Re: [Qemu-devel] Unmaintained QEMU builds

[Blue Swirl <blauwirbel@gmail.com>]

On Sun, Aug 15, 2010 at 9:42 PM, Anthony Liguori <anthony@codemonkey.ws> wrote:
> On 08/11/2010 11:34 AM, Blue Swirl wrote:
>>
>> On Wed, Aug 11, 2010 at 10:58 AM, Stefan Weil<weil@mail.berlios.de>
>>  wrote:
>>
>>>
>>> Hi,
>>>
>>> since several months, QEMU for Windows (and mingw32 cross builds)
>>> no longer builds without error.
>>>
>>
>> Not true for mingw32, it was building fine here until the latest commit.
>>
>>
>>>
>>> I suspect that the same is true for QEMU on Darwin (lots of errors like
>>> darwin-user/qemu.h:149: error: cast to pointer from integer of different
>>> size),
>>> but I'm not sure here because I have no valid Darwin test environment.
>>> Maybe someone can test this.
>>>
>>> What about these environments? They have no maintainers.
>>> Should they be marked as unsupported? Are they still used?
>>> Or should they be removed?
>>>
>>
>> I compile test mingw32 very often, it's part of my build test setup.
>> If the build breaks, I may even fix the problem
>>
>
> But do you do any testing with the Windows build?

Sometime I do a boot test with Wine.

> Historically, even when Windows builds, it spends large periods of time not
> actually working.  I think Stefan can confirm this.  Much of the platform
> specific code is way behind (like the block layer) and has been for many
> years.
>
> I can't remember the last time someone sent a Win32 enhancement for platform
> code.
>
> Given that it's known to have a lot of issues, I would suggest that we
> schedule Windows host support for deprecation in 0.15.  I would not
> recommend that we remove any of the WIN32 code from the build but basically
> stop trying to make it even build until someone steps up to really actively
> maintain and enhance the Windows port.  I would still suggest we take
> patches if anyone wants to submit them but we should not avoid patches that
> are known to break win32 (unless the fix is trivial).

The same strategy applied to all hosts would probably eventually break
everything but Linux on x86 with KVM. There have been very few patches
for Darwin, *Solaris, AIX or BSDs, non-x86 targets or non-x86 host
CPUs. Without Darwin or BSD host support, darwin-user and bsd-user
will be useless. When did we get Xen patches last time before the
recent patch set?

What about other uncommon and possibly already broken (or never
finished) features, like Parallels, VVFAT or VMDK support? What about
new features, do we know in advance that they will be actively
maintained?

But I'm not completely against this. Maybe we should make a list of
features and check which of those work. Features which don't pass are
scheduled for deprecation or removal.

> For instance, I know that some downstreams (like Android) depend heavily on
> Win32 so an official statement of deprecation might cause them to push some
> of their fixes upstream and be more active in upstream maintenance.

We haven't received any patches from VirtualBox downstream either, but
maybe they are still using 0.9.0, so they don't have any.