From ac96f216155002d0c874ff88e301e83495093085 Mon Sep 17 00:00:00 2001
From: Salil Mehta <salil.mehta@huawei.com>
Date: Tue, 16 Jul 2024 12:14:58 +0100
Subject: [PATCH 64/78] hw/acpi: Update ACPI GED framework to support vCPU
 Hotplug

ACPI GED (as described in the ACPI 6.4 spec) uses an interrupt listed in the
_CRS object of GED to intimate OSPM about an event. Later then demultiplexes the
notified event by evaluating ACPI _EVT method to know the type of event. Use
ACPI GED to also notify the guest kernel about any CPU hot(un)plug events.

Note, GED interface is used by many hotplug events like memory hotplug, NVDIMM
hotplug and non-hotplug events like system power down event. Each of these can
be selected using a bit in the 32 bit GED IO interface. A bit has been reserved
for the CPU hotplug event.

ACPI CPU hotplug related initialization should only happen if ACPI_CPU_HOTPLUG
support has been enabled for particular architecture. Add cpu_hotplug_hw_init()
stub to avoid compilation break.

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>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Shaoqin Huang <shahuang@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: Vishnu Pajjuri <vishnu@os.amperecomputing.com>
Tested-by: Zhao Liu <zhao1.liu@intel.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Message-Id: <20240716111502.202344-4-salil.mehta@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Xianglai Li <lixianglai@loongson.cn>
---
 docs/specs/acpi_hw_reduced_hotplug.rst |  3 ++-
 hw/acpi/generic_event_device.c         | 37 ++++++++++++++++++++++++++
 include/hw/acpi/generic_event_device.h |  1 +
 3 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/docs/specs/acpi_hw_reduced_hotplug.rst b/docs/specs/acpi_hw_reduced_hotplug.rst
index 0bd3f9399f..3acd6fcd8b 100644
--- a/docs/specs/acpi_hw_reduced_hotplug.rst
+++ b/docs/specs/acpi_hw_reduced_hotplug.rst
@@ -64,7 +64,8 @@ GED IO interface (4 byte access)
        0: Memory hotplug event
        1: System power down event
        2: NVDIMM hotplug event
-    3-31: Reserved
+       3: CPU hotplug event
+    4-31: Reserved
 
 **write_access:**
 
diff --git a/hw/acpi/generic_event_device.c b/hw/acpi/generic_event_device.c
index 2ce7031f1a..755653dc26 100644
--- a/hw/acpi/generic_event_device.c
+++ b/hw/acpi/generic_event_device.c
@@ -397,6 +397,42 @@ static const VMStateDescription vmstate_acpi_ged = {
     }
 };
 
+static void acpi_ged_realize(DeviceState *dev, Error **errp)
+{
+    SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
+    AcpiGedState *s = ACPI_GED(dev);
+    uint32_t ged_events;
+    int i;
+
+    ged_events = ctpop32(s->ged_event_bitmap);
+
+    for (i = 0; i < ARRAY_SIZE(ged_supported_events) && ged_events; i++) {
+        uint32_t event = s->ged_event_bitmap & ged_supported_events[i];
+
+        if (!event) {
+            continue;
+        }
+
+        switch (event) {
+        case ACPI_GED_CPU_HOTPLUG_EVT:
+            /* initialize CPU Hotplug related regions */
+            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);
+            break;
+        }
+        ged_events--;
+    }
+
+    if (ged_events) {
+        error_report("Unsupported events specified");
+        abort();
+    }
+}
+
 static void acpi_ged_initfn(Object *obj)
 {
     DeviceState *dev = DEVICE(obj);
@@ -447,6 +483,7 @@ static void acpi_ged_class_init(ObjectClass *class, void *data)
     dc->desc = "ACPI Generic Event Device";
     device_class_set_props(dc, acpi_ged_properties);
     dc->vmsd = &vmstate_acpi_ged;
+    dc->realize = acpi_ged_realize;
 
     hc->plug = acpi_ged_device_plug_cb;
     hc->unplug_request = acpi_ged_unplug_request_cb;
diff --git a/include/hw/acpi/generic_event_device.h b/include/hw/acpi/generic_event_device.h
index 8ed9534c57..d1df3c12e5 100644
--- a/include/hw/acpi/generic_event_device.h
+++ b/include/hw/acpi/generic_event_device.h
@@ -63,6 +63,7 @@
 #include "hw/acpi/cpu_hotplug.h"
 #include "hw/acpi/memory_hotplug.h"
 #include "hw/acpi/ghes.h"
+#include "hw/acpi/cpu.h"
 #include "qom/object.h"
 
 #define ACPI_POWER_BUTTON_DEVICE "PWRB"
-- 
2.39.1