On Sat, May 14, 2022 at 03:55:21PM +0200, Lukas Wunner wrote: > Circling back to the SPDM/IDE topic, while NVMe is now capable of > reliably recovering from errors, it does expect the kernel to handle > recovery within a few seconds. I'm not sure we can continue to > guarantee that if the kernel depends on user space to perform > re-authentication with SPDM after reset. That's another headache > that we could avoid with in-kernel SPDM authentication. I wonder if we need kernel bundled and tightly controlled userspace code for these kinds of things (also for NVMe/NFS TLS). That is, bundle a userspace ELF file or files with a module which is unpacked to or accessible by a ramfs-style file systems. Then allow executing it without any interaction with the normal userspace, and non-pagable memory. That way we can reuse existing userspace code, have really nice address space isolation but avoid all the deadlock potential of normal userspace code. And I don't think it would be too hard to implement either.
