From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754838AbcB2PWV (ORCPT ); Mon, 29 Feb 2016 10:22:21 -0500 Received: from mail-wm0-f65.google.com ([74.125.82.65]:36752 "EHLO mail-wm0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751201AbcB2PWT (ORCPT ); Mon, 29 Feb 2016 10:22:19 -0500 Subject: Re: [PATCH 09/11] KVM: MMU: use page track for non-leaf shadow pages To: Xiao Guangrong References: <1456307476-46398-1-git-send-email-guangrong.xiao@linux.intel.com> <1456307476-46398-10-git-send-email-guangrong.xiao@linux.intel.com> Cc: gleb@kernel.org, mtosatti@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, kai.huang@linux.intel.com, jike.song@intel.com From: Paolo Bonzini Message-ID: <56D46226.5060605@redhat.com> Date: Mon, 29 Feb 2016 16:22:14 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.0 MIME-Version: 1.0 In-Reply-To: <1456307476-46398-10-git-send-email-guangrong.xiao@linux.intel.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 24/02/2016 10:51, Xiao Guangrong wrote: > non-leaf shadow pages are always write protected, it can be the user > of page track > > Signed-off-by: Xiao Guangrong > --- > arch/x86/kvm/mmu.c | 26 +++++++++++++++++++++----- > 1 file changed, 21 insertions(+), 5 deletions(-) > > diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c > index 58c067d..74684b2 100644 > --- a/arch/x86/kvm/mmu.c > +++ b/arch/x86/kvm/mmu.c > @@ -806,11 +806,17 @@ static void account_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) > struct kvm_memory_slot *slot; > gfn_t gfn; > > + kvm->arch.indirect_shadow_pages++; > gfn = sp->gfn; > slots = kvm_memslots_for_spte_role(kvm, sp->role); > slot = __gfn_to_memslot(slots, gfn); > + > + /* the non-leaf shadow pages are keeping readonly. */ > + if (sp->role.level > PT_PAGE_TABLE_LEVEL) > + return kvm_slot_page_track_add_page(kvm, slot, gfn, > + KVM_PAGE_TRACK_WRITE); > + > kvm_mmu_gfn_disallow_lpage(slot, gfn); > - kvm->arch.indirect_shadow_pages++; > } > > static void unaccount_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) > @@ -819,11 +825,15 @@ static void unaccount_shadowed(struct kvm *kvm, struct kvm_mmu_page *sp) > struct kvm_memory_slot *slot; > gfn_t gfn; > > + kvm->arch.indirect_shadow_pages--; > gfn = sp->gfn; > slots = kvm_memslots_for_spte_role(kvm, sp->role); > slot = __gfn_to_memslot(slots, gfn); > + if (sp->role.level > PT_PAGE_TABLE_LEVEL) > + return kvm_slot_page_track_remove_page(kvm, slot, gfn, > + KVM_PAGE_TRACK_WRITE); > + > kvm_mmu_gfn_allow_lpage(slot, gfn); > - kvm->arch.indirect_shadow_pages--; > } > > static bool __mmu_gfn_lpage_is_disallowed(gfn_t gfn, int level, > @@ -2132,12 +2142,18 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, > hlist_add_head(&sp->hash_link, > &vcpu->kvm->arch.mmu_page_hash[kvm_page_table_hashfn(gfn)]); > if (!direct) { > - if (rmap_write_protect(vcpu, gfn)) > + /* > + * we should do write protection before syncing pages > + * otherwise the content of the synced shadow page may > + * be inconsistent with guest page table. > + */ > + account_shadowed(vcpu->kvm, sp); > + > + if (level == PT_PAGE_TABLE_LEVEL && > + rmap_write_protect(vcpu, gfn)) > kvm_flush_remote_tlbs(vcpu->kvm); > if (level > PT_PAGE_TABLE_LEVEL && need_sync) > kvm_sync_pages(vcpu, gfn); > - > - account_shadowed(vcpu->kvm, sp); > } > sp->mmu_valid_gen = vcpu->kvm->arch.mmu_valid_gen; > clear_page(sp->spt); > Hi, I'm applying this series with just a very simple change on top of this patch: diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 74684b2b7e69..fe03d2a1d4d3 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -2148,10 +2148,10 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, * be inconsistent with guest page table. */ account_shadowed(vcpu->kvm, sp); - if (level == PT_PAGE_TABLE_LEVEL && rmap_write_protect(vcpu, gfn)) kvm_flush_remote_tlbs(vcpu->kvm); + if (level > PT_PAGE_TABLE_LEVEL && need_sync) kvm_sync_pages(vcpu, gfn); } Yes, it's just moving around an empty line. :) Paolo