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Date: Fri, 19 Apr 2024 07:06:00 -0700
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Subject: Re: [PATCH 1/3] x86/cpu: Actually turn off mitigations by default for SPECULATION_MITIGATIONS=n
From: Sean Christopherson <seanjc@google.com>
To: Will Deacon <will@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>, Michael Ellerman <mpe@ellerman.id.au>, 
	Stephen Rothwell <sfr@canb.auug.org.au>, Jonathan Corbet <corbet@lwn.net>, 
	Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>, 
	Dave Hansen <dave.hansen@linux.intel.com>, x86@kernel.org, 
	Peter Zijlstra <peterz@infradead.org>, Josh Poimboeuf <jpoimboe@kernel.org>, linux-doc@vger.kernel.org, 
	linux-kernel@vger.kernel.org, Pawan Gupta <pawan.kumar.gupta@linux.intel.com>, 
	Daniel Sneddon <daniel.sneddon@linux.intel.com>, linuxppc-dev@lists.ozlabs.org, 
	linux-arch@vger.kernel.org, Catalin Marinas <catalin.marinas@arm.com>, 
	Heiko Carstens <hca@linux.ibm.com>, Linux-Renesas <linux-renesas-soc@vger.kernel.org>
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On Fri, Apr 19, 2024, Will Deacon wrote:
> On Mon, Apr 15, 2024 at 07:31:23AM -0700, Sean Christopherson wrote:
> > On Mon, Apr 15, 2024, Geert Uytterhoeven wrote:
> > Oof.  I completely missed that "cpu_mitigations" wasn't x86-only.  I can't think
> > of better solution than an on-by-default generic Kconfig, though can't that it
> > more simply be:
> > 
> > diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
> > index 2b8fd6bb7da0..5930cb56ee29 100644
> > --- a/drivers/base/Kconfig
> > +++ b/drivers/base/Kconfig
> > @@ -191,6 +191,9 @@ config GENERIC_CPU_AUTOPROBE
> >  config GENERIC_CPU_VULNERABILITIES
> >         bool
> >  
> > +config SPECULATION_MITIGATIONS
> > +       def_bool !X86
> > +
> >  config SOC_BUS
> >         bool
> >         select GLOB
> 
> I can't see this in -next yet. Do you plan to post it as a proper patch
> to collect acks etc?

Sorry, I neglected to Cc everyone.

https://lore.kernel.org/all/20240417001507.2264512-2-seanjc@google.com