Re: [Qemu-devel] [PATCH v3 18/19] target-i386: add x86_cpu_unrealizefn()

[Igor Mammedov]

On Wed, 13 Jul 2016 11:59:29 -0300
Eduardo Habkost <address@hidden> wrote:

> On Wed, Jul 06, 2016 at 08:20:54AM +0200, Igor Mammedov wrote:
> > first remove VCPU from exec loop and only then remove lapic.
> > 
> > Signed-off-by: Chen Fan <address@hidden>
> > Signed-off-by: Gu Zheng <address@hidden>
> > Signed-off-by: Zhu Guihua <address@hidden>
> > Signed-off-by: Igor Mammedov <address@hidden>
> > ---
> >  target-i386/cpu.c | 15 +++++++++++++++
> >  1 file changed, 15 insertions(+)
> > 
> > diff --git a/target-i386/cpu.c b/target-i386/cpu.c
> > index 2fa445d..f86dae0 100644
> > --- a/target-i386/cpu.c
> > +++ b/target-i386/cpu.c
> > @@ -2963,6 +2963,20 @@ out:
> >      }
> >  }
> >  
> > +static void x86_cpu_unrealizefn(DeviceState *dev, Error **errp)
> > +{
> > +    X86CPU *cpu = X86_CPU(dev);
> > +
> > +#ifndef CONFIG_USER_ONLY
> > +    cpu_remove_sync(CPU(dev));
> > +    qemu_unregister_reset(x86_cpu_machine_reset_cb, dev);
> > +#endif
> > +
> > +    if (cpu->apic_state) {
> > +        object_unparent(OBJECT(cpu->apic_state));  
> 
> As patch 17/19 drops the reference corresponding to
> cpu->apic_state (leaving only the child property reference), this
> will leave cpu->apic_state pointing to a dead object. Please set
> it to NULL.
true, if we go with this explicit unparenting then
cpu->apic_state should be set to NULL.

If we only unrealize here then we do not need set cpu->apic_state to NULL
here as apic will die together with CPU instance when it starts to destroy
its children.

> 
> > +    }
> > +}
> > +
> >  typedef struct BitProperty {
> >      uint32_t *ptr;
> >      uint32_t mask;
> > @@ -3205,6 +3219,7 @@ static void x86_cpu_common_class_init(ObjectClass 
> > *oc, void *data)
> >  
> >      xcc->parent_realize = dc->realize;
> >      dc->realize = x86_cpu_realizefn;
> > +    dc->unrealize = x86_cpu_unrealizefn;
> >      dc->props = x86_cpu_properties;
> >  
> >      xcc->parent_reset = cc->reset;
> > -- 
> > 2.7.0
> >   
>