qdev: Add Error parameter to hide_device() callbacks

hide_device() is used for virtio-net failover, where the standby virtio
device delays creation of the primary device. It only makes sense to
have a single primary device for each standby device. Adding a second
one should result in an error instead of hiding it and never using it
afterwards.

Prepare for this by adding an Error parameter to the hide_device()
callback where virtio-net is informed about adding a primary device.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20211008133442.141332-12-kwolf@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Peter Krempa <pkrempa@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/softmmu/qdev-monitor.c b/softmmu/qdev-monitor.c
index 0b6833cc57..ea737db028 100644
--- a/softmmu/qdev-monitor.c
+++ b/softmmu/qdev-monitor.c
@@ -626,6 +626,7 @@ const char *qdev_set_id(DeviceState *dev, char *id, Error **errp)
 
 DeviceState *qdev_device_add(QemuOpts *opts, Error **errp)
 {
+    ERRP_GUARD();
     DeviceClass *dc;
     const char *driver, *path;
     DeviceState *dev = NULL;
@@ -669,11 +670,13 @@ 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 (qdev_should_hide_device(opts, errp)) {
             if (bus && !qbus_is_hotpluggable(bus)) {
                 error_setg(errp, QERR_BUS_NO_HOTPLUG, bus->name);
             }
             return NULL;
+        } else if (*errp) {
+            return NULL;
         }
     }