All of lore.kernel.org
 help / color / mirror / Atom feed
From: Thomas Gleixner <tglx@linutronix.de>
To: Benjamin Lamowski <benjamin.lamowski@kernkonzept.com>,
	xiaoyao.li@intel.com
Cc: bp@alien8.de, fenghua.yu@intel.com, hpa@zytor.com,
	linux-kernel@vger.kernel.org, luto@kernel.org, mingo@redhat.com,
	nivedita@alum.mit.edu, pbonzini@redhat.com, peterz@infradead.org,
	philipp.eppelt@kernkonzept.com, sean.j.christopherson@intel.com,
	tony.luck@intel.com, x86@kernel.org,
	Benjamin Lamowski <benjamin.lamowski@kernkonzept.com>
Subject: Re: [PATCH v3 1/1] x86/split_lock: check split lock support on initialization
Date: Mon, 06 Apr 2020 23:24:53 +0200	[thread overview]
Message-ID: <87zhbojoii.fsf@nanos.tec.linutronix.de> (raw)
In-Reply-To: <20200406161737.258840-1-benjamin.lamowski@kernkonzept.com>

Benjamin Lamowski <benjamin.lamowski@kernkonzept.com> writes:

> While the sld setup code is run only if the TEST_CTRL MSR is available,
> the current sld initialization code unconditionally resets it even on
> systems where this architectural MSR is not available.
>
> This commit introduces a new default sld state sld_unsupported, which is
> changed in split_lock_setup() only if sld is available; and checks for
> split lock detect support before initializing it.

What for? You explain what the patch is doing, but not WHY. See
Documentation/process and while at it please search for 'This patch' as
well.

> Fixes: dbaba47085b0c ("x86/split_lock: Rework the initialization flow
> of split lock detection")

That's blantantly wrong. It fixes your hypervisor which fails to raise a
#GP when an unknown MSR is accessed. 

Are we going to see that kind of 'fixes' everytime we decide to probe an
MSR for simplicity from now on?

Please fix the root cause and not the symptom.

Thanks,

        tglx

  reply	other threads:[~2020-04-06 21:25 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-25  3:09 [PATCH v7 0/2] Fix and optimization of split_lock_detection Xiaoyao Li
2020-03-25  3:09 ` [PATCH v7 1/2] x86/split_lock: Rework the initialization flow of split lock detection Xiaoyao Li
2020-03-28 16:32   ` Sean Christopherson
2020-03-30 13:26     ` Xiaoyao Li
2020-03-30 14:26       ` Sean Christopherson
2020-03-25  3:09 ` [PATCH v7 2/2] x86/split_lock: Avoid runtime reads of the TEST_CTRL MSR Xiaoyao Li
2020-03-28 16:34   ` Sean Christopherson
2020-03-29  9:13     ` Xiaoyao Li
2020-03-30 18:18       ` Sean Christopherson
2020-04-03 17:44 ` [PATCH 0/1] x86/split_lock: check split lock feature on initialization Benjamin Lamowski
2020-04-03 17:44   ` [PATCH 1/1] " Benjamin Lamowski
2020-04-03 18:01     ` Sean Christopherson
2020-04-06  8:23       ` Benjamin Lamowski
2020-04-06 11:48         ` Xiaoyao Li
2020-04-06 15:57           ` [PATCH v2 0/1] x86/split_lock: check split lock support " Benjamin Lamowski
2020-04-06 16:02             ` [PATCH v2 1/1] " Benjamin Lamowski
2020-04-06 16:17               ` [PATCH v3 " Benjamin Lamowski
2020-04-06 21:24                 ` Thomas Gleixner [this message]
2020-04-07 13:25               ` [PATCH v2 " kbuild test robot
2020-04-06 21:21   ` [PATCH 0/1] x86/split_lock: check split lock feature " Thomas Gleixner

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=87zhbojoii.fsf@nanos.tec.linutronix.de \
    --to=tglx@linutronix.de \
    --cc=benjamin.lamowski@kernkonzept.com \
    --cc=bp@alien8.de \
    --cc=fenghua.yu@intel.com \
    --cc=hpa@zytor.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=luto@kernel.org \
    --cc=mingo@redhat.com \
    --cc=nivedita@alum.mit.edu \
    --cc=pbonzini@redhat.com \
    --cc=peterz@infradead.org \
    --cc=philipp.eppelt@kernkonzept.com \
    --cc=sean.j.christopherson@intel.com \
    --cc=tony.luck@intel.com \
    --cc=x86@kernel.org \
    --cc=xiaoyao.li@intel.com \
    /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.