Re: [PATCH v4 14/27] hw/intc/apic: Remove APICCommonState::legacy_instance_id field

[Igor Mammedov <imammedo@redhat.com>]

On Thu,  8 May 2025 15:35:37 +0200
Philippe Mathieu-Daudé <philmd@linaro.org> wrote:

> The APICCommonState::legacy_instance_id boolean was only set
> in the pc_compat_2_6[] array, via the 'legacy-instance-id=on'
> property. We removed all machines using that array, lets remove
> that property, simplifying apic_common_realize().
> 
> Because instance_id is initialized as initial_apic_id, we can
> not register vmstate_apic_common directly via dc->vmsd.

I think just removing this property is pretty save,
it's highly unlikely to be used by any external user
as it's purpose was to keep migration working for 2.6.
With the later gone there is not need for the property at all.
  

> 
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> Reviewed-by: Mark Cave-Ayland <mark.caveayland@nutanix.com>
> Reviewed-by: Thomas Huth <thuth@redhat.com>

Reviewed-by: Igor Mammedov <imammedo@redhat.com>

> ---
>  include/hw/i386/apic_internal.h | 1 -
>  hw/intc/apic_common.c           | 5 -----
>  2 files changed, 6 deletions(-)
> 
> diff --git a/include/hw/i386/apic_internal.h b/include/hw/i386/apic_internal.h
> index 429278da618..db6a9101530 100644
> --- a/include/hw/i386/apic_internal.h
> +++ b/include/hw/i386/apic_internal.h
> @@ -188,7 +188,6 @@ struct APICCommonState {
>      uint32_t vapic_control;
>      DeviceState *vapic;
>      hwaddr vapic_paddr; /* note: persistence via kvmvapic */
> -    bool legacy_instance_id;
>      uint32_t extended_log_dest;
>  };
>  
> diff --git a/hw/intc/apic_common.c b/hw/intc/apic_common.c
> index 37a7a7019d3..1d259b97e63 100644
> --- a/hw/intc/apic_common.c
> +++ b/hw/intc/apic_common.c
> @@ -294,9 +294,6 @@ static void apic_common_realize(DeviceState *dev, Error **errp)
>          info->enable_tpr_reporting(s, true);
>      }
>  
> -    if (s->legacy_instance_id) {
> -        instance_id = VMSTATE_INSTANCE_ID_ANY;
> -    }
>      vmstate_register_with_alias_id(NULL, instance_id, &vmstate_apic_common,
>                                     s, -1, 0, NULL);
>  
> @@ -412,8 +409,6 @@ static const Property apic_properties_common[] = {
>      DEFINE_PROP_UINT8("version", APICCommonState, version, 0x14),
>      DEFINE_PROP_BIT("vapic", APICCommonState, vapic_control, VAPIC_ENABLE_BIT,
>                      true),
> -    DEFINE_PROP_BOOL("legacy-instance-id", APICCommonState, legacy_instance_id,
> -                     false),
>  };
>  
>  static void apic_common_get_id(Object *obj, Visitor *v, const char *name,