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

[li guang]

在 2013-05-27一的 11:00 +0200，Gerd Hoffmann写道：
> 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.
> 

Yes, I will re-consider this.

Thanks!