SFP+ 10GbE Module Interface
Maybe these diagrams will help. It looks like XGMII is implemented between the mac and packet processor.


Source: https://4donline.ihs.com/images/VipMasterIC/IC/TXII/TXIIS100070/TXIIS182093-1.pdf?hkey=EC6BD57738AE6E33B588C5F9AD3CEFA7
Another good datasheet is this one: https://www.renesas.com/us/en/www/doc/datasheet/bbt3420.pdf