diff options
Diffstat (limited to 'kernel/events/core.c')
| -rw-r--r-- | kernel/events/core.c | 41 |
1 files changed, 29 insertions, 12 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 1362b9b770d8..fc18664f49b0 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6525,26 +6525,43 @@ static void perf_pending_event(struct irq_work *entry) perf_swevent_put_recursion_context(rctx); } -/* - * We assume there is only KVM supporting the callbacks. - * Later on, we might change it to a list if there is - * another virtualization implementation supporting the callbacks. - */ -struct perf_guest_info_callbacks *perf_guest_cbs; +#ifdef CONFIG_GUEST_PERF_EVENTS +struct perf_guest_info_callbacks __rcu *perf_guest_cbs; + +DEFINE_STATIC_CALL_RET0(__perf_guest_state, *perf_guest_cbs->state); +DEFINE_STATIC_CALL_RET0(__perf_guest_get_ip, *perf_guest_cbs->get_ip); +DEFINE_STATIC_CALL_RET0(__perf_guest_handle_intel_pt_intr, *perf_guest_cbs->handle_intel_pt_intr); -int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) +void perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) { - perf_guest_cbs = cbs; - return 0; + if (WARN_ON_ONCE(rcu_access_pointer(perf_guest_cbs))) + return; + + rcu_assign_pointer(perf_guest_cbs, cbs); + static_call_update(__perf_guest_state, cbs->state); + static_call_update(__perf_guest_get_ip, cbs->get_ip); + + /* Implementing ->handle_intel_pt_intr is optional. */ + if (cbs->handle_intel_pt_intr) + static_call_update(__perf_guest_handle_intel_pt_intr, + cbs->handle_intel_pt_intr); } EXPORT_SYMBOL_GPL(perf_register_guest_info_callbacks); -int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) +void perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *cbs) { - perf_guest_cbs = NULL; - return 0; + if (WARN_ON_ONCE(rcu_access_pointer(perf_guest_cbs) != cbs)) + return; + + rcu_assign_pointer(perf_guest_cbs, NULL); + static_call_update(__perf_guest_state, (void *)&__static_call_return0); + static_call_update(__perf_guest_get_ip, (void *)&__static_call_return0); + static_call_update(__perf_guest_handle_intel_pt_intr, + (void *)&__static_call_return0); + synchronize_rcu(); } EXPORT_SYMBOL_GPL(perf_unregister_guest_info_callbacks); +#endif static void perf_output_sample_regs(struct perf_output_handle *handle, |