i386: Replace uint32_t* with FeatureWord on feature getter/setter

Instead of passing a pointer to the feature property getter and
setter functions, pass a FeatureWord enum so they can perform
other actions related to the feature flag.

This will be used to add a new "user_features" field to keep
track of features that were explicitly set by the user.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20170327144815.8043-2-ehabkost@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Tested-by: Jiri Denemark <jdenemar@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

target/i386/cpu.c

@@ -3692,22 +3692,25 @@ static void x86_cpu_unrealizefn(DeviceState *dev, Error **errp)
 }
 
 typedef struct BitProperty {
-    uint32_t *ptr;
+    FeatureWord w;
     uint32_t mask;
 } BitProperty;
 
 static void x86_cpu_get_bit_prop(Object *obj, Visitor *v, const char *name,
                                  void *opaque, Error **errp)
 {
+    X86CPU *cpu = X86_CPU(obj);
     BitProperty *fp = opaque;
-    bool value = (*fp->ptr & fp->mask) == fp->mask;
+    uint32_t f = cpu->env.features[fp->w];
+    bool value = (f & fp->mask) == fp->mask;
     visit_type_bool(v, name, &value, errp);
 }
 
 static void x86_cpu_set_bit_prop(Object *obj, Visitor *v, const char *name,
                                  void *opaque, Error **errp)
 {
     DeviceState *dev = DEVICE(obj);
+    X86CPU *cpu = X86_CPU(obj);
     BitProperty *fp = opaque;
     Error *local_err = NULL;
     bool value;
@@ -3724,9 +3727,9 @@ static void x86_cpu_set_bit_prop(Object *obj, Visitor *v, const char *name,
     }
 
     if (value) {
-        *fp->ptr |= fp->mask;
+        cpu->env.features[fp->w] |= fp->mask;
     } else {
-        *fp->ptr &= ~fp->mask;
+        cpu->env.features[fp->w] &= ~fp->mask;
     }
 }
 
@@ -3745,7 +3748,7 @@ static void x86_cpu_release_bit_prop(Object *obj, const char *name,
  */
 static void x86_cpu_register_bit_prop(X86CPU *cpu,
                                       const char *prop_name,
-                                      uint32_t *field,
+                                      FeatureWord w,
                                       int bitnr)
 {
     BitProperty *fp;
@@ -3755,11 +3758,11 @@ static void x86_cpu_register_bit_prop(X86CPU *cpu,
     op = object_property_find(OBJECT(cpu), prop_name, NULL);
     if (op) {
         fp = op->opaque;
-        assert(fp->ptr == field);
+        assert(fp->w == w);
         fp->mask |= mask;
     } else {
         fp = g_new0(BitProperty, 1);
-        fp->ptr = field;
+        fp->w = w;
         fp->mask = mask;
         object_property_add(OBJECT(cpu), prop_name, "bool",
                             x86_cpu_get_bit_prop,
@@ -3787,7 +3790,7 @@ static void x86_cpu_register_feature_bit_props(X86CPU *cpu,
     /* aliases don't use "|" delimiters anymore, they are registered
      * manually using object_property_add_alias() */
     assert(!strchr(name, '|'));
-    x86_cpu_register_bit_prop(cpu, name, &cpu->env.features[w], bitnr);
+    x86_cpu_register_bit_prop(cpu, name, w, bitnr);
 }
 
 static GuestPanicInformation *x86_cpu_get_crash_info(CPUState *cs)