gistfile1.diff

diff --git a/arch/arm/xen/p2m.c b/arch/arm/xen/p2m.c
index 97baf44..38291f6 100644
--- a/arch/arm/xen/p2m.c
+++ b/arch/arm/xen/p2m.c
@@ -41,10 +41,16 @@ static int xen_add_phys_to_mach_entry(struct xen_p2m_entry *new)
                parent = *link;
                entry = rb_entry(parent, struct xen_p2m_entry, rbnode_phys);
 
-               if (new->mfn == entry->mfn)
-                       goto err_out;
-               if (new->pfn == entry->pfn)
+               if (new->mfn == entry->mfn || new->pfn == entry->pfn)
                        goto err_out;
+               if (new->pfn == entry->pfn) {
+                       /* Updating mfn */
+                       pr_warn("%s: updating pfn=%pa -> mfn=%pa to mfn=%pa\n", __func__,
+                                       &entry->pfn, &entry->mfn, &new->mfn);
+                       entry->mfn = new->mfn;
+                       goto out;
+               }
+
 
                if (new->pfn < entry->pfn)
                        link = &(*link)->rb_left;
@@ -99,10 +105,15 @@ static int xen_add_mach_to_phys_entry(struct xen_p2m_entry *new)
                parent = *link;
                entry = rb_entry(parent, struct xen_p2m_entry, rbnode_mach);
 
-               if (new->mfn == entry->mfn)
-                       goto err_out;
-               if (new->pfn == entry->pfn)
+               if (new->mfn == entry->mfn && new->pfn == entry->pfn)
                        goto err_out;
+               if (new->mfn == entry->mfn) {
+                       /* Updating pfn */
+                       pr_warn("%s: updating mfn=%pa -> pfn=%pa to pfn=%pa\n", __func__,
+                                       &entry->mfn, &entry->pfn, &new->pfn);
+                       entry->pfn = new->pfn;
+                       goto out;
+               }
 
                if (new->mfn < entry->mfn)
                        link = &(*link)->rb_left;