Re: [Qemu-devel] [PATCH for-3.2 v5 07/19] hw: apply accel compat properties without touching globals

[Igor Mammedov <imammedo@redhat.com>]

On Wed, 12 Dec 2018 16:00:06 +0400
Marc-André Lureau <marcandre.lureau@gmail.com> wrote:

> Hi
> On Mon, Dec 10, 2018 at 8:55 PM Igor Mammedov <imammedo@redhat.com> wrote:
> >
> > On Mon, 10 Dec 2018 17:45:22 +0100
> > Igor Mammedov <imammedo@redhat.com> wrote:
> >  
> > > On Tue,  4 Dec 2018 18:20:11 +0400
> > > Marc-André Lureau <marcandre.lureau@redhat.com> wrote:
> > >  
> > > > Instead of registering compat properties as globals, let's keep them
> > > > in their own array, to avoid mixing with user globals.
> > > >
> > > > Introduce object_apply_global_props() function, to apply compatibility
> > > > properties from a GPtrArray.
> > > >
> > > > Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> > > > ---
> > > >  include/hw/qdev-core.h | 10 ++++++++++
> > > >  include/qom/object.h   |  3 +++
> > > >  include/sysemu/accel.h |  4 +---
> > > >  accel/accel.c          | 12 ------------
> > > >  hw/core/qdev.c         |  9 +++++++++
> > > >  hw/xen/xen-common.c    |  9 ++++++---
> > > >  qom/object.c           | 25 +++++++++++++++++++++++++
> > > >  vl.c                   |  1 -
> > > >  8 files changed, 54 insertions(+), 19 deletions(-)
> > > >  
> > > [...]  
> > > > diff --git a/hw/xen/xen-common.c b/hw/xen/xen-common.c
> > > > index 6ec14c73ca..4532aa8632 100644
> > > > --- a/hw/xen/xen-common.c
> > > > +++ b/hw/xen/xen-common.c
> > > > @@ -174,18 +174,21 @@ static GlobalProperty xen_compat_props[] = {
> > > >          .driver = "migration",
> > > >          .property = "send-section-footer",
> > > >          .value = "off",
> > > > -    },
> > > > -    { /* end of list */ },
> > > > +    }
> > > >  };
> > > >
> > > >  static void xen_accel_class_init(ObjectClass *oc, void *data)
> > > >  {
> > > >      AccelClass *ac = ACCEL_CLASS(oc);
> > > > +
> > > >      ac->name = "Xen";
> > > >      ac->init_machine = xen_init;
> > > >      ac->setup_post = xen_setup_post;
> > > >      ac->allowed = &xen_allowed;
> > > > -    ac->global_props = xen_compat_props;
> > > > +    ac->compat_props = g_ptr_array_new();  
> > > where is matching free for that?  
> > can we at least annotate it somehow so that valgrind won't complain about this leak?  
> 
> If you check my commits on qemu, you should see that I do care (too
> much?) about leaks :)
> 
> In this case though, I don't see valgrind or asan complaining, I guess
> it's still a reachable reference.
> Do you think a FIXME comment would be helpful?
I've looked at other cases were we leak, and well we leak a lot so it's
probably futile exercise. But the comment won't hurt and will work as remainder.


> (/me wish we had a proper object system, GObject, but that ship as
> long sailed..)
> 
> >  
> > >  
> > > > +
> > > > +    compat_props_add(ac->compat_props,
> > > > +                     xen_compat_props, G_N_ELEMENTS(xen_compat_props));
> > > >  }
> > > >
> > > >  #define TYPE_XEN_ACCEL ACCEL_CLASS_NAME("xen")
> > > > diff --git a/qom/object.c b/qom/object.c
> > > > index 17921c0a71..dbdab0aead 100644
> > > > --- a/qom/object.c
> > > > +++ b/qom/object.c
> > > > @@ -370,6 +370,31 @@ static void object_post_init_with_type(Object *obj, TypeImpl *ti)
> > > >      }
> > > >  }
> > > >
> > > > +void object_apply_global_props(Object *obj, const GPtrArray *props, Error **errp)
> > > > +{
> > > > +    Error *err = NULL;
> > > > +    int i;
> > > > +
> > > > +    if (!props) {
> > > > +        return;
> > > > +    }
> > > > +
> > > > +    for (i = 0; i < props->len; i++) {
> > > > +        GlobalProperty *p = g_ptr_array_index(props, i);
> > > > +
> > > > +        if (object_dynamic_cast(obj, p->driver) == NULL) {
> > > > +            continue;
> > > > +        }
> > > > +        p->used = true;
> > > > +        object_property_parse(obj, p->value, p->property, &err);
> > > > +        if (err != NULL) {
> > > > +            error_prepend(&err, "can't apply global %s.%s=%s: ",
> > > > +                          p->driver, p->property, p->value);
> > > > +            error_propagate(errp, err);
> > > > +        }
> > > > +    }
> > > > +}
> > > > +
> > > >  static void object_initialize_with_type(void *data, size_t size, TypeImpl *type)
> > > >  {
> > > >      Object *obj = data;
> > > > diff --git a/vl.c b/vl.c
> > > > index a5ae5f23d2..88ba658572 100644
> > > > --- a/vl.c
> > > > +++ b/vl.c
> > > > @@ -2968,7 +2968,6 @@ static void user_register_global_props(void)
> > > >   */
> > > >  static void register_global_properties(MachineState *ms)
> > > >  {
> > > > -    accel_register_compat_props(ms->accelerator);
> > > >      machine_register_compat_props(ms);
> > > >      user_register_global_props();
> > > >  }  
> > >
> > >  
> >
> >  
> 
>