Re: [PULL 8/9] meson: Disallow 64-bit on 32-bit emulation

["Daniel P. Berrangé" <berrange@redhat.com>]

On Fri, Apr 11, 2025 at 05:05:20PM +0200, Philippe Mathieu-Daudé wrote:
> On 11/4/25 15:42, Daniel P. Berrangé wrote:
> > On Sat, Feb 08, 2025 at 12:57:23PM -0800, Richard Henderson wrote:
> > > For system mode, we can rarely support the amount of RAM that
> > > the guest requires. TCG emulation is restricted to round-robin
> > > mode, which solves many of the atomicity issues, but not those
> > > associated with virtio.  In any case, round-robin does nothing
> > > to help the speed of emulation.
> > > 
> > > For user mode, most emulation does not succeed at all.  Most
> > > of the time we cannot even load 64-bit non-PIE binaries due
> > > to lack of a 64-bit address space.  Threads are run in
> > > parallel, not round-robin, which means that atomicity
> > > is not handled.
> > > 
> > > Reviewed-by: Thomas Huth <thuth@redhat.com>
> > > Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> > > Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> > > ---
> > >   meson.build | 13 ++++++++++---
> > >   1 file changed, 10 insertions(+), 3 deletions(-)
> > 
> > Shouldn't  this patch and the earlier ones in this series have
> > added something to removed-features.rst, as this is a significant
> > feature removal which is impacting downstream users, and distros
> > in particular.
> 
> IIRC the rationale for not deprecating was the feature is largely
> broken already. Skipping the deprecation process we indeed forgot
> to document in removed-features.rst.
> 
> Do you expect the doc update for the 10.0 release?

The issue is that

  https://wiki.qemu.org/ChangeLog/10.0

delegates to removed-features.rst, so if we don't have time to
update the rst file, then we at least need to edit ChangeLog/10.0
to mention this removal of binaries as a fallback


With regards,
Daniel
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