When there is only console=hvc0 (i.e. no output to emulated VGA) and
GRUB_TIMEOUT is set to 0, VM startup hangs. This may be very well some
race condition broken by either of console=tty0 or GRUB_TIMEOUT > 0, but
even in such a case, apply this as a workaround for now.
This configuration isn't included twice - it's Debian post-installation
script of grub that copy settings to /etc/default/grub, which results in
parameters being duplicated. Leave it as is for now.
Add GRUB_TIMEOUT=0 for faster VM startup.
QubesOS/qubes-issues#2577
Qubes VM require few config options in grub. Ship appropriate
configuration. Debian have grub.d support, so it can be done cleanly.
On Fedora, /etc/default/grub needs to be modified. Still keep the
options in separate file, but include it manually from
/etc/default/grub.
QubesOS/qubes-issues#2577
