Re: [PATCH v3] hw/audio/virtio-snd: Use device endianness instead of target one

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

On 23/4/24 11:18, Manos Pitsidianakis wrote:
> On Tue, 23 Apr 2024 at 11:47, Manos Pitsidianakis
> <manos.pitsidianakis@linaro.org> wrote:
>>
>> On Tue, 23 Apr 2024 at 00:11, Michael S. Tsirkin <mst@redhat.com> wrote:
>>>
>>> On Mon, Apr 22, 2024 at 11:07:21PM +0200, Philippe Mathieu-Daudé wrote:
>>>> On 22/4/24 23:02, Michael S. Tsirkin wrote:
>>>>> On Mon, Apr 22, 2024 at 04:20:56PM +0200, Philippe Mathieu-Daudé wrote:
>>>>>> Since VirtIO devices can change endianness at runtime,
>>>>>> we need to use the device endianness, not the target
>>>>>> one.
>>>>>>
>>>>>> Cc: qemu-stable@nongnu.org
>>>>>> Fixes: eb9ad377bb ("virtio-sound: handle control messages and streams")
>>>>>> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
>>>>>
>>>>>
>>>>>
>>>>> This is all completely bogus. Virtio SND is from Virtio 1.0 only.
>>>>> It is unconditionally little endian.
>>
>>
>> This part of the code is for PCM frames (raw bytes), not virtio spec
>> fields (which indeed must be LE in modern VIRTIO).
> 
> Thought a little more about it. We should keep the target's endianness
> here, if it's mutable then we should query the machine the device is
> attached to somehow. the virtio device should never change endianness
> like Michael says since it's not legacy.

Grr. So as Richard suggested, this need to be pass as a device
property then.
(https://lore.kernel.org/qemu-devel/ed134c9d-6e6f-465b-900f-e39ca4e09876@linaro.org/)