Qemu-simple

Verified

Setup walkthrough

Basic setup that gets you going, you would still need to read main Qemu documentations for advanced features.

Objective

1. Install Alpine Linux.
2. Install Qemu and its dependencies.
3. Download Alpine Linux ISO and required files.
4. Start a Qemu instance of Alpine Linux ISO.
5. Test basic networking.

Test bed

WIP

• Describe here the test bed/setup used to run the scripts below.

1. MODEL: Dell Laptop.
2. CPU: Intel i5 3rd/4th generation with virtualization enabled.
3. RAM: 8GB

Install Alpine Linux

1. Diskless installs (Ram based)
2. SYS installs

Tip: - For further setup to work correctly, its assumed that Alpine Linux installed in done for version between v3.21.x and v3.22.x

v3.21.x-v3.22.x

Install Qemu and its dependencies (as root)

# apk add qemu qemu-img qemu-system-x86_64 qemu-ui-gtk

# cat /proc/cpuinfo | grep -E 'model name|Processor'

model name	: Intel(R) Core(TM) i5-3340M CPU @ 2.70GHz
...

Cpu is INTEL.

# modprobe kvm_intel # for INTEL cpu

# modprobe kvm_amd # for AMD cpu

# modprobe tun

v3.21.x-v3.22.x

Download Alpine Linux ISO and required files

# cd ~ # wget https://cdn.alpinelinux.org/v3.22/releases/x86_64/alpine-extended-3.22.0-x86_64.iso

Tip: - alpine-extended ISO should be used by new users, other images types i.e alpine-virt and alpine-standard can also be used. Learn and use them as you go. See resource links below.

Start a Qemu instance of Alpine Linux ISO

1. Basic setup (with ssh forwarding)
2. Basic tap setup

v3.21.x-v3.22.x

Basic setup (with ssh forwarding)

#!/bin/sh
## -------------------------------------------------
## Simple setup (manually)
##  no root privileges needed
## QEMU emulator version 10.0.0 (Alpine Linux) ####
## -------------------------------------------------
ISO=alpine-extended-3.22.0-x86_64.iso
qemu-system-x86_64 -enable-kvm -m 2048M -cdrom ${ISO} \
    -device virtio-net,netdev=net0 \
    -netdev user,id=net0,hostfwd=tcp::5555-:22 \
    -nographic -display curses \
    -boot d

## ----
## on GUEST
# ifconfig eth0 10.0.2.15
# route add default gw 10.0.2.2
# busybox ping 10.0.2.2
## assuming your HOST gateway is 192.168.1.1
# echo 'nameserver 192.168.1.1' > /etc/resolv.conf
# busybox ping alpinelinux.org
## -------------------------------------------------

v3.21.x-v3.22.x

Basic tap setup

#!/bin/sh
## -------------------------------------------------
## Manual setup with defaults and no preset scripts
## Works in root
## QEMU emulator version 10.0.0+ (Alpine Linux) ####
## modprobe tun # needed if not loaded already
## -------------------------------------------------
ISO=alpine-extended-3.22.0-x86_64.iso
qemu-system-x86_64 -enable-kvm -m 2048M -cdrom ${ISO} \
    -device virtio-net,netdev=nd0 \
    -netdev tap,id=nd0,ifname=tap0,script=no,downscript=no \
    -nographic -display curses \
    -boot d

## ----
## on HOST (after QEMU has booted)
# ifconfig tap0 10.0.2.2
## on GUEST
# ifconfig eth0 10.0.2.15
# route add default gw 10.0.2.2
## ----
## TEST (HOST) - IMPORTANT: remove firewall if any
# nc -l 1234 > filename.out
## TEST (GUEST)
# echo -e "aaa\nbbb" > test.txt
# nc 10.0.2.2 1234 < test.txt
## TEST (HOST)
# cat filename.out
## -------------------------------------------------

See also

• LXC_Alpinelinux_Simple

Resources

1. https://docs.alpinelinux.org/user-handbook/0.1a/Installing/medium.html#_image_type
2. https://wiki.alpinelinux.org/wiki/QEMU
3. https://wiki.alpinelinux.org/wiki/KVM
4. https://wiki.qemu.org/Documentation/Networking#How_to_get_SSH_access_to_a_guest
5. https://www.qemu.org/docs/master/system/invocation.html#hxtool-5
6. https://manned.org/pkg/alpine-3.22/qemu-doc