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=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 416D1C33CB1 for ; Thu, 16 Jan 2020 12:47:20 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id F35432064C for ; Thu, 16 Jan 2020 12:47:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F35432064C 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 ACAE84B16D; Thu, 16 Jan 2020 07:47:19 -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 JlF8+1cYaVfP; Thu, 16 Jan 2020 07:47:15 -0500 (EST) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 6B1014B18D; Thu, 16 Jan 2020 07:47:11 -0500 (EST) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id C7DF24B15D for ; Thu, 16 Jan 2020 07:47:09 -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 769gAhg575RF for ; Thu, 16 Jan 2020 07:47:08 -0500 (EST) Received: from huawei.com (szxga06-in.huawei.com [45.249.212.32]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id 8923F4B192 for ; Thu, 16 Jan 2020 07:47:02 -0500 (EST) Received: from DGGEMS401-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id AA29BC0B62D0F3F8873D; Thu, 16 Jan 2020 20:46:59 +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 20:46:50 +0800 From: Zengruan Ye To: , , , , , Subject: [PATCH v3 7/8] KVM: arm64: Add interface to support vCPU preempted check Date: Thu, 16 Jan 2020 20:46:25 +0800 Message-ID: <20200116124626.1155-8-yezengruan@huawei.com> X-Mailer: git-send-email 2.23.0.windows.1 In-Reply-To: <20200116124626.1155-1-yezengruan@huawei.com> References: <20200116124626.1155-1-yezengruan@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.173.221.248] X-CFilter-Loop: Reflected Cc: kbuild test robot , 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 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. Reported-by: kbuild test robot Signed-off-by: Zengruan Ye --- arch/arm64/include/asm/paravirt.h | 12 ++++++++++++ arch/arm64/include/asm/spinlock.h | 9 +++++++++ arch/arm64/kernel/Makefile | 2 +- arch/arm64/kernel/paravirt-spinlocks.c | 13 +++++++++++++ arch/arm64/kernel/paravirt.c | 4 +++- 5 files changed, 38 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..b5d1982414c5 100644 --- a/arch/arm64/include/asm/spinlock.h +++ b/arch/arm64/include/asm/spinlock.h @@ -7,8 +7,17 @@ #include #include +#include /* See include/linux/spinlock.h */ #define smp_mb__after_spinlock() smp_mb() +#ifdef CONFIG_PARAVIRT +#define vcpu_is_preempted vcpu_is_preempted +static inline bool vcpu_is_preempted(long cpu) +{ + return pv_vcpu_is_preempted(cpu); +} +#endif // CONFIG_PARAVIRT + #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 _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm