Index: kernel/arch/mips32/src/drivers/msim.c
===================================================================
--- kernel/arch/mips32/src/drivers/msim.c	(revision 7688b5d81bb7cda5ecfe3b596ada34a7472b02f2)
+++ kernel/arch/mips32/src/drivers/msim.c	(revision 8440473178e7f4ea175a5f64b0436319e6fee652)
@@ -121,11 +121,19 @@
 void msim_kbd_grab(void)
 {
+	ipl_t ipl = interrupts_disable();
+	spinlock_lock(&msim_irq.lock);
 	msim_irq.notif_cfg.notify = false;
+	spinlock_unlock(&msim_irq.lock);
+	interrupts_restore(ipl);
 }
 
 void msim_kbd_release(void)
 {
+	ipl_t ipl = interrupts_disable();
+	spinlock_lock(&msim_irq.lock);
 	if (msim_irq.notif_cfg.answerbox)
 		msim_irq.notif_cfg.notify = true;
+	spinlock_unlock(&msim_irq.lock);
+	interrupts_restore(ipl);
 }