Protocols used for migration

[linux user <linuxuser26@xxxxxxxxx>]

Hi all,

I'd like to know what are the different protocols used for migration of 
KVM guests on RHEL hosts.I'm actually interested in 'virsh dump' and 
virsh dump executes the qemu 'migrate' command.I understand 'exec' is 
one of the protocols.
Appreciate any pointers.

For eg:(qemu) migrate -d "exec:cat >'/tmp/vm'"

Thanks,
Marc