qdev: qdev_unplug(): use error_set()

It currently uses qerror_report(), but next commit will convert
the drive_del command to the QAPI and this requires using
error_set().

One particularity of qerror_report() is that it knows when it's
running on monitor context or command-line context and prints the
error message accordingly. error_set() doesn't do this, so we
have to be careful not to drop error messages.

qdev_unplug() has three kinds of usages:

 1. It's called when hot adding a device fails, to undo anything
    that has been done before hitting the error

 2. It's called by function monitor functions like device_del(),
    to unplug a device

 3. It's used by xen_platform.c in a way that doesn't _seem_ to
    be in monitor context

Only item 2 can print an error message to the user, this commit
maintains that.

Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/hw/qdev.h b/hw/qdev.h
index a8df42f6fa..7cafa8cd90 100644
--- a/hw/qdev.h
+++ b/hw/qdev.h
@@ -7,6 +7,7 @@
 #include "qemu-option.h"
 #include "qapi/qapi-visit-core.h"
 #include "qemu/object.h"
+#include "error.h"
 
 typedef struct Property Property;
 
@@ -148,7 +149,7 @@ int qdev_init(DeviceState *dev) QEMU_WARN_UNUSED_RESULT;
 void qdev_init_nofail(DeviceState *dev);
 void qdev_set_legacy_instance_id(DeviceState *dev, int alias_id,
                                  int required_for_version);
-int qdev_unplug(DeviceState *dev);
+void qdev_unplug(DeviceState *dev, Error **errp);
 void qdev_free(DeviceState *dev);
 int qdev_simple_unplug_cb(DeviceState *dev);
 void qdev_machine_creation_done(void);