[PATCH 4.14 065/189] perf/x86/intel: Dont enable freeze-on-smi for PerfMon V1

Greg Kroah-Hartman
2018-06-18T08:32:02Z

From: Kan Liang <kan.liang@linux.intel.com>

[ Upstream commit 4e949e9b9d1e3edcdab3b54656c5851bd9e49c67 ]

The SMM freeze feature was introduced since PerfMon V2. But the current
code unconditionally enables the feature for all platforms. It can
generate #GP exception, if the related FREEZE_WHILE_SMM bit is set for
the machine with PerfMon V1.

To disable the feature for PerfMon V1, perf needs to
- Remove the freeze_on_smi sysfs entry by moving intel_pmu_attrs to
intel_pmu, which is only applied to PerfMon V2 and later.
- Check the PerfMon version before flipping the SMM bit when starting CPU

Fixes: 6089327f5424 ("perf/x86: Add sysfs entry to freeze counters on SMI")
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: ak@linux.intel.com
Cc: eranian@google.com
Cc: acme@redhat.com
Link: https://lkml.kernel.org/r/1524682637-63219-1-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/x86/events/intel/core.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -3331,7 +3331,8 @@ static void intel_pmu_cpu_starting(int c

cpuc->lbr_sel = NULL;

- flip_smm_bit(&x86_pmu.attr_freeze_on_smi);
+ if (x86_pmu.version > 1)
+ flip_smm_bit(&x86_pmu.attr_freeze_on_smi);

if (!cpuc->shared_regs)
return;
@@ -3494,6 +3495,8 @@ static __initconst const struct x86_pmu
.cpu_dying = intel_pmu_cpu_dying,
};

+static struct attribute *intel_pmu_attrs[];
+
static __initconst const struct x86_pmu intel_pmu = {
.name = "Intel",
.handle_irq = intel_pmu_handle_irq,
@@ -3524,6 +3527,8 @@ static __initconst const struct x86_pmu
.format_attrs = intel_arch3_formats_attr,
.events_sysfs_show = intel_event_sysfs_show,

+ .attrs = intel_pmu_attrs,
+
.cpu_prepare = intel_pmu_cpu_prepare,
.cpu_starting = intel_pmu_cpu_starting,
.cpu_dying = intel_pmu_cpu_dying,
@@ -3902,8 +3907,6 @@ __init int intel_pmu_init(void)

x86_pmu.max_pebs_events = min_t(unsigned, MAX_PEBS_EVENTS, x86_pmu.num_counters);

-
- x86_pmu.attrs = intel_pmu_attrs;
/*
* Quirk: v2 perfmon does not report fixed-purpose events, so
* assume at least 3 events, when not running in a hypervisor: