From nobody Mon Feb 9 17:56:39 2026 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 4A505C6FD1D for ; Thu, 30 Mar 2023 08:58:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230384AbjC3I6x (ORCPT ); Thu, 30 Mar 2023 04:58:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59934 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230370AbjC3I6k (ORCPT ); Thu, 30 Mar 2023 04:58:40 -0400 Received: from mail-pj1-x102e.google.com (mail-pj1-x102e.google.com [IPv6:2607:f8b0:4864:20::102e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C625983E8 for ; Thu, 30 Mar 2023 01:58:29 -0700 (PDT) Received: by mail-pj1-x102e.google.com with SMTP id lr16-20020a17090b4b9000b0023f187954acso18907777pjb.2 for ; Thu, 30 Mar 2023 01:58:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1680166709; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=DARmMfXxqHb2Ls37OggPINW15nuQ84yCV7KESHjLY2s=; b=OXoX2NCxtPATlq8jnBH3sThb7ycsR+0Oe6TcPImZJi9tCnRpIHfnfMjFvh2OLeHSO7 M7F63PjkEBkJdxcACVhouJSazYLSPB0gy7jVYsu0xN+szgvXnNWoZ7Oh0kFFo4CWOLgC d+rHEFtEcJ4GCWJzO34ClqYb+5IULO9O4L5x8= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680166709; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=DARmMfXxqHb2Ls37OggPINW15nuQ84yCV7KESHjLY2s=; b=hAXdlrP7JemcxZ1ioJbxRq0yjRhi3XJMOR9lU2QErTfHiqTNHfw9YaItx5Uh32uE0S ASyTMvEldTcAElHQtq+6XKh90vDis+ix9/b5JdipcLkR6VW1jEB3p8RWtDL72062BKlK 3BSXtHx1kG6u7Jc9FJ4tvxSVfRzXUICHmo3zA+AmPWRGEkDJ8hNKHsQL/OIDcWi0YsLK NC440GMzlxa2nHIbqw+luygGebqYRza4nkQ864Efq3v9GOScnP82FjqrvbjEMsgvTHBK iUEn972clgAva0mKd4jq/3c7qsLtW6/zX03xJD85EGcPtPqBIz4XFVCYGcDZIYOS3VkH nRRg== X-Gm-Message-State: AAQBX9cdZ5QKFCYT+SgkvMhNZdx4RE7WUdbH4tYjGG3vthZOvBx/suvU Vjh4pjtljTZ7Dm2arfOshmemlw== X-Google-Smtp-Source: AKy350YitOtGSTe/IC945dOZxknelnREFOYZr+go4eGipagCeEp7bTT+/hLXchLclFceYZl0IfvvWw== X-Received: by 2002:a17:902:fb85:b0:19e:b088:5900 with SMTP id lg5-20020a170902fb8500b0019eb0885900mr19155304plb.38.1680166709092; Thu, 30 Mar 2023 01:58:29 -0700 (PDT) Received: from localhost ([2401:fa00:8f:203:1320:eef8:d0bb:b161]) by smtp.gmail.com with UTF8SMTPSA id s5-20020a63e805000000b00502f1256674sm23134697pgh.41.2023.03.30.01.58.26 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 30 Mar 2023 01:58:28 -0700 (PDT) From: David Stevens X-Google-Original-From: David Stevens To: Marc Zyngier , Sean Christopherson Cc: Oliver Upton , Paolo Bonzini , linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, David Stevens Subject: [PATCH v6 4/4] KVM: mmu: remove over-aggressive warnings Date: Thu, 30 Mar 2023 17:58:02 +0900 Message-Id: <20230330085802.2414466-5-stevensd@google.com> X-Mailer: git-send-email 2.40.0.348.gf938b09366-goog In-Reply-To: <20230330085802.2414466-1-stevensd@google.com> References: <20230330085802.2414466-1-stevensd@google.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: David Stevens Remove two warnings that require ref counts for pages to be non-zero, as mapped pfns from follow_pfn may not have an initialized ref count. Signed-off-by: David Stevens --- arch/x86/kvm/mmu/mmu.c | 10 ---------- virt/kvm/kvm_main.c | 5 ++--- 2 files changed, 2 insertions(+), 13 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 86b74e7bccfa..46b3d6c0ff27 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -555,7 +555,6 @@ static u64 mmu_spte_clear_track_bits(struct kvm *kvm, u= 64 *sptep) kvm_pfn_t pfn; u64 old_spte =3D *sptep; int level =3D sptep_to_sp(sptep)->role.level; - struct page *page; =20 if (!is_shadow_present_pte(old_spte) || !spte_has_volatile_bits(old_spte)) @@ -570,15 +569,6 @@ static u64 mmu_spte_clear_track_bits(struct kvm *kvm, = u64 *sptep) =20 pfn =3D spte_to_pfn(old_spte); =20 - /* - * KVM doesn't hold a reference to any pages mapped into the guest, and - * instead uses the mmu_notifier to ensure that KVM unmaps any pages - * before they are reclaimed. Sanity check that, if the pfn is backed - * by a refcounted page, the refcount is elevated. - */ - page =3D kvm_pfn_to_refcounted_page(pfn); - WARN_ON(page && !page_count(page)); - if (is_accessed_spte(old_spte)) kvm_set_pfn_accessed(pfn); =20 diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 007dd984eeea..a80070cb04d7 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -165,10 +165,9 @@ bool kvm_is_zone_device_page(struct page *page) /* * The metadata used by is_zone_device_page() to determine whether or * not a page is ZONE_DEVICE is guaranteed to be valid if and only if - * the device has been pinned, e.g. by get_user_pages(). WARN if the - * page_count() is zero to help detect bad usage of this helper. + * the device has been pinned, e.g. by get_user_pages(). */ - if (WARN_ON_ONCE(!page_count(page))) + if (!page_count(page)) return false; =20 return is_zone_device_page(page); --=20 2.40.0.348.gf938b09366-goog