&gt; Not strictly, no. While currently they only support the &quot;hardware&quot; in KVM&#x2F;QEMU&#x2F;VirtualBox, there&#x27;s nothing stopping anyone implementing drivers for whatever hardware they want to run on, even bare metal.<p>Exokernels (<a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Exokernel" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Exokernel</a>) essentially implement this.  Hardware has been adding more support for virtualization though, so I imagine unikernels are better able to take advantage of things like virtualized page tables, virtualized io-mmu, etc...<p>I&#x27;d be curious to see benchmarks for something generally IO bound like PostgreSQL or HyperTable.  IO scheduling isn&#x27;t trivial, so it might give a good idea of what some of the trade-offs might be.