[vfio-users] GRUB can use framebuffer, but linux cannot?

[Cepheus]

On my attempts to pass through a GeForce GTX 750 (so far, only
successful with the nouveau driver), I have noticed one common thing
with multiple guest distributions: While I can see and interact with
GRUB 2, I cannot see any text messages as soon as linux takes over. Even
when I edit the kernel command line in GRUB: Remove "quiet", remove
anything "vga" or "video". Set GFXPAYLOAD_LINUX to "text".

Once the X server starts, the desktop shell is working fine (with nouveau).

Is this normal? If not - what could be the problem: Misconfiguration of
the host? Buggy graphics card?

I would like to use SystemRescueCD to test one thing at a time in a
minimal configuration, but I don't get far without framebuffer.

An additional SPICE display confuses the SystemRescueCD's GRUB to the
point of being unusable, and SPICE only won't get me far in finding out
what the problem with the nvidia driver is.

Kai