From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Zhai, Edwin" <edwin.zhai@intel.com>
Subject: save/restore compatibility broken
Date: Thu, 12 Feb 2009 21:39:09 +0800
Message-ID: <4994267D.5020903@intel.com>
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To: Keir.Fraser@cl.cam.ac.uk
Cc: xen-devel@lists.xensource.com, "Zhai, Edwin" <edwin.zhai@intel.com>
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Keir,
 From r17037, hvm_{get|set}_segment_register are used to save/restore
the VMCS segment register. But they introduce new compat image format
for xx_arbytes, i.e.
reg->attr.bytes = (attr & 0xff) | ((attr >> 4) & 0xf00);

This caused wrong VMCS setting for arbytes when restore old image on
new changeset.

How to fix it? Can we determine it's old format if bit 12~15 of
cs_arbytes is not zero, and then translate it?

Thanks,
edwin