target-i386: Register QOM properties for feature flags

This uses the feature name arrays to register QOM properties for feature
flags. This simply adds properties that can be configured using -global,
but doesn't change x86_cpu_parse_featurestr() to use them yet.

Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

target-i386/cpu.c

@@ -2841,12 +2841,126 @@ out:
     }
 }
 
+typedef struct BitProperty {
+    uint32_t *ptr;
+    uint32_t mask;
+} BitProperty;
+
+static void x86_cpu_get_bit_prop(Object *obj,
+                                 struct Visitor *v,
+                                 void *opaque,
+                                 const char *name,
+                                 Error **errp)
+{
+    BitProperty *fp = opaque;
+    bool value = (*fp->ptr & fp->mask) == fp->mask;
+    visit_type_bool(v, &value, name, errp);
+}
+
+static void x86_cpu_set_bit_prop(Object *obj,
+                                 struct Visitor *v,
+                                 void *opaque,
+                                 const char *name,
+                                 Error **errp)
+{
+    DeviceState *dev = DEVICE(obj);
+    BitProperty *fp = opaque;
+    Error *local_err = NULL;
+    bool value;
+
+    if (dev->realized) {
+        qdev_prop_set_after_realize(dev, name, errp);
+        return;
+    }
+
+    visit_type_bool(v, &value, name, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
+
+    if (value) {
+        *fp->ptr |= fp->mask;
+    } else {
+        *fp->ptr &= ~fp->mask;
+    }
+}
+
+static void x86_cpu_release_bit_prop(Object *obj, const char *name,
+                                     void *opaque)
+{
+    BitProperty *prop = opaque;
+    g_free(prop);
+}
+
+/* Register a boolean property to get/set a single bit in a uint32_t field.
+ *
+ * The same property name can be registered multiple times to make it affect
+ * multiple bits in the same FeatureWord. In that case, the getter will return
+ * true only if all bits are set.
+ */
+static void x86_cpu_register_bit_prop(X86CPU *cpu,
+                                      const char *prop_name,
+                                      uint32_t *field,
+                                      int bitnr)
+{
+    BitProperty *fp;
+    ObjectProperty *op;
+    uint32_t mask = (1UL << bitnr);
+
+    op = object_property_find(OBJECT(cpu), prop_name, NULL);
+    if (op) {
+        fp = op->opaque;
+        assert(fp->ptr == field);
+        fp->mask |= mask;
+    } else {
+        fp = g_new0(BitProperty, 1);
+        fp->ptr = field;
+        fp->mask = mask;
+        object_property_add(OBJECT(cpu), prop_name, "bool",
+                            x86_cpu_get_bit_prop,
+                            x86_cpu_set_bit_prop,
+                            x86_cpu_release_bit_prop, fp, &error_abort);
+    }
+}
+
+static void x86_cpu_register_feature_bit_props(X86CPU *cpu,
+                                               FeatureWord w,
+                                               int bitnr)
+{
+    Object *obj = OBJECT(cpu);
+    int i;
+    char **names;
+    FeatureWordInfo *fi = &feature_word_info[w];
+
+    if (!fi->feat_names) {
+        return;
+    }
+    if (!fi->feat_names[bitnr]) {
+        return;
+    }
+
+    names = g_strsplit(fi->feat_names[bitnr], "|", 0);
+
+    feat2prop(names[0]);
+    x86_cpu_register_bit_prop(cpu, names[0], &cpu->env.features[w], bitnr);
+
+    for (i = 1; names[i]; i++) {
+        feat2prop(names[i]);
+        object_property_add_alias(obj, names[i], obj, g_strdup(names[0]),
+                                  &error_abort);
+    }
+
+    g_strfreev(names);
+}
+
 static void x86_cpu_initfn(Object *obj)
 {
     CPUState *cs = CPU(obj);
     X86CPU *cpu = X86_CPU(obj);
     X86CPUClass *xcc = X86_CPU_GET_CLASS(obj);
     CPUX86State *env = &cpu->env;
+    FeatureWord w;
     static int inited;
 
     cs->env_ptr = env;
@@ -2887,6 +3001,14 @@ static void x86_cpu_initfn(Object *obj)
     cpu->apic_id = -1;
 #endif
 
+    for (w = 0; w < FEATURE_WORDS; w++) {
+        int bitnr;
+
+        for (bitnr = 0; bitnr < 32; bitnr++) {
+            x86_cpu_register_feature_bit_props(cpu, w, bitnr);
+        }
+    }
+
     x86_cpu_load_def(cpu, xcc->cpu_def, &error_abort);
 
     /* init various static tables used in TCG mode */