)

diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
index 02ac1c50b7f..eecfe794a71 100644
--- a/include/hw/qdev-core.h
+++ b/include/hw/qdev-core.h
@@ -32,7 +32,19 @@ typedef enum DeviceCategory {
 typedef void (*DeviceRealize)(DeviceState *dev, Error **errp);
 typedef void (*DeviceUnrealize)(DeviceState *dev);
 typedef void (*DeviceReset)(DeviceState *dev);
-typedef void (*BusRealize)(BusState *bus, Error **errp);
+/**
+ * BusRealize: Realize @bus.
+ * @bus: bus to realize
+ * @errp: pointer to error object
+ *
+ * On success, return true.
+ * On failure, store an error through @errp and return false.
+ */
+typedef bool (*BusRealize)(BusState *bus, Error **errp);
+/**
+ * BusUnrealize: Unrealize @bus.
+ * @bus: bus to unrealize
+ */
 typedef void (*BusUnrealize)(BusState *bus);
 
 /**
diff --git a/hw/hyperv/vmbus.c b/hw/hyperv/vmbus.c
index 6ef895bc352..8a0452b2464 100644
--- a/hw/hyperv/vmbus.c
+++ b/hw/hyperv/vmbus.c
@@ -2487,7 +2487,7 @@ static const TypeInfo vmbus_dev_type_info = {
     .instance_init = vmbus_dev_instance_init,
 };
 
-static void vmbus_realize(BusState *bus, Error **errp)
+static bool vmbus_realize(BusState *bus, Error **errp)
 {
     int ret = 0;
     Error *local_err = NULL;
@@ -2519,7 +2519,7 @@ static void vmbus_realize(BusState *bus, Error **errp)
         goto clear_event_notifier;
     }
 
-    return;
+    return true;
 
 clear_event_notifier:
     event_notifier_cleanup(&vmbus->notifier);
@@ -2528,6 +2528,7 @@ remove_msg_handler:
 error_out:
     qemu_mutex_destroy(&vmbus->rx_queue_lock);
     error_propagate(errp, local_err);
+    return false;
 }
 
 static void vmbus_unrealize(BusState *bus)
diff --git a/hw/nubus/nubus-bus.c b/hw/nubus/nubus-bus.c
index 942a6d5342d..d20d9c0f72c 100644
--- a/hw/nubus/nubus-bus.c
+++ b/hw/nubus/nubus-bus.c
@@ -65,12 +65,13 @@ static const MemoryRegionOps nubus_super_slot_ops = {
     },
 };
 
-static void nubus_realize(BusState *bus, Error **errp)
+static bool nubus_realize(BusState *bus, Error **errp)
 {
     if (!nubus_find()) {
         error_setg(errp, "at most one %s device is permitted", TYPE_NUBUS_BUS);
-        return;
+        return false;
     }
+    return true;
 }
 
 static void nubus_init(Object *obj)
diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index de0fae10ab9..f535ebac847 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -115,7 +115,7 @@ static void pcibus_machine_done(Notifier *notifier, void 
*data)
     }
 }
 
-static void pci_bus_realize(BusState *qbus, Error **errp)
+static bool pci_bus_realize(BusState *qbus, Error **errp)
 {
     PCIBus *bus = PCI_BUS(qbus);
 
@@ -123,13 +123,17 @@ static void pci_bus_realize(BusState *qbus, Error **errp)
     qemu_add_machine_init_done_notifier(&bus->machine_done);
 
     vmstate_register(NULL, VMSTATE_INSTANCE_ID_ANY, &vmstate_pcibus, bus);
+
+    return true;
 }
 
-static void pcie_bus_realize(BusState *qbus, Error **errp)
+static bool pcie_bus_realize(BusState *qbus, Error **errp)
 {
     PCIBus *bus = PCI_BUS(qbus);
 
-    pci_bus_realize(qbus, errp);
+    if (!pci_bus_realize(qbus, errp)) {
+        return false;
+    }
 
     /*
      * A PCI-E bus can support extended config space if it's the root
@@ -144,6 +148,8 @@ static void pcie_bus_realize(BusState *qbus, Error **errp)
             bus->flags |= PCI_BUS_EXTENDED_CONFIG_SPACE;
         }
     }
+
+    return true;
 }
 
 static void pci_bus_unrealize(BusState *qbus)
diff --git a/hw/xen/xen-bus.c b/hw/xen/xen-bus.c
index 9ce1c9540b9..d7ef5d05e37 100644
--- a/hw/xen/xen-bus.c
+++ b/hw/xen/xen-bus.c
@@ -444,7 +444,7 @@ static void xen_bus_unrealize(BusState *bus)
     }
 }
 
-static void xen_bus_realize(BusState *bus, Error **errp)
+static bool xen_bus_realize(BusState *bus, Error **errp)
 {
     XenBus *xenbus = XEN_BUS(bus);
     unsigned int domid;
@@ -478,10 +478,11 @@ static void xen_bus_realize(BusState *bus, Error **errp)
                           "failed to set up enumeration watch: ");
     }
 
-    return;
+    return true;
 
 fail:
     xen_bus_unrealize(bus);
+    return false;
 }
 
 static void xen_bus_unplug_request(HotplugHandler *hotplug,
-- 
2.26.2