* Re: [PATCH] docs/about: Deprecate the 'next-cube' m68k machine
2026-08-27 17:32 ` Peter Maydell
@ 2026-08-27 17:45 ` Daniel P. Berrangé
2026-08-27 17:51 ` Peter Maydell
` (2 more replies)
2026-08-27 20:28 ` Mark Cave-Ayland
2026-08-27 20:49 ` Thomas Huth
2 siblings, 3 replies; 12+ messages in thread
From: Daniel P. Berrangé @ 2026-08-27 17:45 UTC (permalink / raw)
To: Peter Maydell
Cc: Philippe Mathieu-Daudé, Thomas Huth, Mark Cave-Ayland,
Thomas Huth, qemu-devel, Laurent Vivier, Natalia Portillo
On Thu, Aug 27, 2026 at 06:32:43PM +0100, Peter Maydell wrote:
> On Thu, 27 Aug 2026 at 17:09, Philippe Mathieu-Daudé
> <philmd@oss.qualcomm.com> wrote:
> >
> > Hi Thomas,
> >
> > On 27/8/26 14:54, Thomas Huth wrote:
> > > On 09/10/2023 21.39, Mark Cave-Ayland wrote:
> > >> On 07/10/2023 08:23, Thomas Huth wrote:
> > >>
> > >> (added Natalia who was the GSoC mentor for the NeXT cube work)
> > >>
> > >>> The machine is incomplete, and unfortunately the hoped-for improvements
> > >>> never happened. So it's maybe best if we mark this machine as deprecated
> > >>> and finally remove it again in case it gets into the way of a code
> > >>> refactoring or other reasons.
>
> > >> I'm torn a bit by this one - on the one hand the NeXT code could do
> > >> with some love, but then given that the code already uses qdev/QOM
> > >> then there isn't really much in the way of maintenance burden. The
> > >> main concern for me at the moment is the use of the old-style memory
> > >> accessors that pre-date the memory API.
> > >>
> > >> With my latest ESP patches I think it shouldn't be too hard to update
> > >> the NeXT DMA controller to get SCSI working, so perhaps we can leave
> > >> it for now if it doesn't cause too many problems?
>
> > > Almost three years later, the world changed quite a bit. We're getting
> > > flooded with AI-generated bug reports now, and of course people are
> > > discovering problems in this old and neglected code, e.g.:
> > >
> > > https://gitlab.com/qemu-project/qemu/-/work_items/4303
> > > https://gitlab.com/qemu-project/qemu/-/work_items/4304
> > > https://gitlab.com/qemu-project/qemu/-/work_items/4305
> >
> > Hobbyist motivated machine emulations never committed to be
> > secure. While I appreciate these bug reports for the overall
> > quality of the project, I'm taking these one as lowest priority.
> > I wouldn't even mind of closing them as WONTFIX "Thanks ...".
>
> I agree, but also they can prompt us to look and say "actually
> this machine is no longer used / never got sufficiently
> implemented to be useful / has no maintainer" (cf musicpal).
> So the questions here are:
> * is the machine's functionality better than it was in 2023:
> can we boot something beyond just the firmware now?
> * is anybody planning to actively work on it?
> * is anybody using it?
I don't mind about the quality, as we never claim this stuff
is providing a security boundary, but I do wonder whether the
bar for merging a machine should have been higher than
"shows firmware prompt" ?
Are there other machines we have merged with that level of
very limited functionality ?
Is it reasonable to say "boot a guest OS" is a criteria for
merging machines in future ?
With regards,
Daniel
--
|: https://berrange.com ~~ https://hachyderm.io/@berrange :|
|: https://libvirt.org ~~ https://entangle-photo.org :|
|: https://pixelfed.art/berrange ~~ https://fstop138.berrange.com :|
^ permalink raw reply [flat|nested] 12+ messages in thread* Re: [PATCH] docs/about: Deprecate the 'next-cube' m68k machine
2026-08-27 17:45 ` Daniel P. Berrangé
@ 2026-08-27 17:51 ` Peter Maydell
2026-08-27 20:34 ` Mark Cave-Ayland
2026-08-27 21:05 ` Thomas Huth
2 siblings, 0 replies; 12+ messages in thread
From: Peter Maydell @ 2026-08-27 17:51 UTC (permalink / raw)
To: Daniel P. Berrangé
Cc: Philippe Mathieu-Daudé, Thomas Huth, Mark Cave-Ayland,
Thomas Huth, qemu-devel, Laurent Vivier, Natalia Portillo
On Thu, 27 Aug 2026 at 18:45, Daniel P. Berrangé <berrange@redhat.com> wrote:
> I don't mind about the quality, as we never claim this stuff
> is providing a security boundary, but I do wonder whether the
> bar for merging a machine should have been higher than
> "shows firmware prompt" ?
>
> Are there other machines we have merged with that level of
> very limited functionality ?
>
> Is it reasonable to say "boot a guest OS" is a criteria for
> merging machines in future ?
I think the idea behind merging a machine earlier is/was
that it means it doesn't build up as a huge hard to review
patchset waiting until all the functionality is there enough
to boot a full OS. That can be an awkward workflow, especially
with multiple contributors.
But allowing in a half-finished machine only works out when the
contributors working on it are actually here and continuing
to work on it -- the failure mode is a half-finished thing.
That's why "is anybody planning to actively work on it?" was
one of my questions earlier.
-- PMM
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] docs/about: Deprecate the 'next-cube' m68k machine
2026-08-27 17:45 ` Daniel P. Berrangé
2026-08-27 17:51 ` Peter Maydell
@ 2026-08-27 20:34 ` Mark Cave-Ayland
2026-08-27 21:05 ` Thomas Huth
2 siblings, 0 replies; 12+ messages in thread
From: Mark Cave-Ayland @ 2026-08-27 20:34 UTC (permalink / raw)
To: Daniel P. Berrangé, Peter Maydell
Cc: Philippe Mathieu-Daudé, Thomas Huth, Thomas Huth, qemu-devel,
Laurent Vivier, Natalia Portillo
On 27/08/2026 18:45, Daniel P. Berrangé wrote:
> On Thu, Aug 27, 2026 at 06:32:43PM +0100, Peter Maydell wrote:
>> On Thu, 27 Aug 2026 at 17:09, Philippe Mathieu-Daudé
>> <philmd@oss.qualcomm.com> wrote:
>>>
>>> Hi Thomas,
>>>
>>> On 27/8/26 14:54, Thomas Huth wrote:
>>>> On 09/10/2023 21.39, Mark Cave-Ayland wrote:
>>>>> On 07/10/2023 08:23, Thomas Huth wrote:
>>>>>
>>>>> (added Natalia who was the GSoC mentor for the NeXT cube work)
>>>>>
>>>>>> The machine is incomplete, and unfortunately the hoped-for improvements
>>>>>> never happened. So it's maybe best if we mark this machine as deprecated
>>>>>> and finally remove it again in case it gets into the way of a code
>>>>>> refactoring or other reasons.
>>
>>>>> I'm torn a bit by this one - on the one hand the NeXT code could do
>>>>> with some love, but then given that the code already uses qdev/QOM
>>>>> then there isn't really much in the way of maintenance burden. The
>>>>> main concern for me at the moment is the use of the old-style memory
>>>>> accessors that pre-date the memory API.
>>>>>
>>>>> With my latest ESP patches I think it shouldn't be too hard to update
>>>>> the NeXT DMA controller to get SCSI working, so perhaps we can leave
>>>>> it for now if it doesn't cause too many problems?
>>
>>>> Almost three years later, the world changed quite a bit. We're getting
>>>> flooded with AI-generated bug reports now, and of course people are
>>>> discovering problems in this old and neglected code, e.g.:
>>>>
>>>> https://gitlab.com/qemu-project/qemu/-/work_items/4303
>>>> https://gitlab.com/qemu-project/qemu/-/work_items/4304
>>>> https://gitlab.com/qemu-project/qemu/-/work_items/4305
>>>
>>> Hobbyist motivated machine emulations never committed to be
>>> secure. While I appreciate these bug reports for the overall
>>> quality of the project, I'm taking these one as lowest priority.
>>> I wouldn't even mind of closing them as WONTFIX "Thanks ...".
>>
>> I agree, but also they can prompt us to look and say "actually
>> this machine is no longer used / never got sufficiently
>> implemented to be useful / has no maintainer" (cf musicpal).
>> So the questions here are:
>> * is the machine's functionality better than it was in 2023:
>> can we boot something beyond just the firmware now?
>> * is anybody planning to actively work on it?
>> * is anybody using it?
>
> I don't mind about the quality, as we never claim this stuff
> is providing a security boundary, but I do wonder whether the
> bar for merging a machine should have been higher than
> "shows firmware prompt" ?
That's a tricky one, as Bryce did some really good reverse engineering during GSoC
but I think if this were the situation today we would likely not merge it without
discussion around future direction and maintainership.
> Are there other machines we have merged with that level of
> very limited functionality ?
>
> Is it reasonable to say "boot a guest OS" is a criteria for
> merging machines in future ?
ATB,
Mark.
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] docs/about: Deprecate the 'next-cube' m68k machine
2026-08-27 17:45 ` Daniel P. Berrangé
2026-08-27 17:51 ` Peter Maydell
2026-08-27 20:34 ` Mark Cave-Ayland
@ 2026-08-27 21:05 ` Thomas Huth
2 siblings, 0 replies; 12+ messages in thread
From: Thomas Huth @ 2026-08-27 21:05 UTC (permalink / raw)
To: Daniel P. Berrangé, Peter Maydell
Cc: Philippe Mathieu-Daudé, Mark Cave-Ayland, Thomas Huth,
qemu-devel, Laurent Vivier, Natalia Portillo
On 27/08/2026 19.45, Daniel P. Berrangé wrote:
> On Thu, Aug 27, 2026 at 06:32:43PM +0100, Peter Maydell wrote:
>> On Thu, 27 Aug 2026 at 17:09, Philippe Mathieu-Daudé
>> <philmd@oss.qualcomm.com> wrote:
>>>
>>> Hi Thomas,
>>>
>>> On 27/8/26 14:54, Thomas Huth wrote:
>>>> On 09/10/2023 21.39, Mark Cave-Ayland wrote:
>>>>> On 07/10/2023 08:23, Thomas Huth wrote:
>>>>>
>>>>> (added Natalia who was the GSoC mentor for the NeXT cube work)
>>>>>
>>>>>> The machine is incomplete, and unfortunately the hoped-for improvements
>>>>>> never happened. So it's maybe best if we mark this machine as deprecated
>>>>>> and finally remove it again in case it gets into the way of a code
>>>>>> refactoring or other reasons.
...
> I don't mind about the quality, as we never claim this stuff
> is providing a security boundary, but I do wonder whether the
> bar for merging a machine should have been higher than
> "shows firmware prompt" ?
I think merging machines that are only partially working is fine as long as
there is follow-up work that takes the state of the machine further in the
direction of completion.
The 'next-cube' machine looked promising first, and merging the code was
good to prevent the state from further bit-rotting, but unfortunately it
completely lost traction in the course of time (except for some improvements
in the related SCSI controller, big thanks to Mark for that work!). Anyway,
in such cases when there is hardly any progress anymore, we should admit
that the experiment failed and finally remove such machines again.
> Are there other machines we have merged with that level of
> very limited functionality ?
According to
https://www.mail-archive.com/qemu-devel@nongnu.org/msg605124.html the
xlnx-zynqmp-pmu machine is in a similar unfinished state since years.
Maybe also check https://wiki.qemu.org/Testing/Machines to see whether there
are other machines that don't have a test yet ... those are good candidates,
too.
> Is it reasonable to say "boot a guest OS" is a criteria for
> merging machines in future ?
I'd say no, work in progress code is fine, as long as there is progress. But
if the progress is gone and the machine never reaches the "boot a guest OS"
state, we should also be fine with deprecating and removing it again.
Thomas
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] docs/about: Deprecate the 'next-cube' m68k machine
2026-08-27 17:32 ` Peter Maydell
2026-08-27 17:45 ` Daniel P. Berrangé
@ 2026-08-27 20:28 ` Mark Cave-Ayland
2026-08-27 20:49 ` Thomas Huth
2 siblings, 0 replies; 12+ messages in thread
From: Mark Cave-Ayland @ 2026-08-27 20:28 UTC (permalink / raw)
To: Peter Maydell, Philippe Mathieu-Daudé
Cc: Thomas Huth, Thomas Huth, qemu-devel, Laurent Vivier,
Natalia Portillo
On 27/08/2026 18:32, Peter Maydell wrote:
> On Thu, 27 Aug 2026 at 17:09, Philippe Mathieu-Daudé
> <philmd@oss.qualcomm.com> wrote:
>>
>> Hi Thomas,
>>
>> On 27/8/26 14:54, Thomas Huth wrote:
>>> On 09/10/2023 21.39, Mark Cave-Ayland wrote:
>>>> On 07/10/2023 08:23, Thomas Huth wrote:
>>>>
>>>> (added Natalia who was the GSoC mentor for the NeXT cube work)
>>>>
>>>>> The machine is incomplete, and unfortunately the hoped-for improvements
>>>>> never happened. So it's maybe best if we mark this machine as deprecated
>>>>> and finally remove it again in case it gets into the way of a code
>>>>> refactoring or other reasons.
>
>>>> I'm torn a bit by this one - on the one hand the NeXT code could do
>>>> with some love, but then given that the code already uses qdev/QOM
>>>> then there isn't really much in the way of maintenance burden. The
>>>> main concern for me at the moment is the use of the old-style memory
>>>> accessors that pre-date the memory API.
>>>>
>>>> With my latest ESP patches I think it shouldn't be too hard to update
>>>> the NeXT DMA controller to get SCSI working, so perhaps we can leave
>>>> it for now if it doesn't cause too many problems?
>
>>> Almost three years later, the world changed quite a bit. We're getting
>>> flooded with AI-generated bug reports now, and of course people are
>>> discovering problems in this old and neglected code, e.g.:
>>>
>>> https://gitlab.com/qemu-project/qemu/-/work_items/4303
>>> https://gitlab.com/qemu-project/qemu/-/work_items/4304
>>> https://gitlab.com/qemu-project/qemu/-/work_items/4305
>>
>> Hobbyist motivated machine emulations never committed to be
>> secure. While I appreciate these bug reports for the overall
>> quality of the project, I'm taking these one as lowest priority.
>> I wouldn't even mind of closing them as WONTFIX "Thanks ...".
>
> I agree, but also they can prompt us to look and say "actually
> this machine is no longer used / never got sufficiently
> implemented to be useful / has no maintainer" (cf musicpal).
> So the questions here are:
> * is the machine's functionality better than it was in 2023:
> can we boot something beyond just the firmware now?
> * is anybody planning to actively work on it?
> * is anybody using it?
The ESP rewrite solved a number of problems and it is possible to load a kernel from
a disk image and start executing it. I do have a series that further tidies up the
machine (with fixes for the DMA controller) but it needs a bit more work to finish: I
believe that should be able to get a pre-installed disk image to userspace.
The assert()s are really there to catch unhandled accesses during boot and they
aren't considered a security boundary so I think it's fine to close these as WONTFIX
with a comment that the device is currently unimplemented and not within our security
boundary.
Certainly booting NeXTstep was useful in figuring out parts of the ESP rewrite and
also for helping test the 68040 emulation so it's not completely useless...
ATB,
Mark.
^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH] docs/about: Deprecate the 'next-cube' m68k machine
2026-08-27 17:32 ` Peter Maydell
2026-08-27 17:45 ` Daniel P. Berrangé
2026-08-27 20:28 ` Mark Cave-Ayland
@ 2026-08-27 20:49 ` Thomas Huth
2 siblings, 0 replies; 12+ messages in thread
From: Thomas Huth @ 2026-08-27 20:49 UTC (permalink / raw)
To: Peter Maydell, Philippe Mathieu-Daudé
Cc: Mark Cave-Ayland, Thomas Huth, qemu-devel, Laurent Vivier,
Natalia Portillo
On 27/08/2026 19.32, Peter Maydell wrote:
> On Thu, 27 Aug 2026 at 17:09, Philippe Mathieu-Daudé
> <philmd@oss.qualcomm.com> wrote:
>>
>> Hi Thomas,
>>
>> On 27/8/26 14:54, Thomas Huth wrote:
>>> On 09/10/2023 21.39, Mark Cave-Ayland wrote:
>>>> On 07/10/2023 08:23, Thomas Huth wrote:
>>>>
>>>> (added Natalia who was the GSoC mentor for the NeXT cube work)
>>>>
>>>>> The machine is incomplete, and unfortunately the hoped-for improvements
>>>>> never happened. So it's maybe best if we mark this machine as deprecated
>>>>> and finally remove it again in case it gets into the way of a code
>>>>> refactoring or other reasons.
>
>>>> I'm torn a bit by this one - on the one hand the NeXT code could do
>>>> with some love, but then given that the code already uses qdev/QOM
>>>> then there isn't really much in the way of maintenance burden. The
>>>> main concern for me at the moment is the use of the old-style memory
>>>> accessors that pre-date the memory API.
>>>>
>>>> With my latest ESP patches I think it shouldn't be too hard to update
>>>> the NeXT DMA controller to get SCSI working, so perhaps we can leave
>>>> it for now if it doesn't cause too many problems?
>
>>> Almost three years later, the world changed quite a bit. We're getting
>>> flooded with AI-generated bug reports now, and of course people are
>>> discovering problems in this old and neglected code, e.g.:
>>>
>>> https://gitlab.com/qemu-project/qemu/-/work_items/4303
>>> https://gitlab.com/qemu-project/qemu/-/work_items/4304
>>> https://gitlab.com/qemu-project/qemu/-/work_items/4305
>>
>> Hobbyist motivated machine emulations never committed to be
>> secure. While I appreciate these bug reports for the overall
>> quality of the project, I'm taking these one as lowest priority.
>> I wouldn't even mind of closing them as WONTFIX "Thanks ...".
The problem is that closing such tickets likely won't prevent other
LLM-based "security researchers" to open another ticket for the same problem
again in the future. So as long as we have such spots in the code, we'll get
spammed with such AI-based tickets (IIRC some of the past AI tickets already
had 4 or 5 dups from different people). And every time you have to triage
the ticket, decide whether it's a real issue or not ... it's just very time
intensive.
> I agree, but also they can prompt us to look and say "actually
> this machine is no longer used / never got sufficiently
> implemented to be useful / has no maintainer" (cf musicpal).
> So the questions here are:
> * is the machine's functionality better than it was in 2023:
> can we boot something beyond just the firmware now?
Mark did some work on the SCSI controller, but I think it's still missing
some proper interrupt or DMA handling somewhere, so the kernel still does
not boot properly yet.
> * is anybody planning to actively work on it?
I was originally hoping that the original author would chime in again once
the basics had been merged, but unfortunately that never happened.
> * is anybody using it?
Certainly not. Unless that person enjoys looking at the firmware prompt ;-)
Thomas
^ permalink raw reply [flat|nested] 12+ messages in thread