xe-vm-mode.sh

#!/bin/bash

readonly SUPPORTED_MODES="pv hvm"

ERROREXIT () {
  cat <<EOD

  ERROR! $2
  Aborting.

EOD
  exit $1
}

PV_mode () {
  printf "\n * Disabling HVM Boot Policy"
  xe vm-param-clear uuid=$vmuuid  param-name=HVM-boot-policy

  printf "\n * Activating pygrub PV bootloader"
  xe vm-param-set   uuid=$vmuuid  PV-bootloader=pygrub

  printf "\n * Configuring pygrub PV bootloader: $kernel $ramdisk"
  xe vm-param-set   uuid=$vmuuid  PV-bootloader-args="$kernel $ramdisk"

  printf "\n * Configuring kernel args: $kernelparam $mainconsole $xenconsole"
  xe vm-param-set   uuid=$vmuuid  PV-args="$kernelparam $mainconsole $xenconsole"

  printf "\n * Setting VBD bootable"
  xe vbd-param-set  uuid=$vbduuid bootable=true
}

HVM_mode () {
  printf "\n * Enabling HVM Boot Policy"
  xe vm-param-set   uuid=$vmuuid  HVM-boot-policy="BIOS order"

  printf "\n * Deactivating PV bootloader"
  xe vm-param-clear uuid=$vmuuid  param-name=PV-bootloader

  printf "\n * Erasing PV bootloader settings"
  xe vm-param-clear uuid=$vmuuid  param-name=PV-bootloader-args
  xe vm-param-clear uuid=$vmuuid  param-name=PV-args
}

Nothing_To_Do () {
  printf "\n * Nothing to do."
}

if [[ -z "$2" ]]; then
  cat <<EOD

Syntax: xe-vm-mode MODE FILE

MODE
  pv  : change into PV mode
  hvm : change into

FILE
  Contains the VM description. The fields in this file are:

  vmname      (R) Partial name of the VM
  kernelpath  (R) Full path to the kernel
  initrdpath  (R) Full path to the initrd
  kernelparam (O) Options to be passed to the kernel. No default.
  consolename (O) The console output to be captured. Defaults to "hvc0"

  (R) = Required, (O) = Optional

EOD
fi

mode="$1"
found=0
for m in $SUPPORTED_MODES; do
  [[ $m == "$mode" ]] && found=1
done
[[ $found == "0" ]] && ERROREXIT 1 "Unknown mode: $mode"


if ! [[ -f "$2" ]]; then
  ERROREXIT 2 "File not found: $2"
fi

while read field value; do
  [[ -z $field ]] && continue
  [[ ${field:0:1} == "#" ]] && continue
  case $field in
    vmname)
      vmname="$value"
      ;;
    kernelpath)
      kernel="--kernel=$value"
      ;;
    initrdpath)
      ramdisk="--ramdisk=$value"
      ;;
    kernelparam)
      kernelparam="$value"
      ;;
    consolename)
      consolename="$value"
      ;;
  esac
done < $2

[[ -z "$vmname" ]]  && ERROREXIT 3 "File $2 does not contain the 'vmname' field."
[[ -z "$kernel" ]]  && ERROREXIT 3 "File $2 does not contain the 'kernelpath' field."
[[ -z "$ramdisk" ]] && ERROREXIT 3 "File $2 does not contain the 'initrcpath' field."

[[ -z "$consolename" ]] && consolename="hvc0"
mainconsole="console=$consolename"
xenconsole="xencons=$consolename"

## All checking done. Now for some heavylifting.

printf "\n"

vmlist="$(xe vm-list | awk -v vm="$vmname" '$0 ~ vm {for (i=4; i<=NF; i++) {printf "%s ",$i} print ""}')"
(( $(echo $vmlist | wc -l) > 1 )) && ERROREXIT 5 "Found more than 1 VM matching $partialname:
$vmlist"

printf "\n * Found VM: $vmlist"

vmuuid="$(xe vm-list | awk -v vm="$vmname" '/uuid/ {uuid=$5} $0 ~ vm && !/Control domain/ {printf "%s",uuid}')"
printf "\n * Found VM-UUID: $vmuuid"

vbduuid="$(xe vm-disk-list uuid=$vmuuid | awk '/VBD/ {vbd=1} vbd && $1=="uuid" {print $NF; vbd=0}')"
printf "\n * Found VBD-UUID: $vbduuid"

case $mode in
  pv)  PV_mode  ;;
  hvm) HVM_mode ;;
esac

printf "\n * DONE"
printf "\n\n"

exit 0