[Spice-devel] A question about QXL

[Frediano Ziglio]

> 
> Hi experts,
> 
>   Recently I’m studying QXL XDDM driver to see how the display are
>   accelerated.
> 
>   One thing I do not understand is that I thought some updates should be
>   missing on clients.
>   Say in the implementation of DrvBitBlt function, if it is not supported.
>   the implemention will punt to EngBitBlt.
> 
>   However, in such case, no QXL command is pushed to cmd ring. So how does
>   spice client notice the frame buffer change
> made by EngBitBlt?
> 
>   Can anyone help provide guidance on this?
> 
>   Thanks.

Hi,
  basically when EngBitBlt is called Windows implements the command
using different calls so basically EngBitBlt will call others Drv* functions
to implement DrvBitBlt for QXL driver. That Drv* functions will push commands
to the ring.

Frediano