Use a bridged connection and follow this short guide
Android Debugging with VirtualBox & Androidx86
Androidx86 install guide (http://visualgdb.com/tutorials/android/virtualbox/)
Connecting
To connect Android virtual machine with adb follow these step
-
On Android home screen, press ALT+F1 (Left alt). This will open a terminal with root access.
-
Inside the terminal, type
dhcpcd eth0. Execute the command twice, if you get an error or no result. This will give you an IP address. Now press ALT+F7 for close the terminal. -
Verify your IP address using the command
ping <your IP Address> -
From the android terminal, type
adb tcpip 5555. This will restart adb in tcpip mode. -
From your main OS terminal, type
adb connect <your IP address>
http://stackoverflow.com/questions/12260257/adb-unable-to-connect-to-android-x86-in-virtualbox-today
http://www.android-x86.org/documents/debug-howto
Troubleshooting
Try these steps if you encounter any connection issues.
adb kill-server
sudo adb tcpip 5555
adb connect 192.168.207.1
http://stackoverflow.com/questions/18930050/adb-connection-over-tcp-not-working-now