Re: [Qemu-devel] [PATCH 1/2] Type-safe ioport callbacks

[Blue Swirl]

On Tue, Oct 26, 2010 at 5:35 PM, Avi Kivity <address@hidden> wrote:
>  On 10/26/2010 07:27 PM, Anthony Liguori wrote:
>>>
>>> Sorry, I don't follow your meaning.
>>>
>>> When I said "size is implied" I meant that the IOPort object has a
>>> separate function pointer for sizes 1, 2, and 4, so it ioport_register()
>>> doesn't need a size parameter.  But I don't see how that relates to your
>>> comment.
>>
>>
>> Yeah, I don't think it makes sense to combine "this is how to dispatch
>> I/O" with "this is a region of I/O address space".
>
> Oh, so Blue meant the size of the region in ports, not the size of the
> individual ports.  I think that putting the range length (but not base
> address) in the IOPort structure may make sense.

Yes, that's what I meant. Consider for example the handlers: they
expect that the port is within some range.

>>
>> I think an IORegion should contain an IOPort structure though.  I think
>> the name needs rethinking.
>>
>> Maybe:
>>
>> struct PortIOHandler;
>> struct MemoryIOHandler;
>
> Why two types?  I think some devices use PIO on a PC and MMIO on other
> architectures.  Sharing the type would allow sharing code.

Then there are the functions provided by rwhandler.c. I think that
interface makes even more sense compared to 8/16/32 (and 64?) bit
handlers in many cases.