fix: KVM flag (#504)

: ${CPU_MODEL:='host'}

: ${CPU_FEATURES:='+ssse3,+sse4.1,+sse4.2'}

KVM_ERR=""

KVM_OPTS=""

[ "$ARCH" != "amd64" ] && KVM="N"

if [[ "$ARCH" == "amd64" && "$KVM" != [Nn]* ]]; then

if [[ "$KVM" != [Nn]* ]]; then

  KVM_ERR=""

  if [ -e /dev/kvm ] && sh -c 'echo -n > /dev/kvm' &> /dev/null; then

    if ! grep -q -e vmx -e svm /proc/cpuinfo; then

  fi

  if [ -n "$KVM_ERR" ]; then

    KVM="N"

    error "KVM acceleration not detected $KVM_ERR, this will cause a major loss of performance."

    error "See the FAQ on how to enable it, or skip this error by setting KVM=N (not recommended)."

    error "See the FAQ on how to enable it, or continue without KVM by setting KVM=N (not recommended)."

    [[ "$DEBUG" != [Yy1]* ]] && exit 88

    [[ "$CPU_MODEL" == "host"* ]] && CPU_MODEL="max,$CPU_FEATURES"

  else

    KVM_OPTS=",accel=kvm -enable-kvm"

  fi

  if [ -n "$KVM_OPTS" ]; then

fi

if [[ "$KVM" != [Nn]* ]]; then

  KVM_OPTS=",accel=kvm -enable-kvm"

  if ! grep -qE '^flags.* (sse4_2)' /proc/cpuinfo; then

    error "Your host CPU does not have the SSE4.2 instruction set that Virtual DSM requires to boot."

    error "Disable KVM by setting KVM=N to emulate a compatible CPU, at the cost of performance."

    [[ "$DEBUG" != [Yy1]* ]] && exit 89

  fi

  fi

else

  KVM_OPTS=""

  if [[ "$CPU_MODEL" == "host"* ]]; then

    if [[ "$ARCH" == "amd64" ]]; then

      CPU_MODEL="max,$CPU_FEATURES"