xen/m2p: No need to catch exceptions when we know that there is no RAM

.. beyound what we think is the end of memory. However there might
be more System RAM - but assigned to a guest. Hence jump to the
M2P override check and consult.

[v1: Added Review-by tag]

Reviewed-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This commit is contained in:
Konrad Rzeszutek Wilk 2011-01-14 17:55:44 -05:00
parent fc25151d9a
commit 146c4e5117
1 changed files with 5 additions and 1 deletions

View File

@ -85,6 +85,10 @@ static inline unsigned long mfn_to_pfn(unsigned long mfn)
if (xen_feature(XENFEAT_auto_translated_physmap))
return mfn;
if (unlikely((mfn >> machine_to_phys_order) != 0)) {
pfn = ~0;
goto try_override;
}
pfn = 0;
/*
* The array access can fail (e.g., device space beyond end of RAM).
@ -92,7 +96,7 @@ static inline unsigned long mfn_to_pfn(unsigned long mfn)
* but we must handle the fault without crashing!
*/
__get_user(pfn, &machine_to_phys_mapping[mfn]);
try_override:
/*
* If this appears to be a foreign mfn (because the pfn
* doesn't map back to the mfn), then check the local override