Which Linux Distribution are you using? Modern Linux installations often do not use the elder "ethX" naming scheme anymore.
An example (from my desktop) running ArchLinux:
*-network
description: Ethernet interface
product: Ethernet Connection (5) I219-LM
vendor: Intel Corporation
physical id: 1f.6
bus info: pci@0000:00:1f.6
logical name: eno1
version: 00
serial: d8:9e:f3:33:41:39
size: 1Gbit/s
capacity: 1Gbit/s
width: 32 bits
clock: 33MHz
capabilities: pm msi bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=e1000e driverversion=3.2.6-k duplex=full firmware=0.1-4 ip=192.168.114.138 latency=0 link=yes multicast=yes port=twisted pair speed=1Gbit/s
resources: irq:31 memory:92f00000-92f1ffff
As you can see, the device has got an alias name of "eno1".
You can have a look with tools like dmidecode, lshw, lspci for the specific network device you should configure for your VM.