From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-23.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 034E1C4320A for ; Mon, 26 Jul 2021 21:06:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D70A260F93 for ; Mon, 26 Jul 2021 21:06:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233441AbhGZUZq (ORCPT ); Mon, 26 Jul 2021 16:25:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37030 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233023AbhGZUZn (ORCPT ); Mon, 26 Jul 2021 16:25:43 -0400 Received: from mail-io1-xd2c.google.com (mail-io1-xd2c.google.com [IPv6:2607:f8b0:4864:20::d2c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C5167C061757 for ; Mon, 26 Jul 2021 14:06:11 -0700 (PDT) Received: by mail-io1-xd2c.google.com with SMTP id l18so13560059ioh.11 for ; Mon, 26 Jul 2021 14:06:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=Rkig7bE4hOxzHEgCJPd82apljPN10pQgvqX3gsxGQr8=; b=Dc1ZNs5zRFS+ENDVWCGOlGoSGiMpxdR7eVys+pUw/0VgibLj7iYul3jE5hlZLZ5IqY Ve9c4GJ/vNyHDdYgCSxe6N4QoCJ784+vSsXyPptEYwHSUNmsgO8n+gr1pcR9dcLVFMau V5yO+pytXFDojUXypN6sd+/D1J2EFMgsz1Z2X/zO505WAARzHskCULPZy6nWnESomYd7 blbB67Kd/cSiXf2mQo0FHyL3TpTZ3Vz8BaDclFuMgb6PHcukr3O94YuE0VO9yYjx50n5 oO60e1Qwn7AURxIN0RLvfcV/IhfuXdEWrU5O0SB673yMTW0P7mZCGZJZ8ULLQ59L1zCy yIpw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=Rkig7bE4hOxzHEgCJPd82apljPN10pQgvqX3gsxGQr8=; b=gLhKXQwPnWrmduHsg+/VM3yFYWp+PV3XByu938LhZ77GOazBh8OfU1g1X4DeGUnEJS dof9L3UyFIk5W6R+ExGsolRgLdSKUJk2yzOW9C0PBJf1jMOr951sm1PYN6FDkJ+HfMnx WRc5nvPpqwu5ax8cvfBhOTfdxFh21uAMW7V7MNxec/2NoRvdLYvXMPweERUco2fjOeab S2gyKVG9It+eiVhGA6Xb5iw82+cPgpqsppl2ewsXoR3JjzJax5FNSEtdWP/5zKU2cSUq uermxfDuOZA8TgJpfn9qsXQOg20zrILlaHeYWaMRwmohgGCJZbWV0mLhBVf9gDdgNq4C 4ByQ== X-Gm-Message-State: AOAM5333Cjho0AiplLHQqijyTAEnKW2BYPdk6tzwUNLIotljaHFaOy2d GTs52NVaONVrYUEnZaLDdTIoad31qCoq5UYmkkq+Eg== X-Google-Smtp-Source: ABdhPJxHQ4/K8JqyV+8xDhbhj04xPAp2EiPk5By73klotblAAQyaQoPbqIelufbMjYI1TcjgvZiX+UFVw22JoXT+nrA= X-Received: by 2002:a5e:c912:: with SMTP id z18mr16302923iol.9.1627333571083; Mon, 26 Jul 2021 14:06:11 -0700 (PDT) MIME-Version: 1.0 References: <20210726175357.1572951-1-mizhang@google.com> <20210726175357.1572951-4-mizhang@google.com> In-Reply-To: From: Ben Gardon Date: Mon, 26 Jul 2021 14:06:00 -0700 Message-ID: Subject: Re: [PATCH v2 3/3] KVM: x86/mmu: Add detailed page size stats To: Mingwei Zhang Cc: Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , kvm , LKML , Jing Zhang Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 26, 2021 at 1:41 PM Ben Gardon wrote: > > On Mon, Jul 26, 2021 at 10:54 AM Mingwei Zhang wrote: > > > > Existing KVM code tracks the number of large pages regardless of their > > sizes. Therefore, when large page of 1GB (or larger) is adopted, the > > information becomes less useful because lpages counts a mix of 1G and 2M > > pages. > > > > So remove the lpages since it is easy for user space to aggregate the info. > > Instead, provide a comprehensive page stats of all sizes from 4K to 512G. > > > > Suggested-by: Ben Gardon > > Suggested-by: Jing Zhang > > Signed-off-by: Mingwei Zhang Besides the check which can be dropped in mmu_spte_clear_track_bits, this looks good to me. Reviewed-by: Ben Gardon > > --- > > arch/x86/include/asm/kvm_host.h | 10 +++++++++- > > arch/x86/kvm/mmu.h | 2 ++ > > arch/x86/kvm/mmu/mmu.c | 32 +++++++++++++++++++------------- > > arch/x86/kvm/mmu/tdp_mmu.c | 15 ++------------- > > arch/x86/kvm/x86.c | 7 +++++-- > > 5 files changed, 37 insertions(+), 29 deletions(-) > > > > diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h > > index 974cbfb1eefe..2e4b6fd36e62 100644 > > --- a/arch/x86/include/asm/kvm_host.h > > +++ b/arch/x86/include/asm/kvm_host.h > > @@ -1206,9 +1206,17 @@ struct kvm_vm_stat { > > u64 mmu_recycled; > > u64 mmu_cache_miss; > > u64 mmu_unsync; > > - u64 lpages; > > u64 nx_lpage_splits; > > u64 max_mmu_page_hash_collisions; > > + union { > > + struct { > > + atomic64_t pages_4k; > > + atomic64_t pages_2m; > > + atomic64_t pages_1g; > > + atomic64_t pages_512g; > > + }; > > + atomic64_t pages[4]; > > + } page_stats; > > }; > > > > struct kvm_vcpu_stat { > > diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h > > index 83e6c6965f1e..ad5638815311 100644 > > --- a/arch/x86/kvm/mmu.h > > +++ b/arch/x86/kvm/mmu.h > > @@ -240,4 +240,6 @@ static inline bool kvm_memslots_have_rmaps(struct kvm *kvm) > > return smp_load_acquire(&kvm->arch.memslots_have_rmaps); > > } > > > > +void kvm_update_page_stats(struct kvm *kvm, int level, int count); > > + > > #endif > > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c > > index 442cc554ebd6..7e0fc760739b 100644 > > --- a/arch/x86/kvm/mmu/mmu.c > > +++ b/arch/x86/kvm/mmu/mmu.c > > @@ -588,16 +588,22 @@ static bool mmu_spte_update(u64 *sptep, u64 new_spte) > > return flush; > > } > > > > +void kvm_update_page_stats(struct kvm *kvm, int level, int count) > > +{ > > + atomic64_add(count, &kvm->stat.page_stats.pages[level - 1]); > > +} > > + > > /* > > * Rules for using mmu_spte_clear_track_bits: > > * It sets the sptep from present to nonpresent, and track the > > * state bits, it is used to clear the last level sptep. > > * Returns non-zero if the PTE was previously valid. > > */ > > -static int mmu_spte_clear_track_bits(u64 *sptep) > > +static int mmu_spte_clear_track_bits(struct kvm *kvm, u64 *sptep) > > { > > kvm_pfn_t pfn; > > u64 old_spte = *sptep; > > + int level = sptep_to_sp(sptep)->role.level; > > > > if (!spte_has_volatile_bits(old_spte)) > > __update_clear_spte_fast(sptep, 0ull); > > @@ -607,6 +613,9 @@ static int mmu_spte_clear_track_bits(u64 *sptep) > > if (!is_shadow_present_pte(old_spte)) > > return 0; > > > > + if (is_last_spte(old_spte, level)) > > You can drop this check since it's part of the contract for calling > this function. > > > + kvm_update_page_stats(kvm, level, -1); > > + > > pfn = spte_to_pfn(old_spte); > > > > /* > > @@ -984,9 +993,10 @@ static void __pte_list_remove(u64 *spte, struct kvm_rmap_head *rmap_head) > > } > > } > > > > -static void pte_list_remove(struct kvm_rmap_head *rmap_head, u64 *sptep) > > +static void pte_list_remove(struct kvm *kvm, struct kvm_rmap_head *rmap_head, > > + u64 *sptep) > > { > > - mmu_spte_clear_track_bits(sptep); > > + mmu_spte_clear_track_bits(kvm, sptep); > > __pte_list_remove(sptep, rmap_head); > > } > > > > @@ -1119,7 +1129,7 @@ static u64 *rmap_get_next(struct rmap_iterator *iter) > > > > static void drop_spte(struct kvm *kvm, u64 *sptep) > > { > > - if (mmu_spte_clear_track_bits(sptep)) > > + if (mmu_spte_clear_track_bits(kvm, sptep)) > > rmap_remove(kvm, sptep); > > } > > > > @@ -1129,7 +1139,6 @@ static bool __drop_large_spte(struct kvm *kvm, u64 *sptep) > > if (is_large_pte(*sptep)) { > > WARN_ON(sptep_to_sp(sptep)->role.level == PG_LEVEL_4K); > > drop_spte(kvm, sptep); > > - --kvm->stat.lpages; > > return true; > > } > > > > @@ -1386,7 +1395,7 @@ static bool kvm_zap_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, > > while ((sptep = rmap_get_first(rmap_head, &iter))) { > > rmap_printk("spte %p %llx.\n", sptep, *sptep); > > > > - pte_list_remove(rmap_head, sptep); > > + pte_list_remove(kvm, rmap_head, sptep); > > flush = true; > > } > > > > @@ -1421,13 +1430,13 @@ static bool kvm_set_pte_rmapp(struct kvm *kvm, struct kvm_rmap_head *rmap_head, > > need_flush = 1; > > > > if (pte_write(pte)) { > > - pte_list_remove(rmap_head, sptep); > > + pte_list_remove(kvm, rmap_head, sptep); > > goto restart; > > } else { > > new_spte = kvm_mmu_changed_pte_notifier_make_spte( > > *sptep, new_pfn); > > > > - mmu_spte_clear_track_bits(sptep); > > + mmu_spte_clear_track_bits(kvm, sptep); > > mmu_spte_set(sptep, new_spte); > > } > > } > > @@ -2232,8 +2241,6 @@ static int mmu_page_zap_pte(struct kvm *kvm, struct kvm_mmu_page *sp, > > if (is_shadow_present_pte(pte)) { > > if (is_last_spte(pte, sp->role.level)) { > > drop_spte(kvm, spte); > > - if (is_large_pte(pte)) > > - --kvm->stat.lpages; > > } else { > > child = to_shadow_page(pte & PT64_BASE_ADDR_MASK); > > drop_parent_pte(child, spte); > > @@ -2692,8 +2699,7 @@ static int mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, > > trace_kvm_mmu_set_spte(level, gfn, sptep); > > > > if (!was_rmapped) { > > - if (is_large_pte(*sptep)) > > - ++vcpu->kvm->stat.lpages; > > + kvm_update_page_stats(vcpu->kvm, level, 1); > > rmap_count = rmap_add(vcpu, sptep, gfn); > > if (rmap_count > RMAP_RECYCLE_THRESHOLD) > > rmap_recycle(vcpu, sptep, gfn); > > @@ -5669,7 +5675,7 @@ static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm, > > if (sp->role.direct && !kvm_is_reserved_pfn(pfn) && > > sp->role.level < kvm_mmu_max_mapping_level(kvm, slot, sp->gfn, > > pfn, PG_LEVEL_NUM)) { > > - pte_list_remove(rmap_head, sptep); > > + pte_list_remove(kvm, rmap_head, sptep); > > > > if (kvm_available_flush_tlb_with_range()) > > kvm_flush_remote_tlbs_with_address(kvm, sp->gfn, > > diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c > > index cba2ab5db2a0..eae404c15364 100644 > > --- a/arch/x86/kvm/mmu/tdp_mmu.c > > +++ b/arch/x86/kvm/mmu/tdp_mmu.c > > @@ -413,7 +413,6 @@ static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn, > > bool was_leaf = was_present && is_last_spte(old_spte, level); > > bool is_leaf = is_present && is_last_spte(new_spte, level); > > bool pfn_changed = spte_to_pfn(old_spte) != spte_to_pfn(new_spte); > > - bool was_large, is_large; > > > > WARN_ON(level > PT64_ROOT_MAX_LEVEL); > > WARN_ON(level < PG_LEVEL_4K); > > @@ -472,18 +471,8 @@ static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn, > > return; > > } > > > > - /* > > - * Update large page stats if a large page is being zapped, created, or > > - * is replacing an existing shadow page. > > - */ > > - was_large = was_leaf && is_large_pte(old_spte); > > - is_large = is_leaf && is_large_pte(new_spte); > > - if (was_large != is_large) { > > - if (was_large) > > - atomic64_sub(1, (atomic64_t *)&kvm->stat.lpages); > > - else > > - atomic64_add(1, (atomic64_t *)&kvm->stat.lpages); > > - } > > + if (is_leaf != was_leaf) > > + kvm_update_page_stats(kvm, level, is_leaf ? 1 : -1); > > > > if (was_leaf && is_dirty_spte(old_spte) && > > (!is_present || !is_dirty_spte(new_spte) || pfn_changed)) > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > > index 8166ad113fb2..3858d36d3c49 100644 > > --- a/arch/x86/kvm/x86.c > > +++ b/arch/x86/kvm/x86.c > > @@ -235,9 +235,12 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = { > > STATS_DESC_COUNTER(VM, mmu_recycled), > > STATS_DESC_COUNTER(VM, mmu_cache_miss), > > STATS_DESC_ICOUNTER(VM, mmu_unsync), > > - STATS_DESC_ICOUNTER(VM, lpages), > > STATS_DESC_ICOUNTER(VM, nx_lpage_splits), > > - STATS_DESC_PCOUNTER(VM, max_mmu_page_hash_collisions) > > + STATS_DESC_PCOUNTER(VM, max_mmu_page_hash_collisions), > > + STATS_DESC_ICOUNTER(VM, page_stats.pages_4k), > > + STATS_DESC_ICOUNTER(VM, page_stats.pages_2m), > > + STATS_DESC_ICOUNTER(VM, page_stats.pages_1g), > > + STATS_DESC_ICOUNTER(VM, page_stats.pages_512g) > > }; > > static_assert(ARRAY_SIZE(kvm_vm_stats_desc) == > > sizeof(struct kvm_vm_stat) / sizeof(u64)); > > -- > > 2.32.0.432.gabb21c7263-goog > >