Re: [PATCH for-9.0] docs/about: Mark the iaspc machine type as deprecated

[Bernhard Beschow]

Am 26. März 2024 13:29:58 UTC schrieb "Philippe Mathieu-Daudé" 
<philmd@linaro.org>:
>Hi Igor,
>
>On 26/3/24 14:08, Thomas Huth wrote:
>> 
>> s/iaspc/isapc/ in the subject
>> 
>> On 26/03/2024 13.51, Igor Mammedov wrote:
>>> ISAPC machine was introduced 25 years ago and it's a lot of time since
>>> such machine was around with real ISA only PC hardware practically defunct.
>>> Also it's slowly bit-rots (for example: I was able to boot RHEL6 on RHEL9 
>>> host
>>> in only TCG mode, while in KVM mode it hung in the middle of boot)
>
>I'm quite opposed to this patch. QEMU models various very-old /
>defunct hardware. I'm pretty sure Bernhard and myself are OK to
>keep maintaining it, besides we are working in separating it from
>the i440fx+piix machine.

Yes, I'd rather keep maintaining the isapc machine and separating it from the 
i440fx machine seems like a good idea to me. I'm confident that we can work out 
a way that allows for moving forward the pc-pci machines while keeping the 
isapc machine from getting into the way too much.

Best regards,
Bernhard

> Also, this machine is particularly
>interesting for my single-binary experiments.
>
>Where I agree is we should stop reporting "KVM on ISA/PC machine"
>as supported.
>
>Regards,
>
>Phil.
>
>>> Rather than spending time on fixing 'the oldest' no longer tested machine 
>>> type,
>>> deprecate it so we can clean up QEMU code from legacy fixups and hopefully
>>> make it easier to follow.
>>> 
>>> Folks who have to use ancient guest that requires ISAPC can still
>>> use older QEMU to play with it.
>>> 
>>> Signed-off-by: Igor Mammedov <imammedo@redhat.com>
>>> ---
>>>   docs/about/deprecated.rst | 7 +++++++
>>>   hw/i386/pc_piix.c         | 1 +
>>>   2 files changed, 8 insertions(+)
>>> 
>>> diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst
>>> index 7b548519b5..5708296991 100644
>>> --- a/docs/about/deprecated.rst
>>> +++ b/docs/about/deprecated.rst
>>> @@ -226,6 +226,13 @@ These old machine types are quite neglected nowadays 
>>> and thus might have
>>>   various pitfalls with regards to live migration. Use a newer machine type
>>>   instead.
>>> +``isapc`` (since 9.0)
>>> +'''''''''''''''''''''''''''''''''''''''''''''''''''''
>>> +
>>> +These old machine type are quite neglected nowadays and thus might have
>> 
>> "This old machine type is ..." ?
>> 
>>> +various pitfalls with regards to live migration. Use a newer machine type
>>> +instead.
>> 
>> I doubt that isapc could ever be used reliably for live migration, since 
>> it's an unversioned machine type, so I think it would be better to not 
>> mention live migration here.
>> 
>>   Thomas
>> 
>> 
>