This is TLBleed - the reason OpenBSD disabled SMT (HyperThreading).<p>Overview from security researchers: <a href="https://www.vusec.net/projects/tlbleed/" rel="nofollow">https://www.vusec.net/projects/tlbleed/</a><p>Previous discussions:<p><a href="https://news.ycombinator.com/item?id=17389377" rel="nofollow">https://news.ycombinator.com/item?id=17389377</a><p><a href="https://news.ycombinator.com/item?id=17350278" rel="nofollow">https://news.ycombinator.com/item?id=17350278</a>