From cadbaa039b99a6d5c26ce1c7f2fc0325943e605a Mon Sep 17 00:00:00 2001
From: Stephane Eranian <eranian@google.com>
Date: Wed, 28 Oct 2020 12:42:47 -0700
Subject: [PATCH] perf/x86/intel: Make anythread filter support conditional
Starting with Arch Perfmon v5, the anythread filter on generic counters may be
deprecated. The current kernel was exporting the any filter without checking.
On Icelake, it means you could do cpu/event=0x3c,any/ even though the filter
does not exist. This patch corrects the problem by relying on the CPUID 0xa leaf
function to determine if anythread is supported or not as described in the
Intel SDM Vol3b 18.2.5.1 AnyThread Deprecation section.
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201028194247.3160610-1-eranian@google.com
---
arch/x86/events/intel/core.c | 10 ++++++++++
arch/x86/events/perf_event.h | 1 +
arch/x86/include/asm/perf_event.h | 4 +++-
arch/x86/kvm/cpuid.c | 4 +++-
4 files changed, 17 insertions(+), 2 deletions(-)
diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index c37387c8212a2..af457f8cb29dd 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -4987,6 +4987,12 @@ __init int intel_pmu_init(void)
x86_add_quirk(intel_arch_events_quirk); /* Install first, so it runs last */
+ if (version >= 5) {
+ x86_pmu.intel_cap.anythread_deprecated = edx.split.anythread_deprecated;
+ if (x86_pmu.intel_cap.anythread_deprecated)
+ pr_cont(" AnyThread deprecated, ");
+ }
+
/*
* Install the hw-cache-events table:
*/
@@ -5512,6 +5518,10 @@ __init int intel_pmu_init(void)
x86_pmu.intel_ctrl |=
((1LL << x86_pmu.num_counters_fixed)-1) << INTEL_PMC_IDX_FIXED;
+ /* AnyThread may be deprecated on arch perfmon v5 or later */
+ if (x86_pmu.intel_cap.anythread_deprecated)
+ x86_pmu.format_attrs = intel_arch_formats_attr;
+
if (x86_pmu.event_constraints) {
/*
* event on fixed counter2 (REF_CYCLES) only works on this
diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h
index 1d1fe46552bac..6a8edfe59b09c 100644
--- a/arch/x86/events/perf_event.h
+++ b/arch/x86/events/perf_event.h
@@ -585,6 +585,7 @@ union perf_capabilities {
u64 pebs_baseline:1;
u64 perf_metrics:1;
u64 pebs_output_pt_available:1;
+ u64 anythread_deprecated:1;
};
u64 capabilities;
};
diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h
index 6960cd6d1f231..b9a7fd0a27e2d 100644
--- a/arch/x86/include/asm/perf_event.h
+++ b/arch/x86/include/asm/perf_event.h
@@ -137,7 +137,9 @@ union cpuid10_edx {
struct {
unsigned int num_counters_fixed:5;
unsigned int bit_width_fixed:8;
- unsigned int reserved:19;
+ unsigned int reserved1:2;
+ unsigned int anythread_deprecated:1;
+ unsigned int reserved2:16;
} split;
unsigned int full;
};
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 06a278b3701d1..0752dec66e293 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -672,7 +672,9 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
edx.split.num_counters_fixed = min(cap.num_counters_fixed, MAX_FIXED_COUNTERS);
edx.split.bit_width_fixed = cap.bit_width_fixed;
- edx.split.reserved = 0;
+ edx.split.anythread_deprecated = 1;
+ edx.split.reserved1 = 0;
+ edx.split.reserved2 = 0;
entry->eax = eax.full;
entry->ebx = cap.events_mask;
--
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