From: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
To: Andi Kleen <andi@firstfloor.org>
Cc: Kyle Huey <khuey@kylehuey.com>,
linux-kernel@vger.kernel.org, x86@kernel.org
Subject: Re: [PATCH] prctl,x86 Add PR_[GET|SET]_CPUID for controlling the CPUID instruction.
Date: Mon, 12 Sep 2016 15:25:19 -0300 [thread overview]
Message-ID: <20160912182519.GA23180@khazad-dum.debian.net> (raw)
In-Reply-To: <87twdl9fz8.fsf@tassilo.jf.intel.com>
On Mon, 12 Sep 2016, Andi Kleen wrote:
> The cpuid char driver does this, other code may too.
Such as anything that calls sync_core().
That includes processor hotplug paths, and who knows what else...
> You probably would need to protect these CPUIDs with an exception
> handler that temporarily disables this bit and retries.
Better time that MSR access first. Hopefully, it is fast enough for
that.
--
Henrique Holschuh
prev parent reply other threads:[~2016-09-12 18:25 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-12 0:29 [PATCH] prctl,x86 Add PR_[GET|SET]_CPUID for controlling the CPUID instruction Kyle Huey
2016-09-12 9:07 ` Borislav Petkov
2016-09-12 14:15 ` Kyle Huey
2016-09-12 14:34 ` Borislav Petkov
2016-09-13 18:42 ` Kyle Huey
2016-09-12 16:56 ` Andy Lutomirski
2016-09-12 17:18 ` Borislav Petkov
2016-09-12 17:56 ` Jann Horn
2016-09-12 21:07 ` Andy Lutomirski
2016-09-14 6:13 ` Kyle Huey
2016-09-14 18:52 ` Andy Lutomirski
2016-09-14 19:22 ` Andrew Cooper
2016-09-14 19:23 ` Boris Ostrovsky
2016-09-14 19:28 ` Andrew Cooper
2016-09-14 19:36 ` Andy Lutomirski
2016-09-14 19:42 ` Andrew Cooper
2016-09-12 17:37 ` Andi Kleen
2016-09-12 18:25 ` Henrique de Moraes Holschuh [this message]
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