On 24/09/19 02:51, Andrea Arcangeli wrote: > This was covered in the commit header of patch 2: Oops, sorry. > Lot more patches are needed to get rid of kvm_x86_ops entirely because > there are lots of places checking the actual value of the method > before making the indirect call. I tried to start that, but then it > got into potentially heavily rejecting territory, so I thought it was > simpler to start with what I had, considering from a performance > standpoint it's optimal already as far as retpolines are concerned. The performance may be good enough, but the maintainability is bad. Let's make a list of function pointers that are checked, and function pointers that are written at init time. For the former, it should be possible to make them __weak symbols so that they are NULL if undeclared. For the latter, module parameters can be made extern and then you can have checks like kvm_x86_has_...() in inline functions in a header file. Paolo
