From patchwork Fri Nov 11 09:34:45 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yan Zhao X-Patchwork-Id: 13040054 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 C6C2BC43219 for ; Fri, 11 Nov 2022 09:57:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232574AbiKKJ5u (ORCPT ); Fri, 11 Nov 2022 04:57:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40662 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233315AbiKKJ5s (ORCPT ); Fri, 11 Nov 2022 04:57:48 -0500 Received: from mga06.intel.com (mga06b.intel.com [134.134.136.31]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D5D8168AD8; Fri, 11 Nov 2022 01:57:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1668160667; x=1699696667; h=from:to:cc:subject:date:message-id:in-reply-to: references; bh=wt+vlOzCkH8SLs01r95Dnw3PuDC+sxswMNY5/OeykXY=; b=FRkzOhSH+0vQyTfGXoeSGe4tdYVL9o6MT8JQztsLh5sdm3Nb5DvYPtC/ 5+OTOwsRTcZeMo4VcHIGsNDyLEQWNKr4F1cfWOiNoogYbIn9nvjGP/6Nd HiKPHSgzk/+G+GmoeXr3ksoDj+AYDZiYwqgzBxPwkn3smKPxFD6CM2pxg PRTZuJrLcX2mFR+TDIQn2rLDVAfT++bbIhzCxgABBwBCx+PMfb2RVX/Uh Fsys345+njn4tLnPAxo0Kn1rguJIYNeZQsOnEGcANeid6/CfhzyeIBG59 mObDlgOX5hJmti+UZc7PqgEBsjAF7I7B2jkKPigB7Me66eIZit/bfidYn A==; X-IronPort-AV: E=McAfee;i="6500,9779,10527"; a="373700227" X-IronPort-AV: E=Sophos;i="5.96,156,1665471600"; d="scan'208";a="373700227" Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Nov 2022 01:57:47 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10527"; a="706496838" X-IronPort-AV: E=Sophos;i="5.96,156,1665471600"; d="scan'208";a="706496838" Received: from yzhao56-desk.sh.intel.com ([10.238.200.254]) by fmsmga004-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Nov 2022 01:57:44 -0800 From: Yan Zhao To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: pbonzini@redhat.com, seanjc@google.com, zhenyuw@linux.intel.com, intel-gfx@lists.freedesktop.org, intel-gvt-dev@lists.freedesktop.org, Yan Zhao , Sean Christopherson Subject: [PATCH 1/3] KVM: x86: add a new page track hook track_remove_slot Date: Fri, 11 Nov 2022 17:34:45 +0800 Message-Id: <20221111093445.3212-1-yan.y.zhao@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20221111093222.3148-1-yan.y.zhao@intel.com> References: <20221111093222.3148-1-yan.y.zhao@intel.com> Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org 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/kvm_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); }; 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 *slot); +void kvm_page_track_remove_slot(struct kvm *kvm, struct kvm_memory_slot *slot); #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 *slot) +{ + struct kvm_page_track_notifier_head *head; + struct kvm_page_track_notifier_node *n; + int idx; + + head = &kvm->arch.track_notifier_head; + + if (hlist_empty(&head->track_notifier_list)) + return; + + idx = 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 == KVM_MR_DELETE || change == KVM_MR_MOVE) + kvm_page_track_remove_slot(kvm, old); + if (!kvm->arch.n_requested_mmu_pages && (change == KVM_MR_CREATE || change == KVM_MR_DELETE)) { unsigned long nr_mmu_pages;