Re: [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@xxxxxxxxxx>
> To: "Josh Poimboeuf" <jpoimboe@xxxxxxxxxx>
> Cc: "Peter Zijlstra" <peterz@xxxxxxxxxxxxx>, "Heiko Carstens" <heiko.carstens@xxxxxxxxxx>, "Paul Mackerras"
> <paulus@xxxxxxxxx>, "H . Peter Anvin" <hpa@xxxxxxxxx>, "Ingo Molnar" <mingo@xxxxxxxxxx>, "Andrea Arcangeli"
> <aarcange@xxxxxxxxxx>, linux-s390@xxxxxxxxxxxxxxx, x86@xxxxxxxxxx, "Will Deacon" <will.deacon@xxxxxxx>, "Linus
> Torvalds" <torvalds@xxxxxxxxxxxxxxxxxxxx>, "Catalin Marinas" <catalin.marinas@xxxxxxx>, "Waiman Long"
> <longman@xxxxxxxxxx>, linux-arch@xxxxxxxxxxxxxxx, "Jon Masters" <jcm@xxxxxxxxxx>, "Borislav Petkov" <bp@xxxxxxxxx>,
> "Andy Lutomirski" <luto@xxxxxxxxxx>, "Thomas Gleixner" <tglx@xxxxxxxxxxxxx>, linux-arm-kernel@xxxxxxxxxxxxxxxxxxx,
> "Greg Kroah-Hartman" <gregkh@xxxxxxxxxxxxxxxxxxx>, linux-kernel@xxxxxxxxxxxxxxx, "Tyler Hicks" <tyhicks@xxxxxxxxxxxxx>,
> "Martin Schwidefsky" <schwidefsky@xxxxxxxxxx>, linuxppc-dev@xxxxxxxxxxxxxxxx
> 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@xxxxxxx>
> 
> for the whole set.
> 
> Thanks,
> 
> --
> Jiri Kosina
> SUSE Labs