Re: [PATCH v2 05/23] q800: move CPU object into Q800MachineState

[Markus Armbruster]

Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> writes:

> On 31/05/2023 16:00, Markus Armbruster wrote:
>
>> Philippe Mathieu-Daudé <philmd@linaro.org> writes:
>> 
>>> On 31/5/23 14:53, Mark Cave-Ayland wrote:
>>>> Also change the instantiation of the CPU to use object_initialize_child()
>>>> followed by a separate realisation.
>>>> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
>>>> ---
>>>>    hw/m68k/q800.c         | 13 ++++++++-----
>>>>    include/hw/m68k/q800.h |  2 ++
>>>>    2 files changed, 10 insertions(+), 5 deletions(-)
>>>> diff --git a/hw/m68k/q800.c b/hw/m68k/q800.c
>>>> index 3730b30dd1..c34b2548ca 100644
>>>> --- a/hw/m68k/q800.c
>>>> +++ b/hw/m68k/q800.c
>>>> @@ -364,7 +364,7 @@ static uint8_t fake_mac_rom[] = {
>>>>      static void q800_machine_init(MachineState *machine)
>>>>    {
>>>> -    M68kCPU *cpu = NULL;
>>>> +    Q800MachineState *m = Q800_MACHINE(machine);
>>>>        int linux_boot;
>>>>        int32_t kernel_size;
>>>>        uint64_t elf_entry;
>>>> @@ -407,8 +407,10 @@ static void q800_machine_init(MachineState *machine)
>>>>        }
>>>>          /* init CPUs */
>>>> -    cpu = M68K_CPU(cpu_create(machine->cpu_type));
>>>> -    qemu_register_reset(main_cpu_reset, cpu);
>>>> +    object_initialize_child(OBJECT(machine), "cpu", &m->cpu,
>>>> +                            M68K_CPU_TYPE_NAME("m68040"));
>>>> +    object_property_set_bool(OBJECT(&m->cpu), "realized", true, 
>>>> &error_fatal);
>>>
>>> CPUs are QDev-based, shouldn't we use qdev_realize()?
>>
>> Yes, we should.
>> [...]
>
> Interesting. I remember thinking that CPUs were different, so I'm fairly sure 
> I borrowed this from some similar code in hw/arm :)
>
> Shouldn't the above be directly equivalent to qdev_realize(dev, NULL, 
> &error_fatal) given that the CPU doesn't connect to a bus?

It's been a while since I worked on this...

Commit ce189ab230b (qdev: Convert bus-less devices to qdev_realize()
with Coccinelle) looks like you're right.