CONTROL="your control-node"
scp -r root@$CONTROL:/root/spacewalk-testsuite-base/coverage .
firefox coverage/input.html
IMPORTANT: if you have a lot of failures, the coverage will decrease because the steps were not executed. Ideally, you need to have the testsuite results green to evaluate correctly the code coverage and find dead code.
Code coverage result.html is a great tool, but needs a human interpretation of the results.