Re: [Qemu-devel] [RFC] reduce reported VGA framebuffer to 8 MiB

[Alon Levy]

On Wed, May 25, 2011 at 05:33:59PM +0300, Alon Levy wrote:
> On Wed, May 25, 2011 at 04:06:03PM +0200, Gerd Hoffmann wrote:
> > On 05/25/11 15:53, Alon Levy wrote:
> > >Without this windows xp guests set a 4 bits per pixel graphics mode.
> > 
> > Hmm?  Never seen this.  Details please.
> 
> When I start a windows xp guest with -vga qxl and no qxl driver installed I 
> get
> a 16 color (4 bits) display mode, you notice it straight away because it's 
> just ugly.
> 
> When I looked at the VBE calls the only difference between the calls done 
> with -vga qxl
> and -vga std seemed to be the reported size (reported in 64K chunks, so for 
> qxl the val
> is 0x400 by default, and for std vga it is 0x80). With this patch windows 
> sets the right
> mode (32 bit color).
> 
> Actually it seems this patch make the qxl driver refuse to load, I'm trying 
> to figure out
> why (or if in fact it's this patch).

It is the patch. An alternative that works with and without qxl driver, and 
fixes the problem
I reported, is to just change the VBE reported ram size to at most VGA_RAM_SIZE 
(== 8MiB).

> 
> > 
> > cheers,
> >   Gerd
> > 
>