From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932302AbbHNKJD (ORCPT ); Fri, 14 Aug 2015 06:09:03 -0400 Received: from mga01.intel.com ([192.55.52.88]:14336 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932256AbbHNKJC (ORCPT ); Fri, 14 Aug 2015 06:09:02 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.15,676,1432623600"; d="scan'208";a="625413894" From: Huaitong Han To: alexander.shishkin@linux.intel.com, mingo@redhat.com, acme@kernel.org Cc: linux-kernel@vger.kernel.org, Huaitong Han Subject: [PATCH] RDMSR before test_cpu_capacity brings about KVM warning Date: Fri, 14 Aug 2015 18:07:37 +0800 Message-Id: <1439546857-12791-1-git-send-email-huaitong.han@intel.com> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org rdmsrl_safe does not lead to #GP in native kernel although CPU does not support INTEL_PT, but if KVM does not support INTEL_PT, the codes cannot understand MSR_IA32_RTIT_CTL, and the warning is produced. If KVM does not support INTEL_PT, its guest CPUID also does not. So test_cpu_cap is added before RDMSR, and it is more in line with the code style. Signed-off-by: Huaitong Han diff --git a/arch/x86/kernel/cpu/perf_event_intel_pt.c b/arch/x86/kernel/cpu/perf_event_intel_pt.c index 183de71..4cc6492 100644 --- a/arch/x86/kernel/cpu/perf_event_intel_pt.c +++ b/arch/x86/kernel/cpu/perf_event_intel_pt.c @@ -123,9 +123,6 @@ static int __init pt_pmu_hw_init(void) long i; attrs = NULL; - ret = -ENODEV; - if (!test_cpu_cap(&boot_cpu_data, X86_FEATURE_INTEL_PT)) - goto fail; for (i = 0; i < PT_CPUID_LEAVES; i++) { cpuid_count(20, i, @@ -1061,6 +1058,10 @@ static __init int pt_init(void) int ret, cpu, prior_warn = 0; BUILD_BUG_ON(sizeof(struct topa) > PAGE_SIZE); + + if (!test_cpu_cap(&boot_cpu_data, X86_FEATURE_INTEL_PT)) + return -ENODEV; + get_online_cpus(); for_each_online_cpu(cpu) { u64 ctl; -- 1.9.1