VPID behavior with MOV-TO-CR3 trapping about hypervisor_example_vpid HOT 2 CLOSED

@tklengyel

This sounds like a great use case for Bareflank as this is exactly the kind of thing this hypervisor was built for.

Since we currently don't have support for moving a VMCS from one core to another, pinning a VMCS to a core works today. The challenge is #2 as we don't have the ability in their today, to create more than one VMCS for a core. That being said, I don't think it would take a lot of work to do this. Besides the fact that Bareflank is still in heavy development (so a lot of features are still missing), Bareflank itself is, and always will be geared towards providing the scaffolding for creating a hypervisor for research, specifically so that you don't inherit baggage (which is exactly the case your describing). That however means that when you want to test out and idea, you might have to write a bit of code to get things working.

Testing out your idea with Bareflank should be pretty simple, but we'll need to figure out how to launch a VMCS tied to a specific process. Right now, you can IOCTL from a userspace process to start a VMCS, but the code is setup right now to prevent you from doing this twice, so you would simply need to add the logic to launch the second one, and swap based on the tests your trying to run.

If your interested in trying this out, I would start by looking at BFM, as it's the userspace app that does the IOCTL, and you could probably just use this as is, but keep it running so that you can swap from one VMCS to another. It would be dirty.. but it would be enough to test your theory. The VPID and trapping on CR3 should be pretty trivial with Bareflank (just look at the examples).

Let me know what you need from us. Besides the fact that this would be an awesome win for Bareflank to show how it can be used for this type of work, it's also a topic that I find very interesting. 😄

from hypervisor_example_vpid.

FYI, still working on the global flag and getting rid of the page fault. Once I get a free minute that is 😄 . I'll post my results as a repo on my personal page so that you can play around if you want. @tklengyel

from hypervisor_example_vpid.