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: 12708234 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 D3050C433F5 for ; Mon, 10 Jan 2022 05:42:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Cc:To:From:Subject:Mime-Version: Message-Id:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To: References:List-Owner; bh=tSW2DyrMqwT2oWVYzXuiMi4LT5hSyGUhIG/cA6MBYIE=; b=Erv ZBAZU48A179lhQDcOso+vgcVvooriqO+HbjjORJxh4vte5FfLySYEtK5Us2vlBt+BBnIr49hgQG+w oChYkBAEo+7lb1VVuRidwi2hoWPv/r/OhuU9nyCJztGg/jG8Q8LSyop8LrGs6w1gjGWSZCGfCm0GX F0NGTjc025/Ck0oosH8yEDDEhnfz1UJskt5LNk0BFObFnsJ8/LOp5tLesV+0RBfmNkW8UEoloOtFv 9YQN2kpPJTyVHdqgeimrzJUNcFI9Qv6iZNkDcaXkLgP+KLfCYSABS3yGgYbySPH4utmmZukaI9UKn PKvMq3bZipAHLxUgeV1h7v/B6JBd5Jg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1n6nR1-009LSS-Si; Mon, 10 Jan 2022 05:41:36 +0000 Received: from mail-pj1-x104a.google.com ([2607:f8b0:4864:20::104a]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1n6nQf-009LNi-Eh for linux-arm-kernel@lists.infradead.org; Mon, 10 Jan 2022 05:41:15 +0000 Received: by mail-pj1-x104a.google.com with SMTP id c12-20020a17090a558c00b001b364b735efso7297261pji.6 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=lNtWKqQ3OSMtwDX9RGpZVcJaCldgC97h30LgDt+3ZVQufVoUPjU56yMuXcusV6yK0O /al9iDelBSpLMjnWyXAPKm8/7CYdNK1LX9FVSepkX21RCo94uFS/yyV8rHphYLSgGLoy yOP/NK4ug5yKhwPxLbRgTtXMxEaCTFjtKrNILCzNfg8/TVKqrhDffuqX8SxluyobTFZJ ulXD+is+Ju/+A7+wWsfC0KTvV8EDLzvbInUfz6y3qPc2hAE5P73g+xZUkrEV8uIlAYeg YSvaS4ZD8ghkfas9xpWIOnQ8t4pLHdqyesP88/tzLwGlsmFzxX5egUiSWKsShfOoi+Zs uNmQ== X-Gm-Message-State: AOAM531gj3dNhbH4Min34XdvVEIlsr2XA/9HK/H15NvxTjwhozU0v8/B UjciEs6C/fZShHa+ZA+xSjNEvUUBo70= 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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220109_214113_550597_0AFC69DD X-CRM114-Status: GOOD ( 13.26 ) 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 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; }