Re: [Qemu-devel] [PATCH 6/6] kvm: qemu: fix vga screendump

[Anthony Liguori]

andrzej zaborowski wrote:
> 2008/7/20 Anthony Liguori <address@hidden>:
>   
> With -no-graphic there's no ds->data, or it can have lower bpp than
> what's otherwise available.
>   

Screen dumping with -no-graphic probably should just show a black screen 
anyway.

I don't think a lower depth is really that big of a deal.  It's what the 
user would be seeing anyway.  The simplicity seems really nice to me.

> > I think your patch looks better, but I can also code up a new screen dumping
> > mechanism that doesn't take over DisplayState unless I'm missing something
> > obvious.
> >     
>
> It's worth a try, dumping ds->data is perhaps the way to go but
> ds->depth is being set to 32bit and various video cards are optimised
> on the assumption that ds->depth doesn't change, so maybe there should
> be a notification callback.
>   

Yeah, that's a bug BTW and AFAIK it's only a problem with VMware VGA.  
There's nothing that keeps ds->depth from changing after a screen resize 
with SDL.  If a VNC client does SetPixelFormat that will also change 
ds->depth.  Right now, some VNC clients + VMware VGA will cause a SEGV 
because of the assumptions that ds->depth doesn't change.

Regards,

Anthony Liguori

> Regards
>
>
>