[Qemu-devel] [PATCH v5 4/8] hw/arm/virt: Add memory hotplug framework

[Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>]

From: Eric Auger <eric.auger@redhat.com>

This patch adds the memory hot-plug/hot-unplug infrastructure
in machvirt. The device memory is not yet exposed to the Guest
either through DT or ACPI and hence both cold/hot plug of memory
is explicitly disabled for now.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Kwangwoo Lee <kwangwoo.lee@sk.com>
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
---
 hw/arm/Kconfig |  2 ++
 hw/arm/virt.c  | 51 +++++++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 52 insertions(+), 1 deletion(-)

diff --git a/hw/arm/Kconfig b/hw/arm/Kconfig
index af8cffde9c..6ef22439b5 100644
--- a/hw/arm/Kconfig
+++ b/hw/arm/Kconfig
@@ -19,6 +19,8 @@ config ARM_VIRT
     select PLATFORM_BUS
     select SMBIOS
     select VIRTIO_MMIO
+    select MEM_DEVICE
+    select DIMM
 
 config CHEETAH
     bool
diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 5331ab71e2..3df8c389ff 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -62,6 +62,8 @@
 #include "hw/arm/smmuv3.h"
 #include "hw/acpi/acpi.h"
 #include "target/arm/internals.h"
+#include "hw/mem/pc-dimm.h"
+#include "hw/mem/nvdimm.h"
 
 #define DEFINE_VIRT_MACHINE_LATEST(major, minor, latest) \
     static void virt_##major##_##minor##_class_init(ObjectClass *oc, \
@@ -1862,6 +1864,40 @@ static const CPUArchIdList *virt_possible_cpu_arch_ids(MachineState *ms)
     return ms->possible_cpus;
 }
 
+static void virt_memory_pre_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
+                                 Error **errp)
+{
+
+    /*
+     * The device memory is not yet exposed to the Guest either through
+     * DT or ACPI and hence both cold/hot plug of memory is explicitly
+     * disabled for now.
+     */
+    if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
+        error_setg(errp, "memory cold/hot plug is not yet supported");
+        return;
+    }
+
+    pc_dimm_pre_plug(PC_DIMM(dev), MACHINE(hotplug_dev), NULL, errp);
+}
+
+static void virt_memory_plug(HotplugHandler *hotplug_dev,
+                             DeviceState *dev, Error **errp)
+{
+    VirtMachineState *vms = VIRT_MACHINE(hotplug_dev);
+
+    pc_dimm_plug(PC_DIMM(dev), MACHINE(vms), NULL);
+
+}
+
+static void virt_machine_device_pre_plug_cb(HotplugHandler *hotplug_dev,
+                                            DeviceState *dev, Error **errp)
+{
+    if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
+        virt_memory_pre_plug(hotplug_dev, dev, errp);
+    }
+}
+
 static void virt_machine_device_plug_cb(HotplugHandler *hotplug_dev,
                                         DeviceState *dev, Error **errp)
 {
@@ -1873,12 +1909,23 @@ static void virt_machine_device_plug_cb(HotplugHandler *hotplug_dev,
                                      SYS_BUS_DEVICE(dev));
         }
     }
+    if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
+        virt_memory_plug(hotplug_dev, dev, errp);
+    }
+}
+
+static void virt_machine_device_unplug_request_cb(HotplugHandler *hotplug_dev,
+                                          DeviceState *dev, Error **errp)
+{
+    error_setg(errp, "device unplug request for unsupported device"
+               " type: %s", object_get_typename(OBJECT(dev)));
 }
 
 static HotplugHandler *virt_machine_get_hotplug_handler(MachineState *machine,
                                                         DeviceState *dev)
 {
-    if (object_dynamic_cast(OBJECT(dev), TYPE_SYS_BUS_DEVICE)) {
+    if (object_dynamic_cast(OBJECT(dev), TYPE_SYS_BUS_DEVICE) ||
+       (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM))) {
         return HOTPLUG_HANDLER(machine);
     }
 
@@ -1942,7 +1989,9 @@ static void virt_machine_class_init(ObjectClass *oc, void *data)
     mc->kvm_type = virt_kvm_type;
     assert(!mc->get_hotplug_handler);
     mc->get_hotplug_handler = virt_machine_get_hotplug_handler;
+    hc->pre_plug = virt_machine_device_pre_plug_cb;
     hc->plug = virt_machine_device_plug_cb;
+    hc->unplug_request = virt_machine_device_unplug_request_cb;
 }
 
 static void virt_instance_init(Object *obj)
-- 
2.17.1