Re: [PATCH v2 0/6] hw/mips/malta: Add the 'malta-strict' machine, matching Malta hardware

[Philippe Mathieu-Daudé]

On 6/30/20 6:55 PM, Aleksandar Markovic wrote:
> уто, 30. јун 2020. у 18:46 Philippe Mathieu-Daudé <f4bug@amsat.org> је
> написао/ла:
>>
>> On 6/30/20 5:38 PM, Aleksandar Markovic wrote:
>>> уто, 30. јун 2020. у 16:52 Philippe Mathieu-Daudé <f4bug@amsat.org> је
>>> написао/ла:
>>>>
>>>> Hi,
>>>>
>>>> This series add a new 'malta-strict' machine, that aims to properly
>>>> model the real hardware (which is not what the current 'malta'
>>>> machine models).
>>>>
>>>> As a bonus for Debian builders, a 'malta-unleashed' machine RFC
>>>> patch is included. This might start another endless discussion
>>>> upstream, but this is not the point of, so I still include it
>>>> for people to test. The rest of the series is candidate for merging
>>>> in mainstream QEMU.
>>>>
>>>> Philippe Mathieu-Daudé (6):
>>>>   hw/mips/malta: Trivial code movement
>>>>   hw/mips/malta: Register the machine as a TypeInfo
>>>>   hw/mips/malta: Introduce MaltaMachineClass::max_ramsize
>>>>   hw/mips/malta: Introduce the 'malta-strict' machine
>>>>   hw/mips/malta: Verify malta-strict machine uses correct DIMM sizes
>>>>   hw/mips/malta: Introduce the 'malta-unleashed' 64-bit machine
>>>>
>>>>  hw/mips/malta.c | 125 ++++++++++++++++++++++++++++++++++++++++++------
>>>>  1 file changed, 111 insertions(+), 14 deletions(-)
>>>>
>>>> --
>>>
>>> This whole series is based on idea of emulating physically
>>> non-existing feature, and as such violates the fundamental principles
>>> of QEMU.
>>>
>>> As such, not acceptable for upstreaming.
>>>
>>> I don't see the point of sending again the same series, in just
>>> cosmetically different form, if it was said to you that the concept is
>>> wrong.
>>
>> Have you looked at the patches? What "violates the fundamental
>> principles of QEMU" is the code currently in mainstream. Should
>> we remove it? I can send a patch for it if it pleases you, but
>> you will make QEMU unuseful for many distribution users.
>>
> 
> Past mistakes are past mistakes. We have to live with them. And not
> make them in the future.
> 
> I see the whole series as a precursor for your change that repeats
> past mistakes, a "wolf in sheep clothing".
> 
> That's why I reject the series as a whole.

As a co-maintainer I don't accept that.

The 'malta' machine is not changed, the series adds the 'malta-strict'
machine which check the RAM restriction:

$ qemu-system-mips -M malta-strict -bios /dev/null -m 512
qemu-system-mips: Too much memory for this machine: 512 MiB, maximum 256 MiB

$ qemu-system-mips -M malta-strict -bios /dev/null -m 252
qemu-system-mips: RAM size must be the combination of 4 powers of 2

$ qemu-system-mips -M malta-strict -monitor stdio -S -bios /dev/null -m 100
QEMU 5.0.50 monitor - type 'help' for more information
(qemu) info mtree
address-space: memory
  0000000000000000-ffffffffffffffff (prio 0, i/o): system
    0000000000000000-00000000063fffff (prio 0, ram): alias
mips_malta_low_preio.ram @mips_malta.ram 0000000000000000-00000000063fffff

100 = 64 + 32 + 2 + 2

> 
> Yours,
> Aleksandar
> 
>> What this series does is emulate the physically existing feature
>> that are not yet emulated in QEMU.
>>
>> Please refer to the datasheet 'MIPS Document Number: MD00051
>> Revision 01.07' before rejecting this series, and find the
>> correct arguments.
>>
>> Thanks.
>>
>>>
>>> Regards,
>>> Aleksandar
>>>
>>>
>>>> 2.21.3
>>>>
>>>
>