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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 64590F54AD9 for ; Tue, 24 Mar 2026 16:47:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:MIME-Version: References:In-Reply-To:Subject:Cc:To:From:Message-ID:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=RaYmwN9M/QNSH0/UcxvoZYSN5NEcrQA8nuxUjp6DTlY=; b=nyVR6CA3UucV7ks88ueVepYyKS d5WK9xTX1/t/Yh75GZQ6s83Posysnj+1HfyGXtdMIULUsC23Zstt+x2V1Wm9JBhE9Zeo0sCBNPk9d 61oVJP+g4BhOVh5/iSlQLAtY+OGV4/ZLHo3AVSFcp/S+E5MpDnX4tkUS6xy5fyw/ekxEerzMckGbu uVQ2zFbgUY55CJirf7wW3wtc+goqHOy9mgNBRO0j8qPj/gTu1tqaREXbdZ8Zkg0g6YXVjDPixUJCn OoB+BwPfohX6//01Tl07Wr9HJmPhBUu1A+7NWwth6hszrJfsxd01GKEggj/uWYJ6gRr4QIYqRY37h rgcjVysg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1w54uW-00000001vZ7-48Be; Tue, 24 Mar 2026 16:47:21 +0000 Received: from sea.source.kernel.org ([2600:3c0a:e001:78e:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1w54uU-00000001vYl-3gGv for linux-arm-kernel@lists.infradead.org; Tue, 24 Mar 2026 16:47:19 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 916C943FB8; Tue, 24 Mar 2026 16:47:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6AB3DC19424; Tue, 24 Mar 2026 16:47:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774370838; bh=XnDBIiYViRetm53tsWXR/B7QRmTtoJGHqC9bSVMJ1v4=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=DHyC17NjVJl7bF4XQYna1r84t+tCqrQtoXRFs2ZRfAgBaed+DN6iWpb1L2nvgBK+H 4hVoUKpxFfabUpqjN2dv7sdE0z2D6lInK8myXtcQ5rHt6Zs77/nADpxKwieq+es0Gx 7mRb7LKfz9QQ8R/Qw9Z1QUu0ROnRAwUmCgKgFjdpu3nxgLm8BL2jy8/PG7YASIoZC5 GLzIUwmmnsiOqgWO401TQKo2zhUbDpMelGtn5Nasp9mluL5eCIbevv/BIKnN2OGnUH 5I87BQixz9fwaTJ6vAmxBHbReNGcG7BMCyXdkvLh4XwIm0IZH/37xuoGozIQE7CaXD Bb3VU1+30OYxg== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.98.2) (envelope-from ) id 1w54uS-00000005G3x-0xwZ; Tue, 24 Mar 2026 16:47:16 +0000 Date: Tue, 24 Mar 2026 16:47:15 +0000 Message-ID: <86pl4t41kc.wl-maz@kernel.org> From: Marc Zyngier To: Mark Brown Cc: Joey Gouly , Suzuki K Poulose , Paolo Bonzini , Shuah Khan , Oliver Upton , Ben Horgan , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v5 4/5] KVM: selftests: arm64: Skip all 32 bit IDs when set_id_regs is aarch64 only In-Reply-To: <20260317-kvm-arm64-set-id-regs-aarch64-v5-4-a60f2b956e22@kernel.org> References: <20260317-kvm-arm64-set-id-regs-aarch64-v5-0-a60f2b956e22@kernel.org> <20260317-kvm-arm64-set-id-regs-aarch64-v5-4-a60f2b956e22@kernel.org> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/30.1 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: broonie@kernel.org, joey.gouly@arm.com, suzuki.poulose@arm.com, pbonzini@redhat.com, shuah@kernel.org, oupton@kernel.org, ben.horgan@arm.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260324_094718_952428_82661522 X-CRM114-Status: GOOD ( 17.66 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, 17 Mar 2026 20:10:37 +0000, Mark Brown wrote: > > On an aarch64 only system the 32 bit ID registers have UNDEFINED values. > As a result set_id_regs skips tests for setting fields in these registers > when testing an aarch64 only guest. This has the side effect of meaning > that we don't record an expected value for these registers, meaning that > when the subsequent tests for values being visible in guests and preserved > over reset check the value they can spuriously fail. This can be seen by > running on an emulated system with both NV and 32 bit enabled, NV will > result in the guests created by the test program being 64 bit only but > the 32 bit ID registers will have values. I don't think papering over this problem is the right thing to do. If the issue is that you have HW that has both NV and AArch32, then KVM needs to be fixed to make the 32bit IDregs RAZ when NV is present because that's not a configuration we support. M. -- Without deviation from the norm, progress is not possible.