#!/bin/bash
# Check which virtualization technology to use
# We prefer kvm, kqemu, userspace in that order.

export PATH=/usr/sbin:/usr/bin:/sbin:/bin
QEMU_CPU="${QEMU_CPU:-max}"

[[ -x /usr/bin/qemu ]] && BIN=/usr/bin/qemu && ARGS=(-cpu "$QEMU_CPU")
(lsmod | grep -q '^kqemu ') && BIN=/usr/bin/qemu && ARGS=(-kernel-kqemu -cpu host)
[[ -c /dev/kvm && -x /usr/bin/kvm ]] && BIN=/usr/bin/kvm && ARGS=(-cpu host)
[[ -c /dev/kvm && -x /usr/bin/qemu-kvm ]] && BIN=/usr/bin/qemu-kvm && ARGS=(-cpu host)
[[ -c /dev/kvm && -x /usr/libexec/qemu-kvm ]] && BIN=/usr/libexec/qemu-kvm && ARGS=(-cpu host)
[[ -x /usr/bin/qemu-system-$(uname -m) ]] && BIN=/usr/bin/qemu-system-$(uname -m) && ARGS=(-cpu "$QEMU_CPU")
[[ -c /dev/kvm && -x /usr/bin/qemu-system-$(uname -m) ]] && BIN=/usr/bin/qemu-system-$(uname -m) && ARGS=(-enable-kvm -cpu host)

[[ $BIN ]] || {
    echo "Could not find a working KVM or QEMU to test with!" >&2
    echo "Please install kvm or qemu." >&2
    exit 1
}

# Provide rng device sourcing the hosts /dev/urandom and other standard parameters
ARGS+=(-M q35 -smp 2 -m 512 -nodefaults -vga none -display none -no-reboot -device virtio-rng-pci)

if ! [[ $* == *-daemonize* ]] && ! [[ $* == *-daemonize* ]]; then
    ARGS+=(-serial stdio)
fi

KVERSION=${KVERSION-$(uname -r)}

VMLINUZ="/lib/modules/${KVERSION}/vmlinuz"

if ! [ -f "$VMLINUZ" ]; then
    [[ -f /etc/machine-id ]] && read -r MACHINE_ID < /etc/machine-id

    if [[ $MACHINE_ID ]] && { [[ -d /boot/${MACHINE_ID} ]] || [[ -L /boot/${MACHINE_ID} ]]; }; then
        VMLINUZ="/boot/${MACHINE_ID}/$KVERSION/linux"
    else
        VMLINUZ="/boot/vmlinuz-${KVERSION}"
    fi
fi

exec "$BIN" "${ARGS[@]}" -kernel "$VMLINUZ" "$@"