All of lore.kernel.org
 help / color / mirror / Atom feed
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

      reply	other threads:[~2016-09-12 18:25 UTC|newest]

Thread overview: 36+ 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  0:29 ` Kyle Huey
2016-09-12  9:07 ` Borislav Petkov
2016-09-12  9:07   ` Borislav Petkov
2016-09-12 14:15   ` Kyle Huey
2016-09-12 14:15     ` Kyle Huey
2016-09-12 14:34     ` Borislav Petkov
2016-09-12 14:34       ` Borislav Petkov
2016-09-12 14:34       ` Borislav Petkov
2016-09-13 18:42     ` Kyle Huey
2016-09-13 18:42       ` Kyle Huey
2016-09-12 16:56 ` Andy Lutomirski
2016-09-12 16:56   ` Andy Lutomirski
2016-09-12 17:18   ` Borislav Petkov
2016-09-12 17:18     ` Borislav Petkov
2016-09-12 17:56   ` Jann Horn
2016-09-12 17:56     ` Jann Horn
2016-09-12 21:07     ` Andy Lutomirski
2016-09-12 21:07       ` Andy Lutomirski
2016-09-14  6:13   ` Kyle Huey
2016-09-14  6:13     ` Kyle Huey
2016-09-14 18:52     ` Andy Lutomirski
2016-09-14 18:52       ` Andy Lutomirski
2016-09-14 19:22       ` Andrew Cooper
2016-09-14 19:22         ` Andrew Cooper
2016-09-14 19:23       ` Boris Ostrovsky
2016-09-14 19:23         ` Boris Ostrovsky
2016-09-14 19:28         ` Andrew Cooper
2016-09-14 19:28           ` Andrew Cooper
2016-09-14 19:36           ` Andy Lutomirski
2016-09-14 19:36             ` Andy Lutomirski
2016-09-14 19:42             ` Andrew Cooper
2016-09-14 19:42               ` Andrew Cooper
2016-09-14 19:42             ` [PATCH] prctl, x86 " Andrew Cooper
2016-09-12 17:37 ` [PATCH] prctl,x86 " Andi Kleen
2016-09-12 18:25   ` Henrique de Moraes Holschuh [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20160912182519.GA23180@khazad-dum.debian.net \
    --to=hmh@hmh.eng.br \
    --cc=andi@firstfloor.org \
    --cc=khuey@kylehuey.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.