i386: Don't set CPUClass::cpu_def on "max" model

Host CPUID info is used by the "max" CPU model only in KVM mode.
Move the initialization of CPUID data for "max" from class_init
to instance_init, and don't set CPUClass::cpu_def for "max".

Message-Id: <20170222183919.11928-4-ehabkost@redhat.com>
Tested-by: Richard W.M. Jones <rjones@redhat.com>
Tested-by: Jiri Denemark <jdenemar@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

target/i386/cpu-qom.h

@@ -60,7 +60,9 @@ typedef struct X86CPUClass {
     CPUClass parent_class;
     /*< public >*/
 
-    /* Should be eventually replaced by subclass-specific property defaults. */
+    /* CPU definition, automatically loaded by instance_init if not NULL.
+     * Should be eventually replaced by subclass-specific property defaults.
+     */
     X86CPUDefinition *cpu_def;
 
     bool kvm_required;

target/i386/cpu.c

@@ -1531,47 +1531,27 @@ static int cpu_x86_fill_model_id(char *str)
     return 0;
 }
 
-static X86CPUDefinition host_cpudef;
-
 static Property max_x86_cpu_properties[] = {
     DEFINE_PROP_BOOL("migratable", X86CPU, migratable, true),
     DEFINE_PROP_BOOL("host-cache-info", X86CPU, cache_info_passthrough, false),
     DEFINE_PROP_END_OF_LIST()
 };
 
-/* class_init for the "max" CPU model
- *
- * This function may be called before KVM is initialized.
- */
 static void max_x86_cpu_class_init(ObjectClass *oc, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(oc);
     X86CPUClass *xcc = X86_CPU_CLASS(oc);
-    uint32_t eax = 0, ebx = 0, ecx = 0, edx = 0;
 
     xcc->ordering = 9;
 
-    host_cpuid(0x0, 0, &eax, &ebx, &ecx, &edx);
-    x86_cpu_vendor_words2str(host_cpudef.vendor, ebx, edx, ecx);
-
-    host_cpuid(0x1, 0, &eax, &ebx, &ecx, &edx);
-    host_cpudef.family = ((eax >> 8) & 0x0F) + ((eax >> 20) & 0xFF);
-    host_cpudef.model = ((eax >> 4) & 0x0F) | ((eax & 0xF0000) >> 12);
-    host_cpudef.stepping = eax & 0x0F;
-
-    cpu_x86_fill_model_id(host_cpudef.model_id);
-
-    xcc->cpu_def = &host_cpudef;
     xcc->model_description =
         "Enables all features supported by the accelerator in the current host";
 
-    /* level, xlevel, xlevel2, and the feature words are initialized on
-     * instance_init, because they require KVM to be initialized.
-     */
-
     dc->props = max_x86_cpu_properties;
 }
 
+static void x86_cpu_load_def(X86CPU *cpu, X86CPUDefinition *def, Error **errp);
+
 static void max_x86_cpu_initfn(Object *obj)
 {
     X86CPU *cpu = X86_CPU(obj);
@@ -1584,6 +1564,21 @@ static void max_x86_cpu_initfn(Object *obj)
     cpu->max_features = true;
 
     if (kvm_enabled()) {
+        X86CPUDefinition host_cpudef = { };
+        uint32_t eax = 0, ebx = 0, ecx = 0, edx = 0;
+
+        host_cpuid(0x0, 0, &eax, &ebx, &ecx, &edx);
+        x86_cpu_vendor_words2str(host_cpudef.vendor, ebx, edx, ecx);
+
+        host_cpuid(0x1, 0, &eax, &ebx, &ecx, &edx);
+        host_cpudef.family = ((eax >> 8) & 0x0F) + ((eax >> 20) & 0xFF);
+        host_cpudef.model = ((eax >> 4) & 0x0F) | ((eax & 0xF0000) >> 12);
+        host_cpudef.stepping = eax & 0x0F;
+
+        cpu_x86_fill_model_id(host_cpudef.model_id);
+
+        x86_cpu_load_def(cpu, &host_cpudef, &error_abort);
+
         env->cpuid_min_level =
             kvm_arch_get_supported_cpuid(s, 0x0, 0, R_EAX);
         env->cpuid_min_xlevel =
@@ -2185,7 +2180,7 @@ static void x86_cpu_list_entry(gpointer data, gpointer user_data)
     CPUListState *s = user_data;
     char *name = x86_cpu_class_get_model_name(cc);
     const char *desc = cc->model_description;
-    if (!desc) {
+    if (!desc && cc->cpu_def) {
         desc = cc->cpu_def->model_id;
     }
 
@@ -3683,7 +3678,9 @@ static void x86_cpu_initfn(Object *obj)
     object_property_add_alias(obj, "sse4_1", obj, "sse4.1", &error_abort);
     object_property_add_alias(obj, "sse4_2", obj, "sse4.2", &error_abort);
 
-    x86_cpu_load_def(cpu, xcc->cpu_def, &error_abort);
+    if (xcc->cpu_def) {
+        x86_cpu_load_def(cpu, xcc->cpu_def, &error_abort);
+    }
 }
 
 static int64_t x86_cpu_get_arch_id(CPUState *cs)