Re: [Qemu-devel] Re: Compile files only once: some planning

[Anthony Liguori <anthony@codemonkey.ws>]

On 03/24/2010 06:05 PM, Paul Brook wrote:
>> On 03/24/2010 05:33 PM, Paul Brook wrote:
>>      
>>>> But now there is a bigger problem, how to pass the property to the
>>>> device. It's not fair to require the user to remember to set it.
>>>>          
>>> It should not be a property of the device. All devices have a native
>>> endianness (for PCI this is little-endian), and the intermediate
>>> busses/interconnects should determine whether byteswapping occurs.
>>>        
>> Right, the byte swapping needs to happen at the bus level which requires
>> that the PCI regions use a different callback mechanism (and don't
>> register directly with the cpu).
>>      
> Not necessarily a different callback mechanism, but probably a different
> registration mechanism.
>    

Problem with the current scheme is that it's tied to 
target_phys_addr_t.  It's not a target_phys_addr_t and cannot be used 
with functions that take target_phys_addr_ts.

We can either introduce a generic address type or we can introduce bus 
specific addresses and have different callbacks.  The later has better 
type safety and since this isn't an obvious issue to most developers, 
that's probably an important feature.

Regards,

Anthony Liguori

> Paul
>