[RFC PATCH v2 1/8] qdev: add an Error parameter to the DeviceListener hide_device() function

From: Laurent Vivier <lvivier@redhat.com>
To: qemu-devel@nongnu.org
Cc: "Daniel P. Berrangé" <berrange@redhat.com>,
	"Eduardo Habkost" <ehabkost@redhat.com>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	"Jason Wang" <jasowang@redhat.com>,
	"Juan Quintela" <quintela@redhat.com>,
	"Markus Armbruster" <armbru@redhat.com>,
	"Alex Williamson" <alex.williamson@redhat.com>,
	"Paolo Bonzini" <pbonzini@redhat.com>,
	"Jens Freimann" <jfreimann@redhat.com>
Subject: [RFC PATCH v2 1/8] qdev: add an Error parameter to the DeviceListener hide_device() function
Date: Fri, 20 Aug 2021 16:19:55 +0200	[thread overview]
Message-ID: <20210820142002.152994-2-lvivier@redhat.com> (raw)
In-Reply-To: <20210820142002.152994-1-lvivier@redhat.com>

This allows an error to be reported to the caller of qdev_device_add()

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
---
 include/hw/qdev-core.h | 6 ++++--
 hw/core/qdev.c         | 4 ++--
 hw/net/virtio-net.c    | 2 +-
 softmmu/qdev-monitor.c | 4 ++--
 4 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
index bafc311bfa1b..e23b23a2f8d6 100644
--- a/include/hw/qdev-core.h
+++ b/include/hw/qdev-core.h
@@ -202,7 +202,8 @@ struct DeviceListener {
      * hide a failover device depending for example on the device
      * opts.
      */
-    bool (*hide_device)(DeviceListener *listener, QemuOpts *device_opts);
+    bool (*hide_device)(DeviceListener *listener, QemuOpts *device_opts,
+                        Error **errp);
     QTAILQ_ENTRY(DeviceListener) link;
 };
 
@@ -804,12 +805,13 @@ void device_listener_unregister(DeviceListener *listener);
 /**
  * @qdev_should_hide_device:
  * @opts: QemuOpts as passed on cmdline.
+ * @errp: pointer to error object
  *
  * Check if a device should be added.
  * When a device is added via qdev_device_add() this will be called,
  * and return if the device should be added now or not.
  */
-bool qdev_should_hide_device(QemuOpts *opts);
+bool qdev_should_hide_device(QemuOpts *opts, Error **errp);
 
 typedef enum MachineInitPhase {
     /* current_machine is NULL.  */
diff --git a/hw/core/qdev.c b/hw/core/qdev.c
index cefc5eaa0a92..13f4c1e696bf 100644
--- a/hw/core/qdev.c
+++ b/hw/core/qdev.c
@@ -211,13 +211,13 @@ void device_listener_unregister(DeviceListener *listener)
     QTAILQ_REMOVE(&device_listeners, listener, link);
 }
 
-bool qdev_should_hide_device(QemuOpts *opts)
+bool qdev_should_hide_device(QemuOpts *opts, Error **errp)
 {
     DeviceListener *listener;
 
     QTAILQ_FOREACH(listener, &device_listeners, link) {
         if (listener->hide_device) {
-            if (listener->hide_device(listener, opts)) {
+            if (listener->hide_device(listener, opts, errp)) {
                 return true;
             }
         }
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 16d20cdee52a..542f9e167eb4 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -3279,7 +3279,7 @@ static void virtio_net_migration_state_notifier(Notifier *notifier, void *data)
 }
 
 static bool failover_hide_primary_device(DeviceListener *listener,
-                                         QemuOpts *device_opts)
+                                         QemuOpts *device_opts, Error **errp)
 {
     VirtIONet *n = container_of(listener, VirtIONet, primary_listener);
     const char *standby_id;
diff --git a/softmmu/qdev-monitor.c b/softmmu/qdev-monitor.c
index 721dec2d8200..7adf0d22beb1 100644
--- a/softmmu/qdev-monitor.c
+++ b/softmmu/qdev-monitor.c
@@ -627,8 +627,8 @@ DeviceState *qdev_device_add(QemuOpts *opts, Error **errp)
             error_setg(errp, "Device with failover_pair_id don't have id");
             return NULL;
         }
-        if (qdev_should_hide_device(opts)) {
-            if (bus && !qbus_is_hotpluggable(bus)) {
+        if (qdev_should_hide_device(opts, errp)) {
+            if (errp && !*errp && bus && !qbus_is_hotpluggable(bus)) {
                 error_setg(errp, QERR_BUS_NO_HOTPLUG, bus->name);
             }
             return NULL;
-- 
2.31.1


