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=-13.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 68858C433E0 for ; Fri, 31 Jul 2020 21:23:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3B01322B3F for ; Fri, 31 Jul 2020 21:23:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728893AbgGaVX2 (ORCPT ); Fri, 31 Jul 2020 17:23:28 -0400 Received: from mga14.intel.com ([192.55.52.115]:50224 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728163AbgGaVX1 (ORCPT ); Fri, 31 Jul 2020 17:23:27 -0400 IronPort-SDR: HijNdAYRtKmE9g3tcHzpEd+Rjq9M0BkBonaN4mVbjeCGUmjmX8APcbxKDtoxXg9nAiOI4uwndI s/umPP1CZZug== X-IronPort-AV: E=McAfee;i="6000,8403,9699"; a="151075127" X-IronPort-AV: E=Sophos;i="5.75,419,1589266800"; d="scan'208";a="151075127" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 31 Jul 2020 14:23:26 -0700 IronPort-SDR: oTBERTbqHkpkNNTA9L4r9QbNT7cLdo4vviEhrdixBuUuB1suq+jhUh48eJQdDkxK/zcCQOuEC1 JgHtVsq6+8cQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,419,1589266800"; d="scan'208";a="331191296" Received: from sjchrist-coffee.jf.intel.com ([10.54.74.160]) by orsmga007.jf.intel.com with ESMTP; 31 Jul 2020 14:23:26 -0700 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, eric van tassell , Tom Lendacky Subject: [RFC PATCH 1/8] KVM: x86/mmu: Return old SPTE from mmu_spte_clear_track_bits() Date: Fri, 31 Jul 2020 14:23:16 -0700 Message-Id: <20200731212323.21746-2-sean.j.christopherson@intel.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200731212323.21746-1-sean.j.christopherson@intel.com> References: <20200731212323.21746-1-sean.j.christopherson@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return the old SPTE when clearing a SPTE and push the "old SPTE present" check to the caller. Tracking pinned SPTEs will use the old SPTE in rmap_remove() to determine whether or not the SPTE is pinned. Signed-off-by: Sean Christopherson --- arch/x86/kvm/mmu/mmu.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 289dddff2615f..d737042fea55e 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -930,9 +930,9 @@ static bool mmu_spte_update(u64 *sptep, u64 new_spte) * Rules for using mmu_spte_clear_track_bits: * It sets the sptep from present to nonpresent, and track the * state bits, it is used to clear the last level sptep. - * Returns non-zero if the PTE was previously valid. + * Returns the old PTE. */ -static int mmu_spte_clear_track_bits(u64 *sptep) +static u64 mmu_spte_clear_track_bits(u64 *sptep) { kvm_pfn_t pfn; u64 old_spte = *sptep; @@ -943,7 +943,7 @@ static int mmu_spte_clear_track_bits(u64 *sptep) old_spte = __update_clear_spte_slow(sptep, 0ull); if (!is_shadow_present_pte(old_spte)) - return 0; + return old_spte; pfn = spte_to_pfn(old_spte); @@ -960,7 +960,7 @@ static int mmu_spte_clear_track_bits(u64 *sptep) if (is_dirty_spte(old_spte)) kvm_set_pfn_dirty(pfn); - return 1; + return old_spte; } /* @@ -1484,7 +1484,9 @@ static u64 *rmap_get_next(struct rmap_iterator *iter) static void drop_spte(struct kvm *kvm, u64 *sptep) { - if (mmu_spte_clear_track_bits(sptep)) + u64 old_spte = mmu_spte_clear_track_bits(sptep); + + if (is_shadow_present_pte(old_spte)) rmap_remove(kvm, sptep); } -- 2.28.0