Re: c/s 21886 change to DMAR table hiding

[Juergen Gross <juergen.gross@ts.fujitsu.com>]

On 10/29/10 08:06, Cihula, Joseph wrote:
> Keir,
>
> In c/s 21886, you changed the method by which the DMAR ACPI table was hidden from dom0.  Why was this change needed?
> -    dmar->header.signature[0] = '\0';
> +    dmar->header.signature[0] = 'X';
> +    dmar->header.checksum -= 'X'-'D';
>
> I ask because tboot was using the original method to unhide/re-hide the table during S3 (because the TXT launch on S3 resume requires a valid DMAR table) and this has broken S3 w/ TXT.

Please see discussion under
http://lists.xensource.com/archives/html/xen-devel/2010-07/msg01517.html

Problem was crash kernel not comig up with the original DMAR hide.


Juergen

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