One question about the hypercall to translate gfn to mfn.

["Yu, Zhang" <yu.c.zhang@linux.intel.com>]

Hi all,

   As you can see, we are pushing our XenGT patches to the upstream. One 
feature we need in xen is to translate guests' gfn to mfn in XenGT dom0 
device model.

   Here we may have 2 similar solutions:
   1> Paul told me(and thank you, Paul :)) that there used to be a 
hypercall, XENMEM_translate_gpfn_list, which was removed by Keir in 
commit 2d2f7977a052e655db6748be5dabf5a58f5c5e32, because there was no 
usage at that time. So solution 1 is to revert this commit. However, 
since this hypercall was removed ages ago, the reverting met many 
conflicts, i.e. the gmfn_to_mfn is no longer used in x86, etc.

   2> In our project, we defined a new hypercall 
XENMEM_get_mfn_from_pfn, which has a similar implementation like the 
previous XENMEM_translate_gpfn_list. One of the major differences is 
that this newly defined one is only for x86(called in arch_memory_op), 
so we do not have to worry about the arm side.

   Does anyone has any suggestions about this?
   Thanks in advance. :)

B.R.
Yu