From: Borislav Petkov <bp@alien8.de>
To: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
kitsunyan <kitsunyan@airmail.cc>, X86 ML <x86@kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] x86/msr: do not warn on writes to OC_MAILBOX
Date: Mon, 7 Sep 2020 13:11:09 +0200 [thread overview]
Message-ID: <20200907111109.GB16029@zn.tnic> (raw)
In-Reply-To: <CAHmME9o_Odo97K7QXKO=konVE-UxR7iBCE5S8uAJgc=kJ2EgsA@mail.gmail.com>
Hi,
On Mon, Sep 07, 2020 at 12:46:35PM +0200, Jason A. Donenfeld wrote:
> Are you sure that intel-undervolt using OC_MAILBOX from userspace is
> actually a "misuse"? Should the kernel or kernel drivers actually be
> involved with the task of underclocking? This seems pretty squarely in
> the realm of "hobbyists poking and prodding at their CPUs" rather than
> something made for a kernel driver, right?
The only thing I'm sure is that *if* it makes sense for any driver to
control something in the hardware over MSRs, it should *not* poke at
naked MSRs but use a proper interface.
I'd leave it to the people who actually need this interface, to explain
why they do.
> Also, what was the justification for whitelisting
> MSR_IA32_ENERGY_PERF_BIAS?
That's:
tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c
Once that thing gets converted to a proper interface too, that MSR goes
off the allowlist too.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2020-09-07 11:30 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-07 9:48 Jason A. Donenfeld
2020-09-07 10:06 ` Borislav Petkov
2020-09-07 10:46 ` Jason A. Donenfeld
2020-09-07 11:11 ` Borislav Petkov [this message]
2020-09-07 11:15 ` Jason A. Donenfeld
2020-09-07 11:23 ` Borislav Petkov
2020-09-08 17:10 ` Srinivas Pandruvada
2020-09-08 17:12 ` Jason A. Donenfeld
2020-09-08 17:25 ` Borislav Petkov
2020-09-08 17:29 ` Jason A. Donenfeld
2020-09-08 17:36 ` Borislav Petkov
2020-09-08 17:42 ` Jason A. Donenfeld
2020-09-08 18:01 ` Borislav Petkov
2020-09-08 19:07 ` Jason A. Donenfeld
2020-09-08 19:18 ` Sultan Alsawaf
2020-09-08 19:30 ` Borislav Petkov
2020-09-08 20:35 ` Andy Lutomirski
2020-09-08 22:32 ` Matthew Garrett
2020-09-09 23:56 ` Andy Lutomirski
2020-09-09 1:02 ` Srinivas Pandruvada
2020-09-10 0:08 ` Andy Lutomirski
2020-10-19 17:15 ` Borislav Petkov
2020-10-20 17:21 ` Srinivas Pandruvada
2020-10-20 17:47 ` Borislav Petkov
2020-10-20 18:40 ` Srinivas Pandruvada
2020-10-20 19:40 ` Dave Hansen
2020-10-21 13:11 ` Srinivas Pandruvada
2020-10-22 19:28 ` Borislav Petkov
2020-10-21 13:24 ` Peter Zijlstra
2020-09-08 17:31 ` Borislav Petkov
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