Re: [PATCH v14 00/13] Introduce support for guest CET feature

Paolo Bonzini
2021-01-28T18:14:30Z

On 28/01/21 19:04, Sean Christopherson wrote:
> On Thu, Jan 28, 2021, Paolo Bonzini wrote:
>> On 06/11/20 02:16, Yang Weijiang wrote:
>>> Control-flow Enforcement Technology (CET) provides protection against
>>> Return/Jump-Oriented Programming (ROP/JOP) attack. There're two CET
>>> sub-features: Shadow Stack (SHSTK) and Indirect Branch Tracking (IBT).
>>> SHSTK is to prevent ROP programming and IBT is to prevent JOP programming.
>
> ...
>
>> I reviewed the patch and it is mostly okay. However, if I understand it
>> correctly, it will not do anything until host support materializes, because
>> otherwise XSS will be 0.
>
> IIRC, it won't even compile due to the X86_FEATURE_SHSTK and X86_FEATURE_IBT
> dependencies.

Of course, but if that was the only issue I would sort it out with Boris
as usual. OTOH if it is dead code I won't push it to Linus.

Paolo

>> If this is the case, I plan to apply locally v15 and hold on it until the
>> host code is committed.
>>
>> Paolo
>>
>