Soon, a device removal might only happen on RCU callback execution. This is okay for device-del which provides a DEVICE_DELETED event, but not for the failure case of device-add. To avoid changing monitor semantics, just drain all pending RCU callbacks on error.
Signed-off-by: Maxim Levitsky <[email protected]> Suggested-by: Stefan Hajnoczi <[email protected]> Reviewed-by: Stefan Hajnoczi <[email protected]> Message-Id: <[email protected]> [Don't use it in qmp_device_del. - Paolo] Signed-off-by: Paolo Bonzini <[email protected]> --- qdev-monitor.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/qdev-monitor.c b/qdev-monitor.c index e9b7228480..bcfb90a08f 100644 --- a/qdev-monitor.c +++ b/qdev-monitor.c @@ -803,6 +803,18 @@ void qmp_device_add(QDict *qdict, QObject **ret_data, Error **errp) return; } dev = qdev_device_add(opts, errp); + + /* + * Drain all pending RCU callbacks. This is done because + * some bus related operations can delay a device removal + * (in this case this can happen if device is added and then + * removed due to a configuration error) + * to a RCU callback, but user might expect that this interface + * will finish its job completely once qmp command returns result + * to the user + */ + drain_call_rcu(); + if (!dev) { qemu_opts_del(opts); return; -- 2.26.2
