From patchwork Sat Nov 20 04:50:23 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Christopherson X-Patchwork-Id: 12630077 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 7DACEC433F5 for ; Sat, 20 Nov 2021 04:51:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237116AbhKTEyy (ORCPT ); Fri, 19 Nov 2021 23:54:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55208 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237005AbhKTEyi (ORCPT ); Fri, 19 Nov 2021 23:54:38 -0500 Received: from mail-pg1-x54a.google.com (mail-pg1-x54a.google.com [IPv6:2607:f8b0:4864:20::54a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1AC82C0613FA for ; Fri, 19 Nov 2021 20:51:03 -0800 (PST) Received: by mail-pg1-x54a.google.com with SMTP id t75-20020a63784e000000b002993a9284b0so5052237pgc.11 for ; Fri, 19 Nov 2021 20:51:03 -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=kRbBWHboZP166wiM9/QeB9lQ+gE9kRnPxnSqNsfgwok=; b=PaFW80wYiFDjQHdAjCLfmrfN14ZfxWumhDxGPUy1CIq4CB+K+vmmCN0v9pwe9CmRkk Mr8x1gI36HiXTdKDOZO9gpQq8sTuF5HaIVdwq87aF821wthnTJwvKCzVMZFzGcmKCLvw LqgytiuJ/wnzY2SJvQZ2QIKvBpHyvbJUGKRnCg5U1L+KZ/FwsjBPdgut5KwWGEy2aioG 5Fz72Vqmm/fqc/ns+MGH+BWwJTC1oDlCn88kgnN5gVaSodOxA4LBleVeji22e1FgXtjs i119cpqtAXxBKZ8B3BSyAkFo6N3w573O0EUOtB6mTTzW0ODt2cA0Yk4wK/xSEINKHW/m rPTg== 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=kRbBWHboZP166wiM9/QeB9lQ+gE9kRnPxnSqNsfgwok=; b=F4/4gwgziqmB9UTW0AFeRzljsgqO/JGULISF+F+RiZi6u+bR35W3jqU/14EsF/hasx sPfeFx6xW45mU/fGufu1mX+OIbiO9w2pYC3wJTw+2TD7gqE+hx1rWQ12j8t8B0WQqsfO 4ljbXsMy/5GWTY1KmpHaCn+rJbCkpUfYSVQCLRtFlWGYawnqYftSqVR5BpDORxJpullx lANCkw9jCo6q2kMhri8JZKrIQc2rgbTq43FSSWnp2wbsDvu5WHGHh0PdeKfyjOyPgAFc l+p5Uh5BPChCTyH3OsF3LxSo9DK66EYeOfdv2BDCvIDqI5Ru2Y75s80JLVmhdQhV+eo+ arGw== X-Gm-Message-State: AOAM530ofkyzEH9qX51gnr1o1lBNcfZ9FNg1pWcnp5f2vHEKz6xYWsZb kdORpA/4OKbLZmqIEc869kphALnSYas= X-Google-Smtp-Source: ABdhPJx71YmvgsfQ/dG6SeLwEb0pLrv37b/SWXKbwOSeZ8ogkSRm2uXGsXL7Ih5xQRkauHVuOjsgO9U0Y2E= X-Received: from seanjc.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:3e5]) (user=seanjc job=sendgmr) by 2002:a17:90a:390c:: with SMTP id y12mr737512pjb.0.1637383862178; Fri, 19 Nov 2021 20:51:02 -0800 (PST) Reply-To: Sean Christopherson Date: Sat, 20 Nov 2021 04:50:23 +0000 In-Reply-To: <20211120045046.3940942-1-seanjc@google.com> Message-Id: <20211120045046.3940942-6-seanjc@google.com> Mime-Version: 1.0 References: <20211120045046.3940942-1-seanjc@google.com> X-Mailer: git-send-email 2.34.0.rc2.393.gf8c9666880-goog Subject: [PATCH 05/28] KVM: x86/mmu: Check for present SPTE when clearing dirty bit in TDP MMU 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, Hou Wenlong , Ben Gardon Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Explicitly check for preset 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 1db8496259ad..c575df121b19 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -1246,6 +1246,9 @@ 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;