cmdlib: Explain to people they can set `COSA_NO_KVM`
It's OK, it will just be slow.  In some cases e.g. "I just want
to inject some kernel arguments in a custom AMI building from a Mac",
the performance hit is OK.
@@ -105,7 +105,7 @@ preflight_kvm() {
if test -z "${COSA_NO_KVM:-}"; then
if ! test -c /dev/kvm; then
- fatal "Missing /dev/kvm"
+ fatal "Missing /dev/kvm; you can set COSA_NO_KVM=1 to bypass this at the cost of performance."
fi
if ! [ -w /dev/kvm ]; then
if ! has_privileges; then
