Re: [Qemu-ppc] [Qemu-devel] [PATCH v2 4/6] prep: move int-ack register from PReP to Raven PCI emulation

[Andreas Färber]

Am 30.04.2012 10:43, schrieb Avi Kivity:
> On 04/29/2012 11:12 PM, Andreas Färber wrote:
>> Am 29.04.2012 10:32, schrieb Avi Kivity:
>>> On 04/28/2012 09:46 PM, Andreas Färber wrote:
>>>> Am 14.04.2012 22:48, schrieb Hervé Poussineau:
>>>>> Register is one byte-wide (as per specification), so there is no need to 
>>>>> specify endianness.
>>>>
>>>> The region was 4 bytes before, now it's 1. What happens when a 4-byte
>>>> read is attempted at that address? Do we need to specify the valid
>>>> widths for the MemoryRegion? Or is such a read constructed from this
>>>> region and (assuming) the return value of an unassigned read?
>>>
>>> This area of what happens during access that falls across region
>>> boundaries is very underspecified in qemu; nor is it clear what happens
>>> in real hardware (in all its variations).
>>
>> So, what's your conclusion here? Should we add .valid.max_access_size =
>> 1? Or shall I apply as is?
> 
> If the specification says 1 byte and there are no known guests that
> abuse it, I say change it.

Thanks, applied to prep-up branch (with .max_access_size = 1 and
autobreaking the commit message):
http://repo.or.cz/w/qemu/afaerber.git/shortlog/refs/heads/prep-up

Andreas