Re: [PATCH v4 4/6] powerpc/fsl: Enable cpu vulnerabilities reporting for NXP PPC BOOK3E

[Michael Ellerman <mpe@ellerman.id.au>]

LEROY Christophe <christophe.leroy@c-s.fr> writes:
> Diana Madalina Craciun <diana.craciun@nxp.com> a =C3=A9crit=C2=A0:
>> On 7/17/2018 7:47 PM, LEROY Christophe wrote:
>>> Diana Craciun <diana.craciun@nxp.com> a =C3=A9crit :
>>>> The NXP PPC Book3E platforms are not vulnerable to meltdown and
>>>> Spectre v4, so make them PPC_BOOK3S_64 specific.
>>>>
>>>> Signed-off-by: Diana Craciun <diana.craciun@nxp.com>
>>>> ---
>>>> History:
>>>>
>>>> v2-->v3
>>>> - used the existing functions for spectre v1/v2
>>>>
>>>>  arch/powerpc/Kconfig           | 7 ++++++-
>>>>  arch/powerpc/kernel/security.c | 2 ++
>>>>  2 files changed, 8 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
>>>> index 9f2b75f..116c953 100644
>>>> --- a/arch/powerpc/Kconfig
>>>> +++ b/arch/powerpc/Kconfig
>>>> @@ -165,7 +165,7 @@ config PPC
>>>>  	select GENERIC_CLOCKEVENTS_BROADCAST	if SMP
>>>>  	select GENERIC_CMOS_UPDATE
>>>>  	select GENERIC_CPU_AUTOPROBE
>>>> -	select GENERIC_CPU_VULNERABILITIES	if PPC_BOOK3S_64
>>>> +	select GENERIC_CPU_VULNERABILITIES	if PPC_NOSPEC
>>> I don't understand.  You say this patch is to make something specific
>>> to book3s64 specific, and you are creating a new config param that
>>> make things less specific
>>>
>>> Christophe
>>
>> In order to enable the vulnerabilities reporting on NXP socs I need to
>> enable them for PPC_FSL_BOOK3E. So they will be enabled for both
>> PPC_FSL_BOOK3E and PPC_BOOK3S_64. This is the reason for adding the
>> Kconfig. However this will enable: spectre v1/v2 and meltdown. NXP socs
>> are not vulnerable to meltdown, so I made the meltdown reporting
>> PPC_BOOK3S_64 specific. I guess I can have the PPC_NOSPEC definition in
>> a separate patch to be more clear.
>
> Yes you can. Or keep it as a single patch and add the details you gave=20=
=20
> me in the patch description.

Yeah I think the patch is fine, but the change log is a bit short on detail.

If you just send me a new change log I can fold it in.

cheers