SlackBuildsOrg/system/xf86-video-qxl

This X.Org driver provides support for QEMU QXL paravirt video.
It's meant to be used only in your virtualized guests.

Also an Xspice X server can be built, passing the script
XSPICE=yes. This requires the optional dependency spice.
Note that Xspice is still experimental (=unstable).