[PATCH RFC 3/5] powerpc/speculation: Add support for 'cpu_spec_mitigations=' cmdline options

[Timothy Pearson]

Will be joining in ~ 5 mins.  Getting Chromium set up here.

----- Original Message -----
> From: "Jiri Kosina" <jikos at kernel.org>
> To: "Josh Poimboeuf" <jpoimboe at redhat.com>
> Cc: "Peter Zijlstra" <peterz at infradead.org>, "Heiko Carstens" <heiko.carstens at de.ibm.com>, "Paul Mackerras"
> <paulus at samba.org>, "H . Peter Anvin" <hpa at zytor.com>, "Ingo Molnar" <mingo at kernel.org>, "Andrea Arcangeli"
> <aarcange at redhat.com>, linux-s390 at vger.kernel.org, x86 at kernel.org, "Will Deacon" <will.deacon at arm.com>, "Linus
> Torvalds" <torvalds at linux-foundation.org>, "Catalin Marinas" <catalin.marinas at arm.com>, "Waiman Long"
> <longman at redhat.com>, linux-arch at vger.kernel.org, "Jon Masters" <jcm at redhat.com>, "Borislav Petkov" <bp at alien8.de>,
> "Andy Lutomirski" <luto at kernel.org>, "Thomas Gleixner" <tglx at linutronix.de>, linux-arm-kernel at lists.infradead.org,
> "Greg Kroah-Hartman" <gregkh at linuxfoundation.org>, linux-kernel at vger.kernel.org, "Tyler Hicks" <tyhicks at canonical.com>,
> "Martin Schwidefsky" <schwidefsky at de.ibm.com>, linuxppc-dev at lists.ozlabs.org
> Sent: Thursday, April 4, 2019 2:49:05 PM
> Subject: Re: [PATCH RFC 3/5] powerpc/speculation: Add support for 'cpu_spec_mitigations=' cmdline options

> On Thu, 4 Apr 2019, Josh Poimboeuf wrote:
> 
>> Configure powerpc CPU runtime speculation bug mitigations in accordance
>> with the 'cpu_spec_mitigations=' cmdline options.  This affects
>> Meltdown, Spectre v1, Spectre v2, and Speculative Store Bypass.
> [ ... snip ... ]
>> -	if (!no_nospec)
>> +	if (!no_nospec && cpu_spec_mitigations != CPU_SPEC_MITIGATIONS_OFF)
> 
> '!no_nospec' is something that I am sure will come back to hunt me in my
> bad dreams.
> 
> But that's been there already, and fixing it is out of scope of this
> patch. Other than that, as discussed previously -- I really like this new
> global option. Feel free to add
> 
>	Reviewed-by: Jiri Kosina <jkosina at suse.cz>
> 
> for the whole set.
> 
> Thanks,
> 
> --
> Jiri Kosina
> SUSE Labs