On Fri, Apr 19, 2024, Will Deacon wrote: > > @@ -663,10 +669,22 @@ static __always_inline kvm_mn_ret_t __kvm_handle_hva_range(struct kvm *kvm, > > break; > > } > > r.ret |= range->handler(kvm, &gfn_range); > > + > > + /* > > + * Use a precise gfn-based TLB flush when possible, as > > + * most mmu_notifier events affect a small-ish range. > > + * Fall back to a full TLB flush if the gfn-based flush > > + * fails, and don't bother trying the gfn-based flush > > + * if a full flush is already pending. > > + */ > > + if (range->flush_on_ret && !need_flush && r.ret && > > + kvm_arch_flush_remote_tlbs_range(kvm, gfn_range.start, > > + gfn_range.end - gfn_range.start + 1)) > > What's that '+ 1' needed for here? (a) To see if you're paying attention. (b) Because more is always better. (c) Because math is hard. (d) Because I haven't tested this. (e) Both (c) and (d).
