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=unavailable 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 7C046C433E3 for ; Fri, 31 Jul 2020 21:23:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 55DE622B3F for ; Fri, 31 Jul 2020 21:23:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729079AbgGaVX2 (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 S1728655AbgGaVX2 (ORCPT ); Fri, 31 Jul 2020 17:23:28 -0400 IronPort-SDR: RcyqnpSecoO/Ccf9TaeG6VdztrKD+CF578Zgm+BOiHrpDQZgyFOTz6QrkEtf1hLJvP6+Ia8/On ZIK3n9Ctg60Q== X-IronPort-AV: E=McAfee;i="6000,8403,9699"; a="151075129" X-IronPort-AV: E=Sophos;i="5.75,419,1589266800"; d="scan'208";a="151075129" 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 14:23:27 -0700 IronPort-SDR: RSAMy2OpJI1Dt0mMuQewKa8YeQBi06oPFkDh8y7woTwL97jtt2H4A+yYsdoNwAFpV7Wy3ntjF+ wlx3vGuGYHyA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,419,1589266800"; d="scan'208";a="331191301" 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 3/8] KVM: x86/mmu: Refactor handling of not-present SPTEs in mmu_set_spte() Date: Fri, 31 Jul 2020 14:23:18 -0700 Message-Id: <20200731212323.21746-4-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: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Return early from mmu_set_spte() if the new SPTE is not-present so as to reduce the indentation of the code that performs metadata updates, e.g. rmap manipulation. Additional metadata updates will soon follow... Signed-off-by: Sean Christopherson --- arch/x86/kvm/mmu/mmu.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 82f69a7456004..182f398036248 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -3126,12 +3126,14 @@ static int mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, if (!was_rmapped && is_large_pte(*sptep)) ++vcpu->kvm->stat.lpages; - if (is_shadow_present_pte(*sptep)) { - if (!was_rmapped) { - rmap_count = rmap_add(vcpu, sptep, gfn); - if (rmap_count > RMAP_RECYCLE_THRESHOLD) - rmap_recycle(vcpu, sptep, gfn); - } + /* No additional tracking necessary for not-present SPTEs. */ + if (!is_shadow_present_pte(*sptep)) + return ret; + + if (!was_rmapped) { + rmap_count = rmap_add(vcpu, sptep, gfn); + if (rmap_count > RMAP_RECYCLE_THRESHOLD) + rmap_recycle(vcpu, sptep, gfn); } return ret; -- 2.28.0