Support enhanced networking for Ubuntu based AMIs

[gyuho]

https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/enhanced-networking-ena.html#enhanced-networking-ena-ubuntu

[gyuho]

We can either build an AMI with ENA driver installed, or dynamically install the ENA driver on boot (we may need instance restart?)

[gyuho]

Looks like the latest instance types already supports ENA

c6a.4xlarge output:

+ modinfo ena
filename:       /lib/modules/5.15.0-1038-aws/kernel/drivers/net/ethernet/amazon/ena/ena.ko
license:        GPL
description:    Elastic Network Adapter (ENA)
author:         Amazon.com, Inc. or its affiliates
srcversion:     2BE1C05612C2C8D11204F83
alias:          pci:v00001D0Fd0000EC21sv*sd*bc*sc*i*
alias:          pci:v00001D0Fd0000EC20sv*sd*bc*sc*i*
alias:          pci:v00001D0Fd00001EC2sv*sd*bc*sc*i*
alias:          pci:v00001D0Fd00000EC2sv*sd*bc*sc*i*
alias:          pci:v00001D0Fd00000051sv*sd*bc*sc*i*
depends:
retpoline:      Y
intree:         Y
name:           ena
vermagic:       5.15.0-1038-aws SMP mod_unload modversions
sig_id:         PKCS#7
signer:         Build time autogenerated kernel key
sig_key:        2B:D6:81:3D:B7:2B:73:E7:BE:8D:D3:F5:5E:44:8B:A5:01:94:4E:2E
sig_hashalgo:   sha512

aws ec2 describe-instances --region us-west-2 --instance-ids i-0caf14766586e8ea2 --query 'Reservations[].Instances[].EnaSupport'
[
    true
]

[gyuho]

$ ethtool -i ens5
driver: ena
version: 5.15.0-1038-aws
firmware-version:
expansion-rom-version:
bus-info: 0000:00:05.0
supports-statistics: yes
supports-test: no
supports-eeprom-access: no
supports-register-dump: no
supports-priv-flags: no