From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Razvan Cojocaru <rcojocaru@bitdefender.com>, xen-devel@lists.xen.org
Cc: keir@xen.org, jbeulich@suse.com
Subject: Re: [PATCH] xen: Disable REP MOVSD optimization if introspection is active
Date: Mon, 27 Oct 2014 10:50:43 +0000 [thread overview]
Message-ID: <544E2383.1020604@citrix.com> (raw)
In-Reply-To: <1414406263-11421-1-git-send-email-rcojocaru@bitdefender.com>
On 27/10/14 10:37, Razvan Cojocaru wrote:
> REP MOVSD emulation is optimized to write several pages at once
> if possible. While this is a very good thing in general, it
> can interfere with a memory introspection application's ability
> to detect suspect behaviour, since it supresses potentially
> telling future page faults. This patch disables the optimization,
> gated on introspection being active for the domain.
An individual rep_movs() call should only optimise to within the current
page, then break back out to the emulator when passing the page boundary.
How does this suppress pagefaults?
~Andrew
next prev parent reply other threads:[~2014-10-27 10:50 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-27 10:37 [PATCH] xen: Disable REP MOVSD optimization if introspection is active Razvan Cojocaru
2014-10-27 10:50 ` Andrew Cooper [this message]
2014-10-27 11:09 ` Razvan Cojocaru
2014-10-27 11:14 ` Andrew Cooper
2014-10-27 13:01 ` Jan Beulich
2014-10-27 13:33 ` Razvan Cojocaru
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