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authorLinus Torvalds <torvalds@linux-foundation.org>2022-01-12 16:26:58 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2022-01-12 16:26:58 -0800
commit8e5b0adeea19309c8ce0e3c9119061554973efa9 (patch)
treecfca61dab75ac07f8651ab0bc33b597707abf5cb /kernel/events
parent13eaa5bda0df8f5c1c4f2a4fb4a0bc20787dcc68 (diff)
parenta9f4a6e92b3b319296fb078da2615f618f6cd80c (diff)
downloadlinux-next-8e5b0adeea19309c8ce0e3c9119061554973efa9.tar.gz
Merge tag 'perf_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf updates from Borislav Petkov: "Cleanup of the perf/kvm interaction." * tag 'perf_core_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Drop guest callback (un)register stubs KVM: arm64: Drop perf.c and fold its tiny bits of code into arm.c KVM: arm64: Hide kvm_arm_pmu_available behind CONFIG_HW_PERF_EVENTS=y KVM: arm64: Convert to the generic perf callbacks KVM: x86: Move Intel Processor Trace interrupt handler to vmx.c KVM: Move x86's perf guest info callbacks to generic KVM KVM: x86: More precisely identify NMI from guest when handling PMI KVM: x86: Drop current_vcpu for kvm_running_vcpu + kvm_arch_vcpu variable perf/core: Use static_call to optimize perf_guest_info_callbacks perf: Force architectures to opt-in to guest callbacks perf: Add wrappers for invoking guest callbacks perf/core: Rework guest callbacks to prepare for static_call support perf: Drop dead and useless guest "support" from arm, csky, nds32 and riscv perf: Stop pretending that perf can handle multiple guest callbacks KVM: x86: Register Processor Trace interrupt hook iff PT enabled in guest KVM: x86: Register perf callbacks after calling vendor's hardware_setup() perf: Protect perf_guest_cbs with RCU
Diffstat (limited to 'kernel/events')
-rw-r--r--kernel/events/core.c41
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,