As I understand it, Xen would allow me to contain OSs that aren’t even Linux. What is available for Raspberry pi’s hardware, that I should try?
Is there a compelling advantage to using Xen for a container Linux, versus LXC?
I would not host untrusted customers in docker containers, LXC, but I would in Xen HVM any day.
Intel doesn't recommend running untrusted code even in a separate VM, according to their official explanation of Spectre/Meltdown. At least we can do it on RPi now.
Couldn't we already do it on an RPi with linux/kvm+qemu?
(Addendum: I'm not that experienced when it comes to container tech and I heard you can isolate your containers pretty well these days. Virtualization has also changed over time and isn't as "isolated" as it was once; for example virtualized guests are often executed directly on the host's CPU. I'd definitely look into this more before deciding on one approach.)
Windows runs on the pi4 (and now has x86 emulation, IIRC).
There's more than a few things that only run on windows.
That's new to me. Is the rpi4 and window's x86 emulation performant enough to use popular windows-only apps like the Adobe suite?