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 \\_SB.CPUS.CSCN
Also, macro CPU_SCAN_METHOD might be referred in other places like during GED
intialization so it makes sense to have its definition placed in some common
header file like cpu_hotplug.h. But doing this can cause compilation break
because of the conflicting macro definitions present in cpu.c and cpu_hotplug.c
and because both these files get compiled due to historic reasons of x86 world
i.e. decision to use legacy(GPE.2)/modern(GED) CPU hotplug interface happens
during runtime [1]. To mitigate above, for now, declare a new common macro
ACPI_CPU_SCAN_METHOD for CPU scan method instead.
(This needs a separate discussion later on for clean-up)
Reference:
[1] https://lore.kernel.org/qemu-devel/1463496205-251412-24-git-send-email-imammedo@redhat.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>
---
hw/acpi/cpu.c | 2 +-
hw/acpi/generic_event_device.c | 4 ++++
include/hw/acpi/cpu_hotplug.h | 2 ++
3 files changed, 7 insertions(+), 1 deletion(-)
diff --git a/hw/acpi/cpu.c b/hw/acpi/cpu.c
index 473b37ba88..af2b6655d2 100644
--- a/hw/acpi/cpu.c
+++ b/hw/acpi/cpu.c
@@ -327,7 +327,7 @@ const VMStateDescription vmstate_cpu_hotplug = {
#define CPUHP_RES_DEVICE "PRES"
#define CPU_LOCK "CPLK"
#define CPU_STS_METHOD "CSTA"
-#define CPU_SCAN_METHOD "CSCN"
+#define CPU_SCAN_METHOD ACPI_CPU_SCAN_METHOD
#define CPU_NOTIFY_METHOD "CTFY"
#define CPU_EJECT_METHOD "CEJ0"
#define CPU_OST_METHOD "COST"
diff --git a/hw/acpi/generic_event_device.c b/hw/acpi/generic_event_device.c
index 54d3b4bf9d..63226b0040 100644
--- a/hw/acpi/generic_event_device.c
+++ b/hw/acpi/generic_event_device.c
@@ -109,6 +109,10 @@ 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(ACPI_CPU_CONTAINER "."
+ ACPI_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/cpu_hotplug.h b/include/hw/acpi/cpu_hotplug.h
index 48b291e45e..ef631750b4 100644
--- a/include/hw/acpi/cpu_hotplug.h
+++ b/include/hw/acpi/cpu_hotplug.h
@@ -20,6 +20,8 @@
#include "hw/acpi/cpu.h"
#define ACPI_CPU_HOTPLUG_REG_LEN 12
+#define ACPI_CPU_SCAN_METHOD "CSCN"
+#define ACPI_CPU_CONTAINER "\\_SB.CPUS"
typedef struct AcpiCpuHotplug {
Object *device;
--
2.34.1