AFAIK this is not possible with a PIX Firewall and PVLAN. This is due to the inside working way of a PIX that never allow a packet entering from an Interface to Exit from the same interface.
With Canonical VLAN you will need to configure one logical Interface on the PIX for each of the VLAN , this way you'll be able to use the PIX to route packets beetween different VLANs.
Bye
Francesco