From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0BF15103A9BB for ; Wed, 25 Mar 2026 11:32:44 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1w5MT7-0000yd-T4; Wed, 25 Mar 2026 07:32:13 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1w5MT4-0000yF-JJ for qemu-devel@nongnu.org; Wed, 25 Mar 2026 07:32:11 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1w5MSz-0002cZ-QH for qemu-devel@nongnu.org; Wed, 25 Mar 2026 07:32:08 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1774438323; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=VXAQF2BQW/qmhwFeExGr+jZAnXrFmJ1ZJHcFVXZHdVA=; b=QtQDZYg4xLyXTedoDlptO+swxcLcqnTNglKGaAiSRo1oUwSW0xtQLIWKMz3m0Lr3KCrAws nWoCjpyx/zQkG8V3Zgq90dWC33Q5q97BTqykhYWXUAdwd6otqx/zA4onmlcRFhAimAWhR6 ENBEHkWMyh7/yGWv00ibFCmhauyZB7w= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-275-vQ6-dF6TP--Az-d3MYQv3w-1; Wed, 25 Mar 2026 07:32:00 -0400 X-MC-Unique: vQ6-dF6TP--Az-d3MYQv3w-1 X-Mimecast-MFC-AGG-ID: vQ6-dF6TP--Az-d3MYQv3w_1774438318 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 992331800612; Wed, 25 Mar 2026 11:31:58 +0000 (UTC) Received: from redhat.com (unknown [10.44.34.14]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 0309B180036E; Wed, 25 Mar 2026 11:31:55 +0000 (UTC) Date: Wed, 25 Mar 2026 11:31:52 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= Cc: Peter Maydell , qemu-block , Michael Tokarev , QEMU Development , Richard Henderson , Pierrick Bouvier Subject: Re: QEMU requires a 64-bit CPU host architecture? Message-ID: References: <2c0d6ae0-eb06-4eed-87fe-0954ae59d951@tls.msk.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/2.2.14 (2025-02-20) X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Wed, Mar 25, 2026 at 12:21:27PM +0100, Philippe Mathieu-Daudé wrote: > On 25/3/26 11:24, Peter Maydell wrote: > > On Wed, 25 Mar 2026 at 09:19, Daniel P. Berrangé wrote: > > > > > > On Wed, Mar 25, 2026 at 11:08:41AM +0300, Michael Tokarev wrote: > > > > On 20.03.2026 09:45, Michael Tokarev wrote: > > > > > Hi! > > > > > > > > > > Is it intentional that qemu does not build utilities on 32bit hosts > > > > > anymore? > > > > > > > > This is > > > > > > > > commit 372ec46b9f1215f48a4717f2b7ed969f65bfadc6 > > > > Author: Richard Henderson > > > > Date: Thu Dec 18 09:56:27 2025 +1100 > > > > > > > > meson: Reject 32-bit hosts > > > > > > > > 32-bit hosts have been deprecated since 10.0. > > > > > > > > How would one build qemu-img and especially qemu-guest-agent, say, > > > > on i386 or armhf? > > > > > > > > I tried removing this error message from meson.build (in $subject), > > > > but it fails to build even the qga due to errors in atomic.h, - > > > > even if these aren't used by qga. > > > > > > > > That smells like a bad decision, - to drop qga and qemu-img support > > > > on 32bit architectures. Especially qga. > > > > > > IMHO dropping the block related tools is reasonable, as if you keep > > > that, the dependencies that need to remain 32-bit compatible ripple > > > out across a very large part of the codebase. > > > > > > Not having qga though feels like a pretty undesirable consequence, > > > given our message overall is that we were dropping host support but > > > keeping 32-bit emulation. > > > > Yes, I'm not sure we quite realised that we would be no longer > > building QGA for 32-bits. How much effort would it be to > > reinstate that? > > From the commits in 5053e0a65db...90e2e8ada7c we'd need to (partially) > revert various of the buildsys ones (meson & configure). > > Then we'd need to check if the Stat64 API (90e2e8ada7c) was used by > the block tools, and if so also revert the atomic64 patches (around > 997d86a9bb1). If not some (sane) refactor is needed for some core > components (disentangle qdev from qom due to the atomic uses). Still > we rely heavily on atomic helpers for threads and co-routines used > by the block layer (and also to reference the QOM objects...). > > How / where would we test that (and for how long)? IMHO we should not re-enable the block layer for 32-bit. Beyond the block/ directory, that also pulls in io/, crypto/, auth/, chardev/, and implies both unit testing and I/O tests too. I'd suggest we only make the guest agent work for 32-bit. aka this command line: ./configure --disable-system --disable-user --disable-tools --enable-guest-agent which limits us just to util/, qobject/, qapi/, qga/ dirs, and limited unit tests only. 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 :|