Re: [Qemu-devel] [PATCH 2/4] acpi/gpe: expand bits of gpe register

[Gerd Hoffmann <kraxel@redhat.com>]

On 05/24/13 04:02, li guang wrote:
> 在 2013-05-24五的 10:24 +0900，Isaku Yamahata写道：
>> On Wed, May 22, 2013 at 01:37:41PM +0800, li guang wrote:
>>> 在 2013-05-22三的 14:28 +0900，Isaku Yamahata写道：
>>>> Why?
>>>> And it breaks pointer operation like
>>>
>>> the fact is I can't guess why gpe->sts is defined uint8_t 
>>> but the real hardware is 32-bit width.
>>
>> Which section of ACPI spec?
> 
> seems ACPI SPEC does not define the length,
> but, real hardware does, e.g. ICH9.

Still fail to see what exactly you are trying to fix.

qemu can continue work with uint8_t internally just fine.  memory api
will split dword access by guests into 4 byte accesses.  ich9_gpe_ops
looks correct.

>>> I expand it to 32 because the future usage for me will 
>>> access bit beyond 8.

gpe->sts is an array, so you already have more than 8 bits.

>> I don't have strong opinion wheter uint8_t or uint32_t.
>> But the current patch is broken as the pointer offset 
>> operation needs to be fixed.

Oh, and it breaks live migration too.

cheers,
  Gerd