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=-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 3626FC433ED for ; Wed, 14 Apr 2021 11:24:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 12FB0613D1 for ; Wed, 14 Apr 2021 11:24:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1350458AbhDNLYw (ORCPT ); Wed, 14 Apr 2021 07:24:52 -0400 Received: from szxga05-in.huawei.com ([45.249.212.191]:16456 "EHLO szxga05-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350425AbhDNLYh (ORCPT ); Wed, 14 Apr 2021 07:24:37 -0400 Received: from DGGEMS414-HUB.china.huawei.com (unknown [172.30.72.60]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4FL0Rm4gxQztVy2; Wed, 14 Apr 2021 19:21:56 +0800 (CST) Received: from S00345302A-PC.china.huawei.com (10.47.82.32) by DGGEMS414-HUB.china.huawei.com (10.3.19.214) with Microsoft SMTP Server id 14.3.498.0; Wed, 14 Apr 2021 19:24:03 +0800 From: Shameer Kolothum To: , , CC: , , , , , , , , Subject: [PATCH v4 00/16] kvm/arm: Align the VMID allocation with the arm64 ASID one Date: Wed, 14 Apr 2021 12:22:56 +0100 Message-ID: <20210414112312.13704-1-shameerali.kolothum.thodi@huawei.com> X-Mailer: git-send-email 2.12.0.windows.1 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.47.82.32] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, This is an attempt to revive this series originally posted by Julien Grall[1]. The main motive to work on this now is because of the requirement to have Pinned KVM VMIDs and the RFC discussion for the same basically suggested[2] to have a common/better vmid allocator for KVM which this series provides. Major Changes from v3: -Changes related to Pinned ASID support. -Changes to take care KPTI related bits reservation. -Dropped support for 32 bit KVM. -Rebase to 5.12-rc7 Individual patches have change history for any major changes from v3. Tests were performed on a HiSilicon D06 platform and so far not observed any regressions. For ASID allocation, Avg of 10 runs(hackbench -s 512 -l 200 -g 300 -f 25 -P), 5.12-rc7: Time:18.8119 5.12-rc7+v4: Time: 18.459 ~1.8% improvement. For KVM VMID, The measurement was made with maxcpus set to 8 and with the number of VMID limited to 4-bit. The test involves running concurrently 40 guests with 2 vCPUs. Each guest will then execute hackbench 5 times before exiting. The performance difference between the current algo and the new one are(ag. of 10 runs): - 1.9% less exit from the guest - 0.7% faster For complete series, please see, https://github.com/hisilicon/kernel-dev/tree/private-v5.12-rc7-asid-v4 Please take a look and let me know your feedback. Thanks, Shameer [1].https://patchwork.kernel.org/project/linux-arm-kernel/cover/20190724162534.7390-1-julien.grall@arm.com/ [2].https://lore.kernel.org/linux-arm-kernel/20210222155338.26132-6-shameerali.kolothum.thodi@huawei.com/T/#mff3129997739e2747172f4a2e81fd66be91ffea4 -------- >From V3: -------- Hi all, This patch series is moving out the ASID allocator in a separate file in order to re-use it for the VMID. The benefits are: - CPUs are not forced to exit on a roll-over. - Context invalidation is now per-CPU rather than broadcasted. There are no performance regression on the fastpath for ASID allocation. Actually on the hackbench measurement (300 hackbench) it was .7% faster. The measurement was made on a Seattle based SoC (8 CPUs), with the number of VMID limited to 4-bit. The test involves running concurrently 40 guests with 2 vCPUs. Each guest will then execute hackbench 5 times before exiting. The performance difference (on 5.1-rc1) between the current algo and the new one are: - 2.5% less exit from the guest - 22.4% more flush, although they are now local rather than broadcasted - 0.11% faster (just for the record) The ASID allocator rework to make it generic has been divided in multiple patches to make the review easier. A branch with the patch based on 5.3-rc1 can be found: http://xenbits.xen.org/gitweb/?p=people/julieng/linux-arm.git;a=shortlog;h=refs/heads/vmid-rework/v3 For all the changes see in each patch. Best regards, Julien Grall (13): arm64/mm: Introduce asid_info structure and move asid_generation/asid_map to it arm64/mm: Move active_asids and reserved_asids to asid_info arm64/mm: Move bits to asid_info arm64/mm: Move the variable lock and tlb_flush_pending to asid_info arm64/mm: Remove dependency on MM in new_context arm64/mm: Introduce NUM_CTXT_ASIDS arm64/mm: Split asid_inits in 2 parts arm64/mm: Split the function check_and_switch_context in 3 parts arm64/mm: Introduce a callback to flush the local context arm64: Move the ASID allocator code in a separate file arm64/lib: Add an helper to free memory allocated by the ASID allocator arch/arm64: Introduce a capability to tell whether 16-bit VMID is available kvm/arm: Align the VMID allocation with the arm64 ASID one Shameer Kolothum (3): arm64/mm: Move Pinned ASID related variables to asid_info arm64/mm: Split the arm64_mm_context_get/put arm64/mm: Introduce a callback to set reserved bits arch/arm64/include/asm/cpucaps.h | 3 +- arch/arm64/include/asm/kvm_asm.h | 4 +- arch/arm64/include/asm/kvm_host.h | 5 +- arch/arm64/include/asm/kvm_mmu.h | 7 +- arch/arm64/include/asm/lib_asid.h | 87 +++++++++ arch/arm64/kernel/cpufeature.c | 9 + arch/arm64/kvm/arm.c | 124 +++++-------- arch/arm64/kvm/hyp/nvhe/hyp-main.c | 6 +- arch/arm64/kvm/hyp/nvhe/tlb.c | 10 +- arch/arm64/kvm/hyp/vhe/tlb.c | 10 +- arch/arm64/kvm/mmu.c | 1 - arch/arm64/lib/Makefile | 2 + arch/arm64/lib/asid.c | 264 +++++++++++++++++++++++++++ arch/arm64/mm/context.c | 283 ++++------------------------- 14 files changed, 469 insertions(+), 346 deletions(-) create mode 100644 arch/arm64/include/asm/lib_asid.h create mode 100644 arch/arm64/lib/asid.c -- 2.17.1