cpu: Introduce CPU model deprecation API

Implement the ability of marking some versions deprecated. When
that CPU model is chosen, print a warning.  The warning message
can be customized, e.g. suggesting an alternative CPU model to be
used instead.

The deprecation message will be printed by x86_cpu_list_entry(),
e.g. '-cpu help'.

QMP command 'query-cpu-definitions' will return a bool value
indicating the deprecation status.

Signed-off-by: Robert Hoo <robert.hu@linux.intel.com>
Message-Id: <1600758855-80046-1-git-send-email-robert.hu@linux.intel.com>
[ehabkost: reword commit message]
[ehabkost: Handle NULL cpu_type]
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

1 files changed, 10 insertions, 2 deletions

diff --git a/hw/core/machine.c b/hw/core/machine.c
index 7e2f4ec08e..d740a7e963 100644
--- a/hw/core/machine.c
+++ b/hw/core/machine.c
@@ -1087,6 +1087,8 @@ MemoryRegion *machine_consume_memdev(MachineState *machine,
 void machine_run_board_init(MachineState *machine)
 {
     MachineClass *machine_class = MACHINE_GET_CLASS(machine);
+    ObjectClass *oc = object_class_by_name(machine->cpu_type);
+    CPUClass *cc;
 
     if (machine->ram_memdev_id) {
         Object *o;
@@ -1106,11 +1108,10 @@ void machine_run_board_init(MachineState *machine)
      * specified a CPU with -cpu check here that the user CPU is supported.
      */
     if (machine_class->valid_cpu_types && machine->cpu_type) {
-        ObjectClass *class = object_class_by_name(machine->cpu_type);
         int i;
 
         for (i = 0; machine_class->valid_cpu_types[i]; i++) {
-            if (object_class_dynamic_cast(class,
+            if (object_class_dynamic_cast(oc,
                                           machine_class->valid_cpu_types[i])) {
                 /* The user specificed CPU is in the valid field, we are
                  * good to go.
@@ -1133,6 +1134,13 @@ void machine_run_board_init(MachineState *machine)
         }
     }
 
+    /* Check if CPU type is deprecated and warn if so */
+    cc = CPU_CLASS(oc);
+    if (cc && cc->deprecation_note) {
+        warn_report("CPU model %s is deprecated -- %s", machine->cpu_type,
+                    cc->deprecation_note);
+    }
+
     machine_class->init(machine);
 }