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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 32BBEC433E0 for ; Mon, 4 Jan 2021 13:29:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 074E5207B1 for ; Mon, 4 Jan 2021 13:29:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727150AbhADN3I (ORCPT ); Mon, 4 Jan 2021 08:29:08 -0500 Received: from mga07.intel.com ([134.134.136.100]:23242 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726640AbhADN3H (ORCPT ); Mon, 4 Jan 2021 08:29:07 -0500 IronPort-SDR: /p4PNWsAiwyDZjxp1I1+u/0dKDU8A/HqUWoKOS+EPhplqNig7Fq2rscVeCabDdocLCnaHVXaKE PVpDAOW6BYwQ== X-IronPort-AV: E=McAfee;i="6000,8403,9853"; a="241034382" X-IronPort-AV: E=Sophos;i="5.78,474,1599548400"; d="scan'208";a="241034382" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Jan 2021 05:22:39 -0800 IronPort-SDR: MfCm3DJ8qA3KJSkleaVGOGTNFA5J6/ZgQM+1ZXpfTVL1bXj4NeIXO1ySHba0R7N1/TtzbHvBXv wHWzPbXfk42Q== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.78,474,1599548400"; d="scan'208";a="461944637" Received: from clx-ap-likexu.sh.intel.com ([10.239.48.108]) by fmsmga001.fm.intel.com with ESMTP; 04 Jan 2021 05:22:36 -0800 From: Like Xu To: Peter Zijlstra , Paolo Bonzini , eranian@google.com, kvm@vger.kernel.org Cc: Ingo Molnar , Sean Christopherson , Thomas Gleixner , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Andi Kleen , Kan Liang , wei.w.wang@intel.com, luwei.kang@intel.com, linux-kernel@vger.kernel.org Subject: [PATCH v3 12/17] KVM: x86/pmu: Disable guest PEBS when counters are cross-mapped Date: Mon, 4 Jan 2021 21:15:37 +0800 Message-Id: <20210104131542.495413-13-like.xu@linux.intel.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210104131542.495413-1-like.xu@linux.intel.com> References: <20210104131542.495413-1-like.xu@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org KVM will check if a guest PEBS counter X is cross-mapped to the host counter Y. In this case, the applicable_counter field in the guest PEBS records is filled with the real host counter index(s) which is incorrect. Currently, KVM will disable guest PEBS before vm-entry and the later patches would do more emulations in the KVM to keep PEBS functionality work as host, such as rewriting applicable_counter field in the guest PEBS records buffer. The cross-mapped check should be done right before vm-entry but after local_irq_disable() since perf scheduler would rotate the pmc->perf_event to another host counter or make the event into error state via hrtimer irq. Signed-off-by: Like Xu --- arch/x86/include/asm/kvm_host.h | 2 ++ arch/x86/kvm/pmu.c | 25 +++++++++++++++++++++++++ arch/x86/kvm/pmu.h | 1 + arch/x86/kvm/vmx/vmx.c | 3 +++ arch/x86/kvm/x86.c | 4 ++++ 5 files changed, 35 insertions(+) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 4ff6aa00a325..5de4c14cf526 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -455,6 +455,8 @@ struct kvm_pmu { u64 pebs_data_cfg; u64 pebs_data_cfg_mask; + bool counter_cross_mapped; + /* * The gate to release perf_events not marked in * pmc_in_use only once in a vcpu time slice. diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c index 67c20ab81991..3bfed803ed17 100644 --- a/arch/x86/kvm/pmu.c +++ b/arch/x86/kvm/pmu.c @@ -550,3 +550,28 @@ int kvm_vm_ioctl_set_pmu_event_filter(struct kvm *kvm, void __user *argp) kfree(filter); return r; } + +/* + * The caller needs to ensure that there is no time window for + * perf hrtimer irq or any chance to reschedule pmc->perf_event. + */ +void kvm_pmu_counter_cross_mapped_check(struct kvm_vcpu *vcpu) +{ + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + struct kvm_pmc *pmc = NULL; + int bit; + + pmu->counter_cross_mapped = false; + + for_each_set_bit(bit, (unsigned long *)&pmu->pebs_enable, X86_PMC_IDX_MAX) { + pmc = kvm_x86_ops.pmu_ops->pmc_idx_to_pmc(pmu, bit); + + if (!pmc || !pmc_speculative_in_use(pmc) || !pmc_is_enabled(pmc)) + continue; + + if (pmc->perf_event && (pmc->idx != pmc->perf_event->hw.idx)) { + pmu->counter_cross_mapped = true; + break; + } + } +} diff --git a/arch/x86/kvm/pmu.h b/arch/x86/kvm/pmu.h index ee8f15cc4b5e..f5ec94e9a1dc 100644 --- a/arch/x86/kvm/pmu.h +++ b/arch/x86/kvm/pmu.h @@ -163,6 +163,7 @@ void kvm_pmu_init(struct kvm_vcpu *vcpu); void kvm_pmu_cleanup(struct kvm_vcpu *vcpu); void kvm_pmu_destroy(struct kvm_vcpu *vcpu); int kvm_vm_ioctl_set_pmu_event_filter(struct kvm *kvm, void __user *argp); +void kvm_pmu_counter_cross_mapped_check(struct kvm_vcpu *vcpu); bool is_vmware_backdoor_pmc(u32 pmc_idx); diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 341794b67f9a..bc30c83e0a62 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -6542,6 +6542,9 @@ static void atomic_switch_perf_msrs(struct vcpu_vmx *vmx) if (!msrs) return; + if (pmu->counter_cross_mapped) + msrs[1].guest = 0; + if (nr_msrs > 2 && msrs[1].guest) { msrs[2].guest = pmu->ds_area; if (nr_msrs > 3) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 213368e47500..4ab1ce26244d 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -8936,6 +8936,10 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) * result in virtual interrupt delivery. */ local_irq_disable(); + + if (vcpu_to_pmu(vcpu)->global_ctrl & vcpu_to_pmu(vcpu)->pebs_enable) + kvm_pmu_counter_cross_mapped_check(vcpu); + vcpu->mode = IN_GUEST_MODE; srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx); -- 2.29.2