Re: [Qemu-devel] [PATCH 06/14] exec.c: Make address_space_rw take transaction attributes

[Peter Maydell]

On 9 April 2015 at 11:21, Paolo Bonzini <address@hidden> wrote:
>
>
> On 09/04/2015 12:14, Peter Maydell wrote:
>> On 9 April 2015 at 10:59, Edgar E. Iglesias <address@hidden> wrote:
>>> > On Tue, Apr 07, 2015 at 09:09:52PM +0100, Peter Maydell wrote:
>>>> >> Make address_space_rw take transaction attributes, rather
>>>> >> than always using the 'unspecified' attributes.
>>> >
>>> > Reviewed-by: Edgar E. Iglesias <address@hidden>
>>> >
>>> > I guess that we eventually will need to convert the dma_
>>> > functions?
>> Probably, though I'm not clear what they bring to the party
>> that the basic address_space_* functions don't (part of why
>> I left them alone).
>
> At this point, some memory barriers, basically.

So what distinguishes a device that needs the memory barriers
and does its accesses via dma_* from a device that doesn't and
uses address_space_* or ld/st*_phys ? (Or for that matter a
non-device that does memory accesses...)

thanks
-- PMM