From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751945AbbLRJmR (ORCPT ); Fri, 18 Dec 2015 04:42:17 -0500 Received: from tama500.ecl.ntt.co.jp ([129.60.39.148]:34318 "EHLO tama500.ecl.ntt.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750738AbbLRJmO (ORCPT ); Fri, 18 Dec 2015 04:42:14 -0500 Date: Fri, 18 Dec 2015 18:54:49 +0900 From: Takuya Yoshikawa Subject: [PATCH] KVM: x86: MMU: Use clear_page() instead of init_shadow_page_table() Message-Id: <20151218185449.3ba700d079a21ab9ff1508bb@lab.ntt.co.jp> X-Mailer: Sylpheed 3.4.3 (GTK+ 2.24.28; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit To: pbonzini@redhat.com Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org X-TM-AS-MML: disable Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Not just in order to clean up the code, but to make it faster by using enhanced instructions: the initialization became 20-30% faster on our testing machine. Signed-off-by: Takuya Yoshikawa --- arch/x86/kvm/mmu.c | 10 +--------- 1 file changed, 1 insertion(+), 9 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index a1a3d19..7f5a82b 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -2041,14 +2041,6 @@ static void mmu_sync_children(struct kvm_vcpu *vcpu, } } -static void init_shadow_page_table(struct kvm_mmu_page *sp) -{ - int i; - - for (i = 0; i < PT64_ENT_PER_PAGE; ++i) - sp->spt[i] = 0ull; -} - static void __clear_sp_write_flooding_count(struct kvm_mmu_page *sp) { sp->write_flooding_count = 0; @@ -2128,7 +2120,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, account_shadowed(vcpu->kvm, sp); } sp->mmu_valid_gen = vcpu->kvm->arch.mmu_valid_gen; - init_shadow_page_table(sp); + clear_page(sp->spt); trace_kvm_mmu_get_page(sp, true); return sp; } -- 2.1.0