On Mon, Jun 03, 2024, James Houghton wrote: > On Mon, Jun 3, 2024 at 4:03 PM Sean Christopherson <seanjc@xxxxxxxxxx> wrote: > > But before we do that, I think we need to perform due dilegence (or provide data) > > showing that having KVM take mmu_lock for write in the "fast only" API provides > > better total behavior. I.e. that the additional accuracy is indeed worth the cost. > > That sounds good to me. I'll drop the Kconfig. I'm not really sure > what to do about the self-test, but that's not really all that > important. Enable it only on architectures+setups that are guaranteed to implement the fast-only API? E.g. on x86, it darn well better be active if the TDP MMU is enabled. If the test fails because that doesn't hold true, then we _want_ the failure.