From patchwork Tue Mar 2 12:57:42 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yanan Wang X-Patchwork-Id: 12111881 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 25627C433E6 for ; Tue, 2 Mar 2021 16:47:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E998964F0D for ; Tue, 2 Mar 2021 16:47:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1449408AbhCBQpl (ORCPT ); Tue, 2 Mar 2021 11:45:41 -0500 Received: from szxga05-in.huawei.com ([45.249.212.191]:13040 "EHLO szxga05-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350919AbhCBM7L (ORCPT ); Tue, 2 Mar 2021 07:59:11 -0500 Received: from DGGEMS412-HUB.china.huawei.com (unknown [172.30.72.58]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4DqcZ11GsMzMhCS; Tue, 2 Mar 2021 20:55:53 +0800 (CST) Received: from DESKTOP-TMVL5KK.china.huawei.com (10.174.187.128) by DGGEMS412-HUB.china.huawei.com (10.3.19.212) with Microsoft SMTP Server id 14.3.498.0; Tue, 2 Mar 2021 20:57:53 +0800 From: Yanan Wang To: , , CC: Paolo Bonzini , Ben Gardon , "Sean Christopherson" , Vitaly Kuznetsov , Andrew Jones , Peter Xu , Marc Zyngier , Ingo Molnar , Adrian Hunter , Jiri Olsa , "Arnaldo Carvalho de Melo" , Arnd Bergmann , Michael Kerrisk , Thomas Gleixner , , , , Yanan Wang Subject: [RFC PATCH v4 0/9] KVM: selftests: some improvement and a new test for kvm page table Date: Tue, 2 Mar 2021 20:57:42 +0800 Message-ID: <20210302125751.19080-1-wangyanan55@huawei.com> X-Mailer: git-send-email 2.8.4.windows.1 MIME-Version: 1.0 X-Originating-IP: [10.174.187.128] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Hi, This v4 series can mainly include two parts. Based on kvm queue branch: https://git.kernel.org/pub/scm/virt/kvm/kvm.git/log/?h=queue Links of v1: https://lore.kernel.org/lkml/20210208090841.333724-1-wangyanan55@huawei.com/ Links of v2: https://lore.kernel.org/lkml/20210225055940.18748-1-wangyanan55@huawei.com/ Links of v3: https://lore.kernel.org/lkml/20210301065916.11484-1-wangyanan55@huawei.com/ In the first part, all the known hugetlb backing src types specified with different hugepage sizes are listed, so that we can specify use of hugetlb source of the exact granularity that we want, instead of the system default ones. And as all the known hugetlb page sizes are listed, it's appropriate for all architectures. Besides, a helper that can get granularity of different backing src types(anonumous/thp/hugetlb) is added, so that we can use the accurate backing src granularity for kinds of alignment or guest memory accessing of vcpus. In the second part, a new test is added: This test is added to serve as a performance tester and a bug reproducer for kvm page table code (GPA->HPA mappings), it gives guidance for the people trying to make some improvement for kvm. And the following explains what we can exactly do through this test. The function guest_code() can cover the conditions where a single vcpu or multiple vcpus access guest pages within the same memory region, in three VM stages(before dirty logging, during dirty logging, after dirty logging). Besides, the backing src memory type(ANONYMOUS/THP/HUGETLB) of the tested memory region can be specified by users, which means normal page mappings or block mappings can be chosen by users to be created in the test. If ANONYMOUS memory is specified, kvm will create normal page mappings for the tested memory region before dirty logging, and update attributes of the page mappings from RO to RW during dirty logging. If THP/HUGETLB memory is specified, kvm will create block mappings for the tested memory region before dirty logging, and split the blcok mappings into normal page mappings during dirty logging, and coalesce the page mappings back into block mappings after dirty logging is stopped. So in summary, as a performance tester, this test can present the performance of kvm creating/updating normal page mappings, or the performance of kvm creating/splitting/recovering block mappings, through execution time. When we need to coalesce the page mappings back to block mappings after dirty logging is stopped, we have to firstly invalidate *all* the TLB entries for the page mappings right before installation of the block entry, because a TLB conflict abort error could occur if we can't invalidate the TLB entries fully. We have hit this TLB conflict twice on aarch64 software implementation and fixed it. As this test can imulate process from dirty logging enabled to dirty logging stopped of a VM with block mappings, so it can also reproduce this TLB conflict abort due to inadequate TLB invalidation when coalescing tables. Links about the TLB conflict abort: https://lore.kernel.org/lkml/20201201201034.116760-3-wangyanan55@huawei.com/ --- Change logs: v3->v4: - Add a helper to get system default hugetlb page size - Add tags of Reviewed-by of Ben in the patches v2->v3: - Add tags of Suggested-by, Reviewed-by in the patches - Add a generic micro to get hugetlb page sizes - Some changes for suggestions about v2 series v1->v2: - Add a patch to sync header files - Add helpers to get granularity of different backing src types - Some changes for suggestions about v1 series --- Yanan Wang (9): tools headers: sync headers of asm-generic/hugetlb_encode.h tools headers: Add a macro to get HUGETLB page sizes for mmap KVM: selftests: Use flag CLOCK_MONOTONIC_RAW for timing KVM: selftests: Make a generic helper to get vm guest mode strings KVM: selftests: Add a helper to get system configured THP page size KVM: selftests: Add a helper to get system default hugetlb page size KVM: selftests: List all hugetlb src types specified with page sizes KVM: selftests: Adapt vm_userspace_mem_region_add to new helpers KVM: selftests: Add a test for kvm page table code include/uapi/linux/mman.h | 2 + tools/include/asm-generic/hugetlb_encode.h | 3 + tools/include/uapi/linux/mman.h | 2 + tools/testing/selftests/kvm/Makefile | 3 + .../selftests/kvm/demand_paging_test.c | 8 +- .../selftests/kvm/dirty_log_perf_test.c | 14 +- .../testing/selftests/kvm/include/kvm_util.h | 4 +- .../testing/selftests/kvm/include/test_util.h | 21 +- .../selftests/kvm/kvm_page_table_test.c | 476 ++++++++++++++++++ tools/testing/selftests/kvm/lib/kvm_util.c | 59 ++- tools/testing/selftests/kvm/lib/test_util.c | 122 ++++- tools/testing/selftests/kvm/steal_time.c | 4 +- 12 files changed, 659 insertions(+), 59 deletions(-) create mode 100644 tools/testing/selftests/kvm/kvm_page_table_test.c