As I've mentioned in previous posts, my original idea was to have a "master" bus driver which would manage initializing VMX on each CPU as well as creating the VMs, and then a "child" function driver for controlling each VM. However, I recently realized it would make more sense (and would be much easier in the long run) to just have everything in one driver. Instead of representing VMs as device handles, user-space applications need only a simple ID integer; to operate on a VM, this ID would be passed as a parameter, along with whatever other parameters, into the master driver itself. Furthermore, this avoids potential future issues, such as "half-creation", where a VM has resources allocated, but is not in a state where applications can free them.
I've also done a bit of optimizations with DPCs; instead of creating a new one every time I want to execute a task on a VM, I now have a single DPC per processor that is given an argument which is the task to execute which is called by a main DPC entry. This also means that the task functions no longer have to signal completion - this is done by the DPC entry itself.
Making these changes, I'm now at a point where I can create VM objects and interact with them from user-space code. The next step is to learn how the VMCS region works, how to set up guest registers/memory, and how to actually launch the VM.
In other news, I (finally) head back to school in a couple of hours - not exactly looking forward to the cold!
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