As implemented here, only supported on platforms with VMX HAP.
By default this functionality is force-disabled, it can be enabled
by specifying altp2m=1 on the Xen command line.
Signed-off-by: Ed White <edmund.h.white@intel.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Release-acked-by: Wei Liu <wei.liu2@citrix.com>