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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id DE743C433EF for ; Tue, 26 Apr 2022 07:35:02 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 6B9616B0073; Tue, 26 Apr 2022 03:35:02 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 668A96B0074; Tue, 26 Apr 2022 03:35:02 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 530246B0075; Tue, 26 Apr 2022 03:35:02 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.25]) by kanga.kvack.org (Postfix) with ESMTP id 3FE2E6B0073 for ; Tue, 26 Apr 2022 03:35:02 -0400 (EDT) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 18B3760A55 for ; Tue, 26 Apr 2022 07:35:02 +0000 (UTC) X-FDA: 79398218844.22.86E18E0 Received: from mail-il1-f172.google.com (mail-il1-f172.google.com [209.85.166.172]) by imf19.hostedemail.com (Postfix) with ESMTP id 13BC11A0041 for ; Tue, 26 Apr 2022 07:34:57 +0000 (UTC) Received: by mail-il1-f172.google.com with SMTP id y16so10865298ilc.7 for ; Tue, 26 Apr 2022 00:35:01 -0700 (PDT) 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=T6uVKqz/bxBh0XcbvcuRA0UyoUPF9VXe65F1cQD8y4Q=; b=ObEunFSl4crRLGfpGD9vb4uNjucdcW+SwMC5wjs68ErQM98eX2dd/1bhFqvb4MQrUZ aNBQiYOEZs6DAFrjwy4GxIX9P710BE5dNtb9ren8SoNbyoDCq1JSrqMW6bcxyN3g457u /+gBpA8szyFlMBKjZqPcqtIcg53tpCAgbfmBRZ+EQiSDL0bYkiLUkJAuAA+ESILGYbW5 jVcb61+A+66M7v7MKaJKTdQY27E/r9amtlm20dB0rHCxpqld0qjq5eRsqvCmPNleg1uA MTGwgfxKApBNNdQAeaBp8qoeybFa8FJ6gos+fYTUTeB4wg78apx7w8FkSb2oMxvxLXSe mDTA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=T6uVKqz/bxBh0XcbvcuRA0UyoUPF9VXe65F1cQD8y4Q=; b=sFR4nzurLBgXHAXYQSl4lpFfP5E2w/vOvGbmzpynL0PQZ9gdKs6KBbMEHPS8KgSHgf mNJrH5COgLfRX8RhLhqdGQ9TbF8sySDN9oYRG79xy06EXNOt4CgpiHKvl+aaaOME4lxI qAPJgMMgDqvjCKALyYXrsknZ/jsWxZXa/jWJ5ZPDt3xD8Rv4jz5YmDcXgMHaWcHVFpxj 7wJwYg0+FqKx18UJPIiAvcPh19MYRFdQbYR+w3tH3+u9xG4JHOrUr++IU3Qxuw6RV8x+ QIy/AHdJ/np0ZYElDCMnggYsXMt2DKxssla7x+aap7Tknt70VYD7zgJtcFY0uskvTrhb YAng== X-Gm-Message-State: AOAM5328JVzU9FjJpp2D/GLgktSIqni/X+Nburm77nmKM63F1oY0UJJV IS5PgjXEUt/iDG0zvZqHT1a0Lw== X-Google-Smtp-Source: ABdhPJzzgIPYx4mfeq03H4D4LkohxnIEdiAlT4JnSJ/rUPy7BWzzJro8BOalbut4cMQo3UF9wiXwfw== X-Received: by 2002:a05:6e02:b23:b0:2cd:89db:f685 with SMTP id e3-20020a056e020b2300b002cd89dbf685mr5194103ilu.296.1650958500701; Tue, 26 Apr 2022 00:35:00 -0700 (PDT) Received: from google.com (194.225.68.34.bc.googleusercontent.com. [34.68.225.194]) by smtp.gmail.com with ESMTPSA id w5-20020a05660205c500b006546d0b5f6dsm9257784iox.41.2022.04.26.00.34.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 26 Apr 2022 00:34:59 -0700 (PDT) Date: Tue, 26 Apr 2022 07:34:56 +0000 From: Oliver Upton To: Yosry Ahmed Cc: Sean Christopherson , Huacai Chen , Aleksandar Markovic , Anup Patel , Atish Patra , Paolo Bonzini , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Andrew Morton , Johannes Weiner , Michal Hocko , Roman Gushchin , Shakeel Butt , James Morse , Catalin Marinas , Shameer Kolothum , Marc Zyngier , Alexandru Elisei , Suzuki K Poulose , linux-mips@vger.kernel.org, kvm@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, cgroups@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu Subject: Re: [PATCH v3 4/6] KVM: arm64/mmu: count KVM page table pages in pagetable stats Message-ID: References: <20220426053904.3684293-1-yosryahmed@google.com> <20220426053904.3684293-5-yosryahmed@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220426053904.3684293-5-yosryahmed@google.com> X-Stat-Signature: sfgo1ejxdcsjxtqq1mea6p8f6fpe7iu7 X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 13BC11A0041 Authentication-Results: imf19.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=ObEunFSl; spf=pass (imf19.hostedemail.com: domain of oupton@google.com designates 209.85.166.172 as permitted sender) smtp.mailfrom=oupton@google.com; dmarc=pass (policy=reject) header.from=google.com X-Rspam-User: X-HE-Tag: 1650958497-329893 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Hi Yosry, On Tue, Apr 26, 2022 at 05:39:02AM +0000, Yosry Ahmed wrote: > Count the pages used by KVM in arm64 for page tables in pagetable stats. > > Account pages allocated for PTEs in pgtable init functions and > kvm_set_table_pte(). > > Since most page table pages are freed using put_page(), add a helper > function put_pte_page() that checks if this is the last ref for a pte > page before putting it, and unaccounts stats accordingly. > > Signed-off-by: Yosry Ahmed > --- > arch/arm64/kernel/image-vars.h | 3 ++ > arch/arm64/kvm/hyp/pgtable.c | 50 +++++++++++++++++++++------------- > 2 files changed, 34 insertions(+), 19 deletions(-) > > diff --git a/arch/arm64/kernel/image-vars.h b/arch/arm64/kernel/image-vars.h > index 241c86b67d01..25bf058714f6 100644 > --- a/arch/arm64/kernel/image-vars.h > +++ b/arch/arm64/kernel/image-vars.h > @@ -143,6 +143,9 @@ KVM_NVHE_ALIAS(__hyp_rodata_end); > /* pKVM static key */ > KVM_NVHE_ALIAS(kvm_protected_mode_initialized); > > +/* Called by kvm_account_pgtable_pages() to update pagetable stats */ > +KVM_NVHE_ALIAS(__mod_lruvec_page_state); > + > #endif /* CONFIG_KVM */ > > #endif /* __ARM64_KERNEL_IMAGE_VARS_H */ > diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c > index 2cb3867eb7c2..53e13c3313e9 100644 > --- a/arch/arm64/kvm/hyp/pgtable.c > +++ b/arch/arm64/kvm/hyp/pgtable.c > @@ -152,6 +152,7 @@ static void kvm_set_table_pte(kvm_pte_t *ptep, kvm_pte_t *childp, > > WARN_ON(kvm_pte_valid(old)); > smp_store_release(ptep, pte); > + kvm_account_pgtable_pages((void *)childp, +1); What page tables do we want to account? KVM on ARM manages several page tables. For regular KVM, the host kernel manages allocations for the hyp stage 1 tables in addition to the stage 2 tables used for a particular VM. The former is system overhead whereas the latter could be attributed to a guest VM. I imagine protected KVM is out of scope, since it actually manages its own allocations outside of the host kernel. Given this, I would recommend adding the accounting hooks to mmu.c as that is where we alloc/free table pages and it is in the host address space. kvm_s2_mm_ops and kvm_hyp_mm_ops point to all the relevant functions, though the latter is only relevant if we want to count system page tables too. -- Thanks, Oliver