Merge branch 'master'; commit 'v2.6.38-rc7' into next

1 files changed, 13 insertions, 3 deletions

diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h
index 8760cc60a21c..f25bdf238a33 100644
--- a/arch/x86/include/asm/xen/page.h
+++ b/arch/x86/include/asm/xen/page.h
@@ -42,6 +42,11 @@ extern unsigned int   machine_to_phys_order;
 extern unsigned long get_phys_to_machine(unsigned long pfn);
 extern bool set_phys_to_machine(unsigned long pfn, unsigned long mfn);
 
+extern int m2p_add_override(unsigned long mfn, struct page *page);
+extern int m2p_remove_override(struct page *page);
+extern struct page *m2p_find_override(unsigned long mfn);
+extern unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn);
+
 static inline unsigned long pfn_to_mfn(unsigned long pfn)
 {
 	unsigned long mfn;
@@ -72,9 +77,6 @@ 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))
-		return ~0;
-
 	pfn = 0;
 	/*
 	 * The array access can fail (e.g., device space beyond end of RAM).
@@ -83,6 +85,14 @@ static inline unsigned long mfn_to_pfn(unsigned long mfn)
 	 */
 	__get_user(pfn, &machine_to_phys_mapping[mfn]);
 
+	/*
+	 * If this appears to be a foreign mfn (because the pfn
+	 * doesn't map back to the mfn), then check the local override
+	 * table to see if there's a better pfn to use.
+	 */
+	if (get_phys_to_machine(pfn) != mfn)
+		pfn = m2p_find_override_pfn(mfn, pfn);
+
 	return pfn;
 }