Re: [PATCH v6 0/4] virtio: Convert feature properties to OnOffAuto

[Markus Armbruster <armbru@redhat.com>]

Akihiko Odaki <akihiko.odaki@daynix.com> writes:

> On 2025/04/26 0:08, Markus Armbruster wrote:
>> Daniel P. Berrangé <berrange@redhat.com> writes:
>> 
>>> On Fri, Apr 25, 2025 at 08:14:13AM -0400, Michael S. Tsirkin wrote:
>>>> On Thu, Mar 06, 2025 at 03:16:26PM +0900, Akihiko Odaki wrote:
>>>>> This series was spun off from:
>>>>> "[PATCH 0/3] virtio-net: Convert feature properties to OnOffAuto"
>>>>> (https://patchew.org/QEMU/20240714-auto-v3-0-e27401aabab3@daynix.com/)
>>>>>
>>>>> Some features are not always available with vhost. Legacy features are
>>>>> not available with vp_vdpa in particular. virtio devices used to disable
>>>>> them when not available even if the corresponding properties were
>>>>> explicitly set to "on".
>>>>>
>>>>> QEMU already has OnOffAuto type, which includes the "auto" value to let
>>>>> it automatically decide the effective value. Convert feature properties
>>>>> to OnOffAuto and set them "auto" by default to utilize it. This allows
>>>>> QEMU to report an error if they are set "on" and the corresponding
>>>>> features are not available.
>>>>>
>>>>> Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
>>>>
>>>>
>>>> Marcus, Paolo, Daniel, Eduardo, any feedback on the QOM bits?
>>>
>>> I've said on every previous version that I don't think we should be
>>> changing OnOffAuto to secretly accept bool values. That is bypassing
>>> QAPI schema definitions with a special code hack.
>> 
>> I also objected to v4.  Thread starts at
>>      Message-ID: <87cyfwxveo.fsf@pond.sub.org>
>>      https://lore.kernel.org/qemu-devel/87cyfwxveo.fsf@pond.sub.org/
>> I could be persuaded to accept a patch that changes exactly the
>> properties that need to be changed to tri-state, with suitable
>> rationale.  This patch changes a bunch of unrelated properties, too.
>
> I replied to the thread as I found that I haven't replied to the last message in the thread and the newer versions of the series do not address its discussion points either.

I just reiterated and clarified my objection in said thread, and tried
to point towards possible solutions I could accept.