make fbdev/fbcon switchable per driver?

[Gerd Hoffmann]

  Hi,

> The vgaarb code has a concept of a vga_default_device(), it's rather
> PCI-centric, but maybe better than nothing.  This is typically the
> first VGA class code device found with I/O and MMIO enabled.  If fbcon
> defaulted to running on the vga_default_device(), a user could select
> which to use by re-ordering the VM hardware.

The qemu drivers don't register as vgaarb clients though.  Which easily
explains why igd always wins the primary selection, no matter how you
order your hardware.

So, should they register?  The drivers don't need access to the vga
registers[1][2].

cheers,
  Gerd

[1] Well, except cirrus, but that is deprecated anyway.
[2] And bochs-drm, when running on old qemu versions, where the
    stdvga has no mmio bar yet.  But those qemu versions don't
    support igd pass-through.