[svsm-devel] [EXTERNAL] Re: x86 decoder further steps

[Jörg Rödel]

On Fri, May 03, 2024 at 09:23:21AM +0000, Dong, Chuanxiao wrote:
> We made a prototype
> https://github.com/intel-staging/td-partitioning-svsm/tree/svsm-tdp
> which extended the coconut-SVSM to support Intel TD partitioned guest.
> It can decode and emulate some basic MMIO and String I/O instructions
> used by the Linux guest. Currently it is part of TD partitioned guest
> specific code, but if this code is also helpful to the NAE events
> instruction as well, we can see how to integrate it with the existing
> decoder?

I agree with Jon that it is best to implement our own limited
instruction decoder. This has security advantages as this decoder will
be smaller than a more complete one we pull in, which is especially
important as instruction decoding will mostly be done in the SVSM kernel
for performance reasons. So itegrating the MMIO and String I/O emulation
support from the Intel branch into our own instruction decoder would be
really great. 

Regards,

	Joerg