Run eBPF Tests with Little VM Helper

Prerequisites

Install qemu-utils:
```
$ sudo apt-get install qemu-utils
```

Build Little VM Helper CLI

Checkout the LVH repo:

$ gh repo clone cilium/little-vm-helper

Build the CLI:
```
$ make little-vm-helper
```

VM image selection and preparation

You can find all available image types here. In this tutorial we use the complexity-test image.

Pull the image:

$ ./lvh images pull quay.io/lvh-images/complexity-test:bpf-net-main --dir /var/tmp/

Resize the image (optional):

$ qemu-img resize /var/tmp/images/complexity-test_bpf-net.qcow2 +16G

VM preparation

Run the VM:

$ ./lvh run --image /var/tmp/images/complexity-test_bpf-net.qcow2 \
      --host-mount <path-to-cilium-repo> \
      --cpu-kind=host \
      --cpu=2 \
      --mem=8G \
      -p 2222:22 \
      --console-log-file=/tmp/lvh-console.log

SSH to the VM:

$ ssh -p 2222 root@localhost
$ resize2fs /dev/vda
$ git config --global --add safe.directory /host
$ apt update && apt install -y -o Dpkg::Options::="--force-confold" xxd docker-buildx-plugin

Run tests

All tests:
```
$ cd /host
$ make run_bpf_tests
```

Specific test:

$ cd /host
$ make run_bpf_tests BPF_TEST="xdp_nodeport_lb4_nat_lb"

Verbose mode:

$ cd /host
$ make run_bpf_tests BPF_TEST_VERBOSE=1

Dump context:

$ cd /host
$ make run_bpf_tests BPF_TEST_DUMP_CTX=1 BPF_TEST_VERBOSE=1