qmp: add ACPI_DEVICE_OST event handling

emits event when ACPI OSPM evaluates _OST method
of ACPI device.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

docs/qmp/qmp-events.txt

@@ -1,6 +1,16 @@
                    QEMU Machine Protocol Events
                    ============================
 
+ACPI_DEVICE_OST
+---------------
+
+Emitted when guest executes ACPI _OST method.
+
+ - data: ACPIOSTInfo type as described in qapi-schema.json
+
+{ "event": "ACPI_DEVICE_OST",
+     "data": { "device": "d1", "slot": "0", "slot-type": "DIMM", "source": 1, "status": 0 } }
+
 BALLOON_CHANGE
 --------------
 

hw/acpi/memory_hotplug.c

@@ -3,6 +3,10 @@
 #include "hw/mem/pc-dimm.h"
 #include "hw/boards.h"
 #include "trace.h"
+#include "qapi-visit.h"
+#include "monitor/monitor.h"
+#include "qapi/dealloc-visitor.h"
+#include "qapi/qmp-output-visitor.h"
 
 static ACPIOSTInfo *acpi_memory_device_status(int slot, MemStatus *mdev)
 {
@@ -35,6 +39,29 @@ void acpi_memory_ospm_status(MemHotplugState *mem_st, ACPIOSTInfoList ***list)
     }
 }
 
+static void acpi_memory_ost_mon_event(const MemHotplugState *mem_st)
+{
+    Visitor *v;
+    QObject *out_info;
+    QapiDeallocVisitor *md;
+    QmpOutputVisitor *mo = qmp_output_visitor_new();
+    MemStatus *mdev = &mem_st->devs[mem_st->selector];
+    ACPIOSTInfo *info = acpi_memory_device_status(mem_st->selector, mdev);
+
+    v = qmp_output_get_visitor(mo);
+    visit_type_ACPIOSTInfo(v, &info, "unused", NULL);
+
+    out_info = qmp_output_get_qobject(mo);
+    monitor_protocol_event(QEVENT_ACPI_OST, out_info);
+    qobject_decref(out_info);
+
+    qmp_output_visitor_cleanup(mo);
+    md = qapi_dealloc_visitor_new();
+    v = qapi_dealloc_get_visitor(md);
+    visit_type_ACPIOSTInfo(v, &info, "unused", NULL);
+    qapi_dealloc_visitor_cleanup(md);
+}
+
 static uint64_t acpi_memory_hotplug_read(void *opaque, hwaddr addr,
                                          unsigned int size)
 {
@@ -119,8 +146,8 @@ static void acpi_memory_hotplug_write(void *opaque, hwaddr addr, uint64_t data,
         mdev = &mem_st->devs[mem_st->selector];
         mdev->ost_status = data;
         trace_mhp_acpi_write_ost_status(mem_st->selector, mdev->ost_status);
-        /* TODO: report async error */
         /* TODO: implement memory removal on guest signal */
+        acpi_memory_ost_mon_event(mem_st);
         break;
     case 0x14:
         mdev = &mem_st->devs[mem_st->selector];

include/monitor/monitor.h

@@ -51,6 +51,7 @@ typedef enum MonitorEvent {
     QEVENT_BLOCK_IMAGE_CORRUPTED,
     QEVENT_QUORUM_FAILURE,
     QEVENT_QUORUM_REPORT_BAD,
+    QEVENT_ACPI_OST,
 
     /* Add to 'monitor_event_names' array in monitor.c when
      * defining new events here */

monitor.c

@@ -487,6 +487,7 @@ static const char *monitor_event_names[] = {
     [QEVENT_BLOCK_IMAGE_CORRUPTED] = "BLOCK_IMAGE_CORRUPTED",
     [QEVENT_QUORUM_FAILURE] = "QUORUM_FAILURE",
     [QEVENT_QUORUM_REPORT_BAD] = "QUORUM_REPORT_BAD",
+    [QEVENT_ACPI_OST] = "ACPI_DEVICE_OST",
 };
 QEMU_BUILD_BUG_ON(ARRAY_SIZE(monitor_event_names) != QEVENT_MAX)