kvm: async_pf: fix rcu_irq_enter() with irqs enabled

native_safe_halt enables interrupts, and you just shouldn't
call rcu_irq_enter() with interrupts enabled.  Reorder the
call with the following local_irq_disable() to respect the
invariant.

Reported-by: Ross Zwisler <[email protected]>
Cc: [email protected]
Signed-off-by: Paolo Bonzini <[email protected]>
Acked-by: Paul E. McKenney <[email protected]>
Tested-by: Wanpeng Li <[email protected]>
Signed-off-by: Radim Krčmář <[email protected]>

arch/x86/kernel/kvm.c

@@ -161,8 +161,8 @@ void kvm_async_pf_task_wait(u32 token)
 			 */
 			rcu_irq_exit();
 			native_safe_halt();
-			rcu_irq_enter();
 			local_irq_disable();
+			rcu_irq_enter();
 		}
 	}
 	if (!n.halted)