Intel CPUs report non-available architectural events in cpuid leaf
0AH.EBX. Use it to disable events that are not available according
to CPU.
Signed-off-by: Gleb Natapov <gleb@xxxxxxxxxx>
---
arch/x86/include/asm/perf_event.h | 14 ++++++++++++++
arch/x86/kernel/cpu/perf_event.h | 5 +++++
arch/x86/kernel/cpu/perf_event_intel.c | 29 ++++++++++++++++++++++++-----
3 files changed, 43 insertions(+), 5 deletions(-)
diff --git a/arch/x86/include/asm/perf_event.h b/arch/x86/include/asm/perf_event.h
index f61c62f..c6998bc 100644
--- a/arch/x86/include/asm/perf_event.h
+++ b/arch/x86/include/asm/perf_event.h
@@ -57,6 +57,7 @@
(1 << (ARCH_PERFMON_UNHALTED_CORE_CYCLES_INDEX))
#define ARCH_PERFMON_BRANCH_MISSES_RETIRED 6
+#define ARCH_PERFMON_EVENTS_COUNT 7
/*
* Intel "Architectural Performance Monitoring" CPUID
@@ -72,6 +73,19 @@ union cpuid10_eax {
unsigned int full;
};
+union cpuid10_ebx {
+ struct {
+ unsigned int no_unhalted_core_cycles:1;
+ unsigned int no_instructions_retired:1;
+ unsigned int no_unhalted_reference_cycles:1;
+ unsigned int no_llc_reference:1;
+ unsigned int no_llc_misses:1;
+ unsigned int no_branch_instruction_retired:1;
+ unsigned int no_branch_misses_retired:1;
+ } split;
+ unsigned int full;
+};
+
union cpuid10_edx {
struct {
unsigned int num_counters_fixed:5;
diff --git a/arch/x86/kernel/cpu/perf_event.h b/arch/x86/kernel/cpu/perf_event.h
index b9698d4..cd0ebcd 100644
--- a/arch/x86/kernel/cpu/perf_event.h
+++ b/arch/x86/kernel/cpu/perf_event.h
@@ -259,6 +259,11 @@ struct x86_pmu {
int num_counters_fixed;
int cntval_bits;
u64 cntval_mask;
+ union {
+ unsigned long events_maskl;
+ unsigned long events_mask[BITS_TO_LONGS(ARCH_PERFMON_EVENTS_COUNT)];
+ };
+ int events_mask_len;
int apic;
u64 max_period;
struct event_constraint *
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index e09ca20..301369a 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -1544,13 +1544,23 @@ static void intel_clovertown_quirks(void)
x86_pmu.pebs_constraints = NULL;
}
+static int intel_event_id_to_hw_id[] = {
+ PERF_COUNT_HW_CPU_CYCLES,
+ PERF_COUNT_HW_INSTRUCTIONS,
+ PERF_COUNT_HW_BUS_CYCLES,
+ PERF_COUNT_HW_CACHE_REFERENCES,
+ PERF_COUNT_HW_CACHE_MISSES,
+ PERF_COUNT_HW_BRANCH_INSTRUCTIONS,
+ PERF_COUNT_HW_BRANCH_MISSES,
+};
+
__init int intel_pmu_init(void)
{
union cpuid10_edx edx;
union cpuid10_eax eax;
+ union cpuid10_ebx ebx;
unsigned int unused;
- unsigned int ebx;
- int version;
+ int version, bit;
if (!cpu_has(&boot_cpu_data, X86_FEATURE_ARCH_PERFMON)) {
switch (boot_cpu_data.x86) {
@@ -1566,8 +1576,8 @@ __init int intel_pmu_init(void)
* Check whether the Architectural PerfMon supports
* Branch Misses Retired hw_event or not.
*/
- cpuid(10, &eax.full, &ebx, &unused, &edx.full);
- if (eax.split.mask_length <= ARCH_PERFMON_BRANCH_MISSES_RETIRED)
+ cpuid(10, &eax.full, &ebx.full, &unused, &edx.full);
+ if (eax.split.mask_length < ARCH_PERFMON_EVENTS_COUNT)
return -ENODEV;
version = eax.split.version_id;
@@ -1643,7 +1653,7 @@ __init int intel_pmu_init(void)
/* UOPS_EXECUTED.CORE_ACTIVE_CYCLES,c=1,i=1 */
intel_perfmon_event_map[PERF_COUNT_HW_STALLED_CYCLES_BACKEND] = 0x1803fb1;
- if (ebx & 0x40) {
+ if (ebx.split.no_branch_misses_retired) {
/*
* Erratum AAJ80 detected, we work it around by using
* the BR_MISP_EXEC.ANY event. This will over-count
@@ -1651,6 +1661,7 @@ __init int intel_pmu_init(void)
* architectural event which is often completely bogus:
*/
intel_perfmon_event_map[PERF_COUNT_HW_BRANCH_MISSES] = 0x7f89;
+ ebx.split.no_branch_misses_retired = 0;
pr_cont("erratum AAJ80 worked around, ");
}
@@ -1729,5 +1740,13 @@ __init int intel_pmu_init(void)
break;
}
}
+ x86_pmu.events_maskl = ebx.full;
+ x86_pmu.events_mask_len = eax.split.mask_length;
+
+ /* disable event that reported as not presend by cpuid */
+ for_each_set_bit(bit, x86_pmu.events_mask,
+ min(x86_pmu.events_mask_len, x86_pmu.max_events))
+ intel_perfmon_event_map[intel_event_id_to_hw_id[bit]] = 0;
+
return 0;
}
--
1.7.7.1
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
