On Tue, Dec 17, 2019 at 02:20:59PM -0800, Sean Christopherson wrote: > > For example, I see PPC has this: > > > > struct kvm_arch_memory_slot { > > #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE > > unsigned long *rmap; > > #endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */ > > }; > > > > I started to look into HV code of it a bit, then I see... > > > > - kvm_arch_create_memslot(kvmppc_core_create_memslot_hv) init slot->arch.rmap, > > - kvm_arch_flush_shadow_memslot(kvmppc_core_flush_memslot_hv) didn't free it, > > - kvm_arch_prepare_memory_region(kvmppc_core_prepare_memory_region_hv) is nop. > > > > So Does it have similar issue? > > No, KVM doesn't allow a memslot's size to be changed, and PPC's rmap > allocation is directly tied to the size of the memslot. The x86 bug exists > because the size of its metadata arrays varies based on the alignment of > the base gfn. Yes, I was actually thinking those rmap would be invalid rather than the size after the move. But I think kvm_arch_flush_shadow_memslot() will flush all of them anyways... So yes it seems fine. Thanks, -- Peter Xu