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From: Andi Kleen <andi@firstfloor.org>
To: Avi Kivity <avi@redhat.com>
Cc: Kuniyasu Suzaki <k.suzaki@aist.go.jp>,
	anthony@codemonkey.ws, stefanha@gmail.com, kvm@vger.kernel.org
Subject: Re: EuroSec'11 Presentation
Date: Wed, 13 Apr 2011 11:04:05 -0700	[thread overview]
Message-ID: <m2fwpm9gfe.fsf@firstfloor.org> (raw)
In-Reply-To: <4DA322D9.40304@redhat.com> (Avi Kivity's message of "Mon, 11 Apr 2011 18:48:41 +0300")

Avi Kivity <avi@redhat.com> writes:
>
> With EPT or NPT you cannot detect if a page is read only.

Why not? You can always walk the page tables manually again.

> Furthermore, at least Linux (without highmem) maps all of memory with
> a read/write mapping in addition to the per-process mapping, so no
> page is read-only.

Even with 32bit highmem most memory will be eventually mapped writable by
kmap when. There's currently no concept of a ro-kmap. However I suspect
it wouldn't be too hard to add one.

-Andi

-- 
ak@linux.intel.com -- Speaking for myself only

  parent reply	other threads:[~2011-04-13 18:04 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-04-10 14:23 EuroSec'11 Presentation Kuniyasu Suzaki
2011-04-10 14:49 ` Avi Kivity
2011-04-10 15:19   ` Kuniyasu Suzaki
2011-04-11  8:51     ` Stefan Hajnoczi
2011-04-11 15:26       ` Kuniyasu Suzaki
2011-04-11 15:27       ` Anthony Liguori
2011-04-11 15:46         ` Kuniyasu Suzaki
2011-04-11 15:48           ` Avi Kivity
2011-04-11 16:01             ` Kuniyasu Suzaki
2011-04-13 18:04             ` Andi Kleen [this message]
2011-04-11 17:19           ` Anthony Liguori
2011-04-12 13:16             ` Kuniyasu Suzaki
2011-04-11 16:25         ` Stefan Hajnoczi
2011-04-11 17:22           ` Anthony Liguori

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