Re: [MAINTAINERS SUMMIT] Device Passthrough Considered Harmful?

Christoph Hellwig
2024-07-09T06:09:42Z

Passthrough in general is useful, but the problem is that protocols
aren't designed with it in mind. Look at the list of command that
affect too much state and we have to block in SCSI and NVMe. And
in NVMe I'm fighting a constant fight in the technical working group
to not add new command that instantly disable the access control we've
built into NVMe passthrough. So IMHO passthrough can be good idea,
but only if the protocol is designed for it, and protocol designer
generally have a hard time how software works at all, never mind
the futuristic concepts of layering, abstraction and access control.