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 X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 81202C4321A for ; Tue, 2 Mar 2021 22:07:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 586DD64F2D for ; Tue, 2 Mar 2021 22:07:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1837696AbhCBV6W (ORCPT ); Tue, 2 Mar 2021 16:58:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39288 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1581625AbhCBTA4 (ORCPT ); Tue, 2 Mar 2021 14:00:56 -0500 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 49741C0611C0 for ; Tue, 2 Mar 2021 10:46:04 -0800 (PST) Received: by mail-yb1-xb49.google.com with SMTP id u17so23734855ybi.10 for ; Tue, 02 Mar 2021 10:46:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:reply-to:date:in-reply-to:message-id:mime-version:references :subject:from:to:cc; bh=kSiLnMDkk0ckb4albKKYSCbZaXElHQozT1Z/Ps7GfuI=; b=OHQSzC1bWC97Wo53/ZEgH7WOW5Ud0ZEnUvSaVvwdq0Ra5F8k+TKijqaCAAblPm/5Dj oS9Z5TX7fNhYfkDqOWOquzZMzgUZ0T+Al3eaKVABvAHfEVJQUcb015O9QRMbVLhNcCw0 ThjWF23s8VRE2VMwpEsEZxFwRs0OJwpQ6n6IZpB4w/v9lJukl0TqknRXeh/2uGIOQeNe hkX6ChPh1Iq1RNBAMpC/+dx0BD5GseF6sHk/ffR1CAz4dXqRAmkjyQdy78zTtft+S+cc tKq4/73jmYQ9JJhdJ1oGQbX5eAof9aOBtgXzkB1Np4O+3uF8TGNWJ5cvdDzIThnAjv+Z juMg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:reply-to:date:in-reply-to:message-id :mime-version:references:subject:from:to:cc; bh=kSiLnMDkk0ckb4albKKYSCbZaXElHQozT1Z/Ps7GfuI=; b=DnVWWBQB5eANEHuHfgxO74hBZ8JI8aPDrJCOabqpUdfdYoquOI6+N/2We/Lv98TRSZ WEouZgUDAwHecXKV+/BqYoOk78sDre6gvDh+ywT5/qIgqe3Kor+UmP1sXLzS8/Gnqg3E G3go68T1gK8+bdgKQ7LlhN8Tm1FlwHiFoQGWpIKYqilfR15FjAoYUQBrhY2vNXTbA/Zu 8r4xKG35FlxPwfYNnIOUe10Ron4NI/0oLdtBgGHs+qqTwWFNXJS1SedmdjO4tyMI3D0V w747WkKp0Tauf3XmGoVK2mbo6+r0kxKB5mzKIWzU39R5heOoEoZ8yVPPBNhMMSmtm4ku biNg== X-Gm-Message-State: AOAM532oIQsCoNeQAKwyodj/A2/HMTglBhL7KdQgLyEIWPFKQCPzGgT6 2lp9Pjd/MqwgiH5QSgAAM5kg0QLwVoQ= X-Google-Smtp-Source: ABdhPJyhoCBxSZ78KfAXRL1vCHIkU/3TxPhR2oR2b1EZQg7JjcPgRbrYiftVi5G0tXXzEVlJaeHqFI3Eapk= Sender: "seanjc via sendgmr" X-Received: from seanjc798194.pdx.corp.google.com ([2620:15c:f:10:805d:6324:3372:6183]) (user=seanjc job=sendgmr) by 2002:a25:d296:: with SMTP id j144mr32687925ybg.33.1614710763543; Tue, 02 Mar 2021 10:46:03 -0800 (PST) Reply-To: Sean Christopherson Date: Tue, 2 Mar 2021 10:45:32 -0800 In-Reply-To: <20210302184540.2829328-1-seanjc@google.com> Message-Id: <20210302184540.2829328-8-seanjc@google.com> Mime-Version: 1.0 References: <20210302184540.2829328-1-seanjc@google.com> X-Mailer: git-send-email 2.30.1.766.gb4fecdf3b7-goog Subject: [PATCH 07/15] KVM: x86/mmu: Use '0' as the one and only value for an invalid PAE root From: Sean Christopherson To: Paolo Bonzini Cc: Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Ben Gardon , Brijesh Singh , Tom Lendacky Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Use '0' to denote an invalid pae_root instead of '0' or INVALID_PAGE. Unlike root_hpa, the pae_roots hold permission bits and thus are guaranteed to be non-zero. Having to deal with both values leads to bugs, e.g. failing to set back to INVALID_PAGE, warning on the wrong value, etc... Signed-off-by: Sean Christopherson --- arch/x86/kvm/mmu/mmu.c | 23 ++++++++++++----------- 1 file changed, 12 insertions(+), 11 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 3ef7fb2a9878..59b1709a55b4 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -3191,11 +3191,14 @@ void kvm_mmu_free_roots(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, (mmu->root_level >= PT64_ROOT_4LEVEL || mmu->direct_map)) { mmu_free_root_page(kvm, &mmu->root_hpa, &invalid_list); } else if (mmu->pae_root) { - for (i = 0; i < 4; ++i) - if (mmu->pae_root[i] != 0) - mmu_free_root_page(kvm, - &mmu->pae_root[i], - &invalid_list); + for (i = 0; i < 4; ++i) { + if (!mmu->pae_root[i]) + continue; + + mmu_free_root_page(kvm, &mmu->pae_root[i], + &invalid_list); + mmu->pae_root[i] = 0; + } } mmu->root_hpa = INVALID_PAGE; mmu->root_pgd = 0; @@ -3244,8 +3247,7 @@ static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu) vcpu->arch.mmu->root_hpa = root; } else if (shadow_root_level == PT32E_ROOT_LEVEL) { for (i = 0; i < 4; ++i) { - WARN_ON_ONCE(vcpu->arch.mmu->pae_root[i] && - VALID_PAGE(vcpu->arch.mmu->pae_root[i])); + WARN_ON_ONCE(vcpu->arch.mmu->pae_root[i]); root = mmu_alloc_root(vcpu, i << (30 - PAGE_SHIFT), i << 30, PT32_ROOT_LEVEL, true); @@ -3338,8 +3340,7 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) } for (i = 0; i < 4; ++i) { - WARN_ON_ONCE(vcpu->arch.mmu->pae_root[i] && - VALID_PAGE(vcpu->arch.mmu->pae_root[i])); + WARN_ON_ONCE(vcpu->arch.mmu->pae_root[i]); if (vcpu->arch.mmu->root_level == PT32E_ROOT_LEVEL) { if (!(pdptrs[i] & PT_PRESENT_MASK)) { @@ -3412,7 +3413,7 @@ void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu) for (i = 0; i < 4; ++i) { hpa_t root = vcpu->arch.mmu->pae_root[i]; - if (root && VALID_PAGE(root)) { + if (root && !WARN_ON_ONCE(!VALID_PAGE(root))) { root &= PT64_BASE_ADDR_MASK; sp = to_shadow_page(root); mmu_sync_children(vcpu, sp); @@ -5267,7 +5268,7 @@ static int __kvm_mmu_create(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu) mmu->pae_root = page_address(page); for (i = 0; i < 4; ++i) - mmu->pae_root[i] = INVALID_PAGE; + mmu->pae_root[i] = 0; return 0; } -- 2.30.1.766.gb4fecdf3b7-goog