diff --git a/xen/Rules.mk b/xen/Rules.mk
index 3f0b262..bc6b437 100644
--- a/xen/Rules.mk
+++ b/xen/Rules.mk
@@ -3,6 +3,7 @@
 # If you change any of these configuration options then you must
 # 'make clean' before rebuilding.
 #
+debug := y
 verbose       ?= n
 perfc         ?= n
 perfc_arrays  ?= n
diff --git a/xen/arch/x86/domain_page.c b/xen/arch/x86/domain_page.c
index efda6af..af63d76 100644
--- a/xen/arch/x86/domain_page.c
+++ b/xen/arch/x86/domain_page.c
@@ -59,12 +59,12 @@ void __init mapcache_override_current(struct vcpu *v)
 void *map_domain_page(unsigned long mfn)
 {
     unsigned long flags;
-    unsigned int idx, i;
+    unsigned int idx, i, j = 0;
     struct vcpu *v;
     struct mapcache_domain *dcache;
     struct mapcache_vcpu *vcache;
     struct vcpu_maphash_entry *hashent;
-
+    int branch = 0;
 #ifdef NDEBUG
     if ( mfn <= PFN_DOWN(__pa(HYPERVISOR_VIRT_END - 1)) )
         return mfn_to_virt(mfn);
@@ -115,31 +115,67 @@ void *map_domain_page(unsigned long mfn)
         /* /First/, clean the garbage map and update the inuse list. */
         for ( i = 0; i < BITS_TO_LONGS(dcache->entries); i++ )
         {
+            unsigned long garbage = dcache->garbage[i];
+            unsigned long _inuse = dcache->inuse[i];
+            barrier();
             dcache->inuse[i] &= ~xchg(&dcache->garbage[i], 0);
+            if (v->domain->domain_id) {
+                if (~dcache->inuse[i]) {
+                    gdprintk(XENLOG_INFO, "mfn: %lx, [%d]: %lx, ~%lx, idx: %d garbage: %lx, inuse: %lx\n", mfn, i, dcache->inuse[i], ~dcache->inuse[i],
+                             find_first_zero_bit(dcache->inuse, dcache->entries), garbage, _inuse);
+                    branch |= 8;
+                }
+            }
             accum |= ~dcache->inuse[i];
         }
 
-        if ( accum )
+        if ( accum ) {
             idx = find_first_zero_bit(dcache->inuse, dcache->entries);
+            branch |= 1;
+        }
         else
         {
+            branch |= 2;
             /* Replace a hash entry instead. */
             i = MAPHASH_HASHFN(mfn);
             do {
                 hashent = &vcache->hash[i];
                 if ( hashent->idx != MAPHASHENT_NOTINUSE && !hashent->refcnt )
                 {
+                    branch |= 4;
                     idx = hashent->idx;
                     ASSERT(l1e_get_pfn(MAPCACHE_L1ENT(idx)) == hashent->mfn);
                     l1e_write(&MAPCACHE_L1ENT(idx), l1e_empty());
                     hashent->idx = MAPHASHENT_NOTINUSE;
                     hashent->mfn = ~0UL;
+                    if (idx >= dcache->entries) {
+                        branch |= 8;
+                        gdprintk(XENLOG_INFO, "mfn (%lx) -> %ld idx (iter:%d)\n", mfn,  MAPHASH_HASHFN(mfn), j);
+
+                        for (i = 0; i < MAPHASH_ENTRIES;i++) {
+                            hashent = &vcache->hash[i];
+
+                            gdprintk(XENLOG_INFO, "[%d] idx=%d, mfn=0x%lx, refcnt: %d\n",
+                                    i, hashent->idx, hashent->mfn, hashent->refcnt);
+                        }
+                    }
                     break;
                 }
                 if ( ++i == MAPHASH_ENTRIES )
                     i = 0;
+                j++;
             } while ( i != MAPHASH_HASHFN(mfn) );
         }
+        if (idx >= dcache->entries) {
+           gdprintk(XENLOG_INFO, "mfn (%lx) -> %ld idx: %d(i:%d,j:%d), branch:%x 0x%lx\n", mfn,  MAPHASH_HASHFN(mfn), idx,  i, j, branch, accum);
+
+           for (i = 0; i < MAPHASH_ENTRIES;i++) {
+                    hashent = &vcache->hash[i];
+
+                    gdprintk(XENLOG_INFO, "[%d] idx=%d, mfn=0x%lx, refcnt: %d\n",
+                                    i, hashent->idx, hashent->mfn, hashent->refcnt);
+           }
+        }
         BUG_ON(idx >= dcache->entries);
 
         /* /Second/, flush TLBs. */
@@ -254,6 +290,7 @@ int mapcache_domain_init(struct domain *d)
                  2 * PFN_UP(BITS_TO_LONGS(MAPCACHE_ENTRIES) * sizeof(long))) >
                  MAPCACHE_VIRT_START + (PERDOMAIN_SLOT_MBYTES << 20));
     bitmap_pages = PFN_UP(BITS_TO_LONGS(MAPCACHE_ENTRIES) * sizeof(long));
+    gdprintk(XENLOG_INFO, "domain bitmap pages: %d\n", bitmap_pages);
     dcache->inuse = (void *)MAPCACHE_VIRT_END + PAGE_SIZE;
     dcache->garbage = dcache->inuse +
                       (bitmap_pages + 1) * PAGE_SIZE / sizeof(long);
@@ -276,6 +313,7 @@ int mapcache_vcpu_init(struct vcpu *v)
     if ( is_hvm_vcpu(v) || !dcache->inuse )
         return 0;
 
+    gdprintk(XENLOG_INFO, "ents: %d, entries: %d\n", ents, dcache->entries);
     if ( ents > dcache->entries )
     {
         /* Populate page tables. */