Re: [Qemu-devel] [PATCH 1/2] cpu/apic: drop icc bus/bridge/

[Igor Mammedov <imammedo@redhat.com>]

On Tue, 17 Mar 2015 17:08:30 +0800
Chen Fan <chen.fan.fnst@cn.fujitsu.com> wrote:

> ICC bus was invented only to provide hotplug capability to
> CPU and APIC because at the time being hotplug was available only for
> BUS attached devices.
> 
> Now this patch is to drop ICC bus impl, and switch to bus-less
> CPU+APIC hotplug, handling them in the same manner as pc-dimm.
> 
> Signed-off-by: Chen Fan <chen.fan.fnst@cn.fujitsu.com>
> ---

[...]

> diff --git a/hw/intc/apic_common.c b/hw/intc/apic_common.c
> index 0858b45..020219e 100644
> --- a/hw/intc/apic_common.c
> +++ b/hw/intc/apic_common.c
> @@ -27,6 +27,8 @@
>  static int apic_irq_delivered;
>  bool apic_report_tpr_access;
>  
> +static MemoryRegion *apic_container;
> +
>  void cpu_set_apic_base(DeviceState *dev, uint64_t val)
>  {
>      trace_cpu_set_apic_base(val);
> @@ -314,8 +316,11 @@ static void apic_common_realize(DeviceState *dev, Error **errp)
>      info = APIC_COMMON_GET_CLASS(s);
>      info->realize(dev, errp);
>      if (!mmio_registered) {
> -        ICCBus *b = ICC_BUS(qdev_get_parent_bus(dev));
> -        memory_region_add_subregion(b->apic_address_space, 0, &s->io_memory);
> +        memory_region_add_subregion(apic_container, 0, &s->io_memory);
> +        memory_region_add_subregion_overlap(CPU(s->cpu)->as->root,
> +                                            APIC_DEFAULT_ADDRESS,
> +                                            apic_container,
> +                                            0x1000);
>          mmio_registered = true;
>      }
Provided per CPU address spaces are used,
why do you need static apic_container and mmio_registered thing?
Shouldn't it be possible to register &s->io_memory of each APIC
in CPU's own AS and avoid using globals?


>  
> @@ -431,15 +436,23 @@ static Property apic_properties_common[] = {
>      DEFINE_PROP_END_OF_LIST(),
>  };
>  
> +static void apic_common_initfn(Object *obj)
> +{
> +    if (!apic_container) {
> +        apic_container = g_malloc(sizeof(*apic_container));
> +        memory_region_init(apic_container, obj, "apic-container",
> +                           APIC_SPACE_SIZE);
> +    }
> +}
> +