From nobody Thu Dec 18 07:29:57 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E8E68C43217 for ; Fri, 11 Nov 2022 10:56:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233405AbiKKK4q (ORCPT ); Fri, 11 Nov 2022 05:56:46 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55014 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232918AbiKKK4n (ORCPT ); Fri, 11 Nov 2022 05:56:43 -0500 Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 10A8CC6A; Fri, 11 Nov 2022 02:56:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1668164203; x=1699700203; h=from:to:cc:subject:date:message-id:in-reply-to: references; bh=u7QIWUi0C6/FBWEuiDhVYicRF9D5dHYcVP0Zb/o5lgM=; b=IbNuZXiGuAg/xzRtMi5TEzGdW564+9OE8b1PXsFm3EGMGDev7jKgq2h8 VZTbsxJXwd3wyrCIWHACvhZ+xeD1CQ/CVvhXjeITLnSZ2E072s9/N/mOT KDI728URM/67mTm0A722SCJR1aPNBkc6Ux/zo9GdXv2c8VkpSkjHaqtsk +k7xKzfQYSe7JVAnAtsxxdzX3te75pkT6Da2JhEVJrYs7pa1rfCngkZW/ rIhWgQ7dUfbtFXC3opl0i+drO5QzyFLw4mq0XlqeL4gor222TFTQYehQU DMH14nrcErxFAmJe/fyq8FYGZgW+ECneC5/fLklIhpS5KE4wd19JyP287 w==; X-IronPort-AV: E=McAfee;i="6500,9779,10527"; a="313364622" X-IronPort-AV: E=Sophos;i="5.96,156,1665471600"; d="scan'208";a="313364622" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Nov 2022 02:56:42 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10527"; a="637549316" X-IronPort-AV: E=Sophos;i="5.96,156,1665471600"; d="scan'208";a="637549316" Received: from yzhao56-desk.sh.intel.com ([10.238.200.254]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Nov 2022 02:56:40 -0800 From: Yan Zhao To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: pbonzini@redhat.com, seanjc@google.com, intel-gfx@lists.freedesktop.org, intel-gvt-dev@lists.freedesktop.org, zhenyuw@linux.intel.com, Yan Zhao Subject: [PATCH v2 1/3] KVM: x86: add a new page track hook track_remove_slot Date: Fri, 11 Nov 2022 18:33:50 +0800 Message-Id: <20221111103350.22326-1-yan.y.zhao@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20221111103247.22275-1-yan.y.zhao@intel.com> References: <20221111103247.22275-1-yan.y.zhao@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Page track hook track_remove_slot is used to notify users that a slot has been removed and is called when a slot DELETE/MOVE is about to be completed. Users of this hook can drop write protections in the removed slot. Note: Since KVM_MR_MOVE currently never actually happens in KVM/QEMU, and has never been properly supported in the external page track user, we just use the hook track_remove_slot to notify users of the old slot being removed. Cc: Zhenyu Wang Suggested-by: Sean Christopherson Signed-off-by: Sean Christopherson Signed-off-by: Yan Zhao --- arch/x86/include/asm/kvm_page_track.h | 11 +++++++++++ arch/x86/kvm/mmu/page_track.c | 26 ++++++++++++++++++++++++++ arch/x86/kvm/x86.c | 3 +++ 3 files changed, 40 insertions(+) diff --git a/arch/x86/include/asm/kvm_page_track.h b/arch/x86/include/asm/k= vm_page_track.h index eb186bc57f6a..046b024d1813 100644 --- a/arch/x86/include/asm/kvm_page_track.h +++ b/arch/x86/include/asm/kvm_page_track.h @@ -44,6 +44,16 @@ struct kvm_page_track_notifier_node { */ void (*track_flush_slot)(struct kvm *kvm, struct kvm_memory_slot *slot, struct kvm_page_track_notifier_node *node); + /* + * It is called when memory slot is moved or removed + * users can drop write-protection for the pages in that memory slot + * + * @kvm: the kvm where memory slot being moved or removed + * @slot: the memory slot being moved or removed + * @node: this node + */ + void (*track_remove_slot)(struct kvm *kvm, struct kvm_memory_slot *slot, + struct kvm_page_track_notifier_node *node); }; =20 int kvm_page_track_init(struct kvm *kvm); @@ -76,4 +86,5 @@ kvm_page_track_unregister_notifier(struct kvm *kvm, void kvm_page_track_write(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new, int bytes); void kvm_page_track_flush_slot(struct kvm *kvm, struct kvm_memory_slot *sl= ot); +void kvm_page_track_remove_slot(struct kvm *kvm, struct kvm_memory_slot *s= lot); #endif diff --git a/arch/x86/kvm/mmu/page_track.c b/arch/x86/kvm/mmu/page_track.c index 2e09d1b6249f..4d6bab1d61c9 100644 --- a/arch/x86/kvm/mmu/page_track.c +++ b/arch/x86/kvm/mmu/page_track.c @@ -300,3 +300,29 @@ void kvm_page_track_flush_slot(struct kvm *kvm, struct= kvm_memory_slot *slot) n->track_flush_slot(kvm, slot, n); srcu_read_unlock(&head->track_srcu, idx); } + +/* + * Notify the node that memory slot is removed or moved so that it can + * drop write-protection for the pages in the memory slot. + * + * The node should figure out it has any write-protected pages in this slot + * by itself. + */ +void kvm_page_track_remove_slot(struct kvm *kvm, struct kvm_memory_slot *s= lot) +{ + struct kvm_page_track_notifier_head *head; + struct kvm_page_track_notifier_node *n; + int idx; + + head =3D &kvm->arch.track_notifier_head; + + if (hlist_empty(&head->track_notifier_list)) + return; + + idx =3D srcu_read_lock(&head->track_srcu); + hlist_for_each_entry_srcu(n, &head->track_notifier_list, node, + srcu_read_lock_held(&head->track_srcu)) + if (n->track_remove_slot) + n->track_remove_slot(kvm, slot, n); + srcu_read_unlock(&head->track_srcu, idx); +} diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 916ebbc81e52..a24a4a2ad1a0 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -12844,6 +12844,9 @@ void kvm_arch_commit_memory_region(struct kvm *kvm, const struct kvm_memory_slot *new, enum kvm_mr_change change) { + if (change =3D=3D KVM_MR_DELETE || change =3D=3D KVM_MR_MOVE) + kvm_page_track_remove_slot(kvm, old); + if (!kvm->arch.n_requested_mmu_pages && (change =3D=3D KVM_MR_CREATE || change =3D=3D KVM_MR_DELETE)) { unsigned long nr_mmu_pages; --=20 2.17.1