From 05d22b55133db1a2526cfe305102e075e883b5e2 Mon Sep 17 00:00:00 2001
From: Keqian Zhu <zhukeqian1@huawei.com>
Date: Fri, 3 Apr 2020 15:41:01 +0800
Subject: [PATCH] acpi/ged: Extend ACPI GED to support CPU hotplug

This adds a new GED event called ACPI_GED_CPU_HOTPLUG_EVT.
The basic workflow is that: GED sends this event to guest,
then ACPI driver in guest will call _EVT method of GED aml,
then _EVT will call CSCN method in cpus aml to get status of
all cpus.

The status of cpus is maintained by CPUHotplugState in GED and
is made accessable to guest through memory region.

This also adds migration support to CPUHotplugState.

Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
---
 docs/specs/acpi_hw_reduced_hotplug.rst |  3 ++-
 hw/acpi/cpu.c                          |  1 -
 hw/acpi/generic_event_device.c         | 35 ++++++++++++++++++++++++++
 hw/arm/Kconfig                         |  1 +
 include/hw/acpi/cpu.h                  |  2 ++
 include/hw/acpi/generic_event_device.h |  4 +++
 6 files changed, 44 insertions(+), 2 deletions(-)

diff --git a/docs/specs/acpi_hw_reduced_hotplug.rst b/docs/specs/acpi_hw_reduced_hotplug.rst
index 911a98255b..deb481555d 100644
--- a/docs/specs/acpi_hw_reduced_hotplug.rst
+++ b/docs/specs/acpi_hw_reduced_hotplug.rst
@@ -63,7 +63,8 @@ GED IO interface (4 byte access)
     bits:
        0: Memory hotplug event
        1: System power down event
-    2-31: Reserved
+       2: CPU hotplug event
+    3-31: Reserved

 **write_access:**

diff --git a/hw/acpi/cpu.c b/hw/acpi/cpu.c
index 72ad1fcff2..cb6bb67f3c 100644
--- a/hw/acpi/cpu.c
+++ b/hw/acpi/cpu.c
@@ -6,7 +6,6 @@
 #include "trace.h"
 #include "sysemu/numa.h"

-#define ACPI_CPU_HOTPLUG_REG_LEN 12
 #define ACPI_CPU_SELECTOR_OFFSET_WR 0
 #define ACPI_CPU_FLAGS_OFFSET_RW 4
 #define ACPI_CPU_CMD_OFFSET_WR 5
diff --git a/hw/acpi/generic_event_device.c b/hw/acpi/generic_event_device.c
index 82139b4314..478a4ee87c 100644
--- a/hw/acpi/generic_event_device.c
+++ b/hw/acpi/generic_event_device.c
@@ -23,6 +23,7 @@
 static const uint32_t ged_supported_events[] = {
     ACPI_GED_MEM_HOTPLUG_EVT,
     ACPI_GED_PWR_DOWN_EVT,
+    ACPI_GED_CPU_HOTPLUG_EVT,
 };

 /*
@@ -110,6 +111,9 @@ void build_ged_aml(Aml *table, const char *name, HotplugHandler *hotplug_dev,
                            aml_notify(aml_name(ACPI_POWER_BUTTON_DEVICE),
                                       aml_int(0x80)));
                 break;
+            case ACPI_GED_CPU_HOTPLUG_EVT:
+                aml_append(if_ctx, aml_call0("\\_SB.CPUS.CSCN"));
+                break;
             default:
                 /*
                  * Please make sure all the events in ged_supported_events[]
@@ -176,6 +180,8 @@ static void acpi_ged_device_plug_cb(HotplugHandler *hotplug_dev,

     if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
             acpi_memory_plug_cb(hotplug_dev, &s->memhp_state, dev, errp);
+    } else if (object_dynamic_cast(OBJECT(dev), TYPE_CPU)) {
+        acpi_cpu_plug_cb(hotplug_dev, &s->cpuhp_state, dev, errp);
     } else {
         error_setg(errp, "virt: device plug request for unsupported device"
                    " type: %s", object_get_typename(OBJECT(dev)));
@@ -192,6 +198,8 @@ static void acpi_ged_send_event(AcpiDeviceIf *adev, AcpiEventStatusBits ev)
         sel = ACPI_GED_MEM_HOTPLUG_EVT;
     } else if (ev & ACPI_POWER_DOWN_STATUS) {
         sel = ACPI_GED_PWR_DOWN_EVT;
+    } else if (ev & ACPI_CPU_HOTPLUG_STATUS) {
+        sel = ACPI_GED_CPU_HOTPLUG_EVT;
     } else {
         /* Unknown event. Return without generating interrupt. */
         warn_report("GED: Unsupported event %d. No irq injected", ev);
@@ -224,6 +232,16 @@ static const VMStateDescription vmstate_memhp_state = {
     }
 };

+static const VMStateDescription vmstate_cpuhp_state = {
+    .name = "acpi-ged/cpuhp",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields      = (VMStateField[]) {
+        VMSTATE_CPU_HOTPLUG(cpuhp_state, AcpiGedState),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
 static const VMStateDescription vmstate_ged_state = {
     .name = "acpi-ged-state",
     .version_id = 1,
@@ -244,6 +262,7 @@ static const VMStateDescription vmstate_acpi_ged = {
     },
     .subsections = (const VMStateDescription * []) {
         &vmstate_memhp_state,
+        &vmstate_cpuhp_state,
         NULL
     }
 };
@@ -254,6 +273,7 @@ static void acpi_ged_initfn(Object *obj)
     AcpiGedState *s = ACPI_GED(dev);
     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
     GEDState *ged_st = &s->ged_state;
+    MachineClass *mc;

     memory_region_init_io(&ged_st->io, obj, &ged_ops, ged_st,
                           TYPE_ACPI_GED, ACPI_GED_EVT_SEL_LEN);
@@ -273,6 +293,21 @@ static void acpi_ged_initfn(Object *obj)
      sysbus_init_mmio(sbd, &s->container_memhp);
      acpi_memory_hotplug_init(&s->container_memhp, OBJECT(dev),
                               &s->memhp_state, 0);
+
+    mc = MACHINE_GET_CLASS(qdev_get_machine());
+    if (!mc->possible_cpu_arch_ids) {
+        /*
+         * MachineClass should support possible_cpu_arch_ids in
+         * cpu_hotplug_hw_init below.
+         */
+        return;
+    }
+
+    memory_region_init(&s->container_cpuhp, OBJECT(dev), "cpuhp container",
+                       ACPI_CPU_HOTPLUG_REG_LEN);
+    sysbus_init_mmio(sbd, &s->container_cpuhp);
+    cpu_hotplug_hw_init(&s->container_cpuhp, OBJECT(dev),
+                        &s->cpuhp_state, 0);
 }

 static void acpi_ged_class_init(ObjectClass *class, void *data)
diff --git a/hw/arm/Kconfig b/hw/arm/Kconfig
index ad7f7c089b..15e18b0a48 100644
--- a/hw/arm/Kconfig
+++ b/hw/arm/Kconfig
@@ -24,6 +24,7 @@ config ARM_VIRT
     select DIMM
     select ACPI_MEMORY_HOTPLUG
     select ACPI_HW_REDUCED
+    select ACPI_CPU_HOTPLUG

 config CHEETAH
     bool
diff --git a/include/hw/acpi/cpu.h b/include/hw/acpi/cpu.h
index a30ec84a4f..e726414459 100644
--- a/include/hw/acpi/cpu.h
+++ b/include/hw/acpi/cpu.h
@@ -17,6 +17,8 @@
 #include "hw/acpi/aml-build.h"
 #include "hw/hotplug.h"

+#define ACPI_CPU_HOTPLUG_REG_LEN 12
+
 typedef struct AcpiCpuStatus {
     struct CPUState *cpu;
     uint64_t arch_id;
diff --git a/include/hw/acpi/generic_event_device.h b/include/hw/acpi/generic_event_device.h
index f99efad7a3..e702ff1e18 100644
--- a/include/hw/acpi/generic_event_device.h
+++ b/include/hw/acpi/generic_event_device.h
@@ -62,6 +62,7 @@
 #include "hw/sysbus.h"
 #include "hw/acpi/memory_hotplug.h"
 #include "hw/arm/virt.h"
+#include "hw/acpi/cpu.h"

 #define ACPI_POWER_BUTTON_DEVICE "PWRB"

@@ -83,6 +84,7 @@
  */
 #define ACPI_GED_MEM_HOTPLUG_EVT   0x1
 #define ACPI_GED_PWR_DOWN_EVT      0x2
+#define ACPI_GED_CPU_HOTPLUG_EVT   0x4

 typedef struct GEDState {
     MemoryRegion io;
@@ -93,6 +95,8 @@ typedef struct AcpiGedState {
     SysBusDevice parent_obj;
     MemHotplugState memhp_state;
     MemoryRegion container_memhp;
+    CPUHotplugState cpuhp_state;
+    MemoryRegion container_cpuhp;
     GEDState ged_state;
     uint32_t ged_event_bitmap;
     qemu_irq irq;
--
2.19.1