Re: [PATCH 8/9] hw/i386/pc_sysfw.c: convert pflash0 and pflash1 object props to class props

[Markus Armbruster <armbru@redhat.com>]

Daniel P. Berrangé <berrange@redhat.com> writes:

> On Wed, Jul 08, 2026 at 11:16:30AM +0100, Peter Maydell wrote:
>> On Fri, 3 Jul 2026 at 10:09, Mark Cave-Ayland
>> <mark.caveayland@nutanix.com> wrote:
>> >
>> > Signed-off-by: Mark Cave-Ayland <mark.caveayland@nutanix.com>
>> > ---
>> >  include/hw/i386/pc.h | 2 ++
>> >  hw/i386/pc.c         | 8 ++++++++
>> >  hw/i386/pc_sysfw.c   | 7 +------
>> >  3 files changed, 11 insertions(+), 6 deletions(-)
>> >
>> > diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
>> > index 309de2eda1..16cb0ec01f 100644
>> > --- a/include/hw/i386/pc.h
>> > +++ b/include/hw/i386/pc.h
>> > @@ -40,6 +40,8 @@ typedef struct PCMachineState {
>> >
>> >      Object *alias_pcspk;
>> >      Object *alias_rtc_time;
>> > +    Object *alias_pflash0;
>> > +    Object *alias_pflash1;
>> >
>> >      /* Configuration options: */
>> >      uint64_t max_ram_below_4g;
>> > diff --git a/hw/i386/pc.c b/hw/i386/pc.c
>> > index 13c9c1bfc8..11eef176f4 100644
>> > --- a/hw/i386/pc.c
>> > +++ b/hw/i386/pc.c
>> > @@ -1762,6 +1762,14 @@ static void pc_machine_class_init(ObjectClass *oc, const void *data)
>> >                                     offsetof(X86MachineState, acpi_dev),
>> >                                     object_property_allow_set_link,
>> >                                     OBJ_PROP_LINK_STRONG);
>> > +    object_class_property_add_alias(oc, "pflash0",
>> > +                                    offsetof(PCMachineState, alias_pflash0),
>> > +                                    TYPE_PFLASH_CFI01,
>> > +                                    "drive");
>> > +    object_class_property_add_alias(oc, "pflash1",
>> > +                                    offsetof(PCMachineState, alias_pflash1),
>> > +                                    TYPE_PFLASH_CFI01,
>> > +                                    "drive");
>> 
>> Does making these class properties fix
>> https://gitlab.com/qemu-project/qemu/-/work_items/3254
>> (which is a report that "qemu-system-x86_64 -machine pc-q35,help"
>> doesn't list these properties) ?

Not showing object properties is a bug.

Cannot be fixed for object properties that are created outside the
object's instance_init().

Now, object properties created in instance_init() should almost
certainly be class properties instead.  Converting them all fixes the
fixable part of the bug:

> Yes, it ought to, as that CLI logic iterates over class properties.

One property conversion at a time.

There's a quicker fix, though.

-machine TYPE.help uses type_print_class_properties() to show
properties.  Here's its loop:

    object_class_property_iter_init(&iter, klass);
    while ((prop = object_property_iter_next(&iter))) {
        if (!prop->set) {
            continue;
        }

        g_ptr_array_add(array,
                        object_property_help(prop->name, prop->type,
                                             prop->defval, prop->description));
    }

-device TYPE,help uses qmp_device_list_properties() to show both.
Here's its loop:

        obj = object_new_with_class(klass);

        object_property_iter_init(&iter, obj);
        while ((prop = object_property_iter_next(&iter))) {
            ObjectPropertyInfo *info;

            [...]

            info = g_new0(ObjectPropertyInfo, 1);
            info->name = g_strdup(prop->name);
            info->type = g_strdup(prop->type);
            info->description = g_strdup(prop->description);
            info->default_value = qobject_ref(prop->defval);

            QAPI_LIST_PREPEND(prop_list, info);
        }

        object_unref(obj);

Is there any excuse not to do it this way?