KVM: x86: flush pending lapic jump label updates on module unload

KVM's lapic emulation uses static_key_deferred (apic_{hw,sw}_disabled).
These are implemented with delayed_work structs which can still be
pending when the KVM module is unloaded. We've seen this cause kernel
panics when the kvm_intel module is quickly reloaded.

Use the new static_key_deferred_flush() API to flush pending updates on
module unload.

Signed-off-by: David Matlack <dmatlack@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/x86.c

@@ -6045,6 +6045,7 @@ out:
 
 void kvm_arch_exit(void)
 {
+	kvm_lapic_exit();
 	perf_unregister_guest_info_callbacks(&kvm_guest_cbs);
 
 	if (!boot_cpu_has(X86_FEATURE_CONSTANT_TSC))