[mschuster91]

> Think about eg. randomness of ordering in PCIe bus (i.e. after moving the devices may not come up in the same order as before moving), various machine ids, like MAC address -- if you don't make sure VM isn't affected by these changes, it's likely that it will be, if moved.

QEMU/KVM/libvirt/... are idempotent when it comes to hardware the VM sees - the exception is the CPU model, that one can't be changed on the fly without at least rebooting the VM in question, and hardware in passthrough mode like GPUs.

All the VM sees from a live migration is a few seconds of "lost" time, as if someone had stopped the CPU clock.