[PATCH v7 05/20] perf: arm_pmuv3: Check cntr_mask before using pmccntr

Colton Lewis
2026-05-04T21:18:46Z

Check cntr_mask before using pmccntr to ensure it's available. With a
partitioned PMU, there may be instances where pmccntr is being used by
the guest and will ba absent from cntr_mask.

Signed-off-by: Colton Lewis <coltonlewis@google.com>
---
drivers/perf/arm_pmuv3.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/perf/arm_pmuv3.c b/drivers/perf/arm_pmuv3.c
index 1cceb1f614515..7ff3139dda893 100644
--- a/drivers/perf/arm_pmuv3.c
+++ b/drivers/perf/arm_pmuv3.c
@@ -993,6 +993,9 @@ static bool armv8pmu_can_use_pmccntr(struct pmu_hw_events *cpuc,
if (evtype != ARMV8_PMUV3_PERFCTR_CPU_CYCLES)
return false;

+ if (!test_bit(ARMV8_PMU_CYCLE_IDX, cpu_pmu->cntr_mask))
+ return false;
+
/*
* A CPU_CYCLES event with threshold counting cannot use PMCCNTR_EL0
* since it lacks threshold support.
--
2.54.0.545.g6539524ca2-goog