The
previous patch is not quite correct. It still doesn’t handle
the
case where max_page (derived from the max E820_RAM value) which
could
be less than a reserved range (as was pointed out in an earlier
email).
If that range did not have a correct RMRR then again the 
workaround
would miss it. 
 
This
patch changes it so all memory below 4GB is mapped when the 
parameter
is set (minus unusable and xen range).
 
Signed-off-by:
Ross Philipson <ross.philipson@xxxxxxxxxx>
 
Based
on changeset 19267
 
Thanks
Ross
 
 
From: Ross Philipson 
Sent: Sunday, March 01, 2009 4:49 PM
To: 'xen-devel@xxxxxxxxxxxxxxxxxxx'
Subject: [PATCH] Inclusing memory mapping param for dom0 iommu mappings
 
 
 
OK,
cut two of the iommu reserved memory issue patch as we discussed...
 
This
patch adds a boolean boot parameter to xen to allow inclusive
mapping
of all memory below 4GB to the iommu mappings for dom0. The
unusable
ranges and memory occupied by xen are still excluded. The 
parameter
is “iommu_inclusive_mapping=1” and is off by default. In 
addition
to the parameter, a warning is also traced when incorrect 
RMRR
to system memory map values are detected. These are being added
to
address some incorrect BIOS's that do not report correctly the 
requied
reserved memory ranges in the RMRRs. When this occurs it 
currently
can cause early boot hangs and crashes.
 
Signed-off-by:
Ross Philipson <ross.philipson@xxxxxxxxxx>
 
Based
on changeset 19243
 
Thanks
Ross
 
 
Ross Philipson
Senior Software Engineer
Citrix Systems, Inc
14 Crosby Drive
Bedford, MA 01730
781-301-7949
ross.philipson@xxxxxxxxxx