From patchwork Wed Mar 3 13:57:56 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Like Xu X-Patchwork-Id: 12114967 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 29EFBC433E0 for ; Thu, 4 Mar 2021 00:29:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ECE006023B for ; Thu, 4 Mar 2021 00:29:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1378993AbhCDA22 (ORCPT ); Wed, 3 Mar 2021 19:28:28 -0500 Received: from mga11.intel.com ([192.55.52.93]:44167 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242945AbhCCOSE (ORCPT ); Wed, 3 Mar 2021 09:18:04 -0500 IronPort-SDR: skKflAtxweii8+DZcb16U+hqFcOIR/NtUmhzupaQHDYJlAz1ugUZOmG8kweFrBKj75rQX3UTNh gcnbpcq3jrMw== X-IronPort-AV: E=McAfee;i="6000,8403,9911"; a="183819046" X-IronPort-AV: E=Sophos;i="5.81,220,1610438400"; d="scan'208";a="183819046" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Mar 2021 06:05:52 -0800 IronPort-SDR: ZGZV29hhF3391vVbzakTKbsbPpuGvQwk9XF2rJEh4TH6Hi9X/zzV3yovcsRCh7Tns9Cbj2Vi0h M9nGT5ZHXmhg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.81,220,1610438400"; d="scan'208";a="399729508" Received: from clx-ap-likexu.sh.intel.com ([10.239.48.108]) by fmsmga008.fm.intel.com with ESMTP; 03 Mar 2021 06:05:49 -0800 From: Like Xu To: Peter Zijlstra , Paolo Bonzini , Sean Christopherson Cc: Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Joerg Roedel , Kan Liang , Dave Hansen , wei.w.wang@intel.com, Borislav Petkov , kvm@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, Like Xu Subject: [kvm-unit-tests PATCH] x86: Update guest LBR tests for Architectural LBR Date: Wed, 3 Mar 2021 21:57:56 +0800 Message-Id: <20210303135756.1546253-11-like.xu@linux.intel.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210303135756.1546253-1-like.xu@linux.intel.com> References: <20210303135756.1546253-1-like.xu@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org This unit-test is intended to test the KVM's support for the Architectural LBRs which is a Architectural performance monitor unit (PMU) feature on Intel processors. If the LBR bit is set to 1 in the MSR_ARCH_LBR_CTL, the processor will record a running trace of the most recent branches guest taken in the LBR entries for guest to read. Signed-off-by: Like Xu --- x86/pmu_lbr.c | 62 ++++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 52 insertions(+), 10 deletions(-) diff --git a/x86/pmu_lbr.c b/x86/pmu_lbr.c index 3bd9e9f..588aec8 100644 --- a/x86/pmu_lbr.c +++ b/x86/pmu_lbr.c @@ -6,6 +6,7 @@ #define MAX_NUM_LBR_ENTRY 32 #define DEBUGCTLMSR_LBR (1UL << 0) #define PMU_CAP_LBR_FMT 0x3f +#define KVM_ARCH_LBR_CTL_MASK 0x7f000f #define MSR_LBR_NHM_FROM 0x00000680 #define MSR_LBR_NHM_TO 0x000006c0 @@ -13,6 +14,10 @@ #define MSR_LBR_CORE_TO 0x00000060 #define MSR_LBR_TOS 0x000001c9 #define MSR_LBR_SELECT 0x000001c8 +#define MSR_ARCH_LBR_CTL 0x000014ce +#define MSR_ARCH_LBR_DEPTH 0x000014cf +#define MSR_ARCH_LBR_FROM_0 0x00001500 +#define MSR_ARCH_LBR_TO_0 0x00001600 volatile int count; @@ -66,6 +71,9 @@ int main(int ac, char **av) struct cpuid id = cpuid(10); u64 perf_cap; int max, i; + bool arch_lbr = false; + u32 ctl_msr = MSR_IA32_DEBUGCTLMSR; + u64 ctl_value = DEBUGCTLMSR_LBR; setup_vm(); perf_cap = rdmsr(MSR_IA32_PERF_CAPABILITIES); @@ -80,8 +88,23 @@ int main(int ac, char **av) return report_summary(); } + /* + * On processors that support Architectural LBRs, + * IA32_PERF_CAPABILITIES.LBR_FMT will have the value 03FH. + */ + if (0x3f == (perf_cap & PMU_CAP_LBR_FMT)) { + arch_lbr = true; + ctl_msr = MSR_ARCH_LBR_CTL; + /* DEPTH defaults to the maximum number of LBRs entries. */ + max = rdmsr(MSR_ARCH_LBR_DEPTH) - 1; + ctl_value = KVM_ARCH_LBR_CTL_MASK; + } + printf("PMU version: %d\n", eax.split.version_id); - printf("LBR version: %ld\n", perf_cap & PMU_CAP_LBR_FMT); + if (!arch_lbr) + printf("LBR version: %ld\n", perf_cap & PMU_CAP_LBR_FMT); + else + printf("Architectural LBR depth: %d\n", max + 1); /* Look for LBR from and to MSRs */ lbr_from = MSR_LBR_CORE_FROM; @@ -90,27 +113,46 @@ int main(int ac, char **av) lbr_from = MSR_LBR_NHM_FROM; lbr_to = MSR_LBR_NHM_TO; } + if (test_init_lbr_from_exception(0)) { + lbr_from = MSR_ARCH_LBR_FROM_0; + lbr_to = MSR_ARCH_LBR_TO_0; + } if (test_init_lbr_from_exception(0)) { printf("LBR on this platform is not supported!\n"); return report_summary(); } - wrmsr(MSR_LBR_SELECT, 0); - wrmsr(MSR_LBR_TOS, 0); - for (max = 0; max < MAX_NUM_LBR_ENTRY; max++) { - if (test_init_lbr_from_exception(max)) - break; + /* Reset the guest LBR entries. */ + if (arch_lbr) { + /* On a software write to IA32_LBR_DEPTH, all LBR entries are reset to 0.*/ + wrmsr(MSR_ARCH_LBR_DEPTH, max + 1); + } else { + wrmsr(MSR_LBR_SELECT, 0); + wrmsr(MSR_LBR_TOS, 0); + for (max = 0; max < MAX_NUM_LBR_ENTRY; max++) { + if (test_init_lbr_from_exception(max)) + break; + } } - report(max > 0, "The number of guest LBR entries is good."); + /* Check the guest LBR entries are initialized. */ + for (i = 0; i < max; ++i) { + if (rdmsr(lbr_to + i) || rdmsr(lbr_from + i)) + break; + } + report(i == max, "The guest LBR initialized FROM_IP/TO_IP values are good."); + /* Do some branch instructions. */ - wrmsr(MSR_IA32_DEBUGCTLMSR, DEBUGCTLMSR_LBR); + wrmsr(ctl_msr, ctl_value); lbr_test(); - wrmsr(MSR_IA32_DEBUGCTLMSR, 0); + wrmsr(ctl_msr, 0); - report(rdmsr(MSR_LBR_TOS) != 0, "The guest LBR MSR_LBR_TOS value is good."); + /* Check if the guest LBR has recorded some branches. */ + if (!arch_lbr) { + report(rdmsr(MSR_LBR_TOS) != 0, "The guest LBR MSR_LBR_TOS value is good."); + } for (i = 0; i < max; ++i) { if (!rdmsr(lbr_to + i) || !rdmsr(lbr_from + i)) break;