Unable to make a vsock module that can be loaded in the running kernel:
insmod: error inserting ‘/tmp/vmware-config1/vsock.o’: -1 Unknown symbol in module

What you need to do is the following:

untar vmci.tar (in /usr/lib/vmware/modules/source)
build the module with ‘make’
untar vsock.tar and copy the “Modules.symvers” file resulting from the previous compilation into the “vsock-only” directory.
Rebuild the vsock.tar file and run “vmware-config.pl”.

Speaking in bash language:

cd /usr/lib/vmware/modules/source/
tar xvfp vmci.tar
tar xvfp vsock.tar
cd vmci-only/
make
cp -av Module.symvers ../vsock-only/
cd ..
tar -f vsock.tar -cv vsock-only/
vmware-config.pl

Now it should compile just fine.

Thanks to Javier, I got this solution from http://communities.vmware.com/thread/208316