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From: "Daniel P. Berrangé" <berrange@redhat.com>
To: Michael Tokarev <mjt@tls.msk.ru>
Cc: QEMU Development <qemu-devel@nongnu.org>
Subject: Re: QEMU requires a 64-bit CPU host architecture?
Date: Fri, 20 Mar 2026 08:54:44 +0000	[thread overview]
Message-ID: <ab0LPpXlojZHtMZQ@redhat.com> (raw)
In-Reply-To: <2c0d6ae0-eb06-4eed-87fe-0954ae59d951@tls.msk.ru>

On Fri, Mar 20, 2026 at 09:45:20AM +0300, Michael Tokarev wrote:
> Hi!
> 
> Is it intentional that qemu does not build utilities on 32bit hosts
> anymore?

Yes, per this note:

  https://www.qemu.org/docs/master/about/removed-features.html#bit-host-operating-systems-removed-in-11-0


> I understand system/user emulation on a 32bit host, where there are
> quite some real difficulties with address space sizes.
> 
> But what's wrong with building qemu-img et al on a 32bit host?  It
> doesn't require 64bit address space..

While the acclerator burden was one big factor, there were other
code removals enabled by dropping 32-bit hosts, such as removal
of 64-bit atomics emulation, and removal of some back compat
definitions for 32-bit kernels, and simplifying assumptions about
CPU features in other code, all of which leak out into common
code used by qemu-img & similar tools.

Keeping an arbitrary, and continually changing, subset of QEMU
supporting 32-bit while most code dropped 64-bit would not be
fun situation for maintainers, even with CI to try to detect
problems.

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 :|



  reply	other threads:[~2026-03-20  8:55 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-03-20  6:45 QEMU requires a 64-bit CPU host architecture? Michael Tokarev
2026-03-20  8:54 ` Daniel P. Berrangé [this message]
2026-03-20  9:26   ` Helge Deller
2026-03-25  8:08 ` Michael Tokarev
2026-03-25  9:18   ` Daniel P. Berrangé
2026-03-25 10:24     ` Peter Maydell
2026-03-25 11:21       ` Philippe Mathieu-Daudé
2026-03-25 11:31         ` Daniel P. Berrangé
2026-03-25 11:55         ` Philippe Mathieu-Daudé
2026-03-25 13:05           ` Michael Tokarev

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