From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41628) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dMxfo-0006sc-0W for qemu-devel@nongnu.org; Mon, 19 Jun 2017 10:29:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dMxfk-0004PC-Rt for qemu-devel@nongnu.org; Mon, 19 Jun 2017 10:28:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54714) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dMxfk-0004Ot-I9 for qemu-devel@nongnu.org; Mon, 19 Jun 2017 10:28:56 -0400 Date: Mon, 19 Jun 2017 11:28:52 -0300 From: Eduardo Habkost Message-ID: <20170619142852.GS5016@thinpad.lan.raisama.net> References: <1497877149-19253-1-git-send-email-mark.cave-ayland@ilande.co.uk> <1497877149-19253-4-git-send-email-mark.cave-ayland@ilande.co.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1497877149-19253-4-git-send-email-mark.cave-ayland@ilande.co.uk> Subject: Re: [Qemu-devel] [PATCHv6 3/5] fw_cfg: move assert() and linking of fw_cfg device to the machine into instance_init() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Mark Cave-Ayland Cc: qemu-devel@nongnu.org, lersek@redhat.com, somlo@cmu.edu, mst@redhat.com, pbonzini@redhat.com, rjones@redhat.com, imammedo@redhat.com, peter.maydell@linaro.org 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 > Reviewed-by: Laszlo Ersek > Tested-by: Laszlo Ersek > --- > 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