On 18.12.2023 14:46, Jan Beulich wrote: > On 18.12.2023 13:11, Roger Pau Monné wrote: >> On Tue, Feb 14, 2023 at 05:10:42PM +0100, Jan Beulich wrote: >>> --- >>> I have to admit that I'm not really certain about the placement of the >>> IBPB wrt the MSR_SPEC_CTRL writes. For now I've simply used "opposite of >>> entry". >> >> Maybe it would easier to just add the MSR_PRED_CMD PRED_CMD_IBPB write >> to the vmcs MSR load list? >> >> It's a one-time only AFAICT, as you would only want to do this for >> context-switch AFAICT. > > That would be a back and forth of adding and removing the MSR to/from > that list then, which I'm not convinced is helpful. With these special > MSRs I would further be uncertain as to their effect when used via one > of these lists.
Plus (as only a secondary argument, but still) it would make PV and HVM mechanisms entirely different. Jan
