Re: [PATCH v3 08/10] x86/setcpuid: Add kernel option setcpuid

[Peter Zijlstra]

On Tue, Feb 05, 2019 at 08:46:23AM -0800, Dave Hansen wrote:
> On 2/4/19 10:18 PM, Borislav Petkov wrote:

> > Well, if it breaks old apps, it probably needs to be opt-in anyway.
> 
> Yes, this was my assumption.

It _should_ not break portable code (because RISC has much stronger #AC
requirements).

That said; I really do think we want it default enabled and allow
individual apps to opt-out with a system-wide override to disable the
opt-out.

The cloud vendors and RT thingies will want to disable the opt-out for
example.