On 05/06/2026 00:11, Peter Xu wrote:
Property itself is a well defined interface to either support smooth
conversions to Object's properties, or supports global properties. However
currently it's tied to DeviceClass, aka, qdev. So non-qdev cannot use
Property list.
That's indeed because Property is a qdev-only concept.
My current observation shows Property is almost ready to be used as a
separated exported interface, except two small things that may need touch
up internally:
qdev_prop_allow_set
qdev_prop_check_globals
The 1st one currently checks against realize state (which is part of qdev
attributes only). The 2nd one checks for all global property being used in
all non-pluggable qdevs.
We can loose the check in both spots, keep the check if the driver is a
qdev, otherwise we can safely whitelist non-qdev use cases of Property.
I'm really not sure this is the right approach: surely you would want to
flip this on its head so that -global makes use of the underlying QOM
APIs instead of qdev APIs?
Signed-off-by: Peter Xu <[email protected]>
---
hw/core/qdev-properties.c | 24 ++++++++++++++++++++----
tests/unit/test-qdev-global-props.c | 6 +++++-
2 files changed, 25 insertions(+), 5 deletions(-)
diff --git a/hw/core/qdev-properties.c b/hw/core/qdev-properties.c
index 34d7b26a73..8f870c85fc 100644
--- a/hw/core/qdev-properties.c
+++ b/hw/core/qdev-properties.c
@@ -31,8 +31,14 @@ void qdev_prop_set_after_realize(DeviceState *dev, const
char *name,
static bool qdev_prop_allow_set(Object *obj, const char *name,
const PropertyInfo *info, Error **errp)
{
- DeviceState *dev = DEVICE(obj);
+ DeviceState *dev;
+
+ if (!object_dynamic_cast(obj, TYPE_DEVICE)) {
+ /* Currently, non-qdev can always set Property anytime */
+ return true;
+ }
+ dev = DEVICE(obj);
if (dev->realized && !info->realized_set_allowed) {
qdev_prop_set_after_realize(dev, name, errp);
return false;
@@ -997,6 +1003,7 @@ int qdev_prop_check_globals(void)
for (i = 0; i < global_props()->len; i++) {
GlobalProperty *prop;
+ bool hotpluggable;
ObjectClass *oc;
DeviceClass *dc;
@@ -1005,15 +1012,24 @@ int qdev_prop_check_globals(void)
continue;
}
oc = object_class_by_name(prop->driver);
- oc = object_class_dynamic_cast(oc, TYPE_DEVICE);
if (!oc) {
warn_report("global %s.%s has invalid class name",
prop->driver, prop->property);
ret = 1;
continue;
}
- dc = DEVICE_CLASS(oc);
- if (!dc->hotpluggable && !prop->used) {
+ oc = object_class_dynamic_cast(oc, TYPE_DEVICE);
+ if (oc) {
+ dc = DEVICE_CLASS(oc);
+ hotpluggable = dc->hotpluggable;
+ } else {
+ /*
+ * Currently, to be strict to assume all non-qdev are not
+ * hotpluggable (whoever will use -global).
+ */
+ hotpluggable = false;
+ }
+ if (!hotpluggable && !prop->used) {
warn_report("global %s.%s=%s not used",
prop->driver, prop->property, prop->value);
ret = 1;
diff --git a/tests/unit/test-qdev-global-props.c
b/tests/unit/test-qdev-global-props.c
index 8ea362cbb9..86bb1458d9 100644
--- a/tests/unit/test-qdev-global-props.c
+++ b/tests/unit/test-qdev-global-props.c
@@ -275,8 +275,12 @@ static void test_dynamic_globalprop(void)
g_test_trap_assert_stderr_unmatched("*prop4*");
g_test_trap_assert_stderr(
"*warning: global nohotplug-type.prop5=105 not used*");
+ /*
+ * TYPE_OBJECT can opt-in for global properties, so the error is "not
+ * used" too for nondevice-type.
+ */
g_test_trap_assert_stderr(
- "*warning: global nondevice-type.prop6 has invalid class name*");
+ "*warning: global nondevice-type.prop6=106 not used*");
g_test_trap_assert_stdout("");
}
ATB,
Mark.
