qmp: add architecture specific cpu data for query-cpus-fast

The s390 CPU state can be retrieved without interrupting the
VM execution. Extendend the CpuInfoFast union with architecture
specific data and an implementation for s390.

Return data looks like this:
 [
   {"thread-id":64301,"props":{"core-id":0},
    "arch":"s390","cpu-state":"operating",
    "qom-path":"/machine/unattached/device[0]","cpu-index":0},
   {"thread-id":64302,"props":{"core-id":1},
    "arch":"s390","cpu-state":"operating",
    "qom-path":"/machine/unattached/device[1]","cpu-index":1}
]

Signed-off-by: Viktor Mihajlovski <mihajlov@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1518797321-28356-4-git-send-email-mihajlov@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>

cpus.c

@@ -2166,6 +2166,10 @@ CpuInfoFastList *qmp_query_cpus_fast(Error **errp)
     MachineClass *mc = MACHINE_GET_CLASS(ms);
     CpuInfoFastList *head = NULL, *cur_item = NULL;
     CPUState *cpu;
+#if defined(TARGET_S390X)
+    S390CPU *s390_cpu;
+    CPUS390XState *env;
+#endif
 
     CPU_FOREACH(cpu) {
         CpuInfoFastList *info = g_malloc0(sizeof(*info));
@@ -2183,6 +2187,12 @@ CpuInfoFastList *qmp_query_cpus_fast(Error **errp)
             info->value->props = props;
         }
 
+#if defined(TARGET_S390X)
+        s390_cpu = S390_CPU(cpu);
+        env = &s390_cpu->env;
+        info->value->arch = CPU_INFO_ARCH_S390;
+        info->value->u.s390.cpu_state = env->cpu_state;
+#endif
         if (!cur_item) {
             head = cur_item = info;
         } else {

qapi-schema.json

@@ -408,7 +408,7 @@
 # @CpuInfoArch:
 #
 # An enumeration of cpu types that enable additional information during
-# @query-cpus.
+# @query-cpus and @query-cpus-fast.
 #
 # @s390: since 2.12
 #
@@ -604,12 +604,24 @@
 # @props: properties describing to which node/socket/core/thread
 #         virtual CPU belongs to, provided if supported by board
 #
+# @arch: architecture of the cpu, which determines which additional fields
+#        will be listed
+#
 # Since: 2.12
 #
 ##
-{ 'struct': 'CpuInfoFast',
-  'data': {'cpu-index': 'int', 'qom-path': 'str',
-           'thread-id': 'int', '*props': 'CpuInstanceProperties' } }
+{ 'union': 'CpuInfoFast',
+  'base': {'cpu-index': 'int', 'qom-path': 'str',
+           'thread-id': 'int', '*props': 'CpuInstanceProperties',
+           'arch': 'CpuInfoArch' },
+  'discriminator': 'arch',
+  'data': { 'x86': 'CpuInfoOther',
+            'sparc': 'CpuInfoOther',
+            'ppc': 'CpuInfoOther',
+            'mips': 'CpuInfoOther',
+            'tricore': 'CpuInfoOther',
+            's390': 'CpuInfoS390',
+            'other': 'CpuInfoOther' } }
 
 ##
 # @query-cpus-fast:
@@ -620,9 +632,6 @@
 #
 # Returns: list of @CpuInfoFast
 #
-# Notes: The CPU architecture name is not returned by query-cpus-fast.
-#        Use query-target to retrieve that information.
-#
 # Since: 2.12
 #
 # Example:
@@ -637,6 +646,7 @@
 #                 "socket-id": 0
 #             },
 #             "qom-path": "/machine/unattached/device[0]",
+#             "arch":"x86",
 #             "cpu-index": 0
 #         },
 #         {
@@ -647,6 +657,7 @@
 #                 "socket-id": 1
 #             },
 #             "qom-path": "/machine/unattached/device[2]",
+#             "arch":"x86",
 #             "cpu-index": 1
 #         }
 #     ]