From 65fb66980d3a918ebe1e665cf6ae4ceb8dea2db1 Mon Sep 17 00:00:00 2001
From: Salil Mehta <salil.mehta@huawei.com>
Date: Sun, 3 Nov 2024 10:24:19 +0000
Subject: [PATCH] hw/acpi: Update GED with vCPU Hotplug VMSD for migration

The ACPI CPU hotplug states must be migrated along with other vCPU
hotplug states to the destination VM. Update the GED's VM State
Description (VMSD) table subsection to conditionally include the CPU
Hotplug VM State Description (VMSD).

Excerpt of GED VMSD State Dump at Source:

    "acpi-ged (16)": {
        "ged_state": {
            "sel": "0x00000000"
        },
        [...]
        "acpi-ged/cpuhp": {
            "cpuhp_state": {
                "selector": "0x00000005",
                "command": "0x00",
                "devs": [
                    {
                        "is_inserting": false,
                        "is_removing": false,
                        "ost_event": "0x00000000",
                        "ost_status": "0x00000000"
                    },
		    [...]
                    {
                        "is_inserting": false,
                        "is_removing": false,
                        "ost_event": "0x00000000",
                        "ost_status": "0x00000000"
                    }
                ]
            }
        }
    },

Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Message-Id: <20241103102419.202225-6-salil.mehta@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/acpi/generic_event_device.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/hw/acpi/generic_event_device.c b/hw/acpi/generic_event_device.c
index d00f5a6c1c..663d9cb093 100644
--- a/hw/acpi/generic_event_device.c
+++ b/hw/acpi/generic_event_device.c
@@ -331,6 +331,24 @@ static const VMStateDescription vmstate_memhp_state = {
     }
 };
 
+static bool cpuhp_needed(void *opaque)
+{
+    MachineClass *mc = MACHINE_GET_CLASS(qdev_get_machine());
+
+    return mc->has_hotpluggable_cpus;
+}
+
+static const VMStateDescription vmstate_cpuhp_state = {
+    .name = "acpi-ged/cpuhp",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .needed = cpuhp_needed,
+    .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,
@@ -379,6 +397,7 @@ static const VMStateDescription vmstate_acpi_ged = {
     },
     .subsections = (const VMStateDescription * const []) {
         &vmstate_memhp_state,
+        &vmstate_cpuhp_state,
         &vmstate_ghes_state,
         NULL
     }