Re: [RFC 02/16] KVM: selftests: add hooks for managing encrypted guest memory

[Mingwei Zhang]

> +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?

-Mingwei