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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 B5AB8C43603 for ; Tue, 17 Dec 2019 13:56:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9332B21739 for ; Tue, 17 Dec 2019 13:56:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728671AbfLQN4d (ORCPT ); Tue, 17 Dec 2019 08:56:33 -0500 Received: from szxga07-in.huawei.com ([45.249.212.35]:48956 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728568AbfLQN4c (ORCPT ); Tue, 17 Dec 2019 08:56:32 -0500 Received: from DGGEMS413-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id C086CF8CE4FD6D29296B; Tue, 17 Dec 2019 21:56:30 +0800 (CST) Received: from DESKTOP-1NISPDV.china.huawei.com (10.173.221.248) by DGGEMS413-HUB.china.huawei.com (10.3.19.213) with Microsoft SMTP Server id 14.3.439.0; Tue, 17 Dec 2019 21:56:24 +0800 From: To: , , , , , , CC: , , , , , , , , , Subject: [PATCH 4/5] KVM: arm64: Add interface to support vcpu preempted check Date: Tue, 17 Dec 2019 21:55:48 +0800 Message-ID: <20191217135549.3240-5-yezengruan@huawei.com> X-Mailer: git-send-email 2.23.0.windows.1 In-Reply-To: <20191217135549.3240-1-yezengruan@huawei.com> References: <20191217135549.3240-1-yezengruan@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.173.221.248] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Zengruan Ye This is to fix some lock holder preemption issues. Some other locks implementation do a spin loop before acquiring the lock itself. Currently kernel has an interface of bool vcpu_is_preempted(int cpu). It takes the cpu as parameter and return true if the cpu is preempted. Then kernel can break the spin loops upon the retval of vcpu_is_preempted. As kernel has used this interface, So lets support it. Signed-off-by: Zengruan Ye --- arch/arm64/include/asm/paravirt.h | 12 ++++++++++++ arch/arm64/include/asm/spinlock.h | 7 +++++++ arch/arm64/kernel/Makefile | 2 +- arch/arm64/kernel/paravirt-spinlocks.c | 13 +++++++++++++ arch/arm64/kernel/paravirt.c | 4 +++- 5 files changed, 36 insertions(+), 2 deletions(-) create mode 100644 arch/arm64/kernel/paravirt-spinlocks.c diff --git a/arch/arm64/include/asm/paravirt.h b/arch/arm64/include/asm/paravirt.h index cf3a0fd7c1a7..7b1c81b544bb 100644 --- a/arch/arm64/include/asm/paravirt.h +++ b/arch/arm64/include/asm/paravirt.h @@ -11,8 +11,13 @@ struct pv_time_ops { unsigned long long (*steal_clock)(int cpu); }; +struct pv_lock_ops { + bool (*vcpu_is_preempted)(int cpu); +}; + struct paravirt_patch_template { struct pv_time_ops time; + struct pv_lock_ops lock; }; extern struct paravirt_patch_template pv_ops; @@ -24,6 +29,13 @@ static inline u64 paravirt_steal_clock(int cpu) int __init pv_time_init(void); +__visible bool __native_vcpu_is_preempted(int cpu); + +static inline bool pv_vcpu_is_preempted(int cpu) +{ + return pv_ops.lock.vcpu_is_preempted(cpu); +} + #else #define pv_time_init() do {} while (0) diff --git a/arch/arm64/include/asm/spinlock.h b/arch/arm64/include/asm/spinlock.h index b093b287babf..45ff1b2949a6 100644 --- a/arch/arm64/include/asm/spinlock.h +++ b/arch/arm64/include/asm/spinlock.h @@ -7,8 +7,15 @@ #include #include +#include /* See include/linux/spinlock.h */ #define smp_mb__after_spinlock() smp_mb() +#define vcpu_is_preempted vcpu_is_preempted +static inline bool vcpu_is_preempted(long cpu) +{ + return pv_vcpu_is_preempted(cpu); +} + #endif /* __ASM_SPINLOCK_H */ diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index fc6488660f64..b23cdae433a4 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -50,7 +50,7 @@ obj-$(CONFIG_ARMV8_DEPRECATED) += armv8_deprecated.o obj-$(CONFIG_ACPI) += acpi.o obj-$(CONFIG_ACPI_NUMA) += acpi_numa.o obj-$(CONFIG_ARM64_ACPI_PARKING_PROTOCOL) += acpi_parking_protocol.o -obj-$(CONFIG_PARAVIRT) += paravirt.o +obj-$(CONFIG_PARAVIRT) += paravirt.o paravirt-spinlocks.o obj-$(CONFIG_RANDOMIZE_BASE) += kaslr.o obj-$(CONFIG_HIBERNATION) += hibernate.o hibernate-asm.o obj-$(CONFIG_KEXEC_CORE) += machine_kexec.o relocate_kernel.o \ diff --git a/arch/arm64/kernel/paravirt-spinlocks.c b/arch/arm64/kernel/paravirt-spinlocks.c new file mode 100644 index 000000000000..718aa773d45c --- /dev/null +++ b/arch/arm64/kernel/paravirt-spinlocks.c @@ -0,0 +1,13 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright(c) 2019 Huawei Technologies Co., Ltd + * Author: Zengruan Ye + */ + +#include +#include + +__visible bool __native_vcpu_is_preempted(int cpu) +{ + return false; +} diff --git a/arch/arm64/kernel/paravirt.c b/arch/arm64/kernel/paravirt.c index 1ef702b0be2d..d8f1ba8c22ce 100644 --- a/arch/arm64/kernel/paravirt.c +++ b/arch/arm64/kernel/paravirt.c @@ -26,7 +26,9 @@ struct static_key paravirt_steal_enabled; struct static_key paravirt_steal_rq_enabled; -struct paravirt_patch_template pv_ops; +struct paravirt_patch_template pv_ops = { + .lock.vcpu_is_preempted = __native_vcpu_is_preempted, +}; EXPORT_SYMBOL_GPL(pv_ops); struct pv_time_stolen_time_region { -- 2.19.1