cpu: Use CPUClass->parse_features() as convertor to global properties

Currently CPUClass->parse_features() is used to parse -cpu features string and set properties on created CPU instances. But considering that features specified by -cpu apply to every created CPU instance, it doesn't make sense to parse the same features string for every CPU created. It also makes every target that cares about parsing features string explicitly call CPUClass->parse_features() parser, which gets in a way if we consider using generic device_add for CPU hotplug as device_add has not a clue about CPU specific hooks. Turns out we can use global properties mechanism to set properties on every created CPU instance for a given type. That way it's possible to convert CPU features into a set of global properties for CPU type specified by -cpu cpu_model and common Device.device_post_init() will apply them to CPU of given type automatically regardless whether it's manually created CPU or CPU created with help of device_add. Signed-off-by: Igor Mammedov <[email protected]> Reviewed-by: Eduardo Habkost <[email protected]> Signed-off-by: Eduardo Habkost <[email protected]>
0x3h · Jul 7, 2016 · 62a48a2 · 62a48a2
1 parent cf2887c
commit 62a48a2
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Showing 4 changed files with 54 additions and 22 deletions.
diff --git a/hw/arm/virt.c b/hw/arm/virt.c
@@ -1261,6 +1261,7 @@ static void machvirt_init(MachineState *machine)
 
     for (n = 0; n < smp_cpus; n++) {
         ObjectClass *oc = cpu_class_by_name(TYPE_ARM_CPU, cpustr[0]);
+        const char *typename = object_class_get_name(oc);
         CPUClass *cc = CPU_CLASS(oc);
         Object *cpuobj;
         Error *err = NULL;
@@ -1270,10 +1271,10 @@ static void machvirt_init(MachineState *machine)
             error_report("Unable to find CPU definition");
             exit(1);
         }
-        cpuobj = object_new(object_class_get_name(oc));
+        /* convert -smp CPU options specified by the user into global props */
+        cc->parse_features(typename, cpuopts, &err);
+        cpuobj = object_new(typename);
 
-        /* Handle any CPU options specified by the user */
-        cc->parse_features(CPU(cpuobj), cpuopts, &err);
         g_free(cpuopts);
         if (err) {
             error_report_err(err);

diff --git a/include/qom/cpu.h b/include/qom/cpu.h
@@ -134,7 +134,7 @@ typedef struct CPUClass {
     /*< public >*/
 
     ObjectClass *(*class_by_name)(const char *cpu_model);
-    void (*parse_features)(CPUState *cpu, char *str, Error **errp);
+    void (*parse_features)(const char *typename, char *str, Error **errp);
 
     void (*reset)(CPUState *cpu);
     int reset_dump_flags;

diff --git a/qom/cpu.c b/qom/cpu.c
@@ -28,6 +28,7 @@
 #include "exec/log.h"
 #include "qemu/error-report.h"
 #include "sysemu/sysemu.h"
+#include "hw/qdev-properties.h"
 
 bool cpu_exists(int64_t id)
 {
@@ -46,7 +47,7 @@ bool cpu_exists(int64_t id)
 CPUState *cpu_generic_init(const char *typename, const char *cpu_model)
 {
     char *str, *name, *featurestr;
-    CPUState *cpu;
+    CPUState *cpu = NULL;
     ObjectClass *oc;
     CPUClass *cc;
     Error *err = NULL;
@@ -60,16 +61,18 @@ CPUState *cpu_generic_init(const char *typename, const char *cpu_model)
         return NULL;
     }
 
-    cpu = CPU(object_new(object_class_get_name(oc)));
-    cc = CPU_GET_CLASS(cpu);
-
+    cc = CPU_CLASS(oc);
     featurestr = strtok(NULL, ",");
-    cc->parse_features(cpu, featurestr, &err);
+    /* TODO: all callers of cpu_generic_init() need to be converted to
+     * call parse_features() only once, before calling cpu_generic_init().
+     */
+    cc->parse_features(object_class_get_name(oc), featurestr, &err);
     g_free(str);
     if (err != NULL) {
         goto out;
     }
 
+    cpu = CPU(object_new(object_class_get_name(oc)));
     object_property_set_bool(OBJECT(cpu), true, "realized", &err);
 
 out:
@@ -282,25 +285,39 @@ static ObjectClass *cpu_common_class_by_name(const char *cpu_model)
     return NULL;
 }
 
-static void cpu_common_parse_features(CPUState *cpu, char *features,
+static void cpu_common_parse_features(const char *typename, char *features,
                                       Error **errp)
 {
     char *featurestr; /* Single "key=value" string being parsed */
     char *val;
-    Error *err = NULL;
+    static bool cpu_globals_initialized;
+
+    /* TODO: all callers of ->parse_features() need to be changed to
+     * call it only once, so we can remove this check (or change it
+     * to assert(!cpu_globals_initialized).
+     * Current callers of ->parse_features() are:
+     * - machvirt_init()
+     * - cpu_generic_init()
+     * - cpu_x86_create()
+     */
+    if (cpu_globals_initialized) {
+        return;
+    }
+    cpu_globals_initialized = true;
 
     featurestr = features ? strtok(features, ",") : NULL;
 
     while (featurestr) {
         val = strchr(featurestr, '=');
         if (val) {
+            GlobalProperty *prop = g_new0(typeof(*prop), 1);
             *val = 0;
             val++;
-            object_property_parse(OBJECT(cpu), val, featurestr, &err);
-            if (err) {
-                error_propagate(errp, err);
-                return;
-            }
+            prop->driver = typename;
+            prop->property = g_strdup(featurestr);
+            prop->value = g_strdup(val);
+            prop->errp = &error_fatal;
+            qdev_prop_register_global(prop);
         } else {
             error_setg(errp, "Expected key=value format, found %s.",
                        featurestr);

diff --git a/target-i386/cpu.c b/target-i386/cpu.c
@@ -1958,12 +1958,17 @@ static FeatureWordArray minus_features = { 0 };
 
 /* Parse "+feature,-feature,feature=foo" CPU feature string
  */
-static void x86_cpu_parse_featurestr(CPUState *cs, char *features,
+static void x86_cpu_parse_featurestr(const char *typename, char *features,
                                      Error **errp)
 {
-    X86CPU *cpu = X86_CPU(cs);
     char *featurestr; /* Single 'key=value" string being parsed */
     Error *local_err = NULL;
+    static bool cpu_globals_initialized;
+
+    if (cpu_globals_initialized) {
+        return;
+    }
+    cpu_globals_initialized = true;
 
     if (!features) {
         return;
@@ -1976,6 +1981,7 @@ static void x86_cpu_parse_featurestr(CPUState *cs, char *features,
         const char *val = NULL;
         char *eq = NULL;
         char num[32];
+        GlobalProperty *prop;
 
         /* Compatibility syntax: */
         if (featurestr[0] == '+') {
@@ -2013,7 +2019,12 @@ static void x86_cpu_parse_featurestr(CPUState *cs, char *features,
             name = "tsc-frequency";
         }
 
-        object_property_parse(OBJECT(cpu), val, name, &local_err);
+        prop = g_new0(typeof(*prop), 1);
+        prop->driver = typename;
+        prop->property = g_strdup(name);
+        prop->value = g_strdup(val);
+        prop->errp = &error_fatal;
+        qdev_prop_register_global(prop);
     }
 
     if (local_err) {
@@ -2202,9 +2213,11 @@ X86CPU *cpu_x86_create(const char *cpu_model, Error **errp)
 {
     X86CPU *cpu = NULL;
     ObjectClass *oc;
+    CPUClass *cc;
     gchar **model_pieces;
     char *name, *features;
     Error *error = NULL;
+    const char *typename;
 
     model_pieces = g_strsplit(cpu_model, ",", 2);
     if (!model_pieces[0]) {
@@ -2219,10 +2232,11 @@ X86CPU *cpu_x86_create(const char *cpu_model, Error **errp)
         error_setg(&error, "Unable to find CPU definition: %s", name);
         goto out;
     }
+    cc = CPU_CLASS(oc);
+    typename = object_class_get_name(oc);
 
-    cpu = X86_CPU(object_new(object_class_get_name(oc)));
-
-    x86_cpu_parse_featurestr(CPU(cpu), features, &error);
+    cc->parse_features(typename, features, &error);
+    cpu = X86_CPU(object_new(typename));
     if (error) {
         goto out;
     }