NIC_PF_MAILBOX_INT
nic_reg_write(nic, NIC_PF_MAILBOX_INT, INTR_MASK(vf_cnt));
nic_reg_write(nic, NIC_PF_MAILBOX_INT + sizeof(u64),
intr = nic_reg_read(nic, NIC_PF_MAILBOX_INT + (mbx << 3));
nic_reg_write(nic, NIC_PF_MAILBOX_INT + (mbx_reg << 3), BIT_ULL(vf));