From nobody Sat Sep 13 09:18:54 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 8970DC61DA4 for ; Fri, 3 Feb 2023 19:28:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233068AbjBCT2b (ORCPT ); Fri, 3 Feb 2023 14:28:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33018 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233008AbjBCT22 (ORCPT ); Fri, 3 Feb 2023 14:28:28 -0500 Received: from mail-pl1-x64a.google.com (mail-pl1-x64a.google.com [IPv6:2607:f8b0:4864:20::64a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 99E171C594 for ; Fri, 3 Feb 2023 11:28:27 -0800 (PST) Received: by mail-pl1-x64a.google.com with SMTP id p10-20020a170902eaca00b00198dd431ec1so1535354pld.3 for ; Fri, 03 Feb 2023 11:28:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=QvoxEP7Nplva4MzlDA7W4XNJEUEXXd+N/4Z4GM8dC2Q=; b=dq4cgVqDREWhgjpIoJfDa+A3p6xxbzcLyVJGtvLa/V7CoJW6H9Cu6rQ98CK0vPae0U cD8L4ox0jevG14e4DnZWH8fm72ypGb30L0bmwZCi5nd0Pjn7naE+mKfHmiBB1EK2DAgN cQA8mpsPbslgoxlbZQ2vEPI8PSg/yQOWMSRyLXfgbtWb7nSCKt34OwvNGnq/8qNhW5yt WF4+dgOP4BgUwaUSkwyNdmRkXEHUCoOiqzz1rLjOz8bWLJMiV5WRtQ5jrlkvgHTRVhpV 4q6/7JYef1DTp2adDwnJC/ljaN+vuPvWhnKoRt9yVTxX7bsoAIIQAcLhL+avml5alamo Zhgw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=QvoxEP7Nplva4MzlDA7W4XNJEUEXXd+N/4Z4GM8dC2Q=; b=tYIroD7J/MV75AYPfS0Oio/2F57+YIOKSItK6PaYVoEOWIDrJnuhgiMgmSbSkta6PP WNGOdSLF2qERDjeNDLdhrSe0Ke+zr+WzI20C6uCk7oIVO6z3cBvW+wpyMQ6WsD3GAZa7 Kz1IzQLfT+j58bH+rx/lVvj7gnMVpyrYTQ0e5BrWlgzZ0XNgDREr90LSL3GjWRdip3KI 8iWLuoijbbLsnnr4s2vA5SLIX17XbF1dX2obKGSfuViaRmQkcaOfNrjnsy1XZneNg8kC fQSUeU/C5hBBY+tO96xNSHgmC9G9k07EbLL7H5V1g8xPbjL5rUGRQFlQFy2tTuMx6AJ1 AWNQ== X-Gm-Message-State: AO0yUKVB1uL8Zre30QlxPRoffBaJi4Uz7qMKx1FZjf3TJmwLqUV8zI3b DWyEr5uuYwcKLmbQfuS5ilVgPfmRQfEr X-Google-Smtp-Source: AK7set/ADjbyMhNOe6MyOQvMsn6FzBmUdBWOkNS7y0BtmHvhVqQtCvzROZ0f7hpQMM5qMDfE2WTF1B/0EbXX X-Received: from vipin.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:479f]) (user=vipinsh job=sendgmr) by 2002:a17:902:6b0a:b0:196:7cf5:ba64 with SMTP id o10-20020a1709026b0a00b001967cf5ba64mr2638442plk.14.1675452507082; Fri, 03 Feb 2023 11:28:27 -0800 (PST) Date: Fri, 3 Feb 2023 11:28:18 -0800 In-Reply-To: <20230203192822.106773-1-vipinsh@google.com> Mime-Version: 1.0 References: <20230203192822.106773-1-vipinsh@google.com> X-Mailer: git-send-email 2.39.1.519.gcb327c4b5f-goog Message-ID: <20230203192822.106773-2-vipinsh@google.com> Subject: [Patch v2 1/5] KVM: x86/mmu: Make separate function to check for SPTEs atomic write conditions From: Vipin Sharma To: seanjc@google.com, pbonzini@redhat.com, bgardon@google.com, dmatlack@google.com Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Vipin Sharma Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Move condition checks in kvm_tdp_mmu_write_spte() for writing spte atomically in a separate function. New function will be used in future commits to clear bits in SPTE. Signed-off-by: Vipin Sharma Reviewed-by: Ben Gardon Reviewed-by: David Matlack --- arch/x86/kvm/mmu/tdp_iter.h | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/arch/x86/kvm/mmu/tdp_iter.h b/arch/x86/kvm/mmu/tdp_iter.h index f0af385c56e0..30a52e5e68de 100644 --- a/arch/x86/kvm/mmu/tdp_iter.h +++ b/arch/x86/kvm/mmu/tdp_iter.h @@ -29,11 +29,10 @@ static inline void __kvm_tdp_mmu_write_spte(tdp_ptep_t = sptep, u64 new_spte) WRITE_ONCE(*rcu_dereference(sptep), new_spte); } =20 -static inline u64 kvm_tdp_mmu_write_spte(tdp_ptep_t sptep, u64 old_spte, - u64 new_spte, int level) +static inline bool kvm_tdp_mmu_spte_has_volatile_bits(u64 old_spte, int le= vel) { /* - * Atomically write the SPTE if it is a shadow-present, leaf SPTE with + * Atomically write SPTEs if it is a shadow-present, leaf SPTE with * volatile bits, i.e. has bits that can be set outside of mmu_lock. * The Writable bit can be set by KVM's fast page fault handler, and * Accessed and Dirty bits can be set by the CPU. @@ -44,8 +43,15 @@ static inline u64 kvm_tdp_mmu_write_spte(tdp_ptep_t spte= p, u64 old_spte, * logic needs to be reassessed if KVM were to use non-leaf Accessed * bits, e.g. to skip stepping down into child SPTEs when aging SPTEs. */ - if (is_shadow_present_pte(old_spte) && is_last_spte(old_spte, level) && - spte_has_volatile_bits(old_spte)) + return is_shadow_present_pte(old_spte) && + is_last_spte(old_spte, level) && + spte_has_volatile_bits(old_spte); +} + +static inline u64 kvm_tdp_mmu_write_spte(tdp_ptep_t sptep, u64 old_spte, + u64 new_spte, int level) +{ + if (kvm_tdp_mmu_spte_has_volatile_bits(old_spte, level)) return kvm_tdp_mmu_write_spte_atomic(sptep, new_spte); =20 __kvm_tdp_mmu_write_spte(sptep, new_spte); --=20 2.39.1.519.gcb327c4b5f-goog From nobody Sat Sep 13 09:18:54 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 8FDB5C636CC for ; Fri, 3 Feb 2023 19:28:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233628AbjBCT2j (ORCPT ); Fri, 3 Feb 2023 14:28:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33112 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233119AbjBCT2b (ORCPT ); Fri, 3 Feb 2023 14:28:31 -0500 Received: from mail-pj1-x104a.google.com (mail-pj1-x104a.google.com [IPv6:2607:f8b0:4864:20::104a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B18DDA8A08 for ; 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charset="utf-8" No need to check all of the conditions in __handle_changed_spte() as clearing dirty log only involves resetting dirty or writable bit. Make atomic change to dirty or writable bit and mark pfn dirty. Tested on 160 VCPU-160 GB VM and found that performance of clear dirty log stage improved by ~38% in dirty_log_perf_test Before optimization: -------------------- Test iterations: 3 Testing guest mode: PA-bits:ANY, VA-bits:48, 4K pages guest physical test memory: [0x3fd7c0000000, 0x3fffc0000000) Populate memory time: 6.298459671s Setting dirty log mode took : 0.000000052s Enabling dirty logging time: 0.003815691s Iteration 1 dirty memory time: 0.185538848s Iteration 1 get dirty log time: 0.002562641s Iteration 1 clear dirty log time: 3.638543593s Iteration 2 dirty memory time: 0.192226071s Iteration 2 get dirty log time: 0.001558446s Iteration 2 clear dirty log time: 3.145032742s Iteration 3 dirty memory time: 0.193606295s Iteration 3 get dirty log time: 0.001559425s Iteration 3 clear dirty log time: 3.142340358s Disabling dirty logging time: 3.002873664s Get dirty log over 3 iterations took 0.005680512s. (Avg 0.001893504s/iteration) Clear dirty log over 3 iterations took 9.925916693s. (Avg 3.308638897s/iter= ation) After optimization: ------------------- Test iterations: 3 Testing guest mode: PA-bits:ANY, VA-bits:48, 4K pages guest physical test memory: [0x3fd7c0000000, 0x3fffc0000000) Populate memory time: 6.581448437s Setting dirty log mode took : 0.000000058s Enabling dirty logging time: 0.003981283s Iteration 1 dirty memory time: 0.285693420s Iteration 1 get dirty log time: 0.002743004s Iteration 1 clear dirty log time: 2.384343157s Iteration 2 dirty memory time: 0.290414476s Iteration 2 get dirty log time: 0.001720445s Iteration 2 clear dirty log time: 1.882770288s Iteration 3 dirty memory time: 0.289965965s Iteration 3 get dirty log time: 0.001728232s Iteration 3 clear dirty log time: 1.881043086s Disabling dirty logging time: 2.930387523s Get dirty log over 3 iterations took 0.006191681s. (Avg 0.002063893s/iteration) Clear dirty log over 3 iterations took 6.148156531s. (Avg 2.049385510s/iter= ation) Signed-off-by: Vipin Sharma --- arch/x86/kvm/mmu/tdp_iter.h | 13 ++++++++++ arch/x86/kvm/mmu/tdp_mmu.c | 51 +++++++++++++++---------------------- 2 files changed, 34 insertions(+), 30 deletions(-) diff --git a/arch/x86/kvm/mmu/tdp_iter.h b/arch/x86/kvm/mmu/tdp_iter.h index 30a52e5e68de..21046b34f94e 100644 --- a/arch/x86/kvm/mmu/tdp_iter.h +++ b/arch/x86/kvm/mmu/tdp_iter.h @@ -121,4 +121,17 @@ void tdp_iter_start(struct tdp_iter *iter, struct kvm_= mmu_page *root, void tdp_iter_next(struct tdp_iter *iter); void tdp_iter_restart(struct tdp_iter *iter); =20 +static inline u64 kvm_tdp_mmu_clear_spte_bit(struct tdp_iter *iter, u64 ma= sk) +{ + atomic64_t *sptep; + + if (kvm_tdp_mmu_spte_has_volatile_bits(iter->old_spte, iter->level)) { + sptep =3D (atomic64_t *)rcu_dereference(iter->sptep); + return (u64)atomic64_fetch_and(~mask, sptep); + } + + __kvm_tdp_mmu_write_spte(iter->sptep, iter->old_spte & ~mask); + return iter->old_spte; +} + #endif /* __KVM_X86_MMU_TDP_ITER_H */ diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index bba33aea0fb0..83f15052aa6c 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -710,18 +710,13 @@ static inline int tdp_mmu_zap_spte_atomic(struct kvm = *kvm, * notifier for access tracking. Leaving record_acc_track * unset in that case prevents page accesses from being * double counted. - * @record_dirty_log: Record the page as dirty in the dirty bitmap if - * appropriate for the change being made. Should be set - * unless performing certain dirty logging operations. - * Leaving record_dirty_log unset in that case prevents page - * writes from being double counted. * * Returns the old SPTE value, which _may_ be different than @old_spte if = the * SPTE had voldatile bits. */ static u64 __tdp_mmu_set_spte(struct kvm *kvm, int as_id, tdp_ptep_t sptep, u64 old_spte, u64 new_spte, gfn_t gfn, int level, - bool record_acc_track, bool record_dirty_log) + bool record_acc_track) { lockdep_assert_held_write(&kvm->mmu_lock); =20 @@ -740,42 +735,34 @@ static u64 __tdp_mmu_set_spte(struct kvm *kvm, int as= _id, tdp_ptep_t sptep, =20 if (record_acc_track) handle_changed_spte_acc_track(old_spte, new_spte, level); - if (record_dirty_log) - handle_changed_spte_dirty_log(kvm, as_id, gfn, old_spte, - new_spte, level); + + handle_changed_spte_dirty_log(kvm, as_id, gfn, old_spte, new_spte, + level); return old_spte; } =20 static inline void _tdp_mmu_set_spte(struct kvm *kvm, struct tdp_iter *ite= r, - u64 new_spte, bool record_acc_track, - bool record_dirty_log) + u64 new_spte, bool record_acc_track) { WARN_ON_ONCE(iter->yielded); =20 iter->old_spte =3D __tdp_mmu_set_spte(kvm, iter->as_id, iter->sptep, iter->old_spte, new_spte, iter->gfn, iter->level, - record_acc_track, record_dirty_log); + record_acc_track); } =20 static inline void tdp_mmu_set_spte(struct kvm *kvm, struct tdp_iter *iter, u64 new_spte) { - _tdp_mmu_set_spte(kvm, iter, new_spte, true, true); + _tdp_mmu_set_spte(kvm, iter, new_spte, true); } =20 static inline void tdp_mmu_set_spte_no_acc_track(struct kvm *kvm, struct tdp_iter *iter, u64 new_spte) { - _tdp_mmu_set_spte(kvm, iter, new_spte, false, true); -} - -static inline void tdp_mmu_set_spte_no_dirty_log(struct kvm *kvm, - struct tdp_iter *iter, - u64 new_spte) -{ - _tdp_mmu_set_spte(kvm, iter, new_spte, true, false); + _tdp_mmu_set_spte(kvm, iter, new_spte, false); } =20 #define tdp_root_for_each_pte(_iter, _root, _start, _end) \ @@ -925,7 +912,7 @@ bool kvm_tdp_mmu_zap_sp(struct kvm *kvm, struct kvm_mmu= _page *sp) return false; =20 __tdp_mmu_set_spte(kvm, kvm_mmu_page_as_id(sp), sp->ptep, old_spte, 0, - sp->gfn, sp->role.level + 1, true, true); + sp->gfn, sp->role.level + 1, true); =20 return true; } @@ -1678,7 +1665,7 @@ static void clear_dirty_pt_masked(struct kvm *kvm, st= ruct kvm_mmu_page *root, gfn_t gfn, unsigned long mask, bool wrprot) { struct tdp_iter iter; - u64 new_spte; + u64 clear_bits; =20 rcu_read_lock(); =20 @@ -1694,18 +1681,22 @@ static void clear_dirty_pt_masked(struct kvm *kvm, = struct kvm_mmu_page *root, mask &=3D ~(1UL << (iter.gfn - gfn)); =20 if (wrprot || spte_ad_need_write_protect(iter.old_spte)) { - if (is_writable_pte(iter.old_spte)) - new_spte =3D iter.old_spte & ~PT_WRITABLE_MASK; - else + if (!is_writable_pte(iter.old_spte)) continue; + + clear_bits =3D PT_WRITABLE_MASK; } else { - if (iter.old_spte & shadow_dirty_mask) - new_spte =3D iter.old_spte & ~shadow_dirty_mask; - else + if (!(iter.old_spte & shadow_dirty_mask)) continue; + + clear_bits =3D shadow_dirty_mask; } =20 - tdp_mmu_set_spte_no_dirty_log(kvm, &iter, new_spte); + iter.old_spte =3D kvm_tdp_mmu_clear_spte_bit(&iter, clear_bits); + trace_kvm_tdp_mmu_spte_changed(iter.as_id, iter.gfn, iter.level, + iter.old_spte, + iter.old_spte & ~clear_bits); + kvm_set_pfn_dirty(spte_to_pfn(iter.old_spte)); } =20 rcu_read_unlock(); --=20 2.39.1.519.gcb327c4b5f-goog From nobody Sat Sep 13 09:18:54 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 63D92C05027 for ; Fri, 3 Feb 2023 19:28:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233714AbjBCT2m (ORCPT ); Fri, 3 Feb 2023 14:28:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33390 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233294AbjBCT2g (ORCPT ); Fri, 3 Feb 2023 14:28:36 -0500 Received: from mail-pl1-x649.google.com (mail-pl1-x649.google.com [IPv6:2607:f8b0:4864:20::649]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4482DA913D for ; 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charset="utf-8" No need to check all of the conditions in __handle_changed_spte(). Aging a gfn range implies resetting access bit or marking spte for access tracking. Use atomic operation to only reset those bits. This avoids checking many conditions in __handle_changed_spte() API. Also, clean up code by removing dead code and API parameters. Signed-off-by: Vipin Sharma --- arch/x86/kvm/mmu/tdp_mmu.c | 68 ++++++++++++++------------------------ 1 file changed, 25 insertions(+), 43 deletions(-) diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index 83f15052aa6c..18630a06fa1f 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -697,7 +697,7 @@ static inline int tdp_mmu_zap_spte_atomic(struct kvm *k= vm, =20 =20 /* - * __tdp_mmu_set_spte - Set a TDP MMU SPTE and handle the associated bookk= eeping + * _tdp_mmu_set_spte - Set a TDP MMU SPTE and handle the associated bookke= eping * @kvm: KVM instance * @as_id: Address space ID, i.e. regular vs. SMM * @sptep: Pointer to the SPTE @@ -705,18 +705,12 @@ static inline int tdp_mmu_zap_spte_atomic(struct kvm = *kvm, * @new_spte: The new value that will be set for the SPTE * @gfn: The base GFN that was (or will be) mapped by the SPTE * @level: The level _containing_ the SPTE (its parent PT's level) - * @record_acc_track: Notify the MM subsystem of changes to the accessed s= tate - * of the page. Should be set unless handling an MMU - * notifier for access tracking. Leaving record_acc_track - * unset in that case prevents page accesses from being - * double counted. * * Returns the old SPTE value, which _may_ be different than @old_spte if = the * SPTE had voldatile bits. */ -static u64 __tdp_mmu_set_spte(struct kvm *kvm, int as_id, tdp_ptep_t sptep, - u64 old_spte, u64 new_spte, gfn_t gfn, int level, - bool record_acc_track) +static u64 _tdp_mmu_set_spte(struct kvm *kvm, int as_id, tdp_ptep_t sptep, + u64 old_spte, u64 new_spte, gfn_t gfn, int level) { lockdep_assert_held_write(&kvm->mmu_lock); =20 @@ -732,37 +726,20 @@ static u64 __tdp_mmu_set_spte(struct kvm *kvm, int as= _id, tdp_ptep_t sptep, old_spte =3D kvm_tdp_mmu_write_spte(sptep, old_spte, new_spte, level); =20 __handle_changed_spte(kvm, as_id, gfn, old_spte, new_spte, level, false); - - if (record_acc_track) - handle_changed_spte_acc_track(old_spte, new_spte, level); - + handle_changed_spte_acc_track(old_spte, new_spte, level); handle_changed_spte_dirty_log(kvm, as_id, gfn, old_spte, new_spte, level); return old_spte; } =20 -static inline void _tdp_mmu_set_spte(struct kvm *kvm, struct tdp_iter *ite= r, - u64 new_spte, bool record_acc_track) -{ - WARN_ON_ONCE(iter->yielded); - - iter->old_spte =3D __tdp_mmu_set_spte(kvm, iter->as_id, iter->sptep, - iter->old_spte, new_spte, - iter->gfn, iter->level, - record_acc_track); -} - static inline void tdp_mmu_set_spte(struct kvm *kvm, struct tdp_iter *iter, u64 new_spte) { - _tdp_mmu_set_spte(kvm, iter, new_spte, true); -} + WARN_ON_ONCE(iter->yielded); =20 -static inline void tdp_mmu_set_spte_no_acc_track(struct kvm *kvm, - struct tdp_iter *iter, - u64 new_spte) -{ - _tdp_mmu_set_spte(kvm, iter, new_spte, false); + iter->old_spte =3D _tdp_mmu_set_spte(kvm, iter->as_id, iter->sptep, + iter->old_spte, new_spte, + iter->gfn, iter->level); } =20 #define tdp_root_for_each_pte(_iter, _root, _start, _end) \ @@ -911,8 +888,8 @@ bool kvm_tdp_mmu_zap_sp(struct kvm *kvm, struct kvm_mmu= _page *sp) if (WARN_ON_ONCE(!is_shadow_present_pte(old_spte))) return false; =20 - __tdp_mmu_set_spte(kvm, kvm_mmu_page_as_id(sp), sp->ptep, old_spte, 0, - sp->gfn, sp->role.level + 1, true); + _tdp_mmu_set_spte(kvm, kvm_mmu_page_as_id(sp), sp->ptep, old_spte, 0, + sp->gfn, sp->role.level + 1); =20 return true; } @@ -1251,32 +1228,37 @@ static __always_inline bool kvm_tdp_mmu_handle_gfn(= struct kvm *kvm, /* * Mark the SPTEs range of GFNs [start, end) unaccessed and return non-zero * if any of the GFNs in the range have been accessed. + * + * No need to mark corresponding PFN as accessed as this call is coming fr= om + * MMU notifier for that page via HVA. */ static bool age_gfn_range(struct kvm *kvm, struct tdp_iter *iter, struct kvm_gfn_range *range) { - u64 new_spte =3D 0; + u64 new_spte; =20 /* If we have a non-accessed entry we don't need to change the pte. */ if (!is_accessed_spte(iter->old_spte)) return false; =20 - new_spte =3D iter->old_spte; - - if (spte_ad_enabled(new_spte)) { - new_spte &=3D ~shadow_accessed_mask; + if (spte_ad_enabled(iter->old_spte)) { + iter->old_spte =3D kvm_tdp_mmu_clear_spte_bit(iter, + shadow_accessed_mask); + new_spte =3D iter->old_spte & ~shadow_accessed_mask; } else { + new_spte =3D mark_spte_for_access_track(iter->old_spte); + iter->old_spte =3D kvm_tdp_mmu_write_spte(iter->sptep, iter->old_spte, + new_spte, iter->level); /* * Capture the dirty status of the page, so that it doesn't get * lost when the SPTE is marked for access tracking. */ - if (is_writable_pte(new_spte)) - kvm_set_pfn_dirty(spte_to_pfn(new_spte)); - - new_spte =3D mark_spte_for_access_track(new_spte); + if (is_writable_pte(iter->old_spte)) + kvm_set_pfn_dirty(spte_to_pfn(iter->old_spte)); } =20 - tdp_mmu_set_spte_no_acc_track(kvm, iter, new_spte); + trace_kvm_tdp_mmu_spte_changed(iter->as_id, iter->gfn, iter->level, + iter->old_spte, new_spte); =20 return true; } --=20 2.39.1.519.gcb327c4b5f-goog From nobody Sat Sep 13 09:18:54 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 EB00CC61DA4 for ; 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Fri, 03 Feb 2023 11:28:32 -0800 (PST) Date: Fri, 3 Feb 2023 11:28:21 -0800 In-Reply-To: <20230203192822.106773-1-vipinsh@google.com> Mime-Version: 1.0 References: <20230203192822.106773-1-vipinsh@google.com> X-Mailer: git-send-email 2.39.1.519.gcb327c4b5f-goog Message-ID: <20230203192822.106773-5-vipinsh@google.com> Subject: [Patch v2 4/5] KVM: x86/mmu: Remove handle_changed_spte_dirty_log() From: Vipin Sharma To: seanjc@google.com, pbonzini@redhat.com, bgardon@google.com, dmatlack@google.com Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Vipin Sharma Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Remove handle_changed_spte_dirty_log() as there is no code flow which sets leaf SPTE writable and hit this path. Signed-off-by: Vipin Sharma --- arch/x86/kvm/mmu/tdp_mmu.c | 22 ---------------------- 1 file changed, 22 deletions(-) diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index 18630a06fa1f..afe0dcb1859e 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -345,24 +345,6 @@ static void handle_changed_spte_acc_track(u64 old_spte= , u64 new_spte, int level) kvm_set_pfn_accessed(spte_to_pfn(old_spte)); } =20 -static void handle_changed_spte_dirty_log(struct kvm *kvm, int as_id, gfn_= t gfn, - u64 old_spte, u64 new_spte, int level) -{ - bool pfn_changed; - struct kvm_memory_slot *slot; - - if (level > PG_LEVEL_4K) - return; - - pfn_changed =3D spte_to_pfn(old_spte) !=3D spte_to_pfn(new_spte); - - if ((!is_writable_pte(old_spte) || pfn_changed) && - is_writable_pte(new_spte)) { - slot =3D __gfn_to_memslot(__kvm_memslots(kvm, as_id), gfn); - mark_page_dirty_in_slot(kvm, slot, gfn); - } -} - static void tdp_account_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp) { kvm_account_pgtable_pages((void *)sp->spt, +1); @@ -614,8 +596,6 @@ static void handle_changed_spte(struct kvm *kvm, int as= _id, gfn_t gfn, __handle_changed_spte(kvm, as_id, gfn, old_spte, new_spte, level, shared); handle_changed_spte_acc_track(old_spte, new_spte, level); - handle_changed_spte_dirty_log(kvm, as_id, gfn, old_spte, - new_spte, level); } =20 /* @@ -727,8 +707,6 @@ static u64 _tdp_mmu_set_spte(struct kvm *kvm, int as_id= , tdp_ptep_t sptep, =20 __handle_changed_spte(kvm, as_id, gfn, old_spte, new_spte, level, false); handle_changed_spte_acc_track(old_spte, new_spte, level); - handle_changed_spte_dirty_log(kvm, as_id, gfn, old_spte, new_spte, - level); return old_spte; } =20 --=20 2.39.1.519.gcb327c4b5f-goog From nobody Sat Sep 13 09:18:54 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 8DED3C05027 for ; Fri, 3 Feb 2023 19:28:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233760AbjBCT2v (ORCPT ); Fri, 3 Feb 2023 14:28:51 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33406 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233618AbjBCT2i (ORCPT ); Fri, 3 Feb 2023 14:28:38 -0500 Received: from mail-pl1-x64a.google.com (mail-pl1-x64a.google.com [IPv6:2607:f8b0:4864:20::64a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DB896A9111 for ; Fri, 3 Feb 2023 11:28:34 -0800 (PST) Received: by mail-pl1-x64a.google.com with SMTP id y8-20020a170902b48800b00192a600df83so3006534plr.15 for ; Fri, 03 Feb 2023 11:28:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=SZBOzrPag9qrBF2hWUY6jbrMh9ikRhKVuoUM3SUVBlw=; b=pJq3E8HxuEK4dyqvrQfPM3ldp+gHJEW5GZjifURYqJ01MpDIVkBLWa20dx4quPs/sZ 1ZUgW86Qrb0XAtmmgbtsUN3EfbGwRGdh491O5khsZH4C5htGRlm7IaO5OU/7ViPc2DEc ICQpGLr0Xr/56wm7CFTxlfob8bjIcM8StLtysDeewJRgBwjiXoz9EROyyswUUNnlVmL1 c3oR075IT+ksuaTfm1gJjZ3VqvuZcL0V7DSyrW6LZv3GRhc8i4lFNS3QD05JwJHm+HTZ M8MGZRFd8uoyUJ3BrQe81xgQpwD8qPJEl9bS7KD5u3wkEsXyHu6yR2Usv771+y13Mqhh fDhg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=SZBOzrPag9qrBF2hWUY6jbrMh9ikRhKVuoUM3SUVBlw=; b=3NIf3HAgS5/3uW0+N8s3sDeD2hIWqlRfNiU2QoRHnQHsxcewpY/Aiji3opl/aYQqP0 ycTiM3iOzL8BopfhVj469eh/3fBlaCZ+JyRKvvjRmlSCE0CDRUIr7bRaNcPD3MGdRwY/ dlJFKZIiJhFb4AR9sVDvVm7aIZbbdZY8EvxEPv5eN1f6Eu0pO+YbFLz7gHQgqwUg+rh8 GoH9f/JZR7LzVZW8feAYu9GEPG5gm92q03pN9JA/CmxYHUW8W/J5q9Uwsvr2vPAvWIrz N9qvo2AqaSedGXdeGEQ3kg2n2Q8IFibHf6IFialBL0oZYXdrpV3aaAImeOeVBl1oPFH7 fbCg== X-Gm-Message-State: AO0yUKV97PXRkJFT55Pcyzwil+Nvp/9lm7aKnjtViTlAJiAA7shwg3R+ +bT0ULwtQEVEsHnVVcIUyGq0NQHt3Owa X-Google-Smtp-Source: AK7set9l9TJm2dZktMJyX6mkgCljxrkCu2PY9spP3pxWA4XSjvY7UUJsKm+DEEt+hDjuw+ey9m80gEj+jR/M X-Received: from vipin.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:479f]) (user=vipinsh job=sendgmr) by 2002:a05:6a00:705:b0:594:2b99:77ad with SMTP id 5-20020a056a00070500b005942b9977admr1968810pfl.4.1675452514299; Fri, 03 Feb 2023 11:28:34 -0800 (PST) Date: Fri, 3 Feb 2023 11:28:22 -0800 In-Reply-To: <20230203192822.106773-1-vipinsh@google.com> Mime-Version: 1.0 References: <20230203192822.106773-1-vipinsh@google.com> X-Mailer: git-send-email 2.39.1.519.gcb327c4b5f-goog Message-ID: <20230203192822.106773-6-vipinsh@google.com> Subject: [Patch v2 5/5] KVM: x86/mmu: Merge all handle_changed_pte* functions. From: Vipin Sharma To: seanjc@google.com, pbonzini@redhat.com, bgardon@google.com, dmatlack@google.com Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Vipin Sharma Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" __handle_changed_pte() and handle_changed_spte_acc_track() are always used together. Merge these two functions and name the new function handle_changed_pte(). Remove the existing handle_changed_pte() function which just calls __handle_changed_pte and handle_changed_spte_acc_track(). This converges SPTEs change handling code to a single place. Signed-off-by: Vipin Sharma Reviewed-by: Ben Gardon --- arch/x86/kvm/mmu/tdp_mmu.c | 42 +++++++++++--------------------------- 1 file changed, 12 insertions(+), 30 deletions(-) diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index afe0dcb1859e..9b0c81a28f97 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -334,17 +334,6 @@ static void handle_changed_spte(struct kvm *kvm, int a= s_id, gfn_t gfn, u64 old_spte, u64 new_spte, int level, bool shared); =20 -static void handle_changed_spte_acc_track(u64 old_spte, u64 new_spte, int = level) -{ - if (!is_shadow_present_pte(old_spte) || !is_last_spte(old_spte, level)) - return; - - if (is_accessed_spte(old_spte) && - (!is_shadow_present_pte(new_spte) || !is_accessed_spte(new_spte) || - spte_to_pfn(old_spte) !=3D spte_to_pfn(new_spte))) - kvm_set_pfn_accessed(spte_to_pfn(old_spte)); -} - static void tdp_account_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp) { kvm_account_pgtable_pages((void *)sp->spt, +1); @@ -487,7 +476,7 @@ static void handle_removed_pt(struct kvm *kvm, tdp_ptep= _t pt, bool shared) } =20 /** - * __handle_changed_spte - handle bookkeeping associated with an SPTE chan= ge + * handle_changed_spte - handle bookkeeping associated with an SPTE change * @kvm: kvm instance * @as_id: the address space of the paging structure the SPTE was a part of * @gfn: the base GFN that was mapped by the SPTE @@ -501,9 +490,9 @@ static void handle_removed_pt(struct kvm *kvm, tdp_ptep= _t pt, bool shared) * Handle bookkeeping that might result from the modification of a SPTE. * This function must be called for all TDP SPTE modifications. */ -static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn, - u64 old_spte, u64 new_spte, int level, - bool shared) +static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn, + u64 old_spte, u64 new_spte, int level, + bool shared) { bool was_present =3D is_shadow_present_pte(old_spte); bool is_present =3D is_shadow_present_pte(new_spte); @@ -587,15 +576,10 @@ static void __handle_changed_spte(struct kvm *kvm, in= t as_id, gfn_t gfn, if (was_present && !was_leaf && (is_leaf || !is_present || WARN_ON_ONCE(pfn_changed))) handle_removed_pt(kvm, spte_to_child_pt(old_spte, level), shared); -} =20 -static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn, - u64 old_spte, u64 new_spte, int level, - bool shared) -{ - __handle_changed_spte(kvm, as_id, gfn, old_spte, new_spte, level, - shared); - handle_changed_spte_acc_track(old_spte, new_spte, level); + if (was_leaf && is_accessed_spte(old_spte) && + (!is_present || !is_accessed_spte(new_spte) || pfn_changed)) + kvm_set_pfn_accessed(spte_to_pfn(old_spte)); } =20 /* @@ -638,9 +622,8 @@ static inline int tdp_mmu_set_spte_atomic(struct kvm *k= vm, if (!try_cmpxchg64(sptep, &iter->old_spte, new_spte)) return -EBUSY; =20 - __handle_changed_spte(kvm, iter->as_id, iter->gfn, iter->old_spte, - new_spte, iter->level, true); - handle_changed_spte_acc_track(iter->old_spte, new_spte, iter->level); + handle_changed_spte(kvm, iter->as_id, iter->gfn, iter->old_spte, + new_spte, iter->level, true); =20 return 0; } @@ -705,8 +688,7 @@ static u64 _tdp_mmu_set_spte(struct kvm *kvm, int as_id= , tdp_ptep_t sptep, =20 old_spte =3D kvm_tdp_mmu_write_spte(sptep, old_spte, new_spte, level); =20 - __handle_changed_spte(kvm, as_id, gfn, old_spte, new_spte, level, false); - handle_changed_spte_acc_track(old_spte, new_spte, level); + handle_changed_spte(kvm, as_id, gfn, old_spte, new_spte, level, false); return old_spte; } =20 @@ -1273,7 +1255,7 @@ static bool set_spte_gfn(struct kvm *kvm, struct tdp_= iter *iter, * Note, when changing a read-only SPTE, it's not strictly necessary to * zero the SPTE before setting the new PFN, but doing so preserves the * invariant that the PFN of a present * leaf SPTE can never change. - * See __handle_changed_spte(). + * See handle_changed_spte(). */ tdp_mmu_set_spte(kvm, iter, 0); =20 @@ -1298,7 +1280,7 @@ bool kvm_tdp_mmu_set_spte_gfn(struct kvm *kvm, struct= kvm_gfn_range *range) /* * No need to handle the remote TLB flush under RCU protection, the * target SPTE _must_ be a leaf SPTE, i.e. cannot result in freeing a - * shadow page. See the WARN on pfn_changed in __handle_changed_spte(). + * shadow page. See the WARN on pfn_changed in handle_changed_spte(). */ return kvm_tdp_mmu_handle_gfn(kvm, range, set_spte_gfn); } --=20 2.39.1.519.gcb327c4b5f-goog