4.16-stable review patch. If anyone has any objections, please let me know.
------------------ From: Kan Liang <[email protected]> [ 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 <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Acked-by: Peter Zijlstra (Intel) <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Sasha Levin <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- 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:
