Date: Wed, 24 Jun 2009 20:46:50 +1000 (EST)
From: James Morris <jmorris@namei.org>
To: Joseph Cihula <joseph.cihula@intel.com>
cc: linux-kernel@vger.kernel.org, mingo@elte.hu, arjan@linux.intel.com,
       hpa@zytor.com, andi@firstfloor.org, chrisw@sous-sol.org,
       jbeulich@novell.com, peterm@redhat.com, gang.wei@intel.com,
       shane.wang@intel.com
Subject: Re: [RFC v5][PATCH 2/4] intel_txt: Intel(R) TXT reboot/halt shutdown
 support
In-Reply-To: <4A4024BE.5090206@intel.com>
Message-ID: <alpine.LRH.2.00.0906242045290.18503@tundra.namei.org>
References: <4A4024BE.5090206@intel.com>
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On Mon, 22 Jun 2009, Joseph Cihula wrote:

> Support for graceful handling of kernel reboots after an Intel(R) TXT launch.
> 
> Without this patch, attempting to reboot or halt the system will cause the
> TXT hardware to lock memory upon system restart because the secrets-in-memory
> flag that was set on launch was never cleared.  This will in turn cause BIOS
> to execute a TXT Authenticated Code Module (ACM) that will scrub all of memory
> and then unlock it.  Depending on the amount of memory in the system and its type,
> this may take some time.
> 

Does this mean that after a power failure, the system will perform this 
memory scrub on the next boot?  How long does it take per MB on a typical 
system?


-- 
James Morris
<jmorris@namei.org>
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