From: Michal Hocko <mhocko@kernel.org>
To: Pavel Machek <pavel@ucw.cz>
Cc: vbabka@suse.cz, hpa@zytor.com, torvalds@linux-foundation.org,
ak@linux.intel.com, dave.hansen@intel.com,
kernel list <linux-kernel@vger.kernel.org>,
tglx@linutronix.de, mingo@redhat.com, bp@alien8.de
Subject: Re: l1tf: Kernel suggests I throw away third of my memory. I'd rather not
Date: Wed, 17 Oct 2018 14:17:05 +0200 [thread overview]
Message-ID: <20181017121705.GQ18839@dhcp22.suse.cz> (raw)
In-Reply-To: <20181017113226.GA5176@amd>
On Wed 17-10-18 13:32:26, Pavel Machek wrote:
[...]
> > > Now question is... can we do better? Kernel stores information about
> > > swapped-out pages there, right? That sounds like a cool hack, but
> > > maybe it is time to get rid of that hack?
> >
> > Patches are welcome.
>
> Cooperation will be needed if you want to see patches. As
> in... answering the questions above.
The question is whether that is really worth it. L1TF is mostly about
virtual environments. If you are running in a native HW then I wouldn't
lose much sleep over it. a) pfns stored in PROT_NONE entries are
controlled by the OS b) swap based attacks with something interesting in
L1$ colliding with the swap entry is theoretical at best.
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2018-10-17 12:17 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-17 10:56 Pavel Machek
2018-10-17 11:15 ` Michal Hocko
2018-10-17 11:32 ` Pavel Machek
2018-10-17 12:17 ` Michal Hocko [this message]
2018-10-17 22:21 ` Dave Hansen
2018-10-18 7:10 ` Vlastimil Babka
2018-10-17 14:08 ` Andi Kleen
2018-10-17 14:13 ` Vlastimil Babka
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=20181017121705.GQ18839@dhcp22.suse.cz \
--to=mhocko@kernel.org \
--cc=ak@linux.intel.com \
--cc=bp@alien8.de \
--cc=dave.hansen@intel.com \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=pavel@ucw.cz \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
--cc=vbabka@suse.cz \
/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
all inboxes | Powered by JetHome®