[RFC PATCH 13/14] KVM: arm64: Advertise 0 event counters for IMPDEF PMU

Oliver Upton posted 14 patches 1 year ago
There is a newer version of this series
[RFC PATCH 13/14] KVM: arm64: Advertise 0 event counters for IMPDEF PMU
Posted by Oliver Upton 1 year ago
The programmable event counters on Apple M* parts are quite different
from what's available in PMUv3, as the event counters aren't fungible
(some events only work on specific counters) and the event ID space
doesn't match the architecture.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
---
 arch/arm64/kvm/pmu-emul.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c
index 34d9c08af209..8ac4eee781c9 100644
--- a/arch/arm64/kvm/pmu-emul.c
+++ b/arch/arm64/kvm/pmu-emul.c
@@ -1044,6 +1044,9 @@ u8 kvm_arm_pmu_get_max_counters(struct kvm *kvm)
 {
 	struct arm_pmu *arm_pmu = kvm->arch.arm_pmu;
 
+	if (cpus_have_final_cap(ARM64_WORKAROUND_PMUV3_IMPDEF_TRAPS))
+		return 0;
+
 	/*
 	 * The arm_pmu->cntr_mask considers the fixed counter(s) as well.
 	 * Ignore those and return only the general-purpose counters.
-- 
2.39.5