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 12BF3C433E0 for ; Fri, 5 Mar 2021 01:11:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DACD564F67 for ; Fri, 5 Mar 2021 01:11:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230399AbhCEBLh (ORCPT ); Thu, 4 Mar 2021 20:11:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60918 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230112AbhCEBLa (ORCPT ); Thu, 4 Mar 2021 20:11:30 -0500 Received: from mail-qt1-x84a.google.com (mail-qt1-x84a.google.com [IPv6:2607:f8b0:4864:20::84a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DE878C0613D8 for ; Thu, 4 Mar 2021 17:11:27 -0800 (PST) Received: by mail-qt1-x84a.google.com with SMTP id 4so265641qtc.13 for ; Thu, 04 Mar 2021 17:11:27 -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=70+pbfsr9FN7xUzI6QuNzJ56yN8wNBmmQK3zMq55CLc=; b=pmvh31yoJyb4qrUv2ew3hjgo7ixYIuYizEYdNw1S8Gq+ecXPDzJKFHb3LM+e/2mqlG fSdsnhAOdSBYIPi4Yn9DL7cP7LY+onbUmEF6zZ2YIQba5+ujrgJc2v0BCLWm6SwvtX9m pkB/+anEXQ8lTyWLQ6E3g+cS4mTKDg+RYpwSnWSciyGNxDOeKaoU0RjNRc+d06+gT1b3 1FxItGOw2GqdRP4E4UcBo0GbAbvV4Y0psgkuzUalH67kDa0N08Y/ZgiEem2gbWboUZBr AdGwoXl3tVta/PsBOVFM/z/pfBU6r8PAXyUbeMVY8rNmrNrF9Z/EW8BL/MT9Sv4o9WyC 8ZZw== 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=70+pbfsr9FN7xUzI6QuNzJ56yN8wNBmmQK3zMq55CLc=; b=YcpGJgvAN1vA7FVy3YIirQsYHZ4iDJEjkk7NzToVUlihTq9ygS6ywKzURazvlVmSoY mSdIHlS0iqpKfdWlCFdA/Cod1jnE++5OYo8RvL46igrlOpdKuBSzHJDCyVMQo1fic5hQ e3OOwohH6Af6SGli+Sp98i+cHUkPu4zbUKeI16w4lI2DLKzTV77xi9KV3w9lL+3n/ZyB p3Avzz6VtbXdyiJsYO/hlVAVVrmVAFnmM+exbqq4b6Qd22pesWgqOwWfH71Zp6Z8qUO9 bveBcpKC6LWLYjDeeO9UGSW6KpSp7EAiymoS+l7ZSd5dmdAnuErfPoqurzubxabLJcmP LGVw== X-Gm-Message-State: AOAM533tJ4Vtizg2os4ndlRuc5r0ern/C+Fp62rtfztWU8eSgfPur2Eu /yC5jvkBOXwsdvDPginxPFa/fEp7vyY= X-Google-Smtp-Source: ABdhPJw0wUHUyLIyV84zNUK5PAtf+fBteAA09FyMWMOjiUWzcaumAVi1oNZhRU3hAx+V+kxeA4J903pJaRo= Sender: "seanjc via sendgmr" X-Received: from seanjc798194.pdx.corp.google.com ([2620:15c:f:10:9857:be95:97a2:e91c]) (user=seanjc job=sendgmr) by 2002:a0c:ef11:: with SMTP id t17mr6672405qvr.21.1614906687093; Thu, 04 Mar 2021 17:11:27 -0800 (PST) Reply-To: Sean Christopherson Date: Thu, 4 Mar 2021 17:10:53 -0800 In-Reply-To: <20210305011101.3597423-1-seanjc@google.com> Message-Id: <20210305011101.3597423-10-seanjc@google.com> Mime-Version: 1.0 References: <20210305011101.3597423-1-seanjc@google.com> X-Mailer: git-send-email 2.30.1.766.gb4fecdf3b7-goog Subject: [PATCH v2 09/17] 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 | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index b82c1b0d6d6e..dbf7f0395e4b 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -3197,11 +3197,14 @@ 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; @@ -3250,8 +3253,7 @@ static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu) mmu->root_hpa = root; } else if (shadow_root_level == PT32E_ROOT_LEVEL) { for (i = 0; i < 4; ++i) { - WARN_ON_ONCE(mmu->pae_root[i] && - VALID_PAGE(mmu->pae_root[i])); + WARN_ON_ONCE(mmu->pae_root[i]); root = mmu_alloc_root(vcpu, i << (30 - PAGE_SHIFT), i << 30, PT32_ROOT_LEVEL, true); @@ -3316,7 +3318,7 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu) } for (i = 0; i < 4; ++i) { - WARN_ON_ONCE(mmu->pae_root[i] && VALID_PAGE(mmu->pae_root[i])); + WARN_ON_ONCE(mmu->pae_root[i]); if (mmu->root_level == PT32E_ROOT_LEVEL) { if (!(pdptrs[i] & PT_PRESENT_MASK)) { @@ -3438,7 +3440,7 @@ 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); @@ -5296,7 +5298,7 @@ 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