[PATCH 0/6] arm64: Disabling SVE/SME from the command-line

[Marc Zyngier]

On Mon, 27 Jun 2022 16:18:36 +0100,
Mark Brown <broonie at kernel.org> wrote:
> 
> On Mon, Jun 27, 2022 at 04:14:06PM +0100, Marc Zyngier wrote:
> 
> > The main victim here is SVE, because it seems that people have all
> > sort of broken firmware out there, and that a distribution kernel
> > cannot boot on that. And since we have a dependency between SVE and
> > SME, disabling the former also disables the latter.
> 
> Oh dear, I've not seen any reports of this.  I'm guessing it's TF-A just
> not enabling the requisite traps, coupled with people using prebuilt
> kernels that turned off SVE when doing validation?

Most probably something along these lines. The case I'm aware of
involves booting a vanilla kernel on a system with a half baked
firmware. I have little sympathy for these systems, but this looks
like a reasonable ask to be able to disable a feature from the command
line in order to pinpoint the issue.

Will someone ship a system with this baked into the command line? I
don't believe it for a second (/me ducks).

	M.

-- 
Without deviation from the norm, progress is not possible.