Installing linux system, no screen found when executing startx, my xorg.conf configuration is

  linux, question

My configuration is virtualbox on macbook, equipped with Nvidia driver.

$ cat /etc/X11/xorg.conf
 # nvidia-xconfig: X configuration file generated by nvidia-xconfig
 # nvidia-xconfig:  version 349.16  (buildmeister@swio-display-x86-rhel47-06)  Wed Apr  8 00:52:19 PDT 2015
 Section "ServerLayout"
 Identifier     "Layout0"
 Screen      0  "Screen0"
 InputDevice    "Keyboard0" "CoreKeyboard"
 InputDevice    "Mouse0" "CorePointer"
 Section "Files"
 Section "InputDevice"
 # generated from data in "/etc/conf.d/gpm"
 Identifier     "Mouse0"
 Driver         "mouse"
 Option         "Protocol"
 Option         "Device" "/dev/input/mice"
 Option         "Emulate3Buttons" "no"
 Option         "ZAxisMapping" "4 5"
 Section "InputDevice"
 # generated from default

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