From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gui Jianfeng Subject: [PATCH 1/4] KVM: Move first pte address calculation out of loop to save some cycles Date: Fri, 16 Apr 2010 17:16:40 +0800 Message-ID: <4BC82AF8.8080308@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: Avi Kivity Return-path: Received: from cn.fujitsu.com ([222.73.24.84]:58235 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1752931Ab0DPJRi (ORCPT ); Fri, 16 Apr 2010 05:17:38 -0400 Sender: kvm-owner@vger.kernel.org List-ID: Move first pte address calculation out of loop to save some cycles Signed-off-by: Gui Jianfeng --- arch/x86/kvm/paging_tmpl.h | 6 ++++-- 1 files changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index d9dea28..5910557 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -572,12 +572,15 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) { int i, offset, nr_present; bool reset_host_protection; + gpa_t first_pte_gpa; offset = nr_present = 0; if (PTTYPE == 32) offset = sp->role.quadrant << PT64_LEVEL_BITS; + first_pte_gpa = gfn_to_gpa(sp->gfn) + offset * sizeof(pt_element_t); + for (i = 0; i < PT64_ENT_PER_PAGE; i++) { unsigned pte_access; pt_element_t gpte; @@ -587,8 +590,7 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) if (!is_shadow_present_pte(sp->spt[i])) continue; - pte_gpa = gfn_to_gpa(sp->gfn); - pte_gpa += (i+offset) * sizeof(pt_element_t); + pte_gpa = first_pte_gpa + i * sizeof(pt_element_t); if (kvm_read_guest_atomic(vcpu->kvm, pte_gpa, &gpte, sizeof(pt_element_t))) -- 1.6.5.2