Re: [for-6.0 v5 06/13] securable guest memory: Decouple kvm_memcrypt_*() helpers from KVM

[Philippe Mathieu-Daudé]

On 12/4/20 6:44 AM, David Gibson wrote:
> The kvm_memcrypt_enabled() and kvm_memcrypt_encrypt_data() helper functions
> don't conceptually have any connection to KVM (although it's not possible
> in practice to use them without it).
> 
> They also rely on looking at the global KVMState.  But the same information
> is available from the machine, and the only existing callers have natural
> access to the machine state.
> 
> Therefore, move and rename them to helpers in securable-guest-memory.h,
> taking an explicit machine parameter.
> 
> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  accel/kvm/kvm-all.c                   | 27 --------------------
>  accel/stubs/kvm-stub.c                | 10 --------
>  hw/i386/pc_sysfw.c                    |  6 +++--
>  include/exec/securable-guest-memory.h | 36 +++++++++++++++++++++++++++
>  include/sysemu/kvm.h                  | 17 -------------
>  5 files changed, 40 insertions(+), 56 deletions(-)
...

> +static inline int securable_guest_memory_encrypt(MachineState *machine,
> +                                              uint8_t *ptr, uint64_t len)
> +{
> +    SecurableGuestMemory *sgm = machine->sgm;
> +
> +    if (sgm) {
> +        SecurableGuestMemoryClass *sgmc = 
> SECURABLE_GUEST_MEMORY_GET_CLASS(sgm);
> +
> +        if (sgmc->encrypt_data) {

Can this ever happen? Maybe use assert(sgmc->encrypt_data) instead?

Otherwise:
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

> +            return sgmc->encrypt_data(sgm, ptr, len);
> +        }
> +    }
> +
> +    return 1;
> +}