Re: [PATCH] x86/sgx: Declare sgx_set_attribute() for !CONFIG_X86_SGX

[Paolo Bonzini]

On 03/09/21 17:58, Jarkko Sakkinen wrote:
> > Eh, it doesn't really simplify the usage.  If anything it makes it more convoluted
> > because the capability check in kvm_vm_ioctl_check_extension() still needs an
> > #ifdef, e.g. readers will wonder why the check is conditional but the usage is not.
> It does objectively a bit, since it's one ifdef less.

But you're effectively replacing #ifdef CONFIG_X86_SGX_KVM with #ifdef 
CONFIG_X86_SGX; so the patch is not a no-op as far as KVM is concerned.

So NACK for the KVM parts (yeah I know it's RFC but just to be clearer), 
but I agree that adding a stub inline version of the function is 
standard practice and we do it a lot in KVM too.

Paolo

> This is fairly standard practice to do in kernel APIs, used in countless
> places, for instance in Tony's patch set to add MCE recovery for SGX. And
> it would be nice to share common pattern here how we define API now and
> futre.
>
> I also remarked that declaration of "sgx_provisioning_allowed" is not flagged,
> which is IMHO even more convolved because without SGX it is spare data.