Maybe OS's or hypervisors should support a mode where different processes/security domains are forced into contiguous blocks of physical memory with buffer zone

Maybe OS's or hypervisors should support a mode where different processes/security domains are forced into contiguous blocks of physical memory with buffer zones between. Especially for cloud computing, pre-allocating memory to different VMs should be reasonable. I could even see browsers taking advantage of it, given that they already force javascript threads into per-domain processes for Spectre/Meltdown protection.