From patchwork Wed Mar 3 02:09:46 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Haiwei Li X-Patchwork-Id: 12113131 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 61169C433DB for ; Wed, 3 Mar 2021 07:24:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 15CD464EE1 for ; Wed, 3 Mar 2021 07:24:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1449369AbhCCHUB (ORCPT ); Wed, 3 Mar 2021 02:20:01 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47292 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238045AbhCCCLA (ORCPT ); Tue, 2 Mar 2021 21:11:00 -0500 Received: from mail-pj1-x1033.google.com (mail-pj1-x1033.google.com [IPv6:2607:f8b0:4864:20::1033]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 546B1C061224; Tue, 2 Mar 2021 18:09:58 -0800 (PST) Received: by mail-pj1-x1033.google.com with SMTP id e9so3371051pjj.0; Tue, 02 Mar 2021 18:09:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=Y4CDZC0XRtdxRyUu6upw3DY8PzyuYgSy6jHykMMCFTY=; b=M+m8+IeTn56qvibEzZaBaLzICwpFnGw1QTeozL3il7ZPPhlofSUc32Pqvf9KvcU4Co 1ksSTP9mOLQXpmxuFfe5B09ISx2/2c/OngpINTk7OQwqJa1uM2INoScqO7W+suxk4wUk Dnf3XfWuePpDh1JhqHSdaqT7pvw2FBEc3DgiyoI3eWW0Uwc/qAZw7OeSX8si9cTtjm4H GJXE4NeRLSFyXODVCe1WuRWokDjwtp1eKeEQ8AL5q6hxdP2Rc32Zpns9eWBXIey91Xev A1kRVKb5KOiaCEi8ZmsmmtLmon/o8vAHRBnh3k3E0tVbnI9zTZa8vXSOp15y+PMHolJX FgaQ== 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:mime-version :content-transfer-encoding; bh=Y4CDZC0XRtdxRyUu6upw3DY8PzyuYgSy6jHykMMCFTY=; b=a2oiwdicy+VnrOBNxqEg8JyYkKc2h5cjvjff+zPwnzOsO4xCyUoiouzPJux9BbCm4+ KFnUeNZvejO2foRCDWqpXKqbbo9lrnkrW6aM7K3zifT8C2tVUwfiQnXJvkmhXKkiulOk bTkrF2YbmXQbplNsjJn8q+xps+zV3qdKDDww6g0TIUZvASyjwlUrSQNWooVuvyUuC1rx tx83zzEdPEtBc95i4bV7zyAqpz/RcGMi7/vOHhjP8zdx9DPQ6YlU0dyqbv0Rcr9iBX32 Qn2HlK0gvPLYM0oVjE7AM4bcl+3ujvW991I7IKXBnHsJFHAlYXJKbaa9hQFos7035Af0 Ebsw== X-Gm-Message-State: AOAM5319bW+TbCC+4h+68G2dRcXPR4mDWeon1T3gB21yFM65DxxRyf8u Bw2TxSXKFcRsHcrNL9ThBQx5n9CyHg== X-Google-Smtp-Source: ABdhPJyJ/vLG5EM+mwDq6WrvjKVvipezABEQ4XAsfkBAlmEkSCpxAjE03uaEyDFwX9tlOqQIXfIKjg== X-Received: by 2002:a17:90a:7344:: with SMTP id j4mr7575058pjs.216.1614737397602; Tue, 02 Mar 2021 18:09:57 -0800 (PST) Received: from localhost.localdomain ([203.205.141.39]) by smtp.gmail.com with ESMTPSA id f20sm280415pfa.10.2021.03.02.18.09.55 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 02 Mar 2021 18:09:57 -0800 (PST) From: lihaiwei.kernel@gmail.com To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: pbonzini@redhat.com, seanjc@google.com, vkuznets@redhat.com, wanpengli@tencent.com, jmattson@google.com, joro@8bytes.org, Haiwei Li Subject: [PATCH] kvm: lapic: add module parameters for LAPIC_TIMER_ADVANCE_ADJUST_MAX/MIN Date: Wed, 3 Mar 2021 10:09:46 +0800 Message-Id: <20210303020946.26083-1-lihaiwei.kernel@gmail.com> X-Mailer: git-send-email 2.28.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Haiwei Li In my test environment, advance_expire_delta is frequently greater than the fixed LAPIC_TIMER_ADVANCE_ADJUST_MAX. And this will hinder the adjustment. Adding module parameters for LAPIC_TIMER_ADVANCE_ADJUST_MAX/MIN, so they can be dynamically adjusted. Signed-off-by: Haiwei Li --- arch/x86/kvm/lapic.c | 6 ++---- arch/x86/kvm/x86.c | 8 ++++++++ arch/x86/kvm/x86.h | 3 +++ 3 files changed, 13 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index 45d40bf..730c657 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -61,8 +61,6 @@ #define APIC_VECTORS_PER_REG 32 static bool lapic_timer_advance_dynamic __read_mostly; -#define LAPIC_TIMER_ADVANCE_ADJUST_MIN 100 /* clock cycles */ -#define LAPIC_TIMER_ADVANCE_ADJUST_MAX 10000 /* clock cycles */ #define LAPIC_TIMER_ADVANCE_NS_INIT 1000 #define LAPIC_TIMER_ADVANCE_NS_MAX 5000 /* step-by-step approximation to mitigate fluctuation */ @@ -1563,8 +1561,8 @@ static inline void adjust_lapic_timer_advance(struct kvm_vcpu *vcpu, u64 ns; /* Do not adjust for tiny fluctuations or large random spikes. */ - if (abs(advance_expire_delta) > LAPIC_TIMER_ADVANCE_ADJUST_MAX || - abs(advance_expire_delta) < LAPIC_TIMER_ADVANCE_ADJUST_MIN) + if (abs(advance_expire_delta) > lapic_timer_advance_adjust_cycles_max || + abs(advance_expire_delta) < lapic_timer_advance_adjust_cycles_min) return; /* too early */ diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 828de7d..3bd8d19 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -176,6 +176,14 @@ int __read_mostly pi_inject_timer = -1; module_param(pi_inject_timer, bint, S_IRUGO | S_IWUSR); +u64 __read_mostly lapic_timer_advance_adjust_cycles_max = 10000; +module_param(lapic_timer_advance_adjust_cycles_max, ullong, S_IRUGO | S_IWUSR); +EXPORT_SYMBOL_GPL(lapic_timer_advance_adjust_cycles_max); + +u64 __read_mostly lapic_timer_advance_adjust_cycles_min = 100; +module_param(lapic_timer_advance_adjust_cycles_min, ullong, S_IRUGO | S_IWUSR); +EXPORT_SYMBOL_GPL(lapic_timer_advance_adjust_cycles_min); + /* * Restoring the host value for MSRs that are only consumed when running in * usermode, e.g. SYSCALL MSRs and TSC_AUX, can be deferred until the CPU diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h index ee6e010..3f7eca0 100644 --- a/arch/x86/kvm/x86.h +++ b/arch/x86/kvm/x86.h @@ -305,6 +305,9 @@ static inline bool kvm_mpx_supported(void) extern int pi_inject_timer; +extern u64 lapic_timer_advance_adjust_cycles_max; +extern u64 lapic_timer_advance_adjust_cycles_min; + extern struct static_key kvm_no_apic_vcpu; extern bool report_ignored_msrs;