[Qemu-devel] [PATCH v7 10/17] hw/arm/virt: Add memory hotplug framework

[Eric Auger <eric.auger@redhat.com>]

This patch adds the the memory hot-plug/hot-unplug infrastructure
in machvirt. It is still not enabled as no device memory is allocated.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Signed-off-by: Kwangwoo Lee <kwangwoo.lee@sk.com>

---
v4 -> v5:
- change in pc_dimm_pre_plug signature
- CONFIG_MEM_HOTPLUG replaced by CONFIG_MEM_DEVICE and CONFIG_DIMM

v3 -> v4:
- check the memory device is not hotplugged

v2 -> v3:
- change in pc_dimm_plug()'s signature
- add pc_dimm_pre_plug call

v1 -> v2:
- s/virt_dimm_plug|unplug/virt_memory_plug|unplug
- s/pc_dimm_memory_plug/pc_dimm_plug
- reworded title and commit message
- added pre_plug cb
- don't handle get_memory_region failure anymore
---
 default-configs/arm-softmmu.mak |  2 ++
 hw/arm/virt.c                   | 64 ++++++++++++++++++++++++++++++++-
 2 files changed, 65 insertions(+), 1 deletion(-)

diff --git a/default-configs/arm-softmmu.mak b/default-configs/arm-softmmu.mak
index 734ca721e9..0a78421f72 100644
--- a/default-configs/arm-softmmu.mak
+++ b/default-configs/arm-softmmu.mak
@@ -163,3 +163,5 @@ CONFIG_PCI_EXPRESS_DESIGNWARE=y
 CONFIG_STRONGARM=y
 CONFIG_HIGHBANK=y
 CONFIG_MUSICPAL=y
+CONFIG_MEM_DEVICE=y
+CONFIG_DIMM=y
diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 5b656f9db5..470ca0ce2d 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -60,6 +60,8 @@
 #include "standard-headers/linux/input.h"
 #include "hw/arm/smmuv3.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, \
@@ -1804,6 +1806,49 @@ 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)
+{
+    const bool is_nvdimm = object_dynamic_cast(OBJECT(dev), TYPE_NVDIMM);
+
+    if (dev->hotplugged) {
+        error_setg(errp, "memory hotplug is not supported");
+    }
+
+    if (is_nvdimm) {
+        error_setg(errp, "nvdimm 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);
+    Error *local_err = NULL;
+
+    pc_dimm_plug(PC_DIMM(dev), MACHINE(vms), &local_err);
+
+    error_propagate(errp, local_err);
+}
+
+static void virt_memory_unplug(HotplugHandler *hotplug_dev,
+                               DeviceState *dev, Error **errp)
+{
+    pc_dimm_unplug(PC_DIMM(dev), MACHINE(hotplug_dev));
+    object_unparent(OBJECT(dev));
+}
+
+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)
 {
@@ -1815,12 +1860,27 @@ 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_cb(HotplugHandler *hotplug_dev,
+                                          DeviceState *dev, Error **errp)
+{
+    if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
+        virt_memory_unplug(hotplug_dev, dev, errp);
+    } else {
+        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);
     }
 
@@ -1884,7 +1944,9 @@ 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 = virt_machine_device_unplug_cb;
 }
 
 static void virt_instance_init(Object *obj)
-- 
2.20.1