You could do that (see Singularity OS [0] and Midori [1]), but recently it was discovered that it wouldn't work on modern out-of-order CPUs due to Spectre [2].

You could do that (see Singularity OS [0] and Midori [1]), but recently it was discovered that it wouldn't work on modern out-of-order CPUs due to Spectre [2]. [0] https://research.cs.wisc.edu/areas/os/Seminar/schedules/papers/Deconstructing_Process_Isolation_final.pdf https://research.cs.wisc.edu/areas/os/Seminar/schedules/pape... [1] http://joeduffyblog.com/2015/11/03/blogging-about-midori/ http://joeduffyblog.com/2015/11/03/blogging-about-midori/ [2] https://arxiv.org/abs/1902.05178 https://arxiv.org/abs/1902.05178