KVM_ARM_IRQ_NUM_MASK
irq_num = (irq >> KVM_ARM_IRQ_NUM_SHIFT) & KVM_ARM_IRQ_NUM_MASK;
if (intid > KVM_ARM_IRQ_NUM_MASK)
irq = FIELD_PREP(KVM_ARM_IRQ_NUM_MASK, 3);
u32 irq = intid & KVM_ARM_IRQ_NUM_MASK;