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.me...@huawei.com/ Co-developed-by: Keqian Zhu <zhukeqi...@huawei.com> Signed-off-by: Keqian Zhu <zhukeqi...@huawei.com> Signed-off-by: Salil Mehta <salil.me...@huawei.com> Reviewed-by: Jonathan Cameron <jonathan.came...@huawei.com> Reviewed-by: Gavin Shan <gs...@redhat.com> Tested-by: Vishnu Pajjuri <vis...@os.amperecomputing.com> Tested-by: Xianglai Li <lixiang...@loongson.cn> Tested-by: Miguel Luis <miguel.l...@oracle.com> Reviewed-by: Shaoqin Huang <shahu...@redhat.com> Tested-by: Zhao Liu <zhao1....@intel.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 -- 2.34.1