Only if you used a breakpoint or something similar. I believe a "shadow" exception vector like that can run entirely in the guest context with the guest not eve

Only if you used a breakpoint or something similar. I believe a "shadow" exception vector like that can run entirely in the guest context with the guest not even being aware of this (MRS is generally always trapped so you can return the address of the real one while still taking exceptions to the injected one). Figuring out where to put it and how to keep it mapped is another problem, though!