From patchwork Mon Nov 15 23:45:48 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Gardon X-Patchwork-Id: 12621211 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 06137C433FE for ; Tue, 16 Nov 2021 03:15:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D9C6C6321B for ; Tue, 16 Nov 2021 03:15:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238784AbhKPDSH (ORCPT ); Mon, 15 Nov 2021 22:18:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56010 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237958AbhKPDR4 (ORCPT ); Mon, 15 Nov 2021 22:17:56 -0500 Received: from mail-pf1-x44a.google.com (mail-pf1-x44a.google.com [IPv6:2607:f8b0:4864:20::44a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 31E94C043195 for ; Mon, 15 Nov 2021 15:46:07 -0800 (PST) Received: by mail-pf1-x44a.google.com with SMTP id x25-20020aa79199000000b0044caf0d1ba8so10793449pfa.1 for ; Mon, 15 Nov 2021 15:46:07 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:message-id:mime-version:subject:from:to:cc; bh=eIOcgrBn4CjI7X3tvXpG1QRuiuHXTTvzXh1UFqCSqJk=; b=SQng2vu+fWuCz9L8qbb8p5gwV0sDDFS1pWJLtH4SQFRhFcpvfJOp9blL4dxWn1hBwt kImQ7SkjvhsFV+ybn+YVULZq7YC5zt0bjHId3lLaIfn8qzyYvMvp0I9dzs/1siiisdAV xd2bqqGNrHTKZLPMa3IeiNikwmGSRnJth8lGGKSLPo4OE4UTiWHaqGYr+17u3GY5Wv/S 49M6OYhzND8Jqk+mLmZNNGufBc0e14sPQyKPgmlj2ilMx3B3i0+vVVdgjLy5b+D0yWNb dfYHHiVB4A16JH61dVcD7iaESrA1YORHeywSa3CcB92gPqd6a+wh3tYQb7DEh3B7BzEb DlRA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=eIOcgrBn4CjI7X3tvXpG1QRuiuHXTTvzXh1UFqCSqJk=; b=H9MpvXXdf0MiP0c53dY9Gl8GLG+QfjD8JK/sH6I4LpRJwL1Ndz0BgtMWAgnqigE8RB GSsDE08L8jOSn6DubcUg8gVajbpvMNEmT36V3Col2MQb1Qy+KvAkCmd/hI7whUCqXYcV EBIFVx+K7B9SCItMasUE4YA6s4X1rum1bsYi4o9UaGUt0C/KbaDsjxNkGmgwME7M61kJ 0ygKl47YnzE5lS2vnLO16TvAnbpPvL6F/r0SXBKM1RmvYu0RzyYY4aiaIVF5nT+Oj/jG BVtzjQxbljXM5XxMd7vKFlenjldyyiuxrwJFlnQXrf5qTm7D//gWW7Z8bCfe09NNesEf xVpQ== X-Gm-Message-State: AOAM532nhq0QjqqjAskq55XOvsCGh23aa06lZAFFREDyE7lXVJ3a3aB2 7bci6WawMx88VhpTrHxuVQsX7lHd++iW X-Google-Smtp-Source: ABdhPJwKcBWmJJfS1GjWoDoFkEhyrYjgDmD22gej497BAcM7EpQCW2gmIwyF4mcVrBZKiKvVdj6IsIftLtOW X-Received: from bgardon.sea.corp.google.com ([2620:15c:100:202:916d:2253:5849:9965]) (user=bgardon job=sendgmr) by 2002:a17:90a:ca11:: with SMTP id x17mr22800482pjt.61.1637019966650; Mon, 15 Nov 2021 15:46:06 -0800 (PST) Date: Mon, 15 Nov 2021 15:45:48 -0800 Message-Id: <20211115234603.2908381-1-bgardon@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.34.0.rc1.387.gb447b232ab-goog Subject: [PATCH 00/15] Currently disabling dirty logging with the TDP MMU is extremely slow. On a 96 vCPU / 96G VM it takes ~45 seconds to disable dirty logging with the TDP MMU, as opposed to ~3.5 seconds with the legacy MMU. This series optimizes TLB flushes and introduces in-place large page promotion, to bring the disable dirty log time down to ~2 seconds. From: Ben Gardon To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Paolo Bonzini , Peter Xu , Sean Christopherson , Peter Shier , David Matlack , Mingwei Zhang , Yulei Zhang , Wanpeng Li , Xiao Guangrong , Kai Huang , Keqian Zhu , David Hildenbrand , Ben Gardon Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Testing: Ran KVM selftests and kvm-unit-tests on an Intel Skylake. This series introduced no new failures. Performance: To collect these results I needed to apply Mingwei's patch "selftests: KVM: align guest physical memory base address to 1GB" https://lkml.org/lkml/2021/8/29/310 David Matlack is going to send out an updated version of that patch soon. Without this series, TDP MMU: > ./dirty_log_perf_test -v 96 -s anonymous_hugetlb_1gb Test iterations: 2 Testing guest mode: PA-bits:ANY, VA-bits:48, 4K pages guest physical test memory offset: 0x3fe7c0000000 Populate memory time: 10.966500447s Enabling dirty logging time: 0.002068737s Iteration 1 dirty memory time: 0.047556280s Iteration 1 get dirty log time: 0.001253914s Iteration 1 clear dirty log time: 0.049716661s Iteration 2 dirty memory time: 3.679662016s Iteration 2 get dirty log time: 0.000659546s Iteration 2 clear dirty log time: 1.834329322s Disabling dirty logging time: 45.738439510s Get dirty log over 2 iterations took 0.001913460s. (Avg 0.000956730s/iteration) Clear dirty log over 2 iterations took 1.884045983s. (Avg 0.942022991s/iteration) Without this series, Legacy MMU: > ./dirty_log_perf_test -v 96 -s anonymous_hugetlb_1gb Test iterations: 2 Testing guest mode: PA-bits:ANY, VA-bits:48, 4K pages guest physical test memory offset: 0x3fe7c0000000 Populate memory time: 12.664750666s Enabling dirty logging time: 0.002025510s Iteration 1 dirty memory time: 0.046240875s Iteration 1 get dirty log time: 0.001864342s Iteration 1 clear dirty log time: 0.170243637s Iteration 2 dirty memory time: 31.571088701s Iteration 2 get dirty log time: 0.000626245s Iteration 2 clear dirty log time: 1.294817729s Disabling dirty logging time: 3.566831573s Get dirty log over 2 iterations took 0.002490587s. (Avg 0.001245293s/iteration) Clear dirty log over 2 iterations took 1.465061366s. (Avg 0.732530683s/iteration) With this series, TDP MMU: (Updated since RFC. Pulling out patches 1-4 could have a performance impact.) > ./dirty_log_perf_test -v 96 -s anonymous_hugetlb_1gb Test iterations: 2 Testing guest mode: PA-bits:ANY, VA-bits:48, 4K pages guest physical test memory offset: 0x3fe7c0000000 Populate memory time: 12.225242366s Enabling dirty logging time: 0.002063442s Iteration 1 dirty memory time: 0.047598123s Iteration 1 get dirty log time: 0.001247702s Iteration 1 clear dirty log time: 0.051062420s Iteration 2 dirty memory time: 3.660439803s Iteration 2 get dirty log time: 0.000736229s Iteration 2 clear dirty log time: 1.043469951s Disabling dirty logging time: 1.400549627s Get dirty log over 2 iterations took 0.001983931s. (Avg 0.000991965s/iteration) Clear dirty log over 2 iterations took 1.094532371s. (Avg 0.547266185s/iteration) Patch breakdown: Patches 1 eliminates extra TLB flushes while disabling dirty logging. Patches 2-8 remove the need for a vCPU pointer to make_spte Patches 9-14 are small refactors in perparation for patch 19 Patch 15 implements in-place largepage promotion when disabling dirty logging Changelog: RFC -> v1: Dropped the first 4 patches from the series. Patch 1 was sent separately, patches 2-4 will be taken over by Sean Christopherson. Incorporated David Matlack's Reviewed-by. Ben Gardon (15): KVM: x86/mmu: Remove redundant flushes when disabling dirty logging KVM: x86/mmu: Introduce vcpu_make_spte KVM: x86/mmu: Factor wrprot for nested PML out of make_spte KVM: x86/mmu: Factor mt_mask out of make_spte KVM: x86/mmu: Remove need for a vcpu from kvm_slot_page_track_is_active KVM: x86/mmu: Remove need for a vcpu from mmu_try_to_unsync_pages KVM: x86/mmu: Factor shadow_zero_check out of make_spte KVM: x86/mmu: Replace vcpu argument with kvm pointer in make_spte KVM: x86/mmu: Factor out the meat of reset_tdp_shadow_zero_bits_mask KVM: x86/mmu: Propagate memslot const qualifier KVM: x86/MMU: Refactor vmx_get_mt_mask KVM: x86/mmu: Factor out part of vmx_get_mt_mask which does not depend on vcpu KVM: x86/mmu: Add try_get_mt_mask to x86_ops KVM: x86/mmu: Make kvm_is_mmio_pfn usable outside of spte.c KVM: x86/mmu: Promote pages in-place when disabling dirty logging arch/x86/include/asm/kvm-x86-ops.h | 1 + arch/x86/include/asm/kvm_host.h | 2 + arch/x86/include/asm/kvm_page_track.h | 6 +- arch/x86/kvm/mmu/mmu.c | 45 +++++++------ arch/x86/kvm/mmu/mmu_internal.h | 6 +- arch/x86/kvm/mmu/page_track.c | 8 +-- arch/x86/kvm/mmu/paging_tmpl.h | 6 +- arch/x86/kvm/mmu/spte.c | 43 ++++++++---- arch/x86/kvm/mmu/spte.h | 17 +++-- arch/x86/kvm/mmu/tdp_mmu.c | 97 +++++++++++++++++++++------ arch/x86/kvm/mmu/tdp_mmu.h | 5 +- arch/x86/kvm/svm/svm.c | 8 +++ arch/x86/kvm/vmx/vmx.c | 40 ++++++----- include/linux/kvm_host.h | 10 +-- virt/kvm/kvm_main.c | 12 ++-- 15 files changed, 205 insertions(+), 101 deletions(-)