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=-12.8 required=3.0 tests=BAYES_00, 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 6E8F8C433F4 for ; Sun, 26 Jul 2020 15:35:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5640520759 for ; Sun, 26 Jul 2020 15:35:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727820AbgGZPfE (ORCPT ); Sun, 26 Jul 2020 11:35:04 -0400 Received: from mga03.intel.com ([134.134.136.65]:17603 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727784AbgGZPfD (ORCPT ); Sun, 26 Jul 2020 11:35:03 -0400 IronPort-SDR: YGQ8mwLMcNGp5tFE1BiFGQq5dbztft1Qkb6ER4aMZOYu1Y/Dm8K9aITDzUCe70bYl2Rt9brHNE DEGasmWT/aMA== X-IronPort-AV: E=McAfee;i="6000,8403,9694"; a="150890985" X-IronPort-AV: E=Sophos;i="5.75,399,1589266800"; d="scan'208";a="150890985" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Jul 2020 08:35:02 -0700 IronPort-SDR: cDPb9d5OIa1Nawr5/CwtWo5ppa3/tcu60F1M5MJL29O/7fF4WV90Y1q9RTNfrCbX8/BbEArkSj 6bxtluPKoS5A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,399,1589266800"; d="scan'208";a="303177608" Received: from sqa-gate.sh.intel.com (HELO clx-ap-likexu.tsp.org) ([10.239.48.212]) by orsmga002.jf.intel.com with ESMTP; 26 Jul 2020 08:35:00 -0700 From: Like Xu To: Paolo Bonzini , Vitaly Kuznetsov , Jim Mattson , kvm@vger.kernel.org Cc: Sean Christopherson , Wanpeng Li , Joerg Roedel , linux-kernel@vger.kernel.org, Like Xu Subject: [PATCH v13 07/10] KVM: vmx/pmu: Reduce the overhead of LBR pass-through or cancellation Date: Sun, 26 Jul 2020 23:32:26 +0800 Message-Id: <20200726153229.27149-9-like.xu@linux.intel.com> X-Mailer: git-send-email 2.21.3 In-Reply-To: <20200726153229.27149-1-like.xu@linux.intel.com> References: <20200726153229.27149-1-like.xu@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org When the LBR records msrs has already been pass-through, there is no need to call vmx_update_intercept_for_lbr_msrs() again and again, and vice versa. Signed-off-by: Like Xu --- arch/x86/kvm/vmx/pmu_intel.c | 13 +++++++++++++ arch/x86/kvm/vmx/vmx.h | 3 +++ 2 files changed, 16 insertions(+) diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c index 0358ceea34d4..08d195e08deb 100644 --- a/arch/x86/kvm/vmx/pmu_intel.c +++ b/arch/x86/kvm/vmx/pmu_intel.c @@ -562,6 +562,7 @@ static void intel_pmu_init(struct kvm_vcpu *vcpu) vmx_get_perf_capabilities() : 0; lbr_desc->records.nr = 0; lbr_desc->event = NULL; + lbr_desc->already_passthrough = false; } static void intel_pmu_reset(struct kvm_vcpu *vcpu) @@ -611,12 +612,24 @@ static void vmx_update_intercept_for_lbr_msrs(struct kvm_vcpu *vcpu, bool set) static inline void vmx_disable_lbr_msrs_passthrough(struct kvm_vcpu *vcpu) { + struct lbr_desc *lbr_desc = vcpu_to_lbr_desc(vcpu); + + if (!lbr_desc->already_passthrough) + return; + vmx_update_intercept_for_lbr_msrs(vcpu, true); + lbr_desc->already_passthrough = false; } static inline void vmx_enable_lbr_msrs_passthrough(struct kvm_vcpu *vcpu) { + struct lbr_desc *lbr_desc = vcpu_to_lbr_desc(vcpu); + + if (lbr_desc->already_passthrough) + return; + vmx_update_intercept_for_lbr_msrs(vcpu, false); + lbr_desc->already_passthrough = true; } /* diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h index dd029b57215c..f95d61942a1c 100644 --- a/arch/x86/kvm/vmx/vmx.h +++ b/arch/x86/kvm/vmx/vmx.h @@ -112,6 +112,9 @@ struct lbr_desc { * The records may be inaccurate if the host reclaims the LBR. */ struct perf_event *event; + + /* A flag to reduce the overhead of LBR pass-through or cancellation. */ + bool already_passthrough; }; /* -- 2.21.3