On Fri, 13 Apr 2012 18:33:39 -0300 Marcelo Tosatti <mtosatti@xxxxxxxxxx> wrote: > > kvm_arch_commit_memory_region(kvm, mem, old, user_alloc); > > > > - /* > > - * If the new memory slot is created, we need to clear all > > - * mmio sptes. > > - */ > > - if (npages && old.base_gfn != mem->guest_phys_addr >> PAGE_SHIFT) > > - kvm_arch_flush_shadow(kvm); > > + /* Need to clear all mmio sptes used before. */ > > + if (npages && old.npages && base_gfn != old.base_gfn) > > + kvm_arch_flush_shadow(kvm, mem->slot); > > mmio sptes are not related to any particular slot (by definition), > i think you misunderstood the purpose of this flush. It handles > > 1) [start, end] gpa range unmapped. > 2) mmio sptes are created that map this range. > 3) a new slot is created. mmio sptes that map [start, end] range, > which is now backed by new memslot should be removed. Ah, OK. > Perhaps there is an efficient way to clear all mmio sptes, or all > mmio sptes pointing to [start, end] (instead of all sptes), here. Well, I am OK -- though not happy -- with flushing everything during the guest start-up. But once shadows are fully created, we do not want to do that. So maybe worth thinking such an efficient way! Takuya -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
