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=-12.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 E03AFC63699 for ; Mon, 9 Nov 2020 02:17:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 92698206D8 for ; Mon, 9 Nov 2020 02:17:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729449AbgKICRx (ORCPT ); Sun, 8 Nov 2020 21:17:53 -0500 Received: from mga01.intel.com ([192.55.52.88]:64958 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729431AbgKICRt (ORCPT ); Sun, 8 Nov 2020 21:17:49 -0500 IronPort-SDR: qDq8NWuPZP+Mecl0t7Ek6v3dshS14OumuhbYe2op3f70ghr+2u/MIqWAPmccPvC/5lsznn2CqR 7pf5GpLZpASg== X-IronPort-AV: E=McAfee;i="6000,8403,9799"; a="187684670" X-IronPort-AV: E=Sophos;i="5.77,462,1596524400"; d="scan'208";a="187684670" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Nov 2020 18:17:48 -0800 IronPort-SDR: j5U2XaiU6WXg5m97koqDGeIX7BjV3J97z0p8UgUek0vDkrCUMfKLa+gTuVV9I0mmjZvGrxJkty 48nON/ucXD/Q== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.77,462,1596524400"; d="scan'208";a="540646276" Received: from e5-2699-v4-likexu.sh.intel.com ([10.239.48.39]) by orsmga005.jf.intel.com with ESMTP; 08 Nov 2020 18:17:45 -0800 From: Like Xu To: Peter Zijlstra , Paolo Bonzini , kvm@vger.kernel.org Cc: Sean Christopherson , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Kan Liang , luwei.kang@intel.com, Thomas Gleixner , wei.w.wang@intel.com, Tony Luck , Stephane Eranian , Mark Gross , Srinivas Pandruvada , linux-kernel@vger.kernel.org Subject: [PATCH RFC v2 15/17] KVM: vmx/pmu: Rewrite applicable_counters field in the guest PEBS record Date: Mon, 9 Nov 2020 10:12:52 +0800 Message-Id: <20201109021254.79755-16-like.xu@linux.intel.com> X-Mailer: git-send-email 2.21.3 In-Reply-To: <20201109021254.79755-1-like.xu@linux.intel.com> References: <20201109021254.79755-1-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 The PEBS event counters scheduled by host may different to the counters required by guest. The host counter index will be leaked into the guest PEBS record and the guest driver will be confused by the counter indexes in the "Applicable Counters" field of the PEBS records and ignore them. Before the guest PEBS overflow PMI is injected into the guest through global status, KVM needs to rewrite the "Applicable Counters" field with the right enabled guest pebs counter idx(s) in the guest PEBS records. Co-developed-by: Luwei Kang Signed-off-by: Luwei Kang Signed-off-by: Like Xu --- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/pmu.c | 1 + arch/x86/kvm/vmx/pmu_intel.c | 85 +++++++++++++++++++++++++++++++-- 3 files changed, 82 insertions(+), 5 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 77b529b8c16a..cdc3c6efdd8e 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -457,6 +457,7 @@ struct kvm_pmu { bool counter_cross_mapped; bool need_rewrite_ds_pebs_interrupt_threshold; + bool need_rewrite_pebs_records; /* * The gate to release perf_events not marked in diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c index 7c8e3ca5b7ad..64dce19644e3 100644 --- a/arch/x86/kvm/pmu.c +++ b/arch/x86/kvm/pmu.c @@ -77,6 +77,7 @@ static void kvm_perf_overflow_intr(struct perf_event *perf_event, if (!test_and_set_bit(pmc->idx, pmu->reprogram_pmi)) { if (perf_event->attr.precise_ip) { + pmu->need_rewrite_pebs_records = pmu->counter_cross_mapped; /* Indicate PEBS overflow PMI to guest. */ __set_bit(62, (unsigned long *)&pmu->global_status); } else diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c index 346b1104e674..d58d04ee13a5 100644 --- a/arch/x86/kvm/vmx/pmu_intel.c +++ b/arch/x86/kvm/vmx/pmu_intel.c @@ -551,22 +551,97 @@ static int rewrite_ds_pebs_interrupt_threshold(struct kvm_vcpu *vcpu) return ret; } +static int rewrite_ds_pebs_records(struct kvm_vcpu *vcpu) +{ + struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); + struct kvm_pmc *pmc = NULL; + struct debug_store *ds = NULL; + gpa_t gpa; + u64 pebs_buffer_base, offset, status, new_status, format_size; + int srcu_idx, bit, ret = 0; + + if (!pmu->counter_cross_mapped) + return ret; + + ds = kmalloc(sizeof(struct debug_store), GFP_KERNEL); + if (!ds) + return -ENOMEM; + + ret = -EFAULT; + srcu_idx = srcu_read_lock(&vcpu->kvm->srcu); + gpa = kvm_mmu_gva_to_gpa_system(vcpu, pmu->ds_area, NULL); + if (gpa == UNMAPPED_GVA) + goto out; + + if (kvm_read_guest(vcpu->kvm, gpa, ds, sizeof(struct debug_store))) + goto out; + + if (ds->pebs_index <= ds->pebs_buffer_base) + goto out; + + pebs_buffer_base = ds->pebs_buffer_base; + offset = offsetof(struct pebs_basic, applicable_counters); + + do { + ret = -EFAULT; + gpa = kvm_mmu_gva_to_gpa_system(vcpu, pebs_buffer_base + offset, NULL); + if (gpa == UNMAPPED_GVA) + goto out; + if (kvm_read_guest(vcpu->kvm, gpa, &status, sizeof(u64))) + goto out; + + new_status = 0ull; + 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->perf_event) + continue; + + if (test_bit(pmc->perf_event->hw.idx, (unsigned long *)&status)) + new_status |= BIT_ULL(pmc->idx); + } + if (kvm_write_guest(vcpu->kvm, gpa, &new_status, sizeof(u64))) + goto out; + + gpa = kvm_mmu_gva_to_gpa_system(vcpu, pebs_buffer_base, NULL); + if (gpa == UNMAPPED_GVA) + goto out; + if (kvm_read_guest(vcpu->kvm, gpa, &format_size, sizeof(u64))) + goto out; + ret = 0; + + pebs_buffer_base = pebs_buffer_base + (format_size >> 48); + } while (pebs_buffer_base < ds->pebs_index); + +out: + srcu_read_unlock(&vcpu->kvm->srcu, srcu_idx); + kfree(ds); + return ret; +} + void intel_pmu_handle_event(struct kvm_vcpu *vcpu) { struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); - int ret; + int ret1, ret2; + + if (pmu->need_rewrite_pebs_records) { + pmu->need_rewrite_pebs_records = false; + ret1 = rewrite_ds_pebs_records(vcpu); + } if (!(pmu->global_ctrl & pmu->pebs_enable)) - return; + goto out; if (pmu->counter_cross_mapped && pmu->need_rewrite_ds_pebs_interrupt_threshold) { - ret = rewrite_ds_pebs_interrupt_threshold(vcpu); pmu->need_rewrite_ds_pebs_interrupt_threshold = false; + ret2 = rewrite_ds_pebs_interrupt_threshold(vcpu); } - if (ret == -ENOMEM) +out: + + if (ret1 == -ENOMEM || ret2 == -ENOMEM) pr_debug_ratelimited("%s: Fail to emulate guest PEBS due to OOM.", __func__); - else if (ret == -EFAULT) + else if (ret1 == -EFAULT || ret2 == -EFAULT) pr_debug_ratelimited("%s: Fail to emulate guest PEBS due to GPA fault.", __func__); } -- 2.21.3