qemu run debian + use venus kvm libguestfs video accelaration

fetch_debian.sh

#!/bin/bash

# Current Debian stable is 12 (bookworm)
ISO=debian-12.4.0-amd64-netinst.iso
IMG=debian-12.qcow2

if [ ! -f "$ISO" ]; then
  wget https://deb.debian.org/debian/dists/stable/main/installer-amd64/current/images/netboot/mini.iso -O $ISO

  # Alternative full netinst image if mini.iso is too minimal
  # wget https://cdimage.debian.org/debian-cd/current/amd64/iso-cd/debian-12.4.0-amd64-netinst.iso
fi

if [ ! -f "$IMG" ]; then
  qemu-img create -f qcow2 $IMG 16G
fi

qemu-system-x86_64 \
  -enable-kvm \
  -M q35 \
  -smp 4 \
  -m 4G \
  -cpu host \
  -net nic,model=virtio \
  -net user,hostfwd=tcp::2222-:22 \
  -device virtio-vga-gl,hostmem=4G,blob=true,venus=true \
  -vga none \
  -display gtk,gl=on,show-cursor=on \
  -usb -device usb-tablet \
  -object memory-backend-memfd,id=mem1,size=4G \
  -machine memory-backend=mem1 \
  -hda $IMG \
  -cdrom $ISO