Re: QEMU 32-bit vs. 64-bit binaries

From: Thomas Huth <thuth@redhat.com>
To: Markus Armbruster <armbru@redhat.com>,
	qemu-devel@nongnu.org, qemu-arm <qemu-arm@nongnu.org>,
	Peter Maydell <peter.maydell@linaro.org>,
	Richard Henderson <richard.henderson@linaro.org>
Cc: "Mark Cave-Ayland" <mark.cave-ayland@ilande.co.uk>,
	"Fabiano Rosas" <farosas@linux.ibm.com>,
	muriloo@linux.ibm.com, "Paolo Bonzini" <pbonzini@redhat.com>,
	"Philippe Mathieu-Daudé" <f4bug@amsat.org>,
	"Daniel Henrique Barboza" <danielhb413@gmail.com>,
	"Dr . David Alan Gilbert" <dgilbert@redhat.com>,
	mopsfelder@gmail.com, qemu-ppc@nongnu.org,
	"Cédric Le Goater" <clg@kaod.org>,
	qemu-RISC-V <qemu-riscv@nongnu.org>
Subject: Re: QEMU 32-bit vs. 64-bit binaries
Date: Tue, 10 May 2022 11:01:02 +0200	[thread overview]
Message-ID: <32e5877d-ba45-ac63-d24e-1f9f8676c6bb@redhat.com> (raw)
In-Reply-To: <877d6tzs2e.fsf@pond.sub.org>

On 10/05/2022 10.54, Markus Armbruster wrote:
> Thomas Huth <thuth@redhat.com> writes:
> 
> [...]
> 
>> I once suggested in the past already that we should maybe get rid of
>> the 32-bit variants in case the 64-bit variant is a full superset, so
>> we can save compile- and test times (which is quite a bit for QEMU),
>> but I've been told that the 32-bit variants are mostly still required
>> for supporting KVM on 32-bit host machines.
> 
> Do we still care for 32-bit host machines?

As long as the Linux kernel still supports 32-bit KVM virtualization, I 
think we have to keep the userspace around for that, too.

But I wonder why we're keeping qemu-system-arm around? 32-bit KVM support 
for ARM has been removed with Linux kernel 5.7 as far as I know, so I think 
we could likely drop the qemu-system-arm nowadays, too? Peter, Richard, 
what's your opinion on this?

  Thomas