Re: [PATCH] docs: security: Confidential computing intro and threat model

From: Carlos Bilbao
Date: Wed Apr 26 2023 - 18:28:05 EST


On 4/26/23 4:33 PM, Sean Christopherson wrote:
> On Wed, Apr 26, 2023, Carlos Bilbao wrote:
>> On 4/26/23 2:53 PM, Sean Christopherson wrote:
>>> On Wed, Apr 26, 2023, Carlos Bilbao wrote:
>>>> On 4/26/23 10:51 AM, Sean Christopherson wrote:
>>>>> This document is named confidential-computing.rst, not tdx-and-snp.rst. Not
>>>>> explicitly mentioning SEV doesn't magically warp reality to make descriptions like
>>>>> this one from security/secrets/coco.rst disappear:
>>>>>
>>>>> Introduction
>>>>> ============
>>>>>
>>>>> Confidential Computing (coco) hardware such as AMD SEV (Secure Encrypted
>>>>> Virtualization) allows guest owners to inject secrets into the VMs
>>>>> memory without the host/hypervisor being able to read them.
>>>>>
>>>>> My complaint about this document being too Intel/AMD centric isn't that it doesn't
>>>>> mention other implementations, it's that the doc describes CoCo purely from the
>>>>> narrow viewpoint of Intel TDX and AMD SNP, and to be blunt, reads like a press
>>>>> release and not an objective overview of CoCo.
>>>>
>>>> Be specific about the parts of the document that you feel are too
>>>> AMD/Intel centric, and we will correct them.
>>>
>>> The whole thing? There aren't specific parts that are too SNP/TDX centric, the
>>> entire tone and approach of the document is wrong. As I responded to Dave, I
>>> would feel differently if the document were named tdx-and-snp-threat-model.rst,
>>> but this patch proposes a generic confidential-computing.rst and presents the
>>> SNP+TDX confidential VM use case as if it's the *only* confidential computing use
>>> case.
>>
>> What part of us describing the current Linux kernel threat model or
>> defining basic concepts of confidential computing is SNP/TDX centric?
>>
>> IMHO, simply stating that "the whole thing" is wrong and that you don't
>> like the "tone", is not making a good enough case for us to change
>> anything, including the name of the document.
>
> I honestly don't know how to respond since you are either unable or unwilling to
> see the problems with naming a document "confidential computing" and then talking
> only about one very, very specific flavor of confidential computing as if that is
> the only flavor of confidential computing.
>
> So if you want to push this doc as is, please add my
>
> Nacked-by: Sean Christopherson <seanjc@xxxxxxxxxx>
>

Well, the intent was and still is to work with the community to collect
feedback and finish a version were all flavors are represented --see
Motivation section of the draft. But if you are unable or unwilling to
collaborate with us, just please make sure to read whatever is the final
version. I will assume it has your Nacked-By otherwise.

To the rest, please do point out to specific parts you consider to be
AMD/Intel agnostic. We will do our best effort to fix it.

Thanks,
Carlos