Re: [Qemu-devel] [PATCH] qtest: add read/write accessors with a specific endianness

[Paolo Bonzini <pbonzini@redhat.com>]

On 06/10/2016 17:44, Cédric Le Goater wrote:
> On 10/06/2016 05:36 PM, Paolo Bonzini wrote:
>>
>>
>> On 06/10/2016 16:11, Greg Kurz wrote:
>>> FWIW, Cedric had another proposal which apparently went unnoticed:
>>>
>>> <fc24ad74-da26-a713-9312-a2c2d07fb6a7@kaod.org>
>>>
>>> The idea is to add an optional endianness argument to the read*/write*
>>> commands in the qtest protocol:
>>> - libqtest then provides explicit _le and _be APIs
>>> - no extra byteswap is performed on the test program side: qtest
>>>   actually handles that and does exactly 1 or 0 byteswap.
>>> - it does not use memread/memwrite
>>> - the current 'guest native' API where qtest tswaps is preserved
>>>
>>
>> No, this is a worse idea, because the right place to do the swap is in
>> the "program" (libqtest) not in the "CPU" (QEMU).
> 
> So the current patch, minus the typos, seems to be a "better" solution.

Yes, at least I don't think it's a problem that it uses "memread" and
"memwrite".  It's just address_space_rw under the hood, and we know that
it does the right thing with MMIO addresses.

Paolo