New cpu-max field in query-machines QMP command output

Alter the query-machines QMP command to output information about
maximum number of CPUs for each machine type with default value
set to 1 in case the number of max_cpus is not set.

Signed-off-by: Michal Novotny <minovotn@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>

qapi-schema.json

@@ -2861,11 +2861,14 @@
 #
 # @default: #optional whether the machine is default
 #
+# @cpu-max: maximum number of CPUs supported by the machine type
+#           (since 1.5.0)
+#
 # Since: 1.2.0
 ##
 { 'type': 'MachineInfo',
   'data': { 'name': 'str', '*alias': 'str',
-            '*is-default': 'bool' } }
+            '*is-default': 'bool', 'cpu-max': 'int' } }
 
 ##
 # @query-machines:

vl.c

@@ -1617,6 +1617,7 @@ MachineInfoList *qmp_query_machines(Error **errp)
         }
 
         info->name = g_strdup(m->name);
+        info->cpu_max = !m->max_cpus ? 1 : m->max_cpus;
 
         entry = g_malloc0(sizeof(*entry));
         entry->value = info;