Re: [PATCH] KVM: SVM: Assume a 64-bit hypercall for guests with protected state

From: Tom Lendacky
Date: Mon May 24 2021 - 12:10:10 EST


On 5/24/21 9:20 AM, Paolo Bonzini wrote:
> On 24/05/21 15:58, Tom Lendacky wrote:
>>> Would it hurt if we just move 'vcpu->arch.guest_state_protected' check
>>> to is_64_bit_mode() itself? It seems to be too easy to miss this
>>> peculiar detail about SEV in review if new is_64_bit_mode() users are to
>>> be added.
>> I thought about that, but wondered if is_64_bit_mode() was to be used in
>> other places in the future, if it would be a concern. I think it would be
>> safe since anyone adding it to a new section of code is likely to look at
>> what that function is doing first.
>>
>> I'm ok with this. Paolo, I know you already queued this, but would you
>> prefer moving the check into is_64_bit_mode()?
>
> Let's introduce a new wrapper is_64_bit_hypercall, and add a
> WARN_ON_ONCE(vcpu->arch.guest_state_protected) to is_64_bit_mode.

Will do.

Thanks,
Tom

>
> Paolo
>