Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753456AbbLOIAW (ORCPT ); Tue, 15 Dec 2015 03:00:22 -0500 Received: from mga09.intel.com ([134.134.136.24]:50226 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753156AbbLOIAU (ORCPT ); Tue, 15 Dec 2015 03:00:20 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,431,1444719600"; d="scan'208";a="873852422" Subject: Re: [PATCH 05/11] KVM: page track: introduce kvm_page_track_{add,remove}_page To: Xiao Guangrong , pbonzini@redhat.com References: <1448907973-36066-1-git-send-email-guangrong.xiao@linux.intel.com> <1448907973-36066-6-git-send-email-guangrong.xiao@linux.intel.com> <566FBDF6.9010009@linux.intel.com> Cc: gleb@kernel.org, mtosatti@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org From: Kai Huang Message-ID: <566FC792.3090709@linux.intel.com> Date: Tue, 15 Dec 2015 15:56:02 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.4.0 MIME-Version: 1.0 In-Reply-To: <566FBDF6.9010009@linux.intel.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5778 Lines: 173 On 12/15/2015 03:15 PM, Kai Huang wrote: > > > On 12/01/2015 02:26 AM, Xiao Guangrong wrote: >> These two functions are the user APIs: >> - kvm_page_track_add_page(): add the page to the tracking pool after >> that later specified access on that page will be tracked >> >> - kvm_page_track_remove_page(): remove the page from the tracking pool, >> the specified access on the page is not tracked after the last >> user is >> gone >> >> Both of these are called under the protection of kvm->srcu or >> kvm->slots_lock >> >> Signed-off-by: Xiao Guangrong >> --- >> arch/x86/include/asm/kvm_page_track.h | 5 ++ >> arch/x86/kvm/page_track.c | 95 >> +++++++++++++++++++++++++++++++++++ >> 2 files changed, 100 insertions(+) >> >> diff --git a/arch/x86/include/asm/kvm_page_track.h >> b/arch/x86/include/asm/kvm_page_track.h >> index 347d5c9..9cc17c6 100644 >> --- a/arch/x86/include/asm/kvm_page_track.h >> +++ b/arch/x86/include/asm/kvm_page_track.h >> @@ -10,4 +10,9 @@ int kvm_page_track_create_memslot(struct >> kvm_memory_slot *slot, >> unsigned long npages); >> void kvm_page_track_free_memslot(struct kvm_memory_slot *free, >> struct kvm_memory_slot *dont); >> + >> +void kvm_page_track_add_page(struct kvm *kvm, gfn_t gfn, >> + enum kvm_page_track_mode mode); >> +void kvm_page_track_remove_page(struct kvm *kvm, gfn_t gfn, >> + enum kvm_page_track_mode mode); >> #endif >> diff --git a/arch/x86/kvm/page_track.c b/arch/x86/kvm/page_track.c >> index 0338d36..ad510db 100644 >> --- a/arch/x86/kvm/page_track.c >> +++ b/arch/x86/kvm/page_track.c >> @@ -56,3 +56,98 @@ void kvm_page_track_free_memslot(struct >> kvm_memory_slot *free, >> if (!dont || free->arch.gfn_track != dont->arch.gfn_track) >> page_track_slot_free(free); >> } >> + >> +static bool check_mode(enum kvm_page_track_mode mode) >> +{ >> + if (mode < 0 || mode >= KVM_PAGE_TRACK_MAX) >> + return false; >> + >> + return true; >> +} >> + >> +static void update_gfn_track(struct kvm_memory_slot *slot, gfn_t gfn, >> + enum kvm_page_track_mode mode, int count) >> +{ >> + int index, val; >> + >> + index = gfn_to_index(gfn, slot->base_gfn, PT_PAGE_TABLE_LEVEL); >> + >> + slot->arch.gfn_track[mode][index] += count; >> + val = slot->arch.gfn_track[mode][index]; >> + WARN_ON(val < 0); >> +} >> + >> +/* >> + * add guest page to the tracking pool so that corresponding access >> on that >> + * page will be intercepted. >> + * >> + * It should be called under the protection of kvm->srcu or >> kvm->slots_lock >> + * >> + * @kvm: the guest instance we are interested in. >> + * @gfn: the guest page. >> + * @mode: tracking mode, currently only write track is supported. >> + */ >> +void kvm_page_track_add_page(struct kvm *kvm, gfn_t gfn, >> + enum kvm_page_track_mode mode) >> +{ >> + struct kvm_memslots *slots; >> + struct kvm_memory_slot *slot; >> + int i; >> + >> + WARN_ON(!check_mode(mode)); >> + >> + for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { >> + slots = __kvm_memslots(kvm, i); >> + slot = __gfn_to_memslot(slots, gfn); >> + >> + spin_lock(&kvm->mmu_lock); >> + update_gfn_track(slot, gfn, mode, 1); >> + >> + /* >> + * new track stops large page mapping for the >> + * tracked page. >> + */ >> + kvm_mmu_gfn_disallow_lpage(slot, gfn); > Where is kvm_mmu_gfn_disallow_lpage? Neither did I see it in your > patch nor in my own latest KVM repo without your patch :) > >> + >> + if (mode == KVM_PAGE_TRACK_WRITE) >> + if (kvm_mmu_slot_gfn_write_protect(kvm, slot, gfn)) >> + kvm_flush_remote_tlbs(kvm); > Neither can I find kvm_mmu_slot_gfn_write_protect. Did I miss something? Forget this reply. Looks my thunderbird has something wrong and couldn't show your whole patch series, and I missed patch 1~3. Now I see them. Sorry. Thanks, -Kai > > Thanks, > -Kai >> + spin_unlock(&kvm->mmu_lock); >> + } >> +} >> + >> +/* >> + * remove the guest page from the tracking pool which stops the >> interception >> + * of corresponding access on that page. It is the opposed operation of >> + * kvm_page_track_add_page(). >> + * >> + * It should be called under the protection of kvm->srcu or >> kvm->slots_lock >> + * >> + * @kvm: the guest instance we are interested in. >> + * @gfn: the guest page. >> + * @mode: tracking mode, currently only write track is supported. >> + */ >> +void kvm_page_track_remove_page(struct kvm *kvm, gfn_t gfn, >> + enum kvm_page_track_mode mode) >> +{ >> + struct kvm_memslots *slots; >> + struct kvm_memory_slot *slot; >> + int i; >> + >> + WARN_ON(!check_mode(mode)); >> + >> + for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { >> + slots = __kvm_memslots(kvm, i); >> + slot = __gfn_to_memslot(slots, gfn); >> + >> + spin_lock(&kvm->mmu_lock); >> + update_gfn_track(slot, gfn, mode, -1); >> + >> + /* >> + * allow large page mapping for the tracked page >> + * after the tracker is gone. >> + */ >> + kvm_mmu_gfn_allow_lpage(slot, gfn); >> + spin_unlock(&kvm->mmu_lock); >> + } >> +} > > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/