acpi, mem-hotplug: add unplug request cb for memory device

This patch adds unplug request cb for memory device, and adds the
is_removing boolean field to MemStatus. This field is used to indicate
whether the memory device in slot has been requested to be ejected.
This field is set to true in acpi_memory_unplug_request_cb().
Reviewed-by: NIgor Mammedov <imammedo@redhat.com>
Signed-off-by: NTang Chen <tangchen@cn.fujitsu.com>
Signed-off-by: NZhu Guihua <zhugh.fnst@cn.fujitsu.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

hw/acpi/ich9.c

@@ -400,8 +400,14 @@ void ich9_pm_device_plug_cb(ICH9LPCPMRegs *pm, DeviceState *dev, Error **errp)
 void ich9_pm_device_unplug_request_cb(ICH9LPCPMRegs *pm, DeviceState *dev,
                                       Error **errp)
 {
+    if (pm->acpi_memory_hotplug.is_enabled &&
+        object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
+        acpi_memory_unplug_request_cb(&pm->acpi_regs, pm->irq,
+                                      &pm->acpi_memory_hotplug, dev, errp);
+    } else {
         error_setg(errp, "acpi: device unplug request for not supported device"
                    " type: %s", object_get_typename(OBJECT(dev)));
+    }
 }
 
 void ich9_pm_device_unplug_cb(ICH9LPCPMRegs *pm, DeviceState *dev,

hw/acpi/memory_hotplug.c

@@ -75,6 +75,7 @@ static uint64_t acpi_memory_hotplug_read(void *opaque, hwaddr addr,
     case 0x14: /* pack and return is_* fields */
         val |= mdev->is_enabled   ? 1 : 0;
         val |= mdev->is_inserting ? 2 : 0;
+        val |= mdev->is_removing  ? 4 : 0;
         trace_mhp_acpi_read_flags(mem_st->selector, val);
         break;
     default:
@@ -218,6 +219,24 @@ void acpi_memory_plug_cb(ACPIREGS *ar, qemu_irq irq, MemHotplugState *mem_st,
     return;
 }
 
+void acpi_memory_unplug_request_cb(ACPIREGS *ar, qemu_irq irq,
+                                   MemHotplugState *mem_st,
+                                   DeviceState *dev, Error **errp)
+{
+    MemStatus *mdev;
+
+    mdev = acpi_memory_slot_status(mem_st, dev, errp);
+    if (!mdev) {
+        return;
+    }
+
+    mdev->is_removing = true;
+
+    /* Do ACPI magic */
+    ar->gpe.sts[0] |= ACPI_MEMORY_HOTPLUG_STATUS;
+    acpi_update_sci(ar, irq);
+}
+
 static const VMStateDescription vmstate_memhp_sts = {
     .name = "memory hotplug device state",
     .version_id = 1,

hw/acpi/piix4.c

@@ -361,7 +361,11 @@ static void piix4_device_unplug_request_cb(HotplugHandler *hotplug_dev,
 {
     PIIX4PMState *s = PIIX4_PM(hotplug_dev);
 
-    if (object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) {
+    if (s->acpi_memory_hotplug.is_enabled &&
+        object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
+        acpi_memory_unplug_request_cb(&s->ar, s->irq, &s->acpi_memory_hotplug,
+                                      dev, errp);
+    } else if (object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) {
         acpi_pcihp_device_unplug_cb(&s->ar, s->irq, &s->acpi_pci_hotplug, dev,
                                     errp);
     } else {

hw/i386/pc.c

@@ -1677,6 +1677,26 @@ out:
     error_propagate(errp, local_err);
 }
 
+static void pc_dimm_unplug_request(HotplugHandler *hotplug_dev,
+                                   DeviceState *dev, Error **errp)
+{
+    HotplugHandlerClass *hhc;
+    Error *local_err = NULL;
+    PCMachineState *pcms = PC_MACHINE(hotplug_dev);
+
+    if (!pcms->acpi_dev) {
+        error_setg(&local_err,
+                   "memory hotplug is not enabled: missing acpi device");
+        goto out;
+    }
+
+    hhc = HOTPLUG_HANDLER_GET_CLASS(pcms->acpi_dev);
+    hhc->unplug_request(HOTPLUG_HANDLER(pcms->acpi_dev), dev, &local_err);
+
+out:
+    error_propagate(errp, local_err);
+}
+
 static void pc_cpu_plug(HotplugHandler *hotplug_dev,
                         DeviceState *dev, Error **errp)
 {
@@ -1719,8 +1739,12 @@ static void pc_machine_device_plug_cb(HotplugHandler *hotplug_dev,
 static void pc_machine_device_unplug_request_cb(HotplugHandler *hotplug_dev,
                                                 DeviceState *dev, Error **errp)
 {
+    if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
+        pc_dimm_unplug_request(hotplug_dev, dev, errp);
+    } else {
         error_setg(errp, "acpi: device unplug request for not supported device"
                    " type: %s", object_get_typename(OBJECT(dev)));
+    }
 }
 
 static void pc_machine_device_unplug_cb(HotplugHandler *hotplug_dev,

include/hw/acpi/memory_hotplug.h

@@ -7,10 +7,17 @@
 
 #define ACPI_MEMORY_HOTPLUG_STATUS 8
 
+/**
+ * MemStatus:
+ * @is_removing: the memory device in slot has been requested to be ejected.
+ *
+ * This structure stores memory device's status.
+ */
 typedef struct MemStatus {
     DeviceState *dimm;
     bool is_enabled;
     bool is_inserting;
+    bool is_removing;
     uint32_t ost_event;
     uint32_t ost_status;
 } MemStatus;
@@ -28,6 +35,9 @@ void acpi_memory_hotplug_init(MemoryRegion *as, Object *owner,
 
 void acpi_memory_plug_cb(ACPIREGS *ar, qemu_irq irq, MemHotplugState *mem_st,
                          DeviceState *dev, Error **errp);
+void acpi_memory_unplug_request_cb(ACPIREGS *ar, qemu_irq irq,
+                                   MemHotplugState *mem_st,
+                                   DeviceState *dev, Error **errp);
 
 extern const VMStateDescription vmstate_memory_hotplug;
 #define VMSTATE_MEMORY_HOTPLUG(memhp, state) \