Reticulum-Go/microvm/README.md

Reticulum-Go MicroVM

Minimal Firecracker microVM setup for running Reticulum-Go.

Prerequisites

• Firecracker binary installed
• Go compiler
• Root privileges (for network setup and KVM access)
• Linux host system with KVM support
• Access to /dev/kvm

Important: Nested Virtualization

If running inside a QEMU/KVM VM, nested virtualization must be enabled:

1. Host QEMU configuration: Start your QEMU VM with nested KVM:

   qemu-system-x86_64 -cpu host -enable-kvm -machine q35,accel=kvm ...
   

2. Enable nested KVM on host (if not already):

   # Check if nested is enabled
   cat /sys/module/kvm_intel/parameters/nested  # Intel
   cat /sys/module/kvm_amd/parameters/nested    # AMD
   
   # Enable nested (Intel)
   echo "options kvm_intel nested=1" | sudo tee /etc/modprobe.d/kvm.conf
   
   # Enable nested (AMD)
   echo "options kvm_amd nested=1" | sudo tee /etc/modprobe.d/kvm.conf
   
   # Reboot host
   

3. Inside the VM, check if /dev/kvm exists:

   ls -l /dev/kvm
   

Alternative: If nested virtualization isn't available, consider:

• Running Firecracker directly on the host machine
• Using QEMU directly instead of Firecracker
• Using Docker/LXC containers instead

KVM Setup

Ensure your user has access to /dev/kvm:

# Check if /dev/kvm exists
ls -l /dev/kvm

# Add your user to the kvm group (recommended)
sudo usermod -aG kvm $USER

# Or set ACL (alternative)
sudo setfacl -m u:$USER:rw /dev/kvm

# Log out and back in for group changes to take effect

Setup

Run the setup script:

./setup.sh

This will:

• Check for Firecracker installation
• Download vmlinux.bin kernel
• Build Reticulum-Go binary
• Create rootfs.ext4 disk image
• Generate firecracker-config.json

Running

1. Create tap interface:

sudo ip tuntap add tap0 mode tap
sudo ip addr add 172.16.0.1/24 dev tap0
sudo ip link set tap0 up

2. Enable IP forwarding:

sudo sysctl -w net.ipv4.ip_forward=1

3. Start Firecracker:

# Clean up any old socket files first
rm -f /tmp/firecracker.sock microvm/vsock.sock

firecracker --api-sock /tmp/firecracker.sock --config-file firecracker-config.json

4. Connect to console (in another terminal):

firecracker --api-sock /tmp/firecracker.sock

Configuration

• CPU: 1 vCPU
• Memory: 128 MiB
• Network: tap0 interface
• Disk: rootfs.ext4 (100MB)

Modify firecracker-config.json to adjust resources.

Files

• vmlinux.bin - Linux kernel
• rootfs.ext4 - Root filesystem with binary
• firecracker-config.json - Firecracker configuration
• reticulum-go - Compiled binary