Re: [PATCH V15 4/7] hw/acpi: Update GED _EVT method AML with CPU scan

[Igor Mammedov <imammedo@redhat.com>]

On Sat, 13 Jul 2024 19:25:13 +0100
Salil Mehta <salil.mehta@huawei.com> wrote:

> OSPM evaluates _EVT method to map the event. The CPU hotplug event eventually
> results in start of the CPU scan. Scan figures out the CPU and the kind of
> event(plug/unplug) and notifies it back to the guest. Update the GED AML _EVT
> method with the call to method \\_SB.CPUS.CSCN (via \\_SB.GED.CSCN)
> 
> Architecture specific code [1] might initialize its CPUs AML code by calling
> common function build_cpus_aml() like below for ARM:
> 
> build_cpus_aml(scope, ms, opts, xx_madt_cpu_entry, memmap[VIRT_CPUHP_ACPI].base,
>                "\\_SB", "\\_SB.GED.CSCN", AML_SYSTEM_MEMORY);
> 
> [1] https://lore.kernel.org/qemu-devel/20240613233639.202896-13-salil.mehta@huawei.com/
> 
> Co-developed-by: Keqian Zhu <zhukeqian1@huawei.com>
> Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>
> Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Reviewed-by: Gavin Shan <gshan@redhat.com>
> Tested-by: Vishnu Pajjuri <vishnu@os.amperecomputing.com>
> Tested-by: Xianglai Li <lixianglai@loongson.cn>
> Tested-by: Miguel Luis <miguel.luis@oracle.com>
> Reviewed-by: Shaoqin Huang <shahuang@redhat.com>
> Tested-by: Zhao Liu <zhao1.liu@intel.com>

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

> ---
>  hw/acpi/generic_event_device.c         | 3 +++
>  include/hw/acpi/generic_event_device.h | 1 +
>  2 files changed, 4 insertions(+)
> 
> diff --git a/hw/acpi/generic_event_device.c b/hw/acpi/generic_event_device.c
> index 1b31d633ba..15ffa12cb2 100644
> --- a/hw/acpi/generic_event_device.c
> +++ b/hw/acpi/generic_event_device.c
> @@ -108,6 +108,9 @@ void build_ged_aml(Aml *table, const char *name, HotplugHandler *hotplug_dev,
>                  aml_append(if_ctx, aml_call0(MEMORY_DEVICES_CONTAINER "."
>                                               MEMORY_SLOT_SCAN_METHOD));
>                  break;
> +            case ACPI_GED_CPU_HOTPLUG_EVT:
> +                aml_append(if_ctx, aml_call0(AML_GED_EVT_CPU_SCAN_METHOD));
> +                break;
>              case ACPI_GED_PWR_DOWN_EVT:
>                  aml_append(if_ctx,
>                             aml_notify(aml_name(ACPI_POWER_BUTTON_DEVICE),
> diff --git a/include/hw/acpi/generic_event_device.h b/include/hw/acpi/generic_event_device.h
> index e091ac2108..40af3550b5 100644
> --- a/include/hw/acpi/generic_event_device.h
> +++ b/include/hw/acpi/generic_event_device.h
> @@ -87,6 +87,7 @@ OBJECT_DECLARE_SIMPLE_TYPE(AcpiGedState, ACPI_GED)
>  #define GED_DEVICE      "GED"
>  #define AML_GED_EVT_REG "EREG"
>  #define AML_GED_EVT_SEL "ESEL"
> +#define AML_GED_EVT_CPU_SCAN_METHOD "\\_SB.GED.CSCN"
>  
>  /*
>   * Platforms need to specify the GED event bitmap