From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752389Ab2KEMKU (ORCPT ); Mon, 5 Nov 2012 07:10:20 -0500 Received: from e23smtp06.au.ibm.com ([202.81.31.148]:47565 "EHLO e23smtp06.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751884Ab2KEMKR (ORCPT ); Mon, 5 Nov 2012 07:10:17 -0500 Message-ID: <5097ACA0.7080408@linux.vnet.ibm.com> Date: Mon, 05 Nov 2012 20:10:08 +0800 From: Xiao Guangrong User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:15.0) Gecko/20120911 Thunderbird/15.0.1 MIME-Version: 1.0 To: Xiao Guangrong CC: Avi Kivity , Marcelo Tosatti , LKML , KVM Subject: [PATCH 2/5] KVM: MMU: simplify mmu_set_spte References: <5097AC70.1080904@linux.vnet.ibm.com> In-Reply-To: <5097AC70.1080904@linux.vnet.ibm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit x-cbid: 12110512-7014-0000-0000-000002251E51 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In order to detecting spte remapping, we can simply check whether the spte has already been pointing to the pfn even if the spte is not the last spte for middle spte is pointing to the kernel pfn which can not be mapped to userspace Also, update slot and stat.lpages iff the spte is not remapped Signed-off-by: Xiao Guangrong --- arch/x86/kvm/mmu.c | 40 +++++++++++++--------------------------- 1 files changed, 13 insertions(+), 27 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 692ebb1..4ea731e 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -2420,8 +2420,7 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, pfn_t pfn, bool speculative, bool host_writable) { - int was_rmapped = 0; - int rmap_count; + bool was_rmapped = false; pgprintk("%s: spte %llx access %x write_fault %d" " user_fault %d gfn %llx\n", @@ -2429,25 +2428,13 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, write_fault, user_fault, gfn); if (is_rmap_spte(*sptep)) { - /* - * If we overwrite a PTE page pointer with a 2MB PMD, unlink - * the parent of the now unreachable PTE. - */ - if (level > PT_PAGE_TABLE_LEVEL && - !is_large_pte(*sptep)) { - struct kvm_mmu_page *child; - u64 pte = *sptep; + if (pfn != spte_to_pfn(*sptep)) { + struct kvm_mmu_page *sp = page_header(__pa(sptep)); - child = page_header(pte & PT64_BASE_ADDR_MASK); - drop_parent_pte(child, sptep); - kvm_flush_remote_tlbs(vcpu->kvm); - } else if (pfn != spte_to_pfn(*sptep)) { - pgprintk("hfn old %llx new %llx\n", - spte_to_pfn(*sptep), pfn); - drop_spte(vcpu->kvm, sptep); - kvm_flush_remote_tlbs(vcpu->kvm); + if (mmu_page_zap_pte(vcpu->kvm, sp, sptep)) + kvm_flush_remote_tlbs(vcpu->kvm); } else - was_rmapped = 1; + was_rmapped = true; } if (set_spte(vcpu, sptep, pte_access, user_fault, write_fault, @@ -2466,16 +2453,15 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, is_large_pte(*sptep)? "2MB" : "4kB", *sptep & PT_PRESENT_MASK ?"RW":"R", gfn, *sptep, sptep); - if (!was_rmapped && is_large_pte(*sptep)) - ++vcpu->kvm->stat.lpages; - if (is_shadow_present_pte(*sptep)) { + if (is_shadow_present_pte(*sptep) && !was_rmapped) { + if (is_large_pte(*sptep)) + ++vcpu->kvm->stat.lpages; + page_header_update_slot(vcpu->kvm, sptep, gfn); - if (!was_rmapped) { - rmap_count = rmap_add(vcpu, sptep, gfn); - if (rmap_count > RMAP_RECYCLE_THRESHOLD) - rmap_recycle(vcpu, sptep, gfn); - } + + if (rmap_add(vcpu, sptep, gfn) > RMAP_RECYCLE_THRESHOLD) + rmap_recycle(vcpu, sptep, gfn); } kvm_release_pfn_clean(pfn); -- 1.7.7.6