How to set rDNS record for ipv6 address block?

Occasionally, I open a ticket at my VPS provider to let them create a rDNS record for me. Sometimes, I can find a page in my control panel to add the rDNS record myself. This is simple for ipv4 address. I just input an ip address and a domain name to create the rDNS record. I wonder how to add rDNS record for a block of ipv6 addresses such as a 2^64 address block. Do I have to add 2^64 rDNS records each mapping an ipv6 address to a domain? Can I have one record to map the whole address block to the same domain?