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=-8.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 C78A7C33CB3 for ; Thu, 16 Jan 2020 12:47:04 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id 8BD4A217F4 for ; Thu, 16 Jan 2020 12:47:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8BD4A217F4 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvmarm-bounces@lists.cs.columbia.edu Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 214E34B19F; Thu, 16 Jan 2020 07:47:04 -0500 (EST) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 0LvICurLxzZK; Thu, 16 Jan 2020 07:47:03 -0500 (EST) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id B2A2F4B180; Thu, 16 Jan 2020 07:47:01 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id B367B4B121 for ; Thu, 16 Jan 2020 07:46:59 -0500 (EST) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Y4K8W9i2qB-I for ; Thu, 16 Jan 2020 07:46:58 -0500 (EST) Received: from huawei.com (szxga04-in.huawei.com [45.249.212.190]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id 216014B0F2 for ; Thu, 16 Jan 2020 07:46:58 -0500 (EST) Received: from DGGEMS401-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 9C97F30E39BD4543FFB2; Thu, 16 Jan 2020 20:46:54 +0800 (CST) Received: from DESKTOP-1NISPDV.china.huawei.com (10.173.221.248) by DGGEMS401-HUB.china.huawei.com (10.3.19.201) with Microsoft SMTP Server id 14.3.439.0; Thu, 16 Jan 2020 20:46:44 +0800 From: Zengruan Ye To: , , , , , Subject: [PATCH v3 0/8] KVM: arm64: vCPU preempted check support Date: Thu, 16 Jan 2020 20:46:18 +0800 Message-ID: <20200116124626.1155-1-yezengruan@huawei.com> X-Mailer: git-send-email 2.23.0.windows.1 MIME-Version: 1.0 X-Originating-IP: [10.173.221.248] X-CFilter-Loop: Reflected Cc: peterz@infradead.org, maz@kernel.org, daniel.lezcano@linaro.org, linux@armlinux.org.uk, steven.price@arm.com, longman@redhat.com, catalin.marinas@arm.com, will@kernel.org X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu This patch set aims to support the vcpu_is_preempted() functionality under KVM/arm64, which allowing the guest to obtain the vCPU is currently running or not. This will enhance lock performance on overcommitted hosts (more runnable vCPUs than physical CPUs in the system) as doing busy waits for preempted vCPUs will hurt system performance far worse than early yielding. We have observed some performace improvements in uninx benchmark tests. unix benchmark result: host: kernel 5.5.0-rc5, HiSilicon Kunpeng920, 8 CPUs guest: kernel 5.5.0-rc5, 16 vCPUs test-case | after-patch | before-patch ----------------------------------------+-------------------+------------------ Dhrystone 2 using register variables | 334600751.0 lps | 335319028.3 lps Double-Precision Whetstone | 32856.1 MWIPS | 32849.6 MWIPS Execl Throughput | 3662.1 lps | 2718.0 lps File Copy 1024 bufsize 2000 maxblocks | 432906.4 KBps | 158011.8 KBps File Copy 256 bufsize 500 maxblocks | 116023.0 KBps | 37664.0 KBps File Copy 4096 bufsize 8000 maxblocks | 1432769.8 KBps | 441108.8 KBps Pipe Throughput | 6405029.6 lps | 6021457.6 lps Pipe-based Context Switching | 185872.7 lps | 184255.3 lps Process Creation | 4025.7 lps | 3706.6 lps Shell Scripts (1 concurrent) | 6745.6 lpm | 6436.1 lpm Shell Scripts (8 concurrent) | 998.7 lpm | 931.1 lpm System Call Overhead | 3913363.1 lps | 3883287.8 lps ----------------------------------------+-------------------+------------------ System Benchmarks Index Score | 1835.1 | 1327.6 Changes from v2: https://lore.kernel.org/lkml/20191226135833.1052-1-yezengruan@huawei.com/ * Post Will's patches as part of this series [1][2], and add the probing logic for checking whether the hypervisor is KVM or not * Clear PV-lock interface documentation * Remove preempted state field * Fix build error when CONFIG_PARAVIRT is not set * Bunch of typo fixes. Changes from v1: https://lore.kernel.org/lkml/20191217135549.3240-1-yezengruan@huawei.com/ * Guest kernel no longer allocates the PV lock structure, instead it is allocated by user space to avoid lifetime issues about kexec. * Provide vCPU attributes for PV lock. * Update SMC number of PV lock features. * Report some basic validation when PV lock init. * Document preempted field. * Bunch of typo fixes. [1] https://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git/commit/?h=kvm/hvc&id=464f5a1741e5959c3e4d2be1966ae0093b4dce06 [2] https://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git/commit/?h=kvm/hvc&id=6597490e005d0eeca8ed8c1c1d7b4318ee014681 Will Deacon (2): arm64: Probe for the presence of KVM hypervisor services during boot arm/arm64: KVM: Advertise KVM UID to guests via SMCCC Zengruan Ye (6): KVM: arm64: Document PV-lock interface KVM: arm64: Add SMCCC paravirtualised lock calls KVM: arm64: Support pvlock preempted via shared structure KVM: arm64: Provide vCPU attributes for PV lock KVM: arm64: Add interface to support vCPU preempted check KVM: arm64: Support the vCPU preemption check Documentation/virt/kvm/arm/pvlock.rst | 68 +++++++++++++ Documentation/virt/kvm/devices/vcpu.txt | 14 +++ arch/arm/include/asm/kvm_host.h | 18 ++++ arch/arm64/include/asm/hypervisor.h | 11 ++ arch/arm64/include/asm/kvm_host.h | 27 +++++ arch/arm64/include/asm/paravirt.h | 15 +++ arch/arm64/include/asm/pvlock-abi.h | 16 +++ arch/arm64/include/asm/spinlock.h | 9 ++ arch/arm64/include/uapi/asm/kvm.h | 2 + arch/arm64/kernel/Makefile | 2 +- arch/arm64/kernel/paravirt-spinlocks.c | 13 +++ arch/arm64/kernel/paravirt.c | 129 +++++++++++++++++++++++- arch/arm64/kernel/setup.c | 37 +++++++ arch/arm64/kvm/Makefile | 1 + arch/arm64/kvm/guest.c | 9 ++ include/linux/arm-smccc.h | 36 +++++++ include/linux/cpuhotplug.h | 1 + include/uapi/linux/kvm.h | 2 + virt/kvm/arm/arm.c | 8 ++ virt/kvm/arm/hypercalls.c | 54 +++++++--- virt/kvm/arm/pvlock.c | 102 +++++++++++++++++++ 21 files changed, 559 insertions(+), 15 deletions(-) create mode 100644 Documentation/virt/kvm/arm/pvlock.rst create mode 100644 arch/arm64/include/asm/pvlock-abi.h create mode 100644 arch/arm64/kernel/paravirt-spinlocks.c create mode 100644 virt/kvm/arm/pvlock.c -- 2.19.1 _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm