On Mon, Jun 19, 2017 at 01:59:07PM +0100, Mark Cave-Ayland wrote: > In preparation for calling fw_cfg_init1() during realize rather than during > init, move the assert() checking for existing fw_cfg devices and the linking > of the device to the machine with object_property_add_child() to a new > fw_cfg instance_init() function. > > This guarantees that we will still assert() correctly if more than one fw_cfg > device is instantiated by accident. > > Signed-off-by: Mark Cave-Ayland <mark.cave-ayl...@ilande.co.uk> > Reviewed-by: Laszlo Ersek <ler...@redhat.com> > Tested-by: Laszlo Ersek <ler...@redhat.com> > --- > hw/nvram/fw_cfg.c | 14 ++++++++++---- > 1 file changed, 10 insertions(+), 4 deletions(-) > > diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c > index 99bdbc2..af45012 100644 > --- a/hw/nvram/fw_cfg.c > +++ b/hw/nvram/fw_cfg.c > @@ -915,10 +915,6 @@ static void fw_cfg_init1(DeviceState *dev) > MachineState *machine = MACHINE(qdev_get_machine()); > uint32_t version = FW_CFG_VERSION; > > - assert(!object_resolve_path(FW_CFG_PATH, NULL)); > - > - object_property_add_child(OBJECT(machine), FW_CFG_NAME, OBJECT(s), NULL); > - > qdev_init_nofail(dev); > > fw_cfg_add_bytes(s, FW_CFG_SIGNATURE, (char *)"QEMU", 4); > @@ -1020,6 +1016,15 @@ FWCfgState *fw_cfg_find(void) > return FW_CFG(object_resolve_path(FW_CFG_PATH, NULL)); > } > > +static void fw_cfg_init(Object *obj) > +{ > + MachineState *machine = MACHINE(qdev_get_machine()); > + > + assert(!object_resolve_path(FW_CFG_PATH, NULL)); > + > + object_property_add_child(OBJECT(machine), FW_CFG_NAME, obj, NULL);
I don't think this belongs to instance_init. We must always be able to instantiate objects without crashing QEMU or affecting QEMU global state. This patch makes device-list-properties crash: $ qemu-system-x86_64 -display none -qmp unix:/tmp/qmp,server,nowait & [1] 2848 $ echo 'device-list-properties typename=fw_cfg_mem' | ./scripts/qmp/qmp-shell /tmp/qmp Welcome to the QMP low-level shell! Connected to QEMU 2.9.50 qemu-system-x86_64: qemu/hw/nvram/fw_cfg.c:974: fw_cfg_init: Assertion `!object_resolve_path(FW_CFG_PATH, NULL)' failed. (QEMU) Disconnected [1]+ Aborted (core dumped) qemu-system-x86_64 -display none -qmp unix:/tmp/qmp,server,nowait $ I suggest moving this check to realize, like the rest of fw_cfg_init1(), but change it to do proper error reporting instead of asserting. > +} > + > static void fw_cfg_class_init(ObjectClass *klass, void *data) > { > DeviceClass *dc = DEVICE_CLASS(klass); > @@ -1033,6 +1038,7 @@ static const TypeInfo fw_cfg_info = { > .parent = TYPE_SYS_BUS_DEVICE, > .abstract = true, > .instance_size = sizeof(FWCfgState), > + .instance_init = fw_cfg_init, > .class_init = fw_cfg_class_init, > }; > > -- > 1.7.10.4 > -- Eduardo