Re: [PATCH] KVM: X86: Add missing KVM_AMD dependency

From: Singh, Brijesh
Date: Mon Oct 08 2018 - 10:52:53 EST




On 10/08/2018 06:27 AM, Paolo Bonzini wrote:
> On 06/10/2018 22:43, Guenter Roeck wrote:
>>>
>>>>> Maybe this works as well? I haven't tested it yet:
>>>>>
>>>> I am sure there are many possible solutions. I would personally
>>>> prefer one
>>>> that enforces KVM_AMD=m with CRYPTO_DEV_CCP_DD=m, but that is just me.
>>>
>>> Well, KVM_AMD=y is a relatively unusual choice to begin with. The
>>
>> It is common enough that we are not the only ones affected. Also, even a
>> "relatively unusual choice" should, in my opinion, not result in a build
>> error.
>
> Of course not! The question is whether to solve it by disabling
> KVM_AMD_SEV (which is what the current code attempts to do, and my patch
> should fix that) or KVM_AMD (your patch).


IMHO, Paolo's patch make sense; it removes all the SEV specific code
when KVM_AMD_SEV=n. It saves ~4K in text section.

Paolo,

Does it make sense to move all the SEV specific code in svm-sev.c ?
I am looking to add SEV migration support very soon, and can see
myself adding more SEV command handling which will grow svm.c further.

-Brijesh