diff options
Diffstat (limited to 'arch/arm64/kvm/pmu-emul.c')
| -rw-r--r-- | arch/arm64/kvm/pmu-emul.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c index 5deddc49e745..491ca7eb2a4c 100644 --- a/arch/arm64/kvm/pmu-emul.c +++ b/arch/arm64/kvm/pmu-emul.c @@ -890,7 +890,17 @@ int kvm_arm_pmu_v3_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) return -EBUSY; if (!kvm->arch.arm_pmu) { - /* No PMU set, get the default one */ + /* + * No PMU set, get the default one. + * + * The observant among you will notice that the supported_cpus + * mask does not get updated for the default PMU even though it + * is quite possible the selected instance supports only a + * subset of cores in the system. This is intentional, and + * upholds the preexisting behavior on heterogeneous systems + * where vCPUs can be scheduled on any core but the guest + * counters could stop working. + */ kvm->arch.arm_pmu = kvm_pmu_probe_armpmu(); if (!kvm->arch.arm_pmu) return -ENODEV; |