Re: [PULL v2 40/61] hw/acpi: Update GED _EVT method AML with CPU scan

[Igor Mammedov <imammedo@redhat.com>]

On Mon, 14 Oct 2024 16:52:55 +0800
maobibo <maobibo@loongson.cn> wrote:

> Hi Salil,
> 
> When I debug cpu hotplug on LoongArch system, It reports error like this:
>      ACPI BIOS Error (bug): Could not resolve symbol [\_SB.GED.CSCN], 
> AE_NOT_FOUND
>      ACPI Error: Aborting method \_SB.GED._EVT due to previous error 
> (AE_NOT_FOUND)
>      acpi-ged ACPI0013:00: IRQ method execution failed
> 
> 
> With this patch, GED CPU call method is "\\_SB.GED.CSCN", however in 
> function build_cpus_aml(), its method name is "\\_SB.CPUS.CSCN".
>      method = aml_method(event_handler_method, 0, AML_NOTSERIALIZED);
>      aml_append(method, aml_call0("\\_SB.CPUS." CPU_SCAN_METHOD));
>      aml_append(table, method);
> 
> It seems that CPU scanning method name is not consistent between 
> function build_cpus_aml() and build_ged_aml().
> 
> Regards
> Bibo Mao
> 
> On 2024/7/23 下午6:59, Michael S. Tsirkin wrote:
> > From: Salil Mehta <salil.mehta@huawei.com>
> > 
> > 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);

it should be \\_SB.CPUS.CSCN

> > 
> > [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>
> > Message-Id: <20240716111502.202344-5-salil.mehta@huawei.com>
> > Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
> > Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> > ---
> >   include/hw/acpi/generic_event_device.h | 1 +
> >   hw/acpi/generic_event_device.c         | 3 +++
> >   2 files changed, 4 insertions(+)
> > 
> > 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
> > diff --git a/hw/acpi/generic_event_device.c b/hw/acpi/generic_event_device.c
> > index 4641933a0f..15b4c3ebbf 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),
> >   
>