target-i386: X86CPU model subclasses

Register separate QOM types for each x86 CPU model.

This will allow management code to more easily probe what each CPU model
provides, by simply creating objects using the appropriate class name,
without having to restart QEMU.

This also allows us to eliminate the qdev_prop_set_globals_for_type()
hack to set CPU-model-specific global properties.

Instead of creating separate class_init functions for each class, I just
used class_data to store a pointer to the X86CPUDefinition struct for
each CPU model. This should make the patch shorter and easier to review.
Later we can gradually convert each X86CPUDefinition field to lists of
per-class property defaults.

The "host" CPU model is special, as the feature flags depend on KVM
being initialized. So it has its own class_init and instance_init
function, and feature flags are set on instance_init instead of
class_init.

Signed-off-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Tested-by: Eduardo Habkost <ehabkost@redhat.com>
[AF: Limit the host CPU type to CONFIG_KVM as build fix]
Signed-off-by: Andreas Färber <afaerber@suse.de>

target-i386/cpu-qom.h

@@ -37,8 +37,18 @@
 #define X86_CPU_GET_CLASS(obj) \
     OBJECT_GET_CLASS(X86CPUClass, (obj), TYPE_X86_CPU)
 
+/**
+ * X86CPUDefinition:
+ *
+ * CPU model definition data that was not converted to QOM per-subclass
+ * property defaults yet.
+ */
+typedef struct X86CPUDefinition X86CPUDefinition;
+
 /**
  * X86CPUClass:
+ * @cpu_def: CPU model definition
+ * @kvm_required: Whether CPU model requires KVM to be enabled.
  * @parent_realize: The parent class' realize handler.
  * @parent_reset: The parent class' reset handler.
  *
@@ -49,6 +59,11 @@ typedef struct X86CPUClass {
     CPUClass parent_class;
     /*< public >*/
 
+    /* Should be eventually replaced by subclass-specific property defaults. */
+    X86CPUDefinition *cpu_def;
+
+    bool kvm_required;
+
     DeviceRealize parent_realize;
     void (*parent_reset)(CPUState *cpu);
 } X86CPUClass;

target-i386/cpu.c

@@ -490,16 +490,35 @@ static void add_flagname_to_bitmaps(const char *flagname,
     }
 }
 
+/* CPU class name definitions: */
+
+#define X86_CPU_TYPE_SUFFIX "-" TYPE_X86_CPU
+#define X86_CPU_TYPE_NAME(name) (name X86_CPU_TYPE_SUFFIX)
+
+/* Return type name for a given CPU model name
+ * Caller is responsible for freeing the returned string.
+ */
+static char *x86_cpu_type_name(const char *model_name)
+{
+    return g_strdup_printf(X86_CPU_TYPE_NAME("%s"), model_name);
+}
+
 static ObjectClass *x86_cpu_class_by_name(const char *cpu_model)
 {
+    ObjectClass *oc;
+    char *typename;
+
     if (cpu_model == NULL) {
         return NULL;
     }
 
-    return object_class_by_name(TYPE_X86_CPU);
+    typename = x86_cpu_type_name(cpu_model);
+    oc = object_class_by_name(typename);
+    g_free(typename);
+    return oc;
 }
 
-typedef struct X86CPUDefinition {
+struct X86CPUDefinition {
     const char *name;
     uint32_t level;
     uint32_t xlevel;
@@ -512,7 +531,7 @@ typedef struct X86CPUDefinition {
     FeatureWordArray features;
     char model_id[48];
     bool cache_info_passthrough;
-} X86CPUDefinition;
+};
 
 #define I486_FEATURES (CPUID_FP87 | CPUID_VME | CPUID_PSE)
 #define PENTIUM_FEATURES (I486_FEATURES | CPUID_DE | CPUID_TSC | \
@@ -562,8 +581,6 @@ typedef struct X86CPUDefinition {
           CPUID_7_0_EBX_ERMS, CPUID_7_0_EBX_INVPCID, CPUID_7_0_EBX_RTM,
           CPUID_7_0_EBX_RDSEED */
 
-/* built-in CPU model definitions
- */
 static X86CPUDefinition builtin_x86_defs[] = {
     {
         .name = "qemu64",
@@ -1134,6 +1151,8 @@ void x86_cpu_compat_set_features(const char *cpu_model, FeatureWord w,
     }
 }
 
+#ifdef CONFIG_KVM
+
 static int cpu_x86_fill_model_id(char *str)
 {
     uint32_t eax = 0, ebx = 0, ecx = 0, edx = 0;
@@ -1149,44 +1168,68 @@ static int cpu_x86_fill_model_id(char *str)
     return 0;
 }
 
-/* Fill a X86CPUDefinition struct with information about the host CPU, and
+static X86CPUDefinition host_cpudef;
- * the CPU features supported by the host hardware + host kernel
+
+/* class_init for the "host" CPU model
  *
- * This function may be called only if KVM is enabled.
+ * This function may be called before KVM is initialized.
  */
-static void kvm_cpu_fill_host(X86CPUDefinition *x86_cpu_def)
+static void host_x86_cpu_class_init(ObjectClass *oc, void *data)
 {
-    KVMState *s = kvm_state;
+    X86CPUClass *xcc = X86_CPU_CLASS(oc);
     uint32_t eax = 0, ebx = 0, ecx = 0, edx = 0;
+
+    xcc->kvm_required = true;
+
+    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;
+    host_cpudef.cache_info_passthrough = true;
+
+    /* level, xlevel, xlevel2, and the feature words are initialized on
+     * instance_init, because they require KVM to be initialized.
+     */
+}
+
+static void host_x86_cpu_initfn(Object *obj)
+{
+    X86CPU *cpu = X86_CPU(obj);
+    CPUX86State *env = &cpu->env;
+    KVMState *s = kvm_state;
     FeatureWord w;
 
     assert(kvm_enabled());
 
-    x86_cpu_def->name = "host";
+    env->cpuid_level = kvm_arch_get_supported_cpuid(s, 0x0, 0, R_EAX);
-    x86_cpu_def->cache_info_passthrough = true;
+    env->cpuid_xlevel = kvm_arch_get_supported_cpuid(s, 0x80000000, 0, R_EAX);
-    host_cpuid(0x0, 0, &eax, &ebx, &ecx, &edx);
+    env->cpuid_xlevel2 = kvm_arch_get_supported_cpuid(s, 0xC0000000, 0, R_EAX);
-    x86_cpu_vendor_words2str(x86_cpu_def->vendor, ebx, edx, ecx);
-
-    host_cpuid(0x1, 0, &eax, &ebx, &ecx, &edx);
-    x86_cpu_def->family = ((eax >> 8) & 0x0F) + ((eax >> 20) & 0xFF);
-    x86_cpu_def->model = ((eax >> 4) & 0x0F) | ((eax & 0xF0000) >> 12);
-    x86_cpu_def->stepping = eax & 0x0F;
-
-    x86_cpu_def->level = kvm_arch_get_supported_cpuid(s, 0x0, 0, R_EAX);
-    x86_cpu_def->xlevel = kvm_arch_get_supported_cpuid(s, 0x80000000, 0, R_EAX);
-    x86_cpu_def->xlevel2 =
-        kvm_arch_get_supported_cpuid(s, 0xC0000000, 0, R_EAX);
-
-    cpu_x86_fill_model_id(x86_cpu_def->model_id);
 
     for (w = 0; w < FEATURE_WORDS; w++) {
         FeatureWordInfo *wi = &feature_word_info[w];
-        x86_cpu_def->features[w] =
+        env->features[w] =
             kvm_arch_get_supported_cpuid(s, wi->cpuid_eax, wi->cpuid_ecx,
                                          wi->cpuid_reg);
     }
+    object_property_set_bool(OBJECT(cpu), true, "pmu", &error_abort);
 }
 
+static const TypeInfo host_x86_cpu_type_info = {
+    .name = X86_CPU_TYPE_NAME("host"),
+    .parent = TYPE_X86_CPU,
+    .instance_init = host_x86_cpu_initfn,
+    .class_init = host_x86_cpu_class_init,
+};
+
+#endif
+
 static int unavailable_host_feature(FeatureWordInfo *f, uint32_t mask)
 {
     int i;
@@ -1597,32 +1640,6 @@ static PropertyInfo qdev_prop_spinlocks = {
     .set   = x86_set_hv_spinlocks,
 };
 
-static int cpu_x86_find_by_name(X86CPU *cpu, X86CPUDefinition *x86_cpu_def,
-                                const char *name)
-{
-    X86CPUDefinition *def;
-    int i;
-
-    if (name == NULL) {
-        return -1;
-    }
-    if (kvm_enabled() && strcmp(name, "host") == 0) {
-        kvm_cpu_fill_host(x86_cpu_def);
-        object_property_set_bool(OBJECT(cpu), true, "pmu", &error_abort);
-        return 0;
-    }
-
-    for (i = 0; i < ARRAY_SIZE(builtin_x86_defs); i++) {
-        def = &builtin_x86_defs[i];
-        if (strcmp(name, def->name) == 0) {
-            memcpy(x86_cpu_def, def, sizeof(*def));
-            return 0;
-        }
-    }
-
-    return -1;
-}
-
 /* Convert all '_' in a feature string option name to '-', to make feature
  * name conform to QOM property naming rule, which uses '-' instead of '_'.
  */
@@ -1832,22 +1849,14 @@ static void filter_features_for_kvm(X86CPU *cpu)
     }
 }
 
-/* Load CPU definition for a given CPU model name
+/* Load data from X86CPUDefinition
  */
-static void x86_cpu_load_def(X86CPU *cpu, const char *name, Error **errp)
+static void x86_cpu_load_def(X86CPU *cpu, X86CPUDefinition *def, Error **errp)
 {
     CPUX86State *env = &cpu->env;
-    X86CPUDefinition def1, *def = &def1;
     const char *vendor;
     char host_vendor[CPUID_VENDOR_SZ + 1];
 
-    memset(def, 0, sizeof(*def));
-
-    if (cpu_x86_find_by_name(cpu, def, name) < 0) {
-        error_setg(errp, "Unable to find CPU definition: %s", name);
-        return;
-    }
-
     object_property_set_int(OBJECT(cpu), def->level, "level", errp);
     object_property_set_int(OBJECT(cpu), def->family, "family", errp);
     object_property_set_int(OBJECT(cpu), def->model, "model", errp);
@@ -1899,10 +1908,10 @@ X86CPU *cpu_x86_create(const char *cpu_model, DeviceState *icc_bridge,
                        Error **errp)
 {
     X86CPU *cpu = NULL;
+    X86CPUClass *xcc;
     ObjectClass *oc;
     gchar **model_pieces;
     char *name, *features;
-    char *typename;
     Error *error = NULL;
 
     model_pieces = g_strsplit(cpu_model, ",", 2);
@@ -1918,12 +1927,15 @@ X86CPU *cpu_x86_create(const char *cpu_model, DeviceState *icc_bridge,
         error_setg(&error, "Unable to find CPU definition: %s", name);
         goto out;
     }
-    cpu = X86_CPU(object_new(object_class_get_name(oc)));
+    xcc = X86_CPU_CLASS(oc);
-    x86_cpu_load_def(cpu, name, &error);
+
-    if (error) {
+    if (xcc->kvm_required && !kvm_enabled()) {
+        error_setg(&error, "CPU model '%s' requires KVM", name);
         goto out;
     }
 
+    cpu = X86_CPU(object_new(object_class_get_name(oc)));
+
 #ifndef CONFIG_USER_ONLY
     if (icc_bridge == NULL) {
         error_setg(&error, "Invalid icc-bridge value");
@@ -1933,14 +1945,6 @@ X86CPU *cpu_x86_create(const char *cpu_model, DeviceState *icc_bridge,
     object_unref(OBJECT(cpu));
 #endif
 
-    /* Emulate per-model subclasses for global properties */
-    typename = g_strdup_printf("%s-" TYPE_X86_CPU, name);
-    qdev_prop_set_globals_for_type(DEVICE(cpu), typename, &error);
-    g_free(typename);
-    if (error) {
-        goto out;
-    }
-
     cpu_x86_parse_featurestr(cpu, features, &error);
     if (error) {
         goto out;
@@ -1982,6 +1986,28 @@ out:
     return cpu;
 }
 
+static void x86_cpu_cpudef_class_init(ObjectClass *oc, void *data)
+{
+    X86CPUDefinition *cpudef = data;
+    X86CPUClass *xcc = X86_CPU_CLASS(oc);
+
+    xcc->cpu_def = cpudef;
+}
+
+static void x86_register_cpudef_type(X86CPUDefinition *def)
+{
+    char *typename = x86_cpu_type_name(def->name);
+    TypeInfo ti = {
+        .name = typename,
+        .parent = TYPE_X86_CPU,
+        .class_init = x86_cpu_cpudef_class_init,
+        .class_data = def,
+    };
+
+    type_register(&ti);
+    g_free(typename);
+}
+
 #if !defined(CONFIG_USER_ONLY)
 
 void cpu_clear_apic_feature(CPUX86State *env)
@@ -2643,6 +2669,7 @@ 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;
     static int inited;
 
@@ -2686,6 +2713,8 @@ static void x86_cpu_initfn(Object *obj)
     cpu->hyperv_spinlock_attempts = HYPERV_SPINLOCK_NEVER_RETRY;
     env->cpuid_apic_id = x86_cpu_apic_id_from_index(cs->cpu_index);
 
+    x86_cpu_load_def(cpu, xcc->cpu_def, &error_abort);
+
     /* init various static tables used in TCG mode */
     if (tcg_enabled() && !inited) {
         inited = 1;
@@ -2792,14 +2821,22 @@ static const TypeInfo x86_cpu_type_info = {
     .parent = TYPE_CPU,
     .instance_size = sizeof(X86CPU),
     .instance_init = x86_cpu_initfn,
-    .abstract = false,
+    .abstract = true,
     .class_size = sizeof(X86CPUClass),
     .class_init = x86_cpu_common_class_init,
 };
 
 static void x86_cpu_register_types(void)
 {
+    int i;
+
     type_register_static(&x86_cpu_type_info);
+    for (i = 0; i < ARRAY_SIZE(builtin_x86_defs); i++) {
+        x86_register_cpudef_type(&builtin_x86_defs[i]);
+    }
+#ifdef CONFIG_KVM
+    type_register_static(&host_x86_cpu_type_info);
+#endif
 }
 
 type_init(x86_cpu_register_types)