The goal was to use kvm-pr mode and use powerpc at full speed.
With a Sam460ex it was not possible due it's book3e cpu.
You can configure arbitrary CPU while using QEmu. I often use 750cxe and 7448 when testing (this is in combination with -machine mac99). I don't know how kvm-pr works exactly but it'd be mighty silly if it would somehow restrict the emulated CPU type.
There would not be any emulation of CPU as same (PowerPC) CPU which runs Qemu natively would run MorphOS natively (through Qemu). Like VirtualBox + co. in x86 world. Or AROS/hosted on Linux.