From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mingwei Zhang Subject: Re: [PATCH v4 3/4] KVM: x86/mmu: count KVM mmu usage in secondary pagetable stats. Date: Fri, 22 Jul 2022 20:58:59 +0000 Message-ID: References: <20220429201131.3397875-1-yosryahmed@google.com> <20220429201131.3397875-4-yosryahmed@google.com> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=sRtc60bVHDuSQyy9YfLGbb/EZRQBkQQyTX+neLttrJI=; b=VT9WZjGGoaYO6wyINeAk1IALZT19I8nvGaJlOLvSTsMGMXO2aI48bLngF7CtjZAvoY Nk4dj0ETYHZSQT86zOPNHYg7GeO54xGWEIJhFv/C0BrBO+t5mqhus74Y4xbk+8fyul8M HfArgcswQSvdoHC84nrbwn2mXJxz+9qFiCBQ69YkVOPUHk9BdnilnJfVEOdrt3RS3CJ4 +mBwVu+wySOMJ/nQcZ/3u7v3umsb304sjJE7eni7WKU27HJWuFzI6grkrasDGOuFewyR 5YIPM89seaz3zWvRqyMCiwRGPEmx5/kbjcwH21G8dckWuQ/kFANi+7LycZSgyao947dV do6A== Content-Disposition: inline In-Reply-To: <20220429201131.3397875-4-yosryahmed-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org> List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Yosry Ahmed Cc: Tejun Heo , Johannes Weiner , Zefan Li , Marc Zyngier , James Morse , Alexandru Elisei , Suzuki K Poulose , Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Andrew Morton , Michal Hocko , Roman Gushchin , Shakeel Butt , Oliver Upton , cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org On Fri, Apr 29, 2022, Yosry Ahmed wrote: > Count the pages used by KVM mmu on x86 for in secondary pagetable stats. > > For the legacy mmu, accounting pagetable stats is combined KVM's > existing for mmu pages in newly introduced kvm_[un]account_mmu_page() > helpers. > > For tdp mmu, introduce new tdp_[un]account_mmu_page() helpers. That > combines accounting pagetable stats with the tdp_mmu_pages counter > accounting. > > tdp_mmu_pages counter introduced in this series [1]. This patch was > rebased on top of the first two patches in that series. > > [1]https://lore.kernel.org/lkml/20220401063636.2414200-1-mizhang-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org/ > > Signed-off-by: Yosry Ahmed > --- It looks like there are two metrics for mmu in x86: one for shadow mmu and the other for TDP mmu. Is there any plan to merge them together? > arch/x86/kvm/mmu/mmu.c | 16 ++++++++++++++-- > arch/x86/kvm/mmu/tdp_mmu.c | 16 ++++++++++++++-- > 2 files changed, 28 insertions(+), 4 deletions(-) > > diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c > index 78d8e1d8fb99..e5b0e826445d 100644 > --- a/arch/x86/kvm/mmu/mmu.c > +++ b/arch/x86/kvm/mmu/mmu.c > @@ -1679,6 +1679,18 @@ static inline void kvm_mod_used_mmu_pages(struct kvm *kvm, long nr) > percpu_counter_add(&kvm_total_used_mmu_pages, nr); > } > > +static void kvm_account_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp) > +{ > + kvm_mod_used_mmu_pages(kvm, +1); > + kvm_account_pgtable_pages((void *)sp->spt, +1); > +} > + > +static void kvm_unaccount_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp) > +{ > + kvm_mod_used_mmu_pages(kvm, -1); > + kvm_account_pgtable_pages((void *)sp->spt, -1); > +} > + > static void kvm_mmu_free_page(struct kvm_mmu_page *sp) > { > MMU_WARN_ON(!is_empty_shadow_page(sp->spt)); > @@ -1734,7 +1746,7 @@ static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu, int direct > */ > sp->mmu_valid_gen = vcpu->kvm->arch.mmu_valid_gen; > list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages); > - kvm_mod_used_mmu_pages(vcpu->kvm, +1); > + kvm_account_mmu_page(vcpu->kvm, sp); > return sp; > } > > @@ -2363,7 +2375,7 @@ static bool __kvm_mmu_prepare_zap_page(struct kvm *kvm, > list_add(&sp->link, invalid_list); > else > list_move(&sp->link, invalid_list); > - kvm_mod_used_mmu_pages(kvm, -1); > + kvm_unaccount_mmu_page(kvm, sp); > } else { > /* > * Remove the active root from the active page list, the root > diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c > index 3456277ade18..6295c4da5dee 100644 > --- a/arch/x86/kvm/mmu/tdp_mmu.c > +++ b/arch/x86/kvm/mmu/tdp_mmu.c > @@ -371,6 +371,18 @@ static void handle_changed_spte_dirty_log(struct kvm *kvm, int as_id, gfn_t gfn, > } > } > > +static void tdp_account_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp) > +{ > + atomic64_inc(&kvm->arch.tdp_mmu_pages); > + kvm_account_pgtable_pages((void *)sp->spt, +1); > +} > + > +static void tdp_unaccount_mmu_page(struct kvm *kvm, struct kvm_mmu_page *sp) > +{ > + atomic64_dec(&kvm->arch.tdp_mmu_pages); > + kvm_account_pgtable_pages((void *)sp->spt, -1); > +} > + > /** > * tdp_mmu_unlink_sp() - Remove a shadow page from the list of used pages > * > @@ -383,7 +395,7 @@ static void handle_changed_spte_dirty_log(struct kvm *kvm, int as_id, gfn_t gfn, > static void tdp_mmu_unlink_sp(struct kvm *kvm, struct kvm_mmu_page *sp, > bool shared) > { > - atomic64_dec(&kvm->arch.tdp_mmu_pages); > + tdp_unaccount_mmu_page(kvm, sp); > > if (!sp->lpage_disallowed) > return; > @@ -1121,7 +1133,7 @@ static int tdp_mmu_link_sp(struct kvm *kvm, struct tdp_iter *iter, > tdp_mmu_set_spte(kvm, iter, spte); > } > > - atomic64_inc(&kvm->arch.tdp_mmu_pages); > + tdp_account_mmu_page(kvm, sp); > > return 0; > } > -- > 2.36.0.464.gb9c8b46e94-goog >