On Fri, Sep 13, 2019 at 09:26:04AM -0700, Jim Mattson wrote: > On Fri, Sep 13, 2019 at 8:24 AM Sean Christopherson > <sean.j.christopherson@xxxxxxxxx> wrote: > > > This is a misleading name, e.g. it took me quite a while to realize this > > is testing only the passing scenario. For me, "limit test" implies that > > it'd be deliberately exceeding the limit, or at least testing both the > > passing and failing cases. I suppose we can't easily test the VMX abort > > cases, but we can at least test VM_ENTER_LOAD. > > It's hard to test for "undefined behavior may result." :-) Fortune favors the bold? > One could check to see if the test is running under KVM, and then > check for the behavior that Marc's other patch introduces, but even > that is implementation-dependent. Hmm, what if kvm-unit-tests accepts both VM-Enter success and fail as passing conditions? We can at least verify KVM doesn't explode, and if VM-Enter fails, that the exit qual is correct. The SDM state that the max is a recommendation, which leads me to believe that bare metal will work just fine if the software exceeds the recommended max by an entry or two, but can run into trouble if the list is ludicrously big. There's no way the CPU is tuned so finely that it works at N but fails at N+1.
