IXGBE_VFRDT
regs_buff[22 + i] = IXGBE_READ_REG(hw, IXGBE_VFRDT(i));
{ IXGBE_VFRDT(0), 2, PATTERN_TEST, 0x0000FFFF, 0x0000FFFF },
IXGBE_WRITE_REG(hw, IXGBE_VFRDT(reg_idx), 0);
ring->tail = adapter->io_addr + IXGBE_VFRDT(reg_idx);