From 94826ef61ffe0ca469ff75e5d34e215563cb91c1 Mon Sep 17 00:00:00 2001 From: Kan Liang Date: Thu, 22 Oct 2020 10:23:16 +0800 Subject: [PATCH 2204/2944] Intel: perf/x86/intel: Check perf metrics feature for each CPU to #31064126 commit 80a5ce116fc084e8a25d5a936617699e2931b611 upstream Backport summary: backport to kernel 4.19.57 for ICX perf topdown support It might be possible that different CPUs have different CPU metrics on a platform. In this case, writing the GLOBAL_CTRL_EN_PERF_METRICS bit to the GLOBAL_CTRL register of a CPU, which doesn't support the TopDown perf metrics feature, causes MSR access error. Current TopDown perf metrics feature is enumerated using the boot CPU's PERF_CAPABILITIES MSR. The MSR only indicates the boot CPU supports this feature. Check the PERF_CAPABILITIES MSR for each CPU. If any CPU doesn't support the perf metrics feature, disable the feature globally. Fixes: 59a854e2f3b9 ("perf/x86/intel: Support TopDown metrics on Ice Lake") Signed-off-by: Kan Liang Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20201001211711.25708-1-kan.liang@linux.intel.com Signed-off-by: Yunying Sun Signed-off-by: Peng Wang Reviewed-by: Artie Ding --- arch/x86/events/intel/core.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c index 16be76c..f9f2e85 100644 --- a/arch/x86/events/intel/core.c +++ b/arch/x86/events/intel/core.c @@ -3855,6 +3855,17 @@ static void intel_pmu_cpu_starting(int cpu) if (x86_pmu.version > 1) flip_smm_bit(&x86_pmu.attr_freeze_on_smi); + /* Disable perf metrics if any added CPU doesn't support it. */ + if (x86_pmu.intel_cap.perf_metrics) { + union perf_capabilities perf_cap; + + rdmsrl(MSR_IA32_PERF_CAPABILITIES, perf_cap.capabilities); + if (!perf_cap.perf_metrics) { + x86_pmu.intel_cap.perf_metrics = 0; + x86_pmu.intel_ctrl &= ~(1ULL << GLOBAL_CTRL_EN_PERF_METRICS); + } + } + if (!cpuc->shared_regs) return; -- 1.8.3.1