qom: Allow optional sugar props

Global properties have an @optional field, which allows to apply a given property to a given type even if one of its subclasses doesn't support it. This is especially used in the compat code when dealing with the "disable-modern" and "disable-legacy" properties and the "virtio-pci" type. Allow object_register_sugar_prop() to set this field as well. Signed-off-by: Greg Kurz <[email protected]> Message-Id: <[email protected]> Signed-off-by: David Gibson <[email protected]> Reviewed-by: Eduardo Habkost <[email protected]> Reviewed-by: Cornelia Huck <[email protected]> Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
dreddy · Feb 8, 2021 · a8dc82c · a8dc82c
1 parent 5b19cb6
commit a8dc82c
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Showing 4 changed files with 18 additions and 9 deletions.
diff --git a/include/qom/object.h b/include/qom/object.h
@@ -638,7 +638,8 @@ bool object_apply_global_props(Object *obj, const GPtrArray *props,
                                Error **errp);
 void object_set_machine_compat_props(GPtrArray *compat_props);
 void object_set_accelerator_compat_props(GPtrArray *compat_props);
-void object_register_sugar_prop(const char *driver, const char *prop, const char *value);
+void object_register_sugar_prop(const char *driver, const char *prop,
+                                const char *value, bool optional);
 void object_apply_compat_props(Object *obj);
 
 /**

diff --git a/qom/object.c b/qom/object.c
@@ -442,7 +442,8 @@ static GPtrArray *object_compat_props[3];
  * other than "-global".  These are generally used for syntactic
  * sugar and legacy command line options.
  */
-void object_register_sugar_prop(const char *driver, const char *prop, const char *value)
+void object_register_sugar_prop(const char *driver, const char *prop,
+                                const char *value, bool optional)
 {
     GlobalProperty *g;
     if (!object_compat_props[2]) {
@@ -452,6 +453,7 @@ void object_register_sugar_prop(const char *driver, const char *prop, const char
     g->driver = g_strdup(driver);
     g->property = g_strdup(prop);
     g->value = g_strdup(value);
+    g->optional = optional;
     g_ptr_array_add(object_compat_props[2], g);
 }
 

diff --git a/softmmu/rtc.c b/softmmu/rtc.c
@@ -179,7 +179,8 @@ void configure_rtc(QemuOpts *opts)
         if (!strcmp(value, "slew")) {
             object_register_sugar_prop("mc146818rtc",
                                        "lost_tick_policy",
-                                       "slew");
+                                       "slew",
+                                       false);
         } else if (!strcmp(value, "none")) {
             /* discard is default */
         } else {

diff --git a/softmmu/vl.c b/softmmu/vl.c
@@ -1663,16 +1663,20 @@ static int machine_set_property(void *opaque,
         return 0;
     }
     if (g_str_equal(qom_name, "igd-passthru")) {
-        object_register_sugar_prop(ACCEL_CLASS_NAME("xen"), qom_name, value);
+        object_register_sugar_prop(ACCEL_CLASS_NAME("xen"), qom_name, value,
+                                   false);
         return 0;
     }
     if (g_str_equal(qom_name, "kvm-shadow-mem")) {
-        object_register_sugar_prop(ACCEL_CLASS_NAME("kvm"), qom_name, value);
+        object_register_sugar_prop(ACCEL_CLASS_NAME("kvm"), qom_name, value,
+                                   false);
         return 0;
     }
     if (g_str_equal(qom_name, "kernel-irqchip")) {
-        object_register_sugar_prop(ACCEL_CLASS_NAME("kvm"), qom_name, value);
-        object_register_sugar_prop(ACCEL_CLASS_NAME("whpx"), qom_name, value);
+        object_register_sugar_prop(ACCEL_CLASS_NAME("kvm"), qom_name, value,
+                                   false);
+        object_register_sugar_prop(ACCEL_CLASS_NAME("whpx"), qom_name, value,
+                                   false);
         return 0;
     }
 
@@ -2298,9 +2302,10 @@ static void qemu_process_sugar_options(void)
 
         val = g_strdup_printf("%d",
                  (uint32_t) qemu_opt_get_number(qemu_find_opts_singleton("smp-opts"), "cpus", 1));
-        object_register_sugar_prop("memory-backend", "prealloc-threads", val);
+        object_register_sugar_prop("memory-backend", "prealloc-threads", val,
+                                   false);
         g_free(val);
-        object_register_sugar_prop("memory-backend", "prealloc", "on");
+        object_register_sugar_prop("memory-backend", "prealloc", "on", false);
     }
 
     if (watchdog) {