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=-5.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 83549C10DCE for ; Mon, 9 Mar 2020 00:58:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5113020675 for ; Mon, 9 Mar 2020 00:58:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726641AbgCIA6x convert rfc822-to-8bit (ORCPT ); Sun, 8 Mar 2020 20:58:53 -0400 Received: from mga01.intel.com ([192.55.52.88]:16346 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726346AbgCIA6w (ORCPT ); Sun, 8 Mar 2020 20:58:52 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 08 Mar 2020 17:58:51 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,518,1574150400"; d="scan'208";a="260255816" Received: from fmsmsx106.amr.corp.intel.com ([10.18.124.204]) by orsmga002.jf.intel.com with ESMTP; 08 Mar 2020 17:58:50 -0700 Received: from shsmsx105.ccr.corp.intel.com (10.239.4.158) by FMSMSX106.amr.corp.intel.com (10.18.124.204) with Microsoft SMTP Server (TLS) id 14.3.439.0; Sun, 8 Mar 2020 17:58:50 -0700 Received: from shsmsx102.ccr.corp.intel.com ([169.254.2.50]) by SHSMSX105.ccr.corp.intel.com ([169.254.11.144]) with mapi id 14.03.0439.000; Mon, 9 Mar 2020 08:58:47 +0800 From: "Xu, Like" To: lkp , "Kang, Luwei" CC: "kbuild-all@lists.01.org" , "x86@kernel.org" , "linux-kernel@vger.kernel.org" , "kvm@vger.kernel.org" , "peterz@infradead.org" , "mingo@redhat.com" , "acme@kernel.org" , "mark.rutland@arm.com" , "alexander.shishkin@linux.intel.com" , "jolsa@redhat.com" , "namhyung@kernel.org" , "tglx@linutronix.de" , "bp@alien8.de" , "hpa@zytor.com" , "pbonzini@redhat.com" , "Christopherson, Sean J" , "vkuznets@redhat.com" , "wanpengli@tencent.com" , "jmattson@google.com" , "joro@8bytes.org" , "pawan.kumar.gupta@linux.intel.com" , "ak@linux.intel.com" , "thomas.lendacky@amd.com" , "Yu, Fenghua" , "kan.liang@linux.intel.com" , "like.xu@linux.intel.com" Subject: RE: [PATCH v1 05/11] KVM: x86/pmu: Add support to reprogram PEBS event for guest counters Thread-Topic: [PATCH v1 05/11] KVM: x86/pmu: Add support to reprogram PEBS event for guest counters Thread-Index: AQJvPzxww5HXayZ7yL4sj1CxXq+eMQM8p73NpvL3z6A= Date: Mon, 9 Mar 2020 00:58:47 +0000 Message-ID: References: <1583431025-19802-6-git-send-email-luwei.kang@intel.com> <202003070038.amFy5Etu%lkp@intel.com> In-Reply-To: <202003070038.amFy5Etu%lkp@intel.com> Accept-Language: en-US, zh-CN Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: dlp-product: dlpe-windows dlp-version: 11.2.0.6 dlp-reaction: no-action x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > -----Original Message----- > From: kbuild test robot > Sent: Saturday, March 7, 2020 12:28 AM > To: Luwei Kang > Cc: kbuild-all@lists.01.org; x86@kernel.org; linux-kernel@vger.kernel.org; > kvm@vger.kernel.org; peterz@infradead.org; mingo@redhat.com; > acme@kernel.org; mark.rutland@arm.com; > alexander.shishkin@linux.intel.com; jolsa@redhat.com; > namhyung@kernel.org; tglx@linutronix.de; bp@alien8.de; hpa@zytor.com; > pbonzini@redhat.com; sean.j.christopherson@intel.com; > vkuznets@redhat.com; wanpengli@tencent.com; jmattson@google.com; > joro@8bytes.org; pawan.kumar.gupta@linux.intel.com; ak@linux.intel.com; > thomas.lendacky@amd.com; fenghua.yu@intel.com; > kan.liang@linux.intel.com; like.xu@linux.intel.com > Subject: Re: [PATCH v1 05/11] KVM: x86/pmu: Add support to reprogram PEBS > event for guest counters > > Hi Luwei, > > Thank you for the patch! Yet something to improve: > > [auto build test ERROR on kvm/linux-next] [also build test ERROR on > tip/perf/core tip/auto-latest v5.6-rc4 next-20200306] [if your patch is applied to > the wrong git tree, please drop us a note to help improve the system. BTW, we > also suggest to use '--base' option to specify the base tree in git format-patch, > please see https://stackoverflow.com/a/37406982] > > url: > https://github.com/0day-ci/linux/commits/Luwei-Kang/PEBS-virtualization-ena > bling-via-DS/20200306-013049 > base: https://git.kernel.org/pub/scm/virt/kvm/kvm.git linux-next > config: x86_64-randconfig-h003-20200305 (attached as .config) > compiler: gcc-7 (Debian 7.5.0-5) 7.5.0 > reproduce: > # save the attached .config to linux build tree > make ARCH=x86_64 > > If you fix the issue, kindly add following tag > Reported-by: kbuild test robot > > All errors (new ones prefixed by >>): > > ld: arch/x86/kvm/pmu.o: in function `pmc_reprogram_counter': > >> arch/x86/kvm/pmu.c:199: undefined reference to > `perf_x86_pmu_unset_auto_reload' Since we may not lose PEBS functionality for other x86 vendors on KVM and we already have defined PERF_X86_EVENT_AUTO_RELOAD in the general arch/x86/events/perf_event.h, one of the ways to fix this issue is to move the definition of perf_x86_pmu_unset_auto_reload() to the end of arch/x86/events/core.c instead of making it Intel specific in previous patch "perf/x86: Expose a function to disable auto-reload." Thanks, Like Xu > > vim +199 arch/x86/kvm/pmu.c > > 101 > 102 static void pmc_reprogram_counter(struct kvm_pmc *pmc, u32 type, > 103 unsigned config, bool exclude_user, > 104 bool exclude_kernel, bool intr, > 105 bool in_tx, bool in_tx_cp) > 106 { > 107 struct kvm_pmu *pmu = vcpu_to_pmu(pmc->vcpu); > 108 struct perf_event *event; > 109 struct perf_event_attr attr = { > 110 .type = type, > 111 .size = sizeof(attr), > 112 .pinned = true, > 113 .exclude_idle = true, > 114 .exclude_host = 1, > 115 .exclude_user = exclude_user, > 116 .exclude_kernel = exclude_kernel, > 117 .config = config, > 118 .disabled = 1, > 119 }; > 120 bool pebs = test_bit(pmc->idx, (unsigned long > *)&pmu->pebs_enable); > 121 > 122 attr.sample_period = (-pmc->counter) & pmc_bitmask(pmc); > 123 > 124 if (in_tx) > 125 attr.config |= HSW_IN_TX; > 126 if (in_tx_cp) { > 127 /* > 128 * HSW_IN_TX_CHECKPOINTED is not supported with > nonzero > 129 * period. Just clear the sample period so at least > 130 * allocating the counter doesn't fail. > 131 */ > 132 attr.sample_period = 0; > 133 attr.config |= HSW_IN_TX_CHECKPOINTED; > 134 } > 135 > 136 if (pebs) { > 137 /* > 138 * Host never knows the precision level set by guest. > 139 * Force Host's PEBS event to precision level 1, which will > 140 * not impact the accuracy of the results for guest PEBS > events. > 141 * Because, > 142 * - For most cases, there is no difference among precision > 143 * level 1 to 3 for PEBS events. > 144 * - The functions as below checks the precision level in > host. > 145 * But the results from these functions in host are > replaced > 146 * by guest when sampling the guest. > 147 * The accuracy for guest PEBS events will not be > impacted. > 148 * -- event_constraints() impacts the index of counter. > 149 * The index for host event is exactly the same as guest. > 150 * It's decided by guest. > 151 * -- pebs_update_adaptive_cfg() impacts the value of > 152 * MSR_PEBS_DATA_CFG. When guest is switched in, > 153 * the MSR value will be replaced by the value from > guest. > 154 * -- setup_sample () impacts the output of a PEBS > record. > 155 * Guest handles the PEBS records. > 156 */ > 157 attr.precise_ip = 1; > 158 /* > 159 * When the host's PMI handler completes, it's going to > 160 * enter the guest and trigger the guest's PMI handler. > 161 * > 162 * At this moment, this function may be called by > 163 * kvm_pmu_handle_event(). However the next > sample_period > 164 * hasn't been determined by guest yet and the left period, > 165 * which probably be 0, is used for current sample_period. > 166 * > 167 * In this case, perf will mistakenly treat it as non > 168 * sampling events. The PEBS event will error out. > 169 * > 170 * Fill it with maximum period to prevent the error out. > 171 * The guest PMI handler will soon reprogram the counter. > 172 */ > 173 if (!attr.sample_period) > 174 attr.sample_period = (-1ULL) & pmc_bitmask(pmc); > 175 } > 176 > 177 event = perf_event_create_kernel_counter(&attr, -1, current, > 178 (intr || pebs) ? > 179 kvm_perf_overflow_intr : > 180 kvm_perf_overflow, pmc); > 181 if (IS_ERR(event)) { > 182 pr_debug_ratelimited("kvm_pmu: event creation failed %ld > for pmc->idx = %d\n", > 183 PTR_ERR(event), pmc->idx); > 184 return; > 185 } > 186 > 187 if (pebs) { > 188 event->guest_dedicated_idx = pmc->idx; > 189 /* > 190 * For guest PEBS events, guest takes the responsibility to > 191 * drain PEBS buffers, and load proper values to reset > counters. > 192 * > 193 * Host will unconditionally set auto-reload flag for PEBS > 194 * events with fixed period which is not necessary. Host > should > 195 * do nothing in drain_pebs() but inject the PMI into the > guest. > 196 * > 197 * Unset the auto-reload flag for guest PEBS events. > 198 */ > > 199 perf_x86_pmu_unset_auto_reload(event); > 200 } > 201 pmc->perf_event = event; > 202 pmc_to_pmu(pmc)->event_count++; > 203 perf_event_enable(event); > 204 clear_bit(pmc->idx, pmc_to_pmu(pmc)->reprogram_pmi); > 205 } > 206 > > --- > 0-DAY CI Kernel Test Service, Intel Corporation > https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org