The whole point of being in kernel space is to write unsafe code -- either unsafe in a memory sense or in a "I am just blasting characters at this pcie port" sense.
Yes and no. It's true that there's some portion of the kernel space code that can't be written provably safely. But there's good reason to believe that a lot of it can and that belief is what's driving this integration.
Whether Rust in the kernel succeeds or not will likely be determined by whether or not a sufficiently clear boundary can be drawn between the bit that must be unsafe (in the Rust sense) and the rest. And how much code is in the latter. I don't think we know the answer yet but some knowledgable people are willing to run the experiment on the basis that the probability seems quite high that a safe subset can be determined.
Whether Rust in the kernel succeeds or not will likely be determined by whether or not a sufficiently clear boundary can be drawn between the bit that must be unsafe (in the Rust sense) and the rest. And how much code is in the latter. I don't think we know the answer yet but some knowledgable people are willing to run the experiment on the basis that the probability seems quite high that a safe subset can be determined.