From patchwork Wed Feb 24 09:51:10 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xiao Guangrong X-Patchwork-Id: 8403621 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id DC6A6C0553 for ; Wed, 24 Feb 2016 10:04:11 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id F1692202EB for ; Wed, 24 Feb 2016 10:04:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0BB3F20256 for ; Wed, 24 Feb 2016 10:04:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753362AbcBXKCx (ORCPT ); Wed, 24 Feb 2016 05:02:53 -0500 Received: from mga14.intel.com ([192.55.52.115]:43850 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751298AbcBXJ7x (ORCPT ); Wed, 24 Feb 2016 04:59:53 -0500 Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga103.fm.intel.com with ESMTP; 24 Feb 2016 01:59:45 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.22,493,1449561600"; d="scan'208";a="893499683" Received: from xiaoreal1.sh.intel.com (HELO xiaoreal1.sh.intel.com.sh.intel.com) ([10.239.48.79]) by orsmga001.jf.intel.com with ESMTP; 24 Feb 2016 01:59:42 -0800 From: Xiao Guangrong To: pbonzini@redhat.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, Xiao Guangrong Subject: [PATCH 05/11] KVM: page track: introduce kvm_slot_page_track_{add, remove}_page Date: Wed, 24 Feb 2016 17:51:10 +0800 Message-Id: <1456307476-46398-6-git-send-email-guangrong.xiao@linux.intel.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1456307476-46398-1-git-send-email-guangrong.xiao@linux.intel.com> References: <1456307476-46398-1-git-send-email-guangrong.xiao@linux.intel.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP These two functions are the user APIs: - kvm_slot_page_track_add_page(): add the page to the tracking pool after that later specified access on that page will be tracked - kvm_slot_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 both of mmu-lock and kvm->srcu or kvm->slots_lock Signed-off-by: Xiao Guangrong --- arch/x86/include/asm/kvm_page_track.h | 7 +++ arch/x86/kvm/page_track.c | 85 +++++++++++++++++++++++++++++++++++ 2 files changed, 92 insertions(+) diff --git a/arch/x86/include/asm/kvm_page_track.h b/arch/x86/include/asm/kvm_page_track.h index 55200406..e363e30 100644 --- a/arch/x86/include/asm/kvm_page_track.h +++ b/arch/x86/include/asm/kvm_page_track.h @@ -10,4 +10,11 @@ void kvm_page_track_free_memslot(struct kvm_memory_slot *free, struct kvm_memory_slot *dont); int kvm_page_track_create_memslot(struct kvm_memory_slot *slot, unsigned long npages); + +void kvm_slot_page_track_add_page(struct kvm *kvm, + struct kvm_memory_slot *slot, gfn_t gfn, + enum kvm_page_track_mode mode); +void kvm_slot_page_track_remove_page(struct kvm *kvm, + struct kvm_memory_slot *slot, 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 8c396d0..cd76bc3 100644 --- a/arch/x86/kvm/page_track.c +++ b/arch/x86/kvm/page_track.c @@ -50,3 +50,88 @@ track_free: kvm_page_track_free_memslot(slot, NULL); return -ENOMEM; } + +static inline bool page_track_mode_is_valid(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, short count) +{ + int index, val; + + index = gfn_to_index(gfn, slot->base_gfn, PT_PAGE_TABLE_LEVEL); + + val = slot->arch.gfn_track[mode][index]; + + if (WARN_ON(val + count < 0 || val + count > USHRT_MAX)) + return; + + slot->arch.gfn_track[mode][index] += count; +} + +/* + * add guest page to the tracking pool so that corresponding access on that + * page will be intercepted. + * + * It should be called under the protection both of mmu-lock and kvm->srcu + * or kvm->slots_lock. + * + * @kvm: the guest instance we are interested in. + * @slot: the @gfn belongs to. + * @gfn: the guest page. + * @mode: tracking mode, currently only write track is supported. + */ +void kvm_slot_page_track_add_page(struct kvm *kvm, + struct kvm_memory_slot *slot, gfn_t gfn, + enum kvm_page_track_mode mode) +{ + + if (WARN_ON(!page_track_mode_is_valid(mode))) + return; + + update_gfn_track(slot, gfn, mode, 1); + + /* + * new track stops large page mapping for the + * tracked page. + */ + kvm_mmu_gfn_disallow_lpage(slot, gfn); + + if (mode == KVM_PAGE_TRACK_WRITE) + if (kvm_mmu_slot_gfn_write_protect(kvm, slot, gfn)) + kvm_flush_remote_tlbs(kvm); +} + +/* + * 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_slot_page_track_add_page(). + * + * It should be called under the protection both of mmu-lock and kvm->srcu + * or kvm->slots_lock. + * + * @kvm: the guest instance we are interested in. + * @slot: the @gfn belongs to. + * @gfn: the guest page. + * @mode: tracking mode, currently only write track is supported. + */ +void kvm_slot_page_track_remove_page(struct kvm *kvm, + struct kvm_memory_slot *slot, gfn_t gfn, + enum kvm_page_track_mode mode) +{ + if (WARN_ON(!page_track_mode_is_valid(mode))) + return; + + 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); +}