[Qemu-devel] [PCTCH v4] qdev: set properties after device's parent is assigned

[Qemu-devel] [PCTCH v4] qdev: set properties after device's parent is assigned

[Amos Kong]

Test steps:
 (qemu) device_add e1000,addr=adsf
  Property 'e1000.addr' doesn't take value 'adsf'
 (qemu) info qtree
  Then qemu crashed.

Currently we set a link to the new device for qdev parent bus, but the
device hasn't been added to QOM tree. When it fails to set properties,
object_unparent() can't cleanup the device.

Delay device property setting until device's parent is assigned. This
way when property setting fails, object_unparent() can cleanup failed
device properly.

Signed-off-by: Amos Kong <akong@redhat.com>
Reviewed-By: Igor Mammedov <imammedo@redhat.com>
---
V2: fix bz by adjust the initialization order (Paolo)
V3: fix bug without making it differs with legacy devices
    creation (Andreas)
V4: update subject and commitlog
---
 qdev-monitor.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/qdev-monitor.c b/qdev-monitor.c
index 6673e3c..9268c87 100644
--- a/qdev-monitor.c
+++ b/qdev-monitor.c
@@ -522,7 +522,7 @@ DeviceState *qdev_device_add(QemuOpts *opts)
         return NULL;
     }
 
-    /* create device, set properties */
+    /* create device */
     dev = DEVICE(object_new(driver));
 
     if (bus) {
@@ -533,11 +533,7 @@ DeviceState *qdev_device_add(QemuOpts *opts)
     if (id) {
         dev->id = id;
     }
-    if (qemu_opt_foreach(opts, set_property, dev, 1) != 0) {
-        object_unparent(OBJECT(dev));
-        object_unref(OBJECT(dev));
-        return NULL;
-    }
+
     if (dev->id) {
         object_property_add_child(qdev_get_peripheral(), dev->id,
                                   OBJECT(dev), NULL);
@@ -549,6 +545,13 @@ DeviceState *qdev_device_add(QemuOpts *opts)
         g_free(name);
     }
 
+    /* set properties */
+    if (qemu_opt_foreach(opts, set_property, dev, 1) != 0) {
+        object_unparent(OBJECT(dev));
+        object_unref(OBJECT(dev));
+        return NULL;
+    }
+
     dev->opts = opts;
     object_property_set_bool(OBJECT(dev), true, "realized", &err);
     if (err != NULL) {
-- 
1.8.5.3

Re: [Qemu-devel] [PCTCH v4] qdev: set properties after device's parent is assigned

[Andreas Färber]

Hi,

Am 03.03.2014 16:55, schrieb Amos Kong:
> Test steps:
>  (qemu) device_add e1000,addr=adsf
>   Property 'e1000.addr' doesn't take value 'adsf'
>  (qemu) info qtree
>   Then qemu crashed.
> 
> Currently we set a link to the new device for qdev parent bus, but the
> device hasn't been added to QOM tree. When it fails to set properties,
> object_unparent() can't cleanup the device.
> 
> Delay device property setting until device's parent is assigned. This
> way when property setting fails, object_unparent() can cleanup failed
> device properly.
> 
> Signed-off-by: Amos Kong <akong@redhat.com>
> Reviewed-By: Igor Mammedov <imammedo@redhat.com>
> ---
> V2: fix bz by adjust the initialization order (Paolo)
> V3: fix bug without making it differs with legacy devices
>     creation (Andreas)
> V4: update subject and commitlog

I already applied a variation of v3. In particular I used qdev-monitor
for consistency and clarified that it is about device_add.

https://github.com/afaerber/qemu-cpu/commits/qom-next

If you don't like something in there, can you please just suggest an
alternative sentence/paragraph for me to update?

Thanks,
Andreas

-- 
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg

Re: [Qemu-devel] [PCTCH v4] qdev: set properties after device's parent is assigned

[Amos Kong]

On Mon, Mar 03, 2014 at 05:01:34PM +0100, Andreas Färber wrote:
> Hi,
> 
> Am 03.03.2014 16:55, schrieb Amos Kong:
> > Test steps:
> >  (qemu) device_add e1000,addr=adsf
> >   Property 'e1000.addr' doesn't take value 'adsf'
> >  (qemu) info qtree
> >   Then qemu crashed.
> > 
> > Currently we set a link to the new device for qdev parent bus, but the
> > device hasn't been added to QOM tree. When it fails to set properties,
> > object_unparent() can't cleanup the device.
> > 
> > Delay device property setting until device's parent is assigned. This
> > way when property setting fails, object_unparent() can cleanup failed
> > device properly.
> > 
> > Signed-off-by: Amos Kong <akong@redhat.com>
> > Reviewed-By: Igor Mammedov <imammedo@redhat.com>
> > ---
> > V2: fix bz by adjust the initialization order (Paolo)
> > V3: fix bug without making it differs with legacy devices
> >     creation (Andreas)
> > V4: update subject and commitlog
> 
> I already applied a variation of v3. In particular I used qdev-monitor
> for consistency and clarified that it is about device_add.
> 
> https://github.com/afaerber/qemu-cpu/commits/qom-next
 
Your change's fine. I saw your comment on V3 thread after sent out V4 :-)
Thanks.

> If you don't like something in there, can you please just suggest an
> alternative sentence/paragraph for me to update?
> 
> Thanks,
> Andreas
> 
> -- 
> SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
> GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg

-- 
			Amos.