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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 52E1AC433FE for ; Sat, 26 Feb 2022 00:16:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240333AbiBZAQy (ORCPT ); Fri, 25 Feb 2022 19:16:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49672 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240091AbiBZAQi (ORCPT ); Fri, 25 Feb 2022 19:16:38 -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 6A410214F86 for ; Fri, 25 Feb 2022 16:16:05 -0800 (PST) Received: by mail-yb1-xb49.google.com with SMTP id d17-20020a253611000000b006244e94b7b4so4990998yba.4 for ; Fri, 25 Feb 2022 16:16:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=reply-to:date:in-reply-to:message-id:mime-version:references :subject:from:to:cc; bh=W0dsOEq/PIsQRXnhmEzN4z4vDCVezWtZyWCTAFD0mm4=; b=kkTCjC4tVIj7enFaFMKIYHTANMNAYxjkHrt4FVwFXDe4UpZ9MJGM/QS0YDczVjf7zS xyCmw6fI2EpbOhAcLNPaVAm6RBmzabO5vXpzITVrlUpoTf1wQw4PbIxstYS2SyGOBdd8 ObaNGe64fwLi3o87QsWZ21hi0Zu0f1Knbx5jNrinn0D46zmVKOUU2/5VpUlnm2EybEEa fZ/TaCH4VDiAo0gmuhj9G1xesKLSJ2KCRPDK6t1kNJrbMcld3k6Y6hjYi12nyVC7Hbt6 jMvWvSfnhrHp49CLfuCKLksw6MoPezPBJHQQQyC97WTVDmrWDX/xDhXIWsCx7+7fauCA Ebdg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:reply-to:date:in-reply-to:message-id :mime-version:references:subject:from:to:cc; bh=W0dsOEq/PIsQRXnhmEzN4z4vDCVezWtZyWCTAFD0mm4=; b=T0BexUPmxmKAFIOjT5SW0tU/Oy+7uYeQ8z1At29t5rfa9B3RguLbgfzMuh5hjMk3J5 1QyVgikWDpKg1YiTv2xvsQJXgwYsc3+35Pofu5IoqhkM6fsZ320i9BynmhZYEhMuEZGg OvzEpvg7JAFwN5NSfXeyiKwB+9QIdKReiHmHsBdiaaAcblntsGUKL6MTn9Wz8jKQRETW e4b0cKm1+FodULVz0fOWUjmF45dxgD1j5zFBcRKNZDQzvnZm9wCPWSVjFN3M3COMgDNy /oVIQ7qadwrjelVmpBmoee5Vjc5uBNtZZ3YiuO76lHSF+VQbwdcpVqkkV/LbO+xlgjNV XLeA== X-Gm-Message-State: AOAM533ZcHPakFwI93/ZvbmNi5fxoc4yS23c6Xfdqz43NeW4vIizONh0 EVoASu/ilCxW+rWNq/yzMnAV0kcBda8= X-Google-Smtp-Source: ABdhPJwyWL5owexPrfMNeXvwM0V0pC6xHluXdGFWOU2XldPBciQnXTg/AL4B9+xNVnXtV72T/fRBvSj0OJg= X-Received: from seanjc.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:3e5]) (user=seanjc job=sendgmr) by 2002:a05:690c:3a1:b0:2d6:9324:cb4f with SMTP id bh33-20020a05690c03a100b002d69324cb4fmr10270352ywb.399.1645834564647; Fri, 25 Feb 2022 16:16:04 -0800 (PST) Reply-To: Sean Christopherson Date: Sat, 26 Feb 2022 00:15:20 +0000 In-Reply-To: <20220226001546.360188-1-seanjc@google.com> Message-Id: <20220226001546.360188-3-seanjc@google.com> Mime-Version: 1.0 References: <20220226001546.360188-1-seanjc@google.com> X-Mailer: git-send-email 2.35.1.574.g5d30c73bfb-goog Subject: [PATCH v3 02/28] KVM: x86/mmu: Check for present SPTE when clearing dirty bit in TDP MMU From: Sean Christopherson To: Paolo Bonzini , Christian Borntraeger , Janosch Frank , Claudio Imbrenda Cc: Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , David Hildenbrand , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, David Matlack , Ben Gardon , Mingwei Zhang Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Explicitly check for present SPTEs when clearing dirty bits in the TDP MMU. This isn't strictly required for correctness, as setting the dirty bit in a defunct SPTE will not change the SPTE from !PRESENT to PRESENT. However, the guarded MMU_WARN_ON() in spte_ad_need_write_protect() would complain if anyone actually turned on KVM's MMU debugging. Fixes: a6a0b05da9f3 ("kvm: x86/mmu: Support dirty logging for the TDP MMU") Cc: Ben Gardon Signed-off-by: Sean Christopherson Reviewed-by: Ben Gardon --- arch/x86/kvm/mmu/tdp_mmu.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index 25148e8b711d..9357780ec28f 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -1446,6 +1446,9 @@ static bool clear_dirty_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root, if (tdp_mmu_iter_cond_resched(kvm, &iter, false, true)) continue; + if (!is_shadow_present_pte(iter.old_spte)) + continue; + if (spte_ad_need_write_protect(iter.old_spte)) { if (is_writable_pte(iter.old_spte)) new_spte = iter.old_spte & ~PT_WRITABLE_MASK; -- 2.35.1.574.g5d30c73bfb-goog