From patchwork Mon Jan 4 13:15:40 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Like Xu X-Patchwork-Id: 11996775 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=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 4C94DC43381 for ; Mon, 4 Jan 2021 13:30:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3021F207B1 for ; Mon, 4 Jan 2021 13:30:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727326AbhADNa3 (ORCPT ); Mon, 4 Jan 2021 08:30:29 -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 S1726666AbhADNa2 (ORCPT ); Mon, 4 Jan 2021 08:30:28 -0500 IronPort-SDR: 0m1hGqyg//CUplEbGe58Ee4dysT23WHLgQ80lHgB3HaX72/ThfYZ8sDg/u2H+px/fk3jOG1h1x DFBWT2u/MHzg== X-IronPort-AV: E=McAfee;i="6000,8403,9853"; a="241034459" X-IronPort-AV: E=Sophos;i="5.78,474,1599548400"; d="scan'208";a="241034459" 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 05:22:49 -0800 IronPort-SDR: JocRUK8k8ASaPNfd+Pt3539+sNH+2EnMZDn4Mr51/hdscxbK30Rb/5xYht4apSanqajY8f+mBv lFykmFgSMkXw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.78,474,1599548400"; d="scan'208";a="461944689" Received: from clx-ap-likexu.sh.intel.com ([10.239.48.108]) by fmsmga001.fm.intel.com with ESMTP; 04 Jan 2021 05:22:46 -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 15/17] KVM: vmx/pmu: Rewrite applicable_counters field in guest PEBS records Date: Mon, 4 Jan 2021 21:15:40 +0800 Message-Id: <20210104131542.495413-16-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 Precedence: bulk List-ID: X-Mailing-List: kvm@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 | 2 + arch/x86/kvm/pmu.c | 1 + arch/x86/kvm/vmx/pmu_intel.c | 84 +++++++++++++++++++++++++++++++-- 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 ea204c628f45..e6394ac54f81 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -452,6 +452,7 @@ struct kvm_pmu { u64 ds_area; u64 cached_ds_area; struct gfn_to_hva_cache ds_area_cache; + struct gfn_to_hva_cache pebs_buffer_base_cache; u64 pebs_enable; u64 pebs_enable_mask; u64 pebs_data_cfg; @@ -459,6 +460,7 @@ 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 c0f18b304933..581653589108 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(GLOBAL_STATUS_BUFFER_OVF_BIT, (unsigned long *)&pmu->global_status); diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c index b69e7c47fb05..4c095c31db38 100644 --- a/arch/x86/kvm/vmx/pmu_intel.c +++ b/arch/x86/kvm/vmx/pmu_intel.c @@ -557,22 +557,96 @@ 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, buffer_base, 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); + if (kvm_read_guest_cached(vcpu->kvm, &pmu->ds_area_cache, + 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); + buffer_base = 0; + + gpa = kvm_mmu_gva_to_gpa_system(vcpu, pebs_buffer_base, NULL); + if (kvm_gfn_to_hva_cache_init(vcpu->kvm, &pmu->pebs_buffer_base_cache, + gpa, sizeof(struct pebs_basic))) + goto out; + + do { + ret = -EFAULT; + if (kvm_read_guest_offset_cached(vcpu->kvm, &pmu->pebs_buffer_base_cache, + &status, buffer_base + offset, sizeof(u64))) + goto out; + if (kvm_read_guest_offset_cached(vcpu->kvm, &pmu->pebs_buffer_base_cache, + &format_size, buffer_base, 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_offset_cached(vcpu->kvm, &pmu->pebs_buffer_base_cache, + &new_status, buffer_base + offset, sizeof(u64))) + goto out; + + ret = 0; + buffer_base += format_size >> 48; + } while (pebs_buffer_base + buffer_base < ds->pebs_index); + +out: + srcu_read_unlock(&vcpu->kvm->srcu, srcu_idx); + kfree(ds); + return ret; +} + static 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__); }