Why RISC-V doesn't (yet) support KVM

The patch acceptance policy can become an incentive to game the system:

1. Company X don't have hardware ready that implements an extension

2. Company X slows down ratification of the extension

3. Competitors must ship out of tree code to support the extension in Linux

The conflict of interest is outside Linux, which is what Paul Welmsley alluded to with respect to speeding up the process of ratification, but it affects Linux and the maintainers are caught in the crossfire.

Looking at the history of the hypervisor extension specification[1], the last significant change was done about one year ago (May 15, 2020). There is no justification at all for the specification not to be frozen yet.

[1] https://github.com/riscv/riscv-isa-manual/commits/master/...