[Qemu-devel] [PATCH 21/33] pc: piix4: initialize new CPU hotplug hw

[Igor Mammedov <imammedo@redhat.com>]

add necessary wiring to init new CPU hotplug hardware
if PIIX4_PM.cpu-hotplug-legacy is "off".
Set PIIX4_PM.cpu-hotplug-legacy to "off" by default and
switch legacy hotplug to enabled only for 2.6 and older
machine types.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
v1:
  - drop PIIX4_PM.cpu-hotplug property
---
 hw/acpi/piix4.c     | 55 +++++++++++++++++++++++++++++++++++++++++++++++------
 include/hw/compat.h |  5 +++++
 2 files changed, 54 insertions(+), 6 deletions(-)

diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c
index d25479c..05ce725 100644
--- a/hw/acpi/piix4.c
+++ b/hw/acpi/piix4.c
@@ -34,6 +34,7 @@
 #include "hw/acpi/piix4.h"
 #include "hw/acpi/pcihp.h"
 #include "hw/acpi/cpu_hotplug.h"
+#include "hw/acpi/cpu.h"
 #include "hw/hotplug.h"
 #include "hw/mem/pc-dimm.h"
 #include "hw/acpi/memory_hotplug.h"
@@ -86,7 +87,10 @@ typedef struct PIIX4PMState {
     uint8_t s4_val;
 
     bool cpu_hotplug_legacy;
-    AcpiCpuHotplug gpe_cpu;
+    union {
+        AcpiCpuHotplug legacy; /* used for keeping legacy state */
+        CPUHotplugState state;
+    } cpuhp;
 
     MemHotplugState acpi_memory_hotplug;
 } PIIX4PMState;
@@ -273,6 +277,24 @@ static const VMStateDescription vmstate_memhp_state = {
     }
 };
 
+static bool vmstate_test_use_cpuhp(void *opaque)
+{
+    PIIX4PMState *s = opaque;
+    return !s->cpu_hotplug_legacy;
+}
+
+static const VMStateDescription vmstate_cpuhp_state = {
+    .name = "piix4_pm/cpuhp",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .minimum_version_id_old = 1,
+    .needed = vmstate_test_use_cpuhp,
+    .fields      = (VMStateField[]) {
+        VMSTATE_CPU_HOTPLUG(cpuhp.state, PIIX4PMState),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
 /* qemu-kvm 1.2 uses version 3 but advertised as 2
  * To support incoming qemu-kvm 1.2 migration, change version_id
  * and minimum_version_id to 2 below (which breaks migration from
@@ -307,6 +329,7 @@ static const VMStateDescription vmstate_acpi = {
     },
     .subsections = (const VMStateDescription*[]) {
          &vmstate_memhp_state,
+         &vmstate_cpuhp_state,
          NULL
     }
 };
@@ -351,9 +374,12 @@ static void piix4_device_plug_cb(HotplugHandler *hotplug_dev,
         acpi_memory_plug_cb(hotplug_dev, &s->acpi_memory_hotplug, dev, errp);
     } else if (object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) {
         acpi_pcihp_device_plug_cb(hotplug_dev, &s->acpi_pci_hotplug, dev, errp);
-    } else if (s->cpu_hotplug_legacy &&
-               object_dynamic_cast(OBJECT(dev), TYPE_CPU)) {
-        legacy_acpi_cpu_plug_cb(hotplug_dev, &s->gpe_cpu, dev, errp);
+    } else if (object_dynamic_cast(OBJECT(dev), TYPE_CPU)) {
+        if (s->cpu_hotplug_legacy) {
+            legacy_acpi_cpu_plug_cb(hotplug_dev, &s->cpuhp.legacy, dev, errp);
+        } else {
+            acpi_cpu_plug_cb(hotplug_dev, &s->cpuhp.state, dev, errp);
+        }
     } else {
         error_setg(errp, "acpi: device plug request for not supported device"
                    " type: %s", object_get_typename(OBJECT(dev)));
@@ -372,6 +398,9 @@ static void piix4_device_unplug_request_cb(HotplugHandler *hotplug_dev,
     } else if (object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) {
         acpi_pcihp_device_unplug_cb(hotplug_dev, &s->acpi_pci_hotplug, dev,
                                     errp);
+    } else if (object_dynamic_cast(OBJECT(dev), TYPE_CPU) &&
+               !s->cpu_hotplug_legacy) {
+            acpi_cpu_unplug_request_cb(hotplug_dev, &s->cpuhp.state, dev, errp);
     } else {
         error_setg(errp, "acpi: device unplug request for not supported device"
                    " type: %s", object_get_typename(OBJECT(dev)));
@@ -386,6 +415,9 @@ static void piix4_device_unplug_cb(HotplugHandler *hotplug_dev,
     if (s->acpi_memory_hotplug.is_enabled &&
         object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
         acpi_memory_unplug_cb(&s->acpi_memory_hotplug, dev, errp);
+    } else if (object_dynamic_cast(OBJECT(dev), TYPE_CPU) &&
+               !s->cpu_hotplug_legacy) {
+            acpi_cpu_unplug_cb(&s->cpuhp.state, dev, errp);
     } else {
         error_setg(errp, "acpi: device unplug for not supported device"
                    " type: %s", object_get_typename(OBJECT(dev)));
@@ -572,8 +604,19 @@ static void piix4_acpi_system_hot_add_init(MemoryRegion *parent,
                     s->use_acpi_pci_hotplug);
 
     if (s->cpu_hotplug_legacy) {
-        legacy_acpi_cpu_hotplug_init(parent, OBJECT(s), &s->gpe_cpu,
+        legacy_acpi_cpu_hotplug_init(parent, OBJECT(s), &s->cpuhp.legacy,
                                      PIIX4_CPU_HOTPLUG_IO_BASE);
+    } else {
+        MachineClass *mc = MACHINE_GET_CLASS(qdev_get_machine());
+
+        /* piix4 is also used by MIPS target, so make sure that
+           user provides possible_cpu_arch_ids callback before
+           trying to initialize CPU hotplug
+        */
+        if (mc->possible_cpu_arch_ids) {
+            cpu_hotplug_hw_init(parent, OBJECT(s), &s->cpuhp.state,
+                                PIIX4_CPU_HOTPLUG_IO_BASE);
+        }
     }
 
     if (s->acpi_memory_hotplug.is_enabled) {
@@ -605,7 +648,7 @@ static Property piix4_pm_properties[] = {
     DEFINE_PROP_BOOL("memory-hotplug-support", PIIX4PMState,
                      acpi_memory_hotplug.is_enabled, true),
     DEFINE_PROP_BOOL("cpu-hotplug-legacy", PIIX4PMState,
-                     cpu_hotplug_legacy, true),
+                     cpu_hotplug_legacy, false),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/include/hw/compat.h b/include/hw/compat.h
index a65d9d2..862776e 100644
--- a/include/hw/compat.h
+++ b/include/hw/compat.h
@@ -7,6 +7,11 @@
         .property = "cpu-hotplug-legacy",\
         .value    = "on",\
     },\
+    {\
+        .driver   = "PIIX4_PM",\
+        .property = "cpu-hotplug-legacy",\
+        .value    = "on",\
+    },\
 
 #define HW_COMPAT_2_5 \
     {\
-- 
1.8.3.1