I was trying to run Windows 10 guest in KVMGT with DMA Buf in gtk-gl window.
The guest driver worked but reported a display series of dimensions from 1920x1200
downwards. After changing the screen resolutions from guest Control Panel, the KVMGT still
reported 1920x1200 primary plane size, and was unable to scale gtk window properly, and
the output was drawn in the upper left corner of the plane.
The configuration was:
host OS: Ubuntu 18.04
QEMU: master branch
kernel: 4.19.0-994-generic drm-intel-nightly from kernel.ubuntu.com
GPU: HD Graphics 530
guest: Windows 10 build 1709
guest driver: 126.96.36.19926