From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from zen.linaroharston ([85.9.250.243]) by smtp.gmail.com with ESMTPSA id t25-20020a7bc3d9000000b003e896d953a8sm19318702wmj.17.2023.03.01.04.58.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 01 Mar 2023 04:58:18 -0800 (PST) Received: from zen (localhost [127.0.0.1]) by zen.linaroharston (Postfix) with ESMTP id 2C67D1FFB7; Wed, 1 Mar 2023 12:58:18 +0000 (GMT) References: <20230228192628.26140-1-farosas@suse.de> <20230228192628.26140-10-farosas@suse.de> <87a60wk6st.fsf@secure.mitica> <87zg8wk69m.fsf@suse.de> User-agent: mu4e 1.9.21; emacs 29.0.60 From: Alex =?utf-8?Q?Benn=C3=A9e?= To: Fabiano Rosas Cc: quintela@redhat.com, qemu-devel@nongnu.org, qemu-arm@nongnu.org, Peter Maydell , Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= , Richard Henderson , Paolo Bonzini , Claudio Fontana , Eduardo Habkost , Alexander Graf , Cornelia Huck , "Michael S. Tsirkin" , Igor Mammedov , Ani Sinha , Thomas Huth , Laurent Vivier , "Dr. David Alan Gilbert" Subject: Re: [PATCH RESEND v7 9/9] tests/qtest: Fix tests when no KVM or TCG are present Date: Wed, 01 Mar 2023 12:57:33 +0000 In-reply-to: <87zg8wk69m.fsf@suse.de> Message-ID: <87bklcd3x1.fsf@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-TUID: MYABWm+ze2r5 Fabiano Rosas writes: > Juan Quintela writes: > >> Fabiano Rosas wrote: >>> It is possible to have a build with both TCG and KVM disabled due to >>> Xen requiring the i386 and x86_64 binaries to be present in an aarch64 >>> host. >> >> Ouch. >> >> Just curious: why are they needed? >> > > From https://wiki.xenproject.org/wiki/QEMU_Upstream: > > Why is qemu-system-i386 used even on x86_64 and even non-x86? >=20=20=20 > QEMU in a Xen system only provides device model (DM) emulation and not > any CPU instruction emulation, so the nominal arch doesn't actually > matter and Xen builds i386 everywhere as a basically arbitrary choice. >=20=20=20 > It happens that the Xen DM part of QEMU is quite closely tied to the x86 > scaffolding for various historical reasons, so we end up using > qemu-system-i386 even e.g. on ARM! There is no practical difference > between qemu-system-i386 and qemu-system-x86_64, they should be > interchangeable. However only qemu-system-i386 is regularly tested by > Xen Project (via osstest). That said with the xenpvh model that was added recently we should be able to finally build a Xen only qemu-system-aarch64 which while functionally the same will be less head scratching for users. > >>> >>> If we build with --disable-tcg on the aarch64 host, we will end-up >>> with a QEMU binary (x86) that does not support TCG nor KVM. >>> >>> Fix tests that crash or hang in the above scenario. Do not include any >>> test cases if TCG and KVM are missing. >>> >>> Signed-off-by: Fabiano Rosas >>> --- >>> This currently affects Arm, but will also affect x86 after the xenpvh >>> series gets merged. This patch fixes both scenarios. >> >> Reviewed-by: Juan Quintela > > Thanks! --=20 Alex Benn=C3=A9e Virtualisation Tech Lead @ Linaro