[PATCH RESEND v3 3/3] perf/x86/intel: Expose EPT-friendly PEBS for SPR and future models

From: Like Xu
Date: Tue Dec 06 2022 - 03:30:38 EST


From: Like Xu <likexu@xxxxxxxxxxx>

According to Intel SDM, the EPT-friendly PEBS is supported by all the
platforms after ICX, ADL and the future platforms with PEBS format 5.

Currently the only in-kernel user of this capability is KVM, which has
very limited support for hybrid core pmu, so ADL and its successors do
not currently expose this capability. When both hybrid core and PEBS
format 5 are present, KVM will decide on its own merits.

Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: linux-perf-users@xxxxxxxxxxxxxxx
Suggested-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Signed-off-by: Like Xu <likexu@xxxxxxxxxxx>
Reviewed-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
Nit: This change is proposed to be applied via the KVM tree.

arch/x86/events/intel/core.c | 1 +
arch/x86/events/intel/ds.c | 4 +++-
2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index 1b92bf05fd65..e7e31b9d24d3 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -6351,6 +6351,7 @@ __init int intel_pmu_init(void)
x86_pmu.pebs_constraints = intel_spr_pebs_event_constraints;
x86_pmu.extra_regs = intel_spr_extra_regs;
x86_pmu.limit_period = spr_limit_period;
+ x86_pmu.pebs_ept = 1;
x86_pmu.pebs_aliases = NULL;
x86_pmu.pebs_prec_dist = true;
x86_pmu.pebs_block = true;
diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
index 446d2833efa7..7258dca6882f 100644
--- a/arch/x86/events/intel/ds.c
+++ b/arch/x86/events/intel/ds.c
@@ -2303,8 +2303,10 @@ void __init intel_ds_init(void)
x86_pmu.large_pebs_flags |= PERF_SAMPLE_TIME;
break;

- case 4:
case 5:
+ x86_pmu.pebs_ept = 1;
+ fallthrough;
+ case 4:
x86_pmu.drain_pebs = intel_pmu_drain_pebs_icl;
x86_pmu.pebs_record_size = sizeof(struct pebs_basic);
if (x86_pmu.intel_cap.pebs_baseline) {
--
2.38.1