[Spice-devel] qxl and page flip

[Frediano Ziglio]

> 
> Hi,
> 
> > Switching the qxl kms driver to use a scratchpad model too should be
> > easy for userspace apps not using qxl ioctls (i.e. basically
> > everything
> > but xorg-x11-drv-qxl).  Just use the vga memory region (start of pci
> > bar 0) as scratchpad, then we can safely use framebuffer blits for
> > display updates.  The tricky part here is to not break xorg-x11-drv-
> > qxl.
> 
> Looks workable.  On a quick glance it seems to be as simple as handling
> dumb buffers in a different way, because xorg-x11-drv-qxl doesn't use
> dumb buffers but allocates objects using qxl ioctls instead.
> 
> I'll go investigate more next week.
> 
> cheers,
>   Gerd
> 

Why extending QXL protocol is not worth doing but writing workaround
on workaround is?

By the way, on option is to allocate memory, do any drawing then
build a new offscreen surface (with KEEP_DATA flag) on the allocated
memory and execute a draw from the offscreen surface to the primary one.

Frediano