To make the fuzzer faster and more effective, the guest memory is
setup with a much smaller size (comparing with other virtio device
fuzzers) and a hole between the memory for holding virtio queue and
the rest of guest data. It brings two benefits: 1) avoid writing large
chunk of data from 'urandom' into the available descriptor chain (which
makes the fuzzer faster); 2) reduce substantial amount of overwrites to
the virtio queue data by the data from 'urandom (which makes the fuzzer
more deterministic and hence effective).
Signed-off-by: Bo Chen <chen.bo@intel.com>
