If anyone was looking there are still some Xen VPS providers around, one of the oldest being Tornado VPS (formerly prgmr.com).

https://tornadovps.com/about

The founders literally wrote the book on xen:

https://nostarch.com/releases/xen.html

On HP business PCs, Xen's microkernel architecture was extended for copy-on-write nested virtualization microVMs (VM per browser tab or HTTP connection) and UEFI-in-VM, https://www.platformsecuritysummit.com/2018/speaker/pratt/ | https://news.ycombinator.com/item?id=42282053#42286147

Imminent unification of Android and ChromeOS will likely use a similar h/w nested-virt architecture based on L0 pKVM + L1 KVM hypervisors on Arm devices.

Honda is using Xen, "How to accelerate Software Defined Vehicle" (2025), https://static.sched.com/hosted_files/xensummit2025/93/HowTo...

I guess I don't quite follow. The attack can let an attacker in a normal VM see memory in either the host or a Xen dom0 VM. Why is it less impactful to get memory from the management VM instead of the host?

While it’s interesting that Dom0 avoids Spectre-style branch prediction attacks it’s not clear from TFA exactly why that is so. How does the architecture of the hypervisor avoid an attack that seems to be at the hardware level? From my limited understanding of Spectre and Meltdown, swapping from a monolithic to a microkernel wouldn’t mitigate an attack. The mitigations discussed in the VMscape paper [0] are hardware mitigations in my reading. And I don’t see Xen mentioned anywhere in the paper for that matter.

I guess it’s sort of off topic, but I was enjoying reading this until I got to the “That’s not just elegant — it’s a big deal for security” line that smelled like LLM-generated content.

Maybe that reaction is hypocritical. I like LLMs; I use them every day for coding and writing. I just can’t shake the feeling that I’ve somehow been swindled if the author didn’t care enough to edit out the “obvious” LLM tells.

[0]: https://comsec-files.ethz.ch/papers/vmscape_sp26.pdf