It's my understanding that 32bit PV vms would run on 64bit hosts with Xen 3.1. However, this doesn't seem to work. Attempting to use virt-install from 64bit using a 32bit source files (over http) dies almost instantly. Creating the 32bit PV vm on a 32-bit system and copying to 64bit also doesn't work (dies at start before even a hint of starting.) Same when migrating a 32bit to a 64 bit (again, dies instantly.) Am I wrong about 32bit on 64bit hosts?