Re: [PATCH v5 4/8] vt82c686: Introduce abstract TYPE_VIA_ISA and base vt82c686b_isa on it

[Philippe Mathieu-Daudé]

On 3/4/21 9:16 PM, BALATON Zoltan wrote:
> On Thu, 4 Mar 2021, Philippe Mathieu-Daudé wrote:
>> On 3/2/21 10:11 PM, BALATON Zoltan wrote:
>>> To allow reusing ISA bridge emulation for vt8231_isa move the device
>>> state of vt82c686b_isa emulation in an abstract via_isa class.
>>>
>>> Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
>>> ---
>>>  hw/isa/vt82c686.c        | 70 ++++++++++++++++++++++------------------
>>>  include/hw/pci/pci_ids.h |  2 +-
>>>  2 files changed, 40 insertions(+), 32 deletions(-)
>>>
>>> diff --git a/hw/isa/vt82c686.c b/hw/isa/vt82c686.c
>>> index 72234bc4d1..5137f97f37 100644
>>> --- a/hw/isa/vt82c686.c
>>> +++ b/hw/isa/vt82c686.c
>>> @@ -609,24 +609,48 @@ static const TypeInfo vt8231_superio_info = {
>>>  };
>>>
>>>
>>> -OBJECT_DECLARE_SIMPLE_TYPE(VT82C686BISAState, VT82C686B_ISA)
>>> +#define TYPE_VIA_ISA "via-isa"
>>> +OBJECT_DECLARE_SIMPLE_TYPE(ViaISAState, VIA_ISA)
>>>
>>> -struct VT82C686BISAState {
>>> +struct ViaISAState {
>>>      PCIDevice dev;
>>>      qemu_irq cpu_intr;
>>>      ViaSuperIOState *via_sio;
>>>  };
>>>
>>> +static const VMStateDescription vmstate_via = {
>>> +    .name = "via-isa",
>>
>> You changed the migration stream name, so I think we have
>> a problem with migration... No clue how to do that properly.
> 
> I don't think these machines support migration or state description of
> vt86c686b was not missing something before these patches that would make
> it not work anyway so I did not worry about this too much. I doubt
> anybody wants to migrate a fuloong2e machine so this should not be a
> problem in practice but maybe you can mention it in the release notes if
> you think that would be necessary.

Maybe just add in the description:

 This change breaks migration back compatibility, but
 this is not an issue for the Fuloong2E machine.

?