public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Borislav Petkov <bp@alien8.de>
To: "Luck, Tony" <tony.luck@intel.com>
Cc: Daniel Verkamp <dverkamp@chromium.org>,
	"x86@kernel.org" <x86@kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"andrew.cooper3@citrix.com" <andrew.cooper3@citrix.com>
Subject: Re: [PATCH] x86: also disable FSRM if ERMS is disabled
Date: Tue, 11 Oct 2022 22:56:37 +0200	[thread overview]
Message-ID: <Y0XYhftUTqd2BDHn@zn.tnic> (raw)
In-Reply-To: <SJ1PR11MB608345C36F1D52B8185E46E1FC239@SJ1PR11MB6083.namprd11.prod.outlook.com>

On Tue, Oct 11, 2022 at 07:08:51PM +0000, Luck, Tony wrote:
> I don't think Intel will deliberately release a CPU that has FSRM=1, ERMS=0.

Sure, but I don't mean that. Rather: if for some reason the kernel or
BIOS is supposed to fix an erratum related to those enhanced REP moving
routines and goes and clears the MSR bit.

That won't help because userspace will still use them since the CPUID
flags remain set.

I guess such a case is probably not going to happen in real life but if
it happened, that bit clearing is kinda useless.

I'd say.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

  reply	other threads:[~2022-10-11 20:56 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-09-23  0:58 [PATCH] x86: also disable FSRM if ERMS is disabled Daniel Verkamp
2022-09-23 11:13 ` Borislav Petkov
2022-09-23 17:25   ` Daniel Verkamp
2022-09-23 17:51     ` Borislav Petkov
2022-10-07 18:08       ` Daniel Verkamp
2022-10-11 11:28         ` Borislav Petkov
2022-10-11 17:09           ` Luck, Tony
2022-10-11 17:52             ` Borislav Petkov
2022-10-11 19:08               ` Luck, Tony
2022-10-11 20:56                 ` Borislav Petkov [this message]
2022-10-11 22:19                   ` Luck, Tony
2022-10-11 22:59                     ` Andrew Cooper
2023-01-04  7:43         ` Jiri Slaby
2023-01-04 11:39           ` Borislav Petkov
2023-01-14  9:19             ` Ingo Molnar
2023-01-14  9:58               ` Borislav Petkov
2023-01-16  5:26             ` Jiri Slaby
2023-01-16 21:17               ` Borislav Petkov

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=Y0XYhftUTqd2BDHn@zn.tnic \
    --to=bp@alien8.de \
    --cc=andrew.cooper3@citrix.com \
    --cc=dverkamp@chromium.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=tony.luck@intel.com \
    --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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox