Currently tests are run into batch mode to speed up there is a need to add support to run concurrently. Some considerations are to define a way for mutual exclusive tests and to dependencies between tests.
I just added a loader support creating a list of individual test runs. http://git.yoctoproject.org/cgit/cgit.cgi/poky-contrib/commit/?h=alimon/oeqa_parallel&id=65c97766aea7010768815feb14fe3598eef2eab4
I finished the first implementation, in review at, http://lists.openembedded.org/pipermail/openembedded-core/2017-May/136514.html
This support is on oeqa core module and now enabled into {,e}SDK test components, i'm working on the selftest test content to adapt it to threaded runs. Merge at, http://git.yoctoproject.org/cgit/cgit.cgi/poky/commit/?id=a4eef558c9933eb32413b61ff80a11b999951b40