wuyifan <[email protected]> writes:
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.
I will fix that.
Thanks, Yifan
