BSOD on r3 memory access

[hyvealtushka]

I've been exploring the hypervisor features but I ran into a problem when accessing r3 memory from the vmcall execute handler. I tried to read my r3 struct from the vmcall handler and got "IRQL NOT LESS OR EQUAL". I can also get this error when reading the PTE I passed as rdx. I tested on Windows 10 (1903 ), but I don't think it matters