Re: [PATCH for-5.0 3/4] xics: Link ICP_PROP_CPU property to ICPState::cs pointer

["Cédric Le Goater" <clg@kaod.org>]

On 18/11/2019 00:20, Greg Kurz wrote:
> The ICP object has both a pointer and an ICP_PROP_CPU property pointing
> to the cpu. Confusing bugs could arise if these ever go out of sync.
> 
> Change the property definition so that it explicitely sets the pointer.

 explicitly

> The property isn't optional : not being able to set the link is a bug
> and QEMU should rather abort than exit in this case.
> 
> Signed-off-by: Greg Kurz <groug@kaod.org>



Reviewed-by: Cédric Le Goater <clg@kaod.org>


> ---
>  hw/intc/xics.c |   21 ++++-----------------
>  1 file changed, 4 insertions(+), 17 deletions(-)
> 
> diff --git a/hw/intc/xics.c b/hw/intc/xics.c
> index 35dddb88670e..0b259a09c545 100644
> --- a/hw/intc/xics.c
> +++ b/hw/intc/xics.c
> @@ -305,25 +305,13 @@ void icp_reset(ICPState *icp)
>  static void icp_realize(DeviceState *dev, Error **errp)
>  {
>      ICPState *icp = ICP(dev);
> -    PowerPCCPU *cpu;
>      CPUPPCState *env;
> -    Object *obj;
>      Error *err = NULL;
>  
>      assert(icp->xics);
> +    assert(icp->cs);
>  
> -    obj = object_property_get_link(OBJECT(dev), ICP_PROP_CPU, &err);
> -    if (!obj) {
> -        error_propagate_prepend(errp, err,
> -                                "required link '" ICP_PROP_CPU
> -                                "' not found: ");
> -        return;
> -    }
> -
> -    cpu = POWERPC_CPU(obj);
> -    icp->cs = CPU(obj);
> -
> -    env = &cpu->env;
> +    env = &POWERPC_CPU(icp->cs)->env;
>      switch (PPC_INPUT(env)) {
>      case PPC_FLAGS_INPUT_POWER7:
>          icp->output = env->irq_inputs[POWER7_INPUT_INT];
> @@ -363,6 +351,7 @@ static void icp_unrealize(DeviceState *dev, Error **errp)
>  static Property icp_properties[] = {
>      DEFINE_PROP_LINK(ICP_PROP_XICS, ICPState, xics, TYPE_XICS_FABRIC,
>                       XICSFabric *),
> +    DEFINE_PROP_LINK(ICP_PROP_CPU, ICPState, cs, TYPE_CPU, CPUState *),
>      DEFINE_PROP_END_OF_LIST(),
>  };
>  
> @@ -397,8 +386,7 @@ Object *icp_create(Object *cpu, const char *type, XICSFabric *xi, Error **errp)
>      object_property_add_child(cpu, type, obj, &error_abort);
>      object_unref(obj);
>      object_property_set_link(obj, OBJECT(xi), ICP_PROP_XICS, &error_abort);
> -    object_ref(cpu);
> -    object_property_add_const_link(obj, ICP_PROP_CPU, cpu, &error_abort);
> +    object_property_set_link(obj, cpu, ICP_PROP_CPU, &error_abort);
>      object_property_set_bool(obj, true, "realized", &local_err);
>      if (local_err) {
>          object_unparent(obj);
> @@ -413,7 +401,6 @@ void icp_destroy(ICPState *icp)
>  {
>      Object *obj = OBJECT(icp);
>  
> -    object_unref(object_property_get_link(obj, ICP_PROP_CPU, &error_abort));
>      object_unparent(obj);
>  }
>  
>