To implement QoS in networks running IPv6, follow the same steps that you would follow to implement QoS in networks running only IPv4.
Create classes based on the criteria you establish
for your network. In particular, if the same network is also carrying
IPv4 traffic along with IPv6, decide if you want to treat both of them
the same way or treat them separately and specify match criteria
accordingly. If you want to treat them the same, use match statements
such as match precedence, match dscp, set precedence, and set dscp. If you want to treat them separately, add match criteria such as match protocol ip and match protocol ipv6 in a match-all class map.
Except for the modifications to the match dscp and match precedence commands and the addition of the IPv6-specific match access-group name command, the functionality of all of the match commands is the same for both IPv4 and IPv6.