From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756782Ab0EFJdw (ORCPT ); Thu, 6 May 2010 05:33:52 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:59595 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1756579Ab0EFJdt (ORCPT ); Thu, 6 May 2010 05:33:49 -0400 Message-ID: <4BE28C40.2060501@cn.fujitsu.com> Date: Thu, 06 May 2010 17:30:40 +0800 From: Xiao Guangrong User-Agent: Thunderbird 2.0.0.24 (Windows/20100228) MIME-Version: 1.0 To: Avi Kivity CC: Marcelo Tosatti , KVM list , LKML Subject: [PATCH v4 2/9] KVM MMU: don't write-protect if have new mapping to unsync page References: <4BE2818A.5000301@cn.fujitsu.com> In-Reply-To: <4BE2818A.5000301@cn.fujitsu.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Two cases maybe happen in kvm_mmu_get_page() function: - one case is, the goal sp is already in cache, if the sp is unsync, we only need update it to assure this mapping is valid, but not mark it sync and not write-protect sp->gfn since it not broke unsync rule(one shadow page for a gfn) - another case is, the goal sp not existed, we need create a new sp for gfn, i.e, gfn (may)has another shadow page, to keep unsync rule, we should sync(mark sync and write-protect) gfn's unsync shadow page. After enabling multiple unsync shadows, we sync those shadow pages only when the new sp not allow to become unsync(also for the unsyc rule, the new rule is: allow all pte page become unsync) Changlog: - fix for forget to mark parent's unsync_children bit when mapping a new parent to unsync shadow page Signed-off-by: Xiao Guangrong --- arch/x86/kvm/mmu.c | 18 ++++++++++++++---- 1 files changed, 14 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 72238ec..1dbb96e 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -1333,7 +1333,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, unsigned index; unsigned quadrant; struct hlist_head *bucket; - struct kvm_mmu_page *sp; + struct kvm_mmu_page *sp, *unsync_sp = NULL; struct hlist_node *node, *tmp; role = vcpu->arch.mmu.base_role; @@ -1352,20 +1352,30 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, hlist_for_each_entry_safe(sp, node, tmp, bucket, hash_link) if (sp->gfn == gfn) { if (sp->unsync) - if (kvm_sync_page(vcpu, sp)) - continue; + unsync_sp = sp; if (sp->role.word != role.word) continue; + if (!direct && unsync_sp && + kvm_sync_page_transient(vcpu, unsync_sp)) { + unsync_sp = NULL; + break; + } + mmu_page_add_parent_pte(vcpu, sp, parent_pte); if (sp->unsync_children) { set_bit(KVM_REQ_MMU_SYNC, &vcpu->requests); kvm_mmu_mark_parents_unsync(sp); - } + } else if (sp->unsync) + kvm_mmu_mark_parents_unsync(sp); + trace_kvm_mmu_get_page(sp, false); return sp; } + if (!direct && unsync_sp) + kvm_sync_page(vcpu, unsync_sp); + ++vcpu->kvm->stat.mmu_cache_miss; sp = kvm_mmu_alloc_page(vcpu, parent_pte); if (!sp) -- 1.6.1.2