Intel

intel is the open source graphics driver for Intel GMA onboard graphics card, starting with the Intel i810.

Kernel
You need to activate the following kernel options:

Driver
Note the USE flags of :

VAAPI
Intel GMA X4500HD and newer supports VAAPI hardware video acceleration.

KDM freezes
A workaround is to set TerminateServer=true in all sections of the file, which starts with X-.

External resources

 * X.Org Wiki