[pmontra]

So, CPUs or cores (and maybe RAM) dedicated to run only trusted and only untrusted code?

Examples (I'm running Debian)

The kernel, the X11 server, terminal, ssh, bash, anything coming from the official Debian repos including the password manager: in the trusted environment.

browsers, electron apps, anything installed from unofficial repos or language and package managers (npm, rvm, asdf, etc): in the untrusted environment.

It reminds me of mainframes and their redundant and compartmentalized hardware architecture.

[sofixa]

> terminal, ssh, bash

> X11 server

Those can very easily execute untrusted code.

[pmontra]

Yes, but it can be countered by pinning "random-script-from-the-internet.sh" to the untrusted environment. The fork/exec inside bash (or whatever bash is using now) should take care or that, or the kernel itself which is probably a better option. bash + ls -> trusted because ls is in some way marked as trusted, bash + random-script -> untrusted, possibly by default.

[PhilipRoman]

Well it makes no sense to worry about side channel attacks if you don't have isolation in the first place, so there is an implicit assumption that you have a sandboxing layer like VM/container/browser (or the built in unix user separation) which don't care about terminals or X11 (usually a separate X server is used which is running inside the sandbox context).