[Qemu-devel] [RFC PATCH v1 09/13] spapr: CPU hot unplug support

[Bharata B Rao <bharata@linux.vnet.ibm.com>]

Support hot removal of CPU for sPAPR guests.

Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
---
 hw/ppc/spapr.c | 43 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 4347471..ec793b1 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -1908,6 +1908,22 @@ static void spapr_cpu_hotplug_add(DeviceState *dev, CPUState *cs)
     drck->attach(drc, dev, fdt, offset, false);
 }
 
+static void spapr_cpu_release(DeviceState *dev, void *opaque)
+{
+    /* Release vCPU */
+}
+
+static void spapr_cpu_hotplug_remove(DeviceState *dev, CPUState *cs)
+{
+    PowerPCCPU *cpu = POWERPC_CPU(cs);
+    int id = ppc_get_vcpu_dt_id(cpu);
+    sPAPRDRConnector *drc =
+        spapr_dr_connector_by_id(SPAPR_DR_CONNECTOR_TYPE_CPU, id);
+    sPAPRDRConnectorClass *drck = SPAPR_DR_CONNECTOR_GET_CLASS(drc);
+
+    drck->detach(drc, dev, spapr_cpu_release, NULL);
+}
+
 static void spapr_cpu_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
                             Error **errp)
 {
@@ -1948,6 +1964,21 @@ static void spapr_cpu_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
     return;
 }
 
+static void spapr_cpu_unplug(HotplugHandler *hotplug_dev, DeviceState *dev,
+                            Error **errp)
+{
+    Error *local_err = NULL;
+    CPUState *cs = CPU(dev);
+    PowerPCCPU *cpu = POWERPC_CPU(cs);
+    sPAPRDRConnector *drc =
+        spapr_dr_connector_by_id(SPAPR_DR_CONNECTOR_TYPE_CPU, cpu->cpu_dt_id);
+
+    spapr_cpu_hotplug_remove(dev, cs);
+    spapr_hotplug_req_remove_event(drc);
+    error_propagate(errp, local_err);
+    return;
+}
+
 static void spapr_machine_device_plug(HotplugHandler *hotplug_dev,
                                       DeviceState *dev, Error **errp)
 {
@@ -1958,6 +1989,16 @@ static void spapr_machine_device_plug(HotplugHandler *hotplug_dev,
     }
 }
 
+static void spapr_machine_device_unplug(HotplugHandler *hotplug_dev,
+                                      DeviceState *dev, Error **errp)
+{
+    if (object_dynamic_cast(OBJECT(dev), TYPE_CPU)) {
+        if (dev->hotplugged) {
+            spapr_cpu_unplug(hotplug_dev, dev, errp);
+        }
+    }
+}
+
 static HotplugHandler *spapr_get_hotpug_handler(MachineState *machine,
                                              DeviceState *dev)
 {
@@ -1986,6 +2027,8 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data)
     mc->get_hotplug_handler = spapr_get_hotpug_handler;
 
     hc->plug = spapr_machine_device_plug;
+    hc->unplug = spapr_machine_device_unplug;
+
     smc->dr_phb_enabled = false;
     smc->dr_cpu_enabled = false;
     smc->dr_lmb_enabled = false;
-- 
2.1.0