All of lore.kernel.org
 help / color / mirror / Atom feed
From: Thomas Gleixner <tglx@linutronix.de>
To: speck@linutronix.de
Subject: Re: [PATCH v2 2/4] L1TF KVM ARCH_CAPABILITIES #2
Date: Mon, 30 Jul 2018 23:27:20 +0200 (CEST)	[thread overview]
Message-ID: <alpine.DEB.2.21.1807302321240.1725@nanos.tec.linutronix.de> (raw)
In-Reply-To: <20180725143100.16309-3-pbonzini@redhat.com>

On Wed, 25 Jul 2018, speck for Paolo Bonzini wrote:

> From: Paolo Bonzini <pbonzini@redhat.com>
> Subject: [PATCH v2 2/4] x86: SMT doesn't matter for VMX L1TF if EPT disabled or
>  mitigation disabled
> 
> If EPT is disabled, L1TF cannot be exploited even across threads on the
> same core, and SMT is irrelevant.

Ack.

> If mitigation is completely disabled, L1TF can be exploited even within a
> single thread, so SMT is again irrelevant.

I'm not sure about this one. You might decide that the risk of not flushing
is acceptable if SMT is off, but then if SMT is enabled the whole thing
might be less acceptable. So keeping that information in the sysfs file
makes some sense. No strong opionion though.

Thanks,

	tglx

  reply	other threads:[~2018-07-30 21:27 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-07-25 14:30 [MODERATED] [PATCH v2 0/4] L1TF KVM ARCH_CAPABILITIES #0 Paolo Bonzini
2018-07-25 14:30 ` [MODERATED] [PATCH v2 1/4] L1TF KVM ARCH_CAPABILITIES #1 Paolo Bonzini
2018-07-25 19:43   ` [MODERATED] " Andrew Cooper
2018-07-26  8:15     ` Paolo Bonzini
2018-07-25 14:30 ` [MODERATED] [PATCH v2 2/4] L1TF KVM ARCH_CAPABILITIES #2 Paolo Bonzini
2018-07-30 21:27   ` Thomas Gleixner [this message]
2018-07-31  8:22     ` [MODERATED] " Paolo Bonzini
2018-07-31  9:15       ` Thomas Gleixner
2018-07-31  9:35         ` [MODERATED] " Paolo Bonzini
2018-07-25 14:30 ` [MODERATED] [PATCH v2 3/4] L1TF KVM ARCH_CAPABILITIES #3 Paolo Bonzini
2018-07-25 14:31 ` [MODERATED] [PATCH v2 4/4] L1TF KVM ARCH_CAPABILITIES #4 Paolo Bonzini
2018-07-30 21:36   ` Thomas Gleixner
2018-07-31  7:39     ` [MODERATED] " Paolo Bonzini
2018-07-31  7:59       ` Thomas Gleixner
2018-07-25 15:52 ` [MODERATED] Re: [PATCH v2 0/4] L1TF KVM ARCH_CAPABILITIES #0 Greg KH
2018-07-26  8:12   ` Paolo Bonzini
2018-07-26 10:04     ` Greg KH
2018-07-26 10:41       ` Paolo Bonzini
2018-07-30 21:40         ` Thomas Gleixner
2018-08-02  2:51 ` [MODERATED] " Konrad Rzeszutek Wilk
2018-08-02 12:07   ` Paolo Bonzini

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=alpine.DEB.2.21.1807302321240.1725@nanos.tec.linutronix.de \
    --to=tglx@linutronix.de \
    --cc=speck@linutronix.de \
    /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.