On Tue, Oct 26, 2021 at 8:48 AM Mingwei Zhang <mizhang@xxxxxxxxxx> wrote: > > On Wed, Oct 20, 2021 at 8:46 PM Michael Roth <michael.roth@xxxxxxx> wrote: > > > > On Mon, Oct 18, 2021 at 08:00:00AM -0700, Mingwei Zhang wrote: > > > > +void vm_set_memory_encryption(struct kvm_vm *vm, bool enc_by_default, bool has_enc_bit, > > > > + uint8_t enc_bit) > > > > +{ > > > > + vm->memcrypt.enabled = true; > > > > + vm->memcrypt.enc_by_default = enc_by_default; > > > > + vm->memcrypt.has_enc_bit = has_enc_bit; > > > > + vm->memcrypt.enc_bit = enc_bit; > > > > +} > > > > + > > > > +struct sparsebit * > > > > +vm_get_encrypted_phy_pages(struct kvm_vm *vm, int slot, vm_paddr_t *gpa_start, > > > > + uint64_t *size) > > > > +{ > > > > + struct userspace_mem_region *region; > > > > + struct sparsebit *encrypted_phy_pages; > > > > + > > > > + if (!vm->memcrypt.enabled) > > > > + return NULL; > > > > + > > > > + region = memslot2region(vm, slot); > > > > + if (!region) > > > > + return NULL; > > > > + > > > > + encrypted_phy_pages = sparsebit_alloc(); > > > > + sparsebit_copy(encrypted_phy_pages, region->encrypted_phy_pages); > > > > > > Do we have to make a copy for the sparsebit? Why not just return the > > > pointer? By looking at your subsequent patches, I find that this data > > > structure seems to be just read-only? > > > > Yes, it's only intended to be used for read access. But I'll if I can > > enforce that without the need to use a copy. > > > > Understood. Thanks for the clarification. Yeah, I think both making a > copy and returning a const pointer should work. I will leave that to > you then. > > Thanks. > -Mingwei Reviewed-by: Mingwei Zhang <mizhang@xxxxxxxxxx> Thanks. -Mingwei