qmp/hmp: add query-vm-generation-id and 'info vm-generation-id' commands

Add commands to query Virtual Machine Generation ID counter.

QMP command example:
    { "execute": "query-vm-generation-id" }

HMP command example:
    info vm-generation-id

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Ben Warren <ben@skyportsystems.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hmp-commands-info.hx

@@ -801,6 +801,20 @@ STEXI
 Show information about hotpluggable CPUs
 ETEXI
 
+STEXI
+@item info vm-generation-id
+@findex vm-generation-id
+Show Virtual Machine Generation ID
+ETEXI
+
+    {
+        .name       = "vm-generation-id",
+        .args_type  = "",
+        .params     = "",
+        .help       = "Show Virtual Machine Generation ID",
+        .cmd = hmp_info_vm_generation_id,
+    },
+
 STEXI
 @end table
 ETEXI

hmp.c

@@ -2576,3 +2576,12 @@ void hmp_hotpluggable_cpus(Monitor *mon, const QDict *qdict)
 
     qapi_free_HotpluggableCPUList(saved);
 }
+
+void hmp_info_vm_generation_id(Monitor *mon, const QDict *qdict)
+{
+    GuidInfo *info = qmp_query_vm_generation_id(NULL);
+    if (info) {
+        monitor_printf(mon, "%s\n", info->guid);
+    }
+    qapi_free_GuidInfo(info);
+}

hmp.h

@@ -137,5 +137,6 @@ void hmp_rocker_of_dpa_flows(Monitor *mon, const QDict *qdict);
 void hmp_rocker_of_dpa_groups(Monitor *mon, const QDict *qdict);
 void hmp_info_dump(Monitor *mon, const QDict *qdict);
 void hmp_hotpluggable_cpus(Monitor *mon, const QDict *qdict);
+void hmp_info_vm_generation_id(Monitor *mon, const QDict *qdict);
 
 #endif

hw/acpi/vmgenid.c

@@ -240,3 +240,19 @@ static void vmgenid_register_types(void)
 }
 
 type_init(vmgenid_register_types)
+
+GuidInfo *qmp_query_vm_generation_id(Error **errp)
+{
+    GuidInfo *info;
+    VmGenIdState *vms;
+    Object *obj = find_vmgenid_dev();
+
+    if (!obj) {
+        return NULL;
+    }
+    vms = VMGENID(obj);
+
+    info = g_malloc0(sizeof(*info));
+    info->guid = qemu_uuid_unparse_strdup(&vms->guid);
+    return info;
+}

qapi-schema.json

@@ -6188,3 +6188,23 @@
 #
 ##
 { 'command': 'query-hotpluggable-cpus', 'returns': ['HotpluggableCPU'] }
+
+##
+# @GuidInfo:
+#
+# GUID information.
+#
+# @guid: the globally unique identifier
+#
+# Since: 2.9
+##
+{ 'struct': 'GuidInfo', 'data': {'guid': 'str'} }
+
+##
+# @query-vm-generation-id:
+#
+# Show Virtual Machine Generation ID
+#
+# Since 2.9
+##
+{ 'command': 'query-vm-generation-id', 'returns': 'GuidInfo' }

stubs/Makefile.objs

@@ -36,3 +36,4 @@ stub-obj-y += qmp_pc_dimm_device_list.o
 stub-obj-y += target-monitor-defs.o
 stub-obj-y += target-get-monitor-def.o
 stub-obj-y += pc_madt_cpu_entry.o
+stub-obj-y += vmgenid.o

stubs/vmgenid.c

@@ -0,0 +1,9 @@
+#include "qemu/osdep.h"
+#include "qmp-commands.h"
+#include "qapi/qmp/qerror.h"
+
+GuidInfo *qmp_query_vm_generation_id(Error **errp)
+{
+    error_setg(errp, QERR_UNSUPPORTED);
+    return NULL;
+}