[brendangregg]

Thanks! We have to work through each capability carefully. Some won't be safe, and will be available on bare-metal instances only. That may be ok, as it fits with the following evolution of an application (this is something I did for some recent talks):

  1. FaaS
  2. Containers
  3. Lightweight VMs (e.g., Firecracker)
  4. Bare-metal instances

As (and if) an application grows, it migrates to platforms with greater performance and observability.

The ship has sailed on neighbor detection BTW. There's so many ways to know you're a VM with neighbors that disabling PMCs for that reason alone doesn't make sense.

[cperciva]

The ship has sailed on neighbor detection BTW.

In the crudest sense of "do I have a neighbour", sure. Of course, that's hardly secret -- if you're in EC2 you can just count your CPUs to figure that out.

But there's more questions you can ask:

1. Is my neighbour busy right now?

2. Is my neighbour a busy web server, a busy database, or a busy application server?

3. Is my neighbour hosting Brendan's website?

4. Is my neighbour hosting Brendan's website and he's logged in writing a blog post in vi right now?

5. What's Brendan writing right now?

It's not immediately clear which of these questions can be answered using certain capabilities! Few people would have guessed that you could read text off someone's screen using hyperthreading prior to 2005, for example. (Pretty simple although I don't know if anyone has published exploit code for it: Just look at which cache lines are fetched fetching glyphs to render to the screen.)

[bostonsre]

Congrats man, it sounds like a dream job for you. It will be fun to follow your blog at your next job. Thanks again for sharing everything that you do, it is so incredibly humbling and such a great learning experience.