The way you are using the rdmsr tool is incorrect. You are specifying the address in correctly.
You should use it like this:
sudo rdmsr -f 11:11 0xc00000080
This will give you the correct bit value other wise you will get 0 each time without any error.
Now you can set the value using the wrmsr
tool the same way.
sudo wrmsr -p processor_no address value
So in this case it should be like this
sudo wrmsr 0xc0000080 0xvalue
Tested on AMD..