Re: [Qemu-devel] [PATCH] qdev: Fix qdev_try_create() semantics

[Anthony Liguori]

On 02/16/2012 08:00 PM, Andreas Färber wrote:
> Am 17.02.2012 02:47, schrieb Andreas Färber:
> > Since QOM'ification, qdev_try_create() uses object_new() internally,
> > which asserts "type != NULL" when the type is not registered.
> > This was revealed by the combination of kvmclock's kvm_enabled() check
> > and early QOM type registration.
> >
> > Check whether the class exists before calling object_new(), so that
> > the caller (e.g., qdev_create) can fail gracefully, telling us which
> > device could not be created.
> >
> > Signed-off-by: Andreas Färber<address@hidden>
> > Cc: Anthony Liguori<address@hidden>
>
> Er, it's late here... ;)
>
> As one can guess I've managed to convert x86. Still need to cleanup but
> I pushed my work branch for the curious (and as backup!):
>
> http://repo.or.cz/w/qemu/afaerber.git/shortlog/refs/heads/qom-cpu

Applied.  Thanks.

Regards,

Anthony Liguori

> Andreas
>
> > ---
> >   hw/qdev.c |    3 +++
> >   1 files changed, 3 insertions(+), 0 deletions(-)
> >
> > diff --git a/hw/qdev.c b/hw/qdev.c
> > index f0eb3a7..ee21d90 100644
> > --- a/hw/qdev.c
> > +++ b/hw/qdev.c
> > @@ -117,6 +117,9 @@ DeviceState *qdev_try_create(BusState *bus, const char 
> > *name)
> >   {
> >       DeviceState *dev;
> >
> > +    if (object_class_by_name(name) == NULL) {
> > +        return NULL;
> > +    }
> >       dev = DEVICE(object_new(name));
> >       if (!dev) {
> >           return NULL;