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=-17.8 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, 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 2B51BC433EC for ; Tue, 21 Jul 2020 13:31:53 +0000 (UTC) Received: from mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by mail.kernel.org (Postfix) with ESMTP id D545720792 for ; Tue, 21 Jul 2020 13:31:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="bqhSzg4Q" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D545720792 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.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 8E2CE4B1D7; Tue, 21 Jul 2020 09:31:52 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Authentication-Results: mm01.cs.columbia.edu (amavisd-new); dkim=softfail (fail, message has been altered) header.i=@gmail.com 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 B1Eu6pfUAS6o; Tue, 21 Jul 2020 09:31:51 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 287E84B1D9; Tue, 21 Jul 2020 09:31:50 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 466804B13A for ; Tue, 21 Jul 2020 00:18:10 -0400 (EDT) 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 qnyn0MtGNRuF for ; Tue, 21 Jul 2020 00:18:09 -0400 (EDT) Received: from mail-pg1-f194.google.com (mail-pg1-f194.google.com [209.85.215.194]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id DBDCA4B23A for ; Tue, 21 Jul 2020 00:18:08 -0400 (EDT) Received: by mail-pg1-f194.google.com with SMTP id w2so11327393pgg.10 for ; Mon, 20 Jul 2020 21:18:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=QhRkRM1m4qgsAo9eZ39otcpFvlPpO24W7mp8anbogBw=; b=bqhSzg4QOmAx8vDaoW+qgWApTlOrQm4qYUFBFPFk5eJ0mJKUnH+PBOy0rrPoVLuSvj G5nYm2pK68MYqj6x+TCFJB+f5jSKEM8VQr4aztw9FuTmTF+mMsEgmg/KgI32RN54P7bo Bn2WB2MaubV4PEisl9ole2vBWAje7/6zJzcOgvSaMXBVKWeu1m54/+zJ11AFQ9IAPZFj 91rrJTGVdFDuaP2F5FGqiWP3c4TtwHUsRxjZmJ/tHtgrRdyF4+P1bosWHGypJBEIDb/5 Aw3/2v/i3mKymhzPQPRC/tYJPoKK3JPXXYId/NMpEGilerA3j8tWesrhzp4XC8U4VWSl qwfA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=QhRkRM1m4qgsAo9eZ39otcpFvlPpO24W7mp8anbogBw=; b=N0URV5AS70cTPqGfdmClsWH//PRkNeZ8YIjceBx6+suTlrrDYVGfPfMu8o+8ct0Hq/ tqxZ/yI2xxQRDGCBBUvgsBQ6mdsxb3SvSLw2R12Iv1rjvs7LbY3LJ4De1K3zurV/iA7o BTbgMVM8LSYIBeCMJh6hrDaM2C7jjI01hi1j0Ptmmum6D2ucnjsbaS5vqAQTyGnRpRE/ MwvF78J8gmE0A2/C67k3hnc+aji0ghhLyszoNqvmYZvbVhRQEbC4u+cpnsiXkGVCwHA1 YuDrpcNYTs1KJcQnqth5G6E5Ir9ifD7SffqJIU4ruVIfFzOvFHK9KHGWMe7RLGx3Bqa1 1SCg== X-Gm-Message-State: AOAM533z7K5aBEuhAbOUc8fkS61Im9cUgtLOHlZxx+OVghodhNiQyNBI tNLNHMdlHzikOepayxN6xHU= X-Google-Smtp-Source: ABdhPJx4iEq46mQUJiDEqXIx/wrx7qJP7HCND86/POVGHX0/iSnb09hQdnlfUa/C3gaz4EjedXYGBg== X-Received: by 2002:aa7:9a84:: with SMTP id w4mr21905832pfi.13.1595305088045; Mon, 20 Jul 2020 21:18:08 -0700 (PDT) Received: from localhost.localdomain ([2409:10:2e40:5100:6e29:95ff:fe2d:8f34]) by smtp.gmail.com with ESMTPSA id e28sm18467270pfm.177.2020.07.20.21.18.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 20 Jul 2020 21:18:07 -0700 (PDT) From: Sergey Senozhatsky To: Will Deacon , Marc Zyngier , James Morse , Julien Thierry , Suzuki K Poulose Subject: [RFC][PATCH 2/4] arm64: add guest pvstate support Date: Tue, 21 Jul 2020 13:17:40 +0900 Message-Id: <20200721041742.197354-3-sergey.senozhatsky@gmail.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200721041742.197354-1-sergey.senozhatsky@gmail.com> References: <20200721041742.197354-1-sergey.senozhatsky@gmail.com> MIME-Version: 1.0 X-Mailman-Approved-At: Tue, 21 Jul 2020 09:31:48 -0400 Cc: joelaf@google.com, linux-kernel@vger.kernel.org, Sergey Senozhatsky , suleiman@google.com, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.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 PV-state is a per-CPU struct, which, for the time being, holds boolean `preempted' vCPU state. During the startup, given that host supports PV-state, each guest vCPU sends a pointer to its per-CPU variable to the host as a payload with the SMCC HV call, so that host can update vCPU state when it puts or loads vCPU. This has impact on the guest's scheduler - it does check the state of the vCPU it wants to run a task on: [..] wake_up_process() try_to_wake_up() select_task_rq_fair() available_idle_cpu() vcpu_is_preempted() Some sched benchmarks data is available on the github page [0]. [0] https://github.com/sergey-senozhatsky/arm64-vcpu_is_preempted Signed-off-by: Sergey Senozhatsky --- arch/arm64/include/asm/paravirt.h | 15 ++++ arch/arm64/kernel/Makefile | 2 +- arch/arm64/kernel/paravirt-state.c | 117 +++++++++++++++++++++++++++++ arch/arm64/kernel/paravirt.c | 4 +- arch/arm64/kernel/time.c | 1 + 5 files changed, 137 insertions(+), 2 deletions(-) create mode 100644 arch/arm64/kernel/paravirt-state.c diff --git a/arch/arm64/include/asm/paravirt.h b/arch/arm64/include/asm/paravirt.h index cf3a0fd7c1a7..1bf164b2041b 100644 --- a/arch/arm64/include/asm/paravirt.h +++ b/arch/arm64/include/asm/paravirt.h @@ -7,12 +7,22 @@ struct static_key; extern struct static_key paravirt_steal_enabled; extern struct static_key paravirt_steal_rq_enabled; +struct pvstate_vcpu_info { + bool preempted; + u8 reserved[63]; +}; + +struct pv_state_ops { + bool (*vcpu_is_preempted)(int cpu); +}; + struct pv_time_ops { unsigned long long (*steal_clock)(int cpu); }; struct paravirt_patch_template { struct pv_time_ops time; + struct pv_state_ops state; }; extern struct paravirt_patch_template pv_ops; @@ -22,10 +32,15 @@ static inline u64 paravirt_steal_clock(int cpu) return pv_ops.time.steal_clock(cpu); } +bool native_vcpu_is_preempted(int cpu); +bool paravirt_vcpu_is_preempted(int cpu); + +int __init pv_state_init(void); int __init pv_time_init(void); #else +#define pv_state_init() do {} while (0) #define pv_time_init() do {} while (0) #endif // CONFIG_PARAVIRT diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index 5fb9b728459b..18974d5e798d 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -48,7 +48,7 @@ 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-state.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-state.c b/arch/arm64/kernel/paravirt-state.c new file mode 100644 index 000000000000..4ae92a84c73d --- /dev/null +++ b/arch/arm64/kernel/paravirt-state.c @@ -0,0 +1,117 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#define pr_fmt(fmt) "arm-pvstate: " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +static DEFINE_PER_CPU(struct pvstate_vcpu_info, vcpus_states); + +bool native_vcpu_is_preempted(int cpu) +{ + return false; +} + +static bool pv_vcpu_is_preempted(int cpu) +{ + struct pvstate_vcpu_info *st; + + st = &per_cpu(vcpus_states, cpu); + return READ_ONCE(st->preempted); +} + +bool paravirt_vcpu_is_preempted(int cpu) +{ + return pv_ops.state.vcpu_is_preempted(cpu); +} + +static bool has_pvstate(void) +{ + struct arm_smccc_res res; + + /* To detect the presence of PV time support we require SMCCC 1.1+ */ + if (arm_smccc_1_1_get_conduit() == SMCCC_CONDUIT_NONE) + return false; + + arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_FEATURES_FUNC_ID, + ARM_SMCCC_HV_PV_STATE_FEATURES, + &res); + + if (res.a0 != SMCCC_RET_SUCCESS) + return false; + return true; +} + +static int __pvstate_cpu_hook(unsigned int cpu, int event) +{ + struct arm_smccc_res res; + struct pvstate_vcpu_info *st; + + st = &per_cpu(vcpus_states, cpu); + arm_smccc_1_1_invoke(event, virt_to_phys(st), &res); + if (res.a0 != SMCCC_RET_SUCCESS) + return -EINVAL; + return 0; +} + +static int pvstate_cpu_init(unsigned int cpu) +{ + int ret = __pvstate_cpu_hook(cpu, ARM_SMCCC_HV_PV_STATE_INIT); + + if (ret) + pr_warn("Unable to ARM_SMCCC_HV_PV_STATE_INIT\n"); + return ret; +} + +static int pvstate_cpu_release(unsigned int cpu) +{ + int ret = __pvstate_cpu_hook(cpu, ARM_SMCCC_HV_PV_STATE_RELEASE); + + if (ret) + pr_warn("Unable to ARM_SMCCC_HV_PV_STATE_RELEASE\n"); + return ret; +} + +static int pvstate_register_hooks(void) +{ + int ret; + + ret = cpuhp_setup_state(CPUHP_AP_ARM_KVMPV_STARTING, + "hypervisor/arm/pvstate:starting", + pvstate_cpu_init, + pvstate_cpu_release); + if (ret < 0) + pr_warn("Failed to register CPU hooks\n"); + return ret; +} + +static int __pvstate_init(void) +{ + return pvstate_register_hooks(); +} + +int __init pv_state_init(void) +{ + int ret; + + if (!has_pvstate()) + return 0; + + ret = __pvstate_init(); + if (ret) + return ret; + + pv_ops.state.vcpu_is_preempted = pv_vcpu_is_preempted; + return 0; +} diff --git a/arch/arm64/kernel/paravirt.c b/arch/arm64/kernel/paravirt.c index 295d66490584..3fec7563ac27 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 = { + .state.vcpu_is_preempted = native_vcpu_is_preempted, +}; EXPORT_SYMBOL_GPL(pv_ops); struct pv_time_stolen_time_region { diff --git a/arch/arm64/kernel/time.c b/arch/arm64/kernel/time.c index eebbc8d7123e..50c55792f72b 100644 --- a/arch/arm64/kernel/time.c +++ b/arch/arm64/kernel/time.c @@ -68,4 +68,5 @@ void __init time_init(void) lpj_fine = arch_timer_rate / HZ; pv_time_init(); + pv_state_init(); } -- 2.27.0 _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm