From mboxrd@z Thu Jan 1 00:00:00 1970 From: Xiao Guangrong Subject: [PATCH 3/7] KVM: MMU: avoid double write protected in sync page path Date: Fri, 11 Jun 2010 21:30:36 +0800 Message-ID: <4C123A7C.1070205@cn.fujitsu.com> References: <4C1239EE.3090904@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: Marcelo Tosatti , LKML , KVM list To: Avi Kivity Return-path: Received: from cn.fujitsu.com ([222.73.24.84]:53458 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1760244Ab0FKNeJ (ORCPT ); Fri, 11 Jun 2010 09:34:09 -0400 In-Reply-To: <4C1239EE.3090904@cn.fujitsu.com> Sender: kvm-owner@vger.kernel.org List-ID: The sync page is already write protected in mmu_sync_children(), don't write protected it again Signed-off-by: Xiao Guangrong --- arch/x86/kvm/mmu.c | 6 ++---- 1 files changed, 2 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 21ab85b..2ffd673 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -1216,6 +1216,7 @@ static void kvm_mmu_commit_zap_page(struct kvm *kvm, if ((sp)->gfn != (gfn) || (sp)->role.direct || \ (sp)->role.invalid) {} else +/* @sp->gfn should be write-protected at the call site */ static int __kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, struct list_head *invalid_list, bool clear_unsync) { @@ -1224,11 +1225,8 @@ static int __kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, return 1; } - if (clear_unsync) { - if (rmap_write_protect(vcpu->kvm, sp->gfn)) - kvm_flush_remote_tlbs(vcpu->kvm); + if (clear_unsync) kvm_unlink_unsync_page(vcpu->kvm, sp); - } if (vcpu->arch.mmu.sync_page(vcpu, sp)) { kvm_mmu_prepare_zap_page(vcpu->kvm, sp, invalid_list); -- 1.6.1.2