cpu_claim_irq
extern int cpu_claim_irq(unsigned int irq, struct irq_chip *, void *);
return cpu_claim_irq(irq, NULL, NULL) ? -1 : irq;
if (cpu_claim_irq(irq, NULL, NULL) < 0)
cpu_claim_irq(vi->txn_irq, &iosapic_interrupt_type, vi);
cpu_claim_irq(vi->txn_irq, &iosapic_interrupt_type, vi);