Re: [Qemu-devel] Re: [PATCH] spice: add qxl device

[Gerd Hoffmann]

On 11/18/10 09:09, Gleb Natapov wrote:
> On Wed, Nov 17, 2010 at 08:00:08PM +0200, Michael S. Tsirkin wrote:
> > > > >   If so: does qemu
> > > > > emulate this correctly?
> > > >
> > > > It mostly does.
> > >
> > > I doubt it actually enables/disables the legacy vga ports.
> >
> > I'll check when I have the time. We can fix it if it doesn't,
> So many guests (all of them?) just assume that vga ports and
> framebuffer is there. So what "fixing" this will buy us?

Nothing?

Certainly not for the qemu standard vga.  The only way for guests is to 
drive that one is via legacy vga ports and vesa vga bios.  Hotplug is 
never ever going to work here.  Also the vga memory window @ 0xa0000 
with the piix chipset interactions is good for some extra fun ...

cirrus might be fixable to be hotpluggable.  It also can be programmed 
via mmio bar instead of legacy vga ports, so having two cirrus cards in 
one system might be possible to get work.  I doubt it is worth the 
trouble though.

I still think that vga cards should simply be flagged to be not 
hot-pluggable.

cheers,
  Gerd