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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 416C8C433F5 for ; Sat, 15 Jan 2022 05:24:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230290AbiAOFYq (ORCPT ); Sat, 15 Jan 2022 00:24:46 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54304 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229458AbiAOFYo (ORCPT ); Sat, 15 Jan 2022 00:24:44 -0500 Received: from mail-pg1-x549.google.com (mail-pg1-x549.google.com [IPv6:2607:f8b0:4864:20::549]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 61DBEC061574 for ; Fri, 14 Jan 2022 21:24:44 -0800 (PST) Received: by mail-pg1-x549.google.com with SMTP id r9-20020a6560c9000000b00343fa9529e5so3119628pgv.18 for ; Fri, 14 Jan 2022 21:24:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=jeO9F3WI9S80Ci5R46EtVlwqG1Ul3dTIO9SoeO2/dfQ=; b=ciP6AZ7D+dqxz8y2EneYJWr45reR4t9S8rM8w3MSrvabQihO2MibBGgpZ6xowIjPQx LOfxnjTxyeE63n4NyuFoKKf+Dnc382E1n8B8P7e2saACe9IPGdpHtRhIZWoSry1FXgu0 EpX1YxGrm9IOhHb/CBNPlR7Xw8ejYQeN50eq9PCDd1aCcHQjPaqgsejSdhghwZCGw+l8 PoxWc+h/VxtRBDk+qUUy73I2pEtEkm10ED4NFQXyYyOUCOZ0vJlLEHu2+dj1MOYTBZfh 3QgPIW0ybFKwLIKCVOEVKxa/geztuJGaEOCV9yosCXBifZyXzQzt4Vmc1dLNpt24SWgW YV0A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=jeO9F3WI9S80Ci5R46EtVlwqG1Ul3dTIO9SoeO2/dfQ=; b=VITP+EEp3d8TpTnhigK2SaO5TbzGeu8nEyuJbbcnNT3yskPhmzQmilmLquE6TyTvAQ vNLfPg0jwjriDrDFC3v1yrcEnCtOu1PWqT14TL2lUamMR1wVcqlNwDJc3cXXsP0jXXuM 9NAEtW2ahrNpU8/kHVB368MH/WJfV+2Cvifwc+Ofq+o7SsZeTc6msy0WCnTL4i9vLeQX dcGdIBVIf6r2A3OfoZzZBbIDKFXaclgj6/4nqLi6mM1XJQIBiYjORGo3fO/oDjArkH+A LzXHNt1TfaaGx0L7Ip1+daqPG/auxCMah3nddIF7lyB/hx6XJO7e8FB7SXkS/Bo8+IQB KFxw== X-Gm-Message-State: AOAM531N+RkDxojCf2NetLIkYafc3PkBDDVCIMrecqnKQWwMN8PW8wJP 1qU/gWLy9FahxmVuJf38KpkeB5648ktwzeXCCHwwCxYUCTCeOvKbhDcBMljwLZoKdR6/7IqWJr7 Dq3KZtU5WxPM5jH4sMX3buRzazl6YOasZN6j12aVqKbOGtMRsyFbn8QrDDZKU6KQ= X-Google-Smtp-Source: ABdhPJxMzi8y3wHi+EI3am51I6ZP9yHei2qscYod9QbesxjVbvetYasI8wpfSppbDGAUCycx2WpU+JTZkeUAKg== X-Received: from tortoise.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:1a0d]) (user=jmattson job=sendgmr) by 2002:a63:8543:: with SMTP id u64mr8252942pgd.474.1642224283689; Fri, 14 Jan 2022 21:24:43 -0800 (PST) Date: Fri, 14 Jan 2022 21:24:26 -0800 In-Reply-To: <20220115052431.447232-1-jmattson@google.com> Message-Id: <20220115052431.447232-2-jmattson@google.com> Mime-Version: 1.0 References: <20220115052431.447232-1-jmattson@google.com> X-Mailer: git-send-email 2.34.1.703.g22d0c6ccf7-goog Subject: [PATCH v3 1/6] KVM: x86/pmu: Use binary search to check filtered events From: Jim Mattson To: kvm@vger.kernel.org, pbonzini@redhat.com, like.xu.linux@gmail.com, daviddunn@google.com, cloudliang@tencent.com Cc: Jim Mattson Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org The PMU event filter may contain up to 300 events. Replace the linear search in reprogram_gp_counter() with a binary search. Signed-off-by: Jim Mattson --- arch/x86/kvm/pmu.c | 30 +++++++++++++++++++----------- 1 file changed, 19 insertions(+), 11 deletions(-) diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c index e632693a2266..2c98f3ee8df4 100644 --- a/arch/x86/kvm/pmu.c +++ b/arch/x86/kvm/pmu.c @@ -13,6 +13,8 @@ #include #include #include +#include +#include #include #include "x86.h" #include "cpuid.h" @@ -172,12 +174,16 @@ static bool pmc_resume_counter(struct kvm_pmc *pmc) return true; } +static int cmp_u64(const void *a, const void *b) +{ + return *(__u64 *)a - *(__u64 *)b; +} + void reprogram_gp_counter(struct kvm_pmc *pmc, u64 eventsel) { unsigned config, type = PERF_TYPE_RAW; struct kvm *kvm = pmc->vcpu->kvm; struct kvm_pmu_event_filter *filter; - int i; bool allow_event = true; if (eventsel & ARCH_PERFMON_EVENTSEL_PIN_CONTROL) @@ -192,16 +198,13 @@ void reprogram_gp_counter(struct kvm_pmc *pmc, u64 eventsel) filter = srcu_dereference(kvm->arch.pmu_event_filter, &kvm->srcu); if (filter) { - for (i = 0; i < filter->nevents; i++) - if (filter->events[i] == - (eventsel & AMD64_RAW_EVENT_MASK_NB)) - break; - if (filter->action == KVM_PMU_EVENT_ALLOW && - i == filter->nevents) - allow_event = false; - if (filter->action == KVM_PMU_EVENT_DENY && - i < filter->nevents) - allow_event = false; + __u64 key = eventsel & AMD64_RAW_EVENT_MASK_NB; + + if (bsearch(&key, filter->events, filter->nevents, + sizeof(__u64), cmp_u64)) + allow_event = filter->action == KVM_PMU_EVENT_ALLOW; + else + allow_event = filter->action == KVM_PMU_EVENT_DENY; } if (!allow_event) return; @@ -576,6 +579,11 @@ int kvm_vm_ioctl_set_pmu_event_filter(struct kvm *kvm, void __user *argp) /* Ensure nevents can't be changed between the user copies. */ *filter = tmp; + /* + * Sort the in-kernel list so that we can search it with bsearch. + */ + sort(&filter->events, filter->nevents, sizeof(__u64), cmp_u64, NULL); + mutex_lock(&kvm->lock); filter = rcu_replace_pointer(kvm->arch.pmu_event_filter, filter, mutex_is_locked(&kvm->lock)); -- 2.34.1.703.g22d0c6ccf7-goog