Comment 37 for bug 513273

On Fri, Apr 2, 2010 at 10:20 PM, Steve Langasek
<email address hidden> wrote:
> What is the risk of regression here by downgrading?  Is use of vgabios
> entirely broken today for all users to where things can only get better,
> or are there some cases where it works?

The only users positively affected by the new upload are those that
want to use kvm or qemu with the -vga std option. This VGA mode adds
higher resolutions to the SDL window than the default cirrus driver
(which only allows up to 1024x768). I can confirm that the current
vgabios is broken for -vga std, and is working with the pending
upload.

Most users of kvm/qemu either don't use SDL at all (ie, they are using
virt-manager, virsh, or Eucalyptus to launch VMs), and of the
remaining users that do launch KVM from the command line and SDL, most
of those are probably just using the default cirrus driver. Thus, I
suspect that the affect users of this problem are a vocal minority.

That said, I would love to see this fixed for them. Anyone who
launches KVM directly from the command line, and toys around with the
obscure QEMU options are a friend to me, as they're helping test the
dark corners of qemu-kvm.

I have seen no negative effects thus far of "downgrading" vgabios.
And I really, really, really like the idea of being code-identical
with the vgabios that upstream QEMU released with qemu 0.12.3, as our
support burden is shared.

That said, if we upload this, and the "majority" of qemu/kvm users
(those not using -vga std) are negatively affect, I'm perfectly fine
with reverting this change in a heartbeat, and asking someone to track
down the precise part of the diff that causes/fixes the current issue.

> vgabios has two reverse-dependencies in lucid: qemu-common and bochs.
> Has anyone regression-tested this for bochs?

I suspect that the bochs package can possibly be dropped from the
archive. I think qemu was the only user of bochs previously, and
upstream QEMU has switched away from bochs to seabios and vgabios
instead. This needs to be investigated a bit more (perhaps a post on
ubuntu-devel, in case anyone else knows of what in Lucid might still
require bochs.

:-Dustin