Please look at the P2020 QorIQ Integrated Processor Hardware Specifications, Table 6. I/O Power Supply Estimated Values.
Here you can find the power consumption of SERDES for different protocols. Actually XVDD (1.05 V) means here XVDD+SVDD (1.05 V).
On both P2020DS and P2020RBD we use the VDD core power 1,05V for both SVDD and XVDD.