Hi Colton,
On 5/5/2026 5:18 AM, Colton Lewis wrote:
static irqreturn_t armv8pmu_handle_irq(struct arm_pmu *cpu_pmu)
{
- u64 pmovsr;
struct perf_sample_data data;
struct pmu_hw_events *cpuc = this_cpu_ptr(cpu_pmu->hw_events);
struct pt_regs *regs;
+ u64 host_set = kvm_pmu_host_counter_mask(cpu_pmu);
+ u64 pmovsr;
kvm_pmu_host_counter_mask() is called from armv8pmu_handle_irq(). This
interrupt fires in both host and guest contexts.
However, kvm_pmu_host_counter_mask() dereferences
host_data_ptr(nr_event_counters). This indirection requires
kvm_arm_hyp_percpu_base[cpu] to be initialized, which only happens during
KVM hypervisor setup. When the interrupt fires in a guest kernel where
KVM is
compiled but not active, the per-CPU base is NULL and the dereference
faults.
Thanks,
Yifan
