If you’re getting kernel module installation errors, probably the module is not compiled for the current kernel or its dependencies are not loaded.
# insmod datapath/linux/openvswitch.ko
datapath/linux/openvswitch.ko: Unknown symbol in module
By using the command modinfo, you can take clues about the module, such as its dependencies and kernel version that was used to compile.
If the problem is dependencies, instead of using insmod to install openvswitch.ko module, you can first type the command in the OVS root directory (after compiling):
# make install
This will install all compiled modules in the Linux system. Then, type:
# modprobe openvswitch
The command should automatically load openvswitch module and its dependencies.