Re: [Qemu-devel] [PATCH arm-devs v3 1/9] qom/object: Make uintXX added properties writable

["Michael S. Tsirkin" <mst@redhat.com>]

On Tue, Dec 03, 2013 at 02:19:34PM +0100, Andreas Färber wrote:
> Am 03.12.2013 07:59, schrieb Peter Crosthwaite:
> > Currently the uintXX property adders make a read only property. This
> > is not useful for devices that want to create board (or container)
> > configurable dynamic device properties. Fix by trivially adding property
> > setters to object_property_add_uintXX.
> > 
> > Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
> > ---
> > changed since v2:
> > msg typo: "trivially"
> 
> Not sure if I've asked already, but these functions were added by mst
> (so let's CC him) for accessing read-only constants in ACPI code.

Yes - for ACPI we used these for properties which users shouldn't
be able to change.

> Your
> change seems to make them writable - can anything go wrong when the
> setters are used via QMP?

Guest won't boot.

> I fear we may need two separate sets of
> functions, one read-only, one read-write.
> 
> Andreas

I think so, yes.

> > 
> >  qom/object.c | 44 ++++++++++++++++++++++++++++++++++++++++----
> >  1 file changed, 40 insertions(+), 4 deletions(-)
> > 
> > diff --git a/qom/object.c b/qom/object.c
> > index fc19cf6..07b454b 100644
> > --- a/qom/object.c
> > +++ b/qom/object.c
> > @@ -1353,6 +1353,15 @@ static void property_get_uint8_ptr(Object *obj, Visitor *v,
> >      visit_type_uint8(v, &value, name, errp);
> >  }
> >  
> > +static void property_set_uint8_ptr(Object *obj, Visitor *v,
> > +                                   void *opaque, const char *name,
> > +                                   Error **errp)
> > +{
> > +    uint8_t value;
> > +    visit_type_uint8(v, &value, name, errp);
> > +    *(uint8_t *)opaque = value;
> > +}
> > +
> >  static void property_get_uint16_ptr(Object *obj, Visitor *v,
> >                                     void *opaque, const char *name,
> >                                     Error **errp)
> > @@ -1361,6 +1370,15 @@ static void property_get_uint16_ptr(Object *obj, Visitor *v,
> >      visit_type_uint16(v, &value, name, errp);
> >  }
> >  
> > +static void property_set_uint16_ptr(Object *obj, Visitor *v,
> > +                                    void *opaque, const char *name,
> > +                                    Error **errp)
> > +{
> > +    uint16_t value;
> > +    visit_type_uint16(v, &value, name, errp);
> > +    *(uint16_t *)opaque = value;
> > +}
> > +
> >  static void property_get_uint32_ptr(Object *obj, Visitor *v,
> >                                     void *opaque, const char *name,
> >                                     Error **errp)
> > @@ -1369,6 +1387,15 @@ static void property_get_uint32_ptr(Object *obj, Visitor *v,
> >      visit_type_uint32(v, &value, name, errp);
> >  }
> >  
> > +static void property_set_uint32_ptr(Object *obj, Visitor *v,
> > +                                    void *opaque, const char *name,
> > +                                    Error **errp)
> > +{
> > +    uint32_t value;
> > +    visit_type_uint32(v, &value, name, errp);
> > +    *(uint32_t *)opaque = value;
> > +}
> > +
> >  static void property_get_uint64_ptr(Object *obj, Visitor *v,
> >                                     void *opaque, const char *name,
> >                                     Error **errp)
> > @@ -1377,32 +1404,41 @@ static void property_get_uint64_ptr(Object *obj, Visitor *v,
> >      visit_type_uint64(v, &value, name, errp);
> >  }
> >  
> > +static void property_set_uint64_ptr(Object *obj, Visitor *v,
> > +                                    void *opaque, const char *name,
> > +                                    Error **errp)
> > +{
> > +    uint64_t value;
> > +    visit_type_uint64(v, &value, name, errp);
> > +    *(uint64_t *)opaque = value;
> > +}
> > +
> >  void object_property_add_uint8_ptr(Object *obj, const char *name,
> >                                     const uint8_t *v, Error **errp)
> >  {
> >      object_property_add(obj, name, "uint8", property_get_uint8_ptr,
> > -                        NULL, NULL, (void *)v, errp);
> > +                        property_set_uint8_ptr, NULL, (void *)v, errp);
> >  }
> >  
> >  void object_property_add_uint16_ptr(Object *obj, const char *name,
> >                                      const uint16_t *v, Error **errp)
> >  {
> >      object_property_add(obj, name, "uint16", property_get_uint16_ptr,
> > -                        NULL, NULL, (void *)v, errp);
> > +                        property_set_uint16_ptr, NULL, (void *)v, errp);
> >  }
> >  
> >  void object_property_add_uint32_ptr(Object *obj, const char *name,
> >                                      const uint32_t *v, Error **errp)
> >  {
> >      object_property_add(obj, name, "uint32", property_get_uint32_ptr,
> > -                        NULL, NULL, (void *)v, errp);
> > +                        property_set_uint32_ptr, NULL, (void *)v, errp);
> >  }
> >  
> >  void object_property_add_uint64_ptr(Object *obj, const char *name,
> >                                      const uint64_t *v, Error **errp)
> >  {
> >      object_property_add(obj, name, "uint64", property_get_uint64_ptr,
> > -                        NULL, NULL, (void *)v, errp);
> > +                        property_set_uint64_ptr, NULL, (void *)v, errp);
> >  }
> >  
> >  static void object_instance_init(Object *obj)
> > 
> 
> 
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