Comment # 1 on bug 1127552 from Takashi Iwai

BTW, the behavior on KVM isn't seen as default for non-EFI BIOS boot just
because the kernel spews an error message ("efi: EFI_MEMMAP is not enabled") at
the beginning, and fbcon appears immediately before starting the plymouth.

But after turning this error off, KVM really shows only the garbage for the
plymouth boot splash, then jumps to the X screen.  After switch back to VT1
(via "chvt 1"), the fbcon still doesn't appear and the window remains blank
until you hit some key.  That's really odd.