On Thu, May 28, 2026, Christian Ludloff wrote: > > It appears it was a deliberate decision, due in part to the fact that the > > traditional flow of checking CPL exceptions before intercepts typically > > applies to using instructions in an illegal way, but the user is not doing > > anything illegal here by executing CPUID which is normally a legal > > instruction at CPL3. > > > > That said, clearly the behavior is different now between the vendors, > > however at this point the feedback I got is that our architects want to > > stick with the existing behavior unless there is a strong reason that it is > > a problem for SW. > > What is a HV expected to do for such a CPUID guest exit?
Emulate hardware behavior. The only question we had was whether the observed hardware behavior (VM-Exit takes precedence over #GP) was AMD's architectural behavior.
