Installed
apt-get install xserver-xorg-video-dummy
Then
vim /etc/X11/xorg.conf
Then
Section "Device" Identifier "Configured Video Device"
Driver "dummy"
VideoRam 256000
EndSection
Section "Monitor"
Identifier "Configured Monitor"
HorizSync 5.0 - 1000.0
VertRefresh 5.0 - 200.0
ModeLine "1920x1080" 148.50 1920 2448 2492 2640 1080 1084 1089 1125 +Hsync +Vsync
# Modeline "1280x800" 24.15 1280 1312 1400 1432 800 819 822 841
EndSection
Section "Screen"
Identifier "Default Screen"
Monitor "Configured Monitor"
Device "Configured Video Device"
DefaultDepth 24
SubSection "Display"
Depth 24
Modes "1920x1080"
EndSubSection
EndSection
Ref: