Avi Kivity wrote: >> spin_lock(&vcpu->kvm->mmu_lock); >> + index = kvm_page_table_hashfn(gfn); >> + bucket =&vcpu->kvm->arch.mmu_page_hash[index]; >> + hlist_for_each_entry_safe(s, node, tmp, bucket, hash_link) >> + if (s == sp) { >> + if (s->gfn == gfn&& s->role.word == role.word) >> + live = true; >> + break; >> + } >> + >> + if (!live) >> + goto unlock_exit; >> + >> > > Did you try the root_count method? I think it's cleaner. Avi, Thanks for your idea. I have considered this method, but i'm not sure when it's the good time to real free this page, and i think we also need a way to synchronize the real free path and this path. Do you have any comment for it :-( Xiao -- 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