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

From: Like Xu
Date: Wed Nov 09 2022 - 03:29:21 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>
---
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 a646a5f9a235..15e061fbb2f3 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -6350,6 +6350,7 @@ __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 7839507b3844..185e66b4ce31 100644
--- a/arch/x86/events/intel/ds.c
+++ b/arch/x86/events/intel/ds.c
@@ -2293,8 +2293,10 @@ 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