Re: [Qemu-devel] [PATCH 0/3] Add new utility function memory_region_allocate_aux_memory()

[Paolo Bonzini]

On 07/07/2017 13:58, Peter Maydell wrote:
>>>
>>>     memory_region_init_ram(mr, owner, name, ram_size, &err);
>>>     if (err) {
>>>         error_propagate(errp, err);
>>>         return;
>>>     }
>>>     /* Note that owner_dev may be NULL if owner is not a DeviceState;
>>>      * in that case this is equivalent to calling 
>>> vmstate_register_ram_global().
>>>      */
>>>     owner_dev = object_dynamic_cast(owner, TYPE_DEVICE);
>>>     vmstate_register_ram(mr, owner_dev);
>> Maybe, for memory_region_init_ram only, the owner argument can be made a
>> DeviceState (or NULL)?
> Hmm. I don't much like the way that breaks the symmetry of the
> API with the other memory region init functions, and it makes
> it harder to script the conversion. I'd rather keep it as an
> Object*, especially since the only purpose of the pointer is to
> make the RAM name unique for migration purposes.

In that case, I would assert the object is a device and add a TODO to
support non-device objects.

Paolo

> (Better still would be if we had a uniquification mechanism
> for Objects...)