From: Brendan Jackman <jackmanb@google.com>
To: lsf-pc@lists.linux-foundation.org
Cc: linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>,
Mel Gorman <mgorman@suse.de>,
David Hildenbrand <david@redhat.com>,
Vlastimil Babka <vbabka@suse.cz>,
Michal Hocko <mhocko@kernel.org>,
Johannes Weiner <hannes@cmpxchg.org>
Subject: Re: [LSF/MM/BPF TOPIC] Page allocation for ASI
Date: Fri, 31 Jan 2025 12:08:37 +0100 [thread overview]
Message-ID: <CA+i-1C1gOBLxRxE5YFGzeayYWBYyE_X6oH4D=9eVePt4=ehTig@mail.gmail.com> (raw)
In-Reply-To: <CA+i-1C1oTMZQ51DLPzyC_SD6Z22r1K9LXLcmBaMkPXQJe55jDA@mail.gmail.com>
On Wed, 29 Jan 2025 at 17:35, Brendan Jackman <jackmanb@google.com> wrote:
>
> On Wed, 29 Jan 2025 at 13:40, Brendan Jackman <jackmanb@google.com> wrote:
> > - Can we totally avoid the need to allocate pagetables during allocation, by
> > keeping ASI’s restricted copy of the physmap in-sync with the unrestricted one,
> > different only in _PAGE_PRESENT?
Er, doing that specifically (relying on _PAGE_PRESENT) would be a bad
idea, I forgot how broken the old CPUs are, this would probably let
you exploit L1TF or something.
We would have to munge the PFN too. Anyway as long as we only have to
do that at the leaf pagetable, I think the idea still works, we can
actually just make the entry pmd_none().
next prev parent reply other threads:[~2025-01-31 11:09 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-01-29 12:40 Brendan Jackman
2025-01-29 16:35 ` Brendan Jackman
2025-01-31 11:08 ` Brendan Jackman [this message]
2025-02-05 13:32 ` Brendan Jackman
2025-03-26 15:36 ` Brendan Jackman
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='CA+i-1C1gOBLxRxE5YFGzeayYWBYyE_X6oH4D=9eVePt4=ehTig@mail.gmail.com' \
--to=jackmanb@google.com \
--cc=akpm@linux-foundation.org \
--cc=david@redhat.com \
--cc=hannes@cmpxchg.org \
--cc=linux-mm@kvack.org \
--cc=lsf-pc@lists.linux-foundation.org \
--cc=mgorman@suse.de \
--cc=mhocko@kernel.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