From patchwork Mon Jan 10 05:40:41 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Reiji Watanabe X-Patchwork-Id: 12708238 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CD360C433EF for ; Mon, 10 Jan 2022 05:41:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238805AbiAJFlN (ORCPT ); Mon, 10 Jan 2022 00:41:13 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53352 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238757AbiAJFlM (ORCPT ); Mon, 10 Jan 2022 00:41:12 -0500 Received: from mail-pj1-x1049.google.com (mail-pj1-x1049.google.com [IPv6:2607:f8b0:4864:20::1049]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4CAABC06173F for ; Sun, 9 Jan 2022 21:41:12 -0800 (PST) Received: by mail-pj1-x1049.google.com with SMTP id y15-20020a17090a600f00b001b3501d9e7eso9541951pji.8 for ; Sun, 09 Jan 2022 21:41:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:message-id:mime-version:subject:from:to:cc; bh=P1aAJUJH4MNJA7hqf+LRqj2aY6nDmgn4ybYnyTkArAE=; b=DKYr9uQS09X33zIc7+1zVb3NQ0xRf8HBTMLLm3p4pinup+CxLE+HbHLqhHvzqvqAb3 olhmXPyqbPsUCCdHiJUGtosE19JLvR49S1qjZI4NX924Y68uziCJNmqT7LElQs3CUgru ExwQbM7Qg6Bp7LwtNaXcprLPD7B9xYFoOVH2UWJDlxBXG+XmnTWYmM1BLt8KxaIs0Ln/ W4dqLxfV+V9VxkGMAIITblVgrtK4ZoaKN54r589zJ60edJKeaDB8mrTHaHEhBl8zRdZ5 R3D+YC4m8EYrXYfBL75jWzbnqUsG/7N57JvFqLytLroLG8h0FO7JdV6M7gHFF0CP0/Lb 9J2g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=P1aAJUJH4MNJA7hqf+LRqj2aY6nDmgn4ybYnyTkArAE=; b=byipa7fZXC81zhQfgzrf+QO60813s1OmoAYw8G2CydFAtMYLaEJn4Iw4v32yLyCaU3 X3U0C407cvlBRKunePVLQSmq6W3u9RcnqjiUoXF57CU5mekFgDn6wfFrCvVXmQxWInsl 99i1/Qy7f1RaJHU3q++TRWDwemziUejiqci73Y1dRj2hGH3mcjOQdyTfkjpX5YZqwKt3 uzeAWh26XuizxTfbHVV+t47RyT5GQNaglzbMBmyAgd1rXwPvywwiEqCWxLu7tQ5kpbK5 hcqpP5cpAevaQLUvlQPeNTFBkixf5qby2apw7O5n3yr8ylO71vvxN2m6h6jlgoWH8v2v 3aNw== X-Gm-Message-State: AOAM5321GpujtkA0LYmSdmS/tFL1HG5towjAKuHjNk4xCM8o8gly736v BUEnF4V48f2N96oowNMSC50MZFzryDc= X-Google-Smtp-Source: ABdhPJy2ff3+Ra0eAAdVIR8qPPRFVBp537t4vFeJtOPbXf4dGRZKqRvR8mgwpxO5W3cOouanq7W4upyND6M= X-Received: from reiji-vws-sp.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:3d59]) (user=reijiw job=sendgmr) by 2002:a05:6a00:d64:b0:4ba:cb6f:87e0 with SMTP id n36-20020a056a000d6400b004bacb6f87e0mr74125375pfv.72.1641793271719; Sun, 09 Jan 2022 21:41:11 -0800 (PST) Date: Sun, 9 Jan 2022 21:40:41 -0800 Message-Id: <20220110054042.1079932-1-reijiw@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.34.1.575.g55b058a8bb-goog Subject: [PATCH 1/2] KVM: arm64: mixed-width check should be skipped for uninitialized vCPUs From: Reiji Watanabe To: Marc Zyngier , kvmarm@lists.cs.columbia.edu Cc: kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, James Morse , Alexandru Elisei , Suzuki K Poulose , Paolo Bonzini , Will Deacon , Peter Shier , Ricardo Koller , Oliver Upton , Jing Zhang , Raghavendra Rao Anata , Reiji Watanabe Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org vcpu_allowed_register_width() checks if all the VCPUs are either all 32bit or all 64bit. Since the checking is done even for vCPUs that are not initialized (KVM_ARM_VCPU_INIT has not been done) yet, the non-initialized vCPUs are erroneously treated as 64bit vCPU, which causes the function to incorrectly detect a mixed-width VM. Fix vcpu_allowed_register_width() to skip the check for vCPUs that are not initialized yet. Fixes: 66e94d5cafd4 ("KVM: arm64: Prevent mixed-width VM creation") Signed-off-by: Reiji Watanabe --- arch/arm64/kvm/reset.c | 11 +++++++++++ 1 file changed, 11 insertions(+) base-commit: df0cc57e057f18e44dac8e6c18aba47ab53202f9 diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c index 426bd7fbc3fd..ef78bbc7566a 100644 --- a/arch/arm64/kvm/reset.c +++ b/arch/arm64/kvm/reset.c @@ -180,8 +180,19 @@ static bool vcpu_allowed_register_width(struct kvm_vcpu *vcpu) if (kvm_has_mte(vcpu->kvm) && is32bit) return false; + /* + * Make sure vcpu->arch.target setting is visible from others so + * that the width consistency checking between two vCPUs is done + * by at least one of them at KVM_ARM_VCPU_INIT. + */ + smp_mb(); + /* Check that the vcpus are either all 32bit or all 64bit */ kvm_for_each_vcpu(i, tmp, vcpu->kvm) { + /* Skip if KVM_ARM_VCPU_INIT is not done for the vcpu yet */ + if (tmp->arch.target == -1) + continue; + if (vcpu_has_feature(tmp, KVM_ARM_VCPU_EL1_32BIT) != is32bit) return false; }