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 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),
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
--
2.34.1