diff --git a/xen-all.c b/xen-all.c
index 61def2ec8f48e615b2818150cd4c0a5f425b9315..f76b051eee2d9f0a98a0be7d75d5928ac6cc108a 100644
--- a/xen-all.c
+++ b/xen-all.c
@@ -712,7 +712,8 @@ static void cpu_ioreq_pio(ioreq_t *req)
 
             for (i = 0; i < req->count; i++) {
                 tmp = do_inp(req->addr, req->size);
-                cpu_physical_memory_write(req->data + (sign * i * req->size),
+                cpu_physical_memory_write(
+                        req->data + (sign * i * (int64_t)req->size),
                         (uint8_t *) &tmp, req->size);
             }
         }
@@ -723,7 +724,8 @@ static void cpu_ioreq_pio(ioreq_t *req)
             for (i = 0; i < req->count; i++) {
                 uint32_t tmp = 0;
 
-                cpu_physical_memory_read(req->data + (sign * i * req->size),
+                cpu_physical_memory_read(
+                        req->data + (sign * i * (int64_t)req->size),
                         (uint8_t*) &tmp, req->size);
                 do_outp(req->addr, req->size, tmp);
             }
@@ -740,12 +742,14 @@ static void cpu_ioreq_move(ioreq_t *req)
     if (!req->data_is_ptr) {
         if (req->dir == IOREQ_READ) {
             for (i = 0; i < req->count; i++) {
-                cpu_physical_memory_read(req->addr + (sign * i * req->size),
+                cpu_physical_memory_read(
+                        req->addr + (sign * i * (int64_t)req->size),
                         (uint8_t *) &req->data, req->size);
             }
         } else if (req->dir == IOREQ_WRITE) {
             for (i = 0; i < req->count; i++) {
-                cpu_physical_memory_write(req->addr + (sign * i * req->size),
+                cpu_physical_memory_write(
+                        req->addr + (sign * i * (int64_t)req->size),
                         (uint8_t *) &req->data, req->size);
             }
         }
@@ -754,16 +758,20 @@ static void cpu_ioreq_move(ioreq_t *req)
 
         if (req->dir == IOREQ_READ) {
             for (i = 0; i < req->count; i++) {
-                cpu_physical_memory_read(req->addr + (sign * i * req->size),
+                cpu_physical_memory_read(
+                        req->addr + (sign * i * (int64_t)req->size),
                         (uint8_t*) &tmp, req->size);
-                cpu_physical_memory_write(req->data + (sign * i * req->size),
+                cpu_physical_memory_write(
+                        req->data + (sign * i * (int64_t)req->size),
                         (uint8_t*) &tmp, req->size);
             }
         } else if (req->dir == IOREQ_WRITE) {
             for (i = 0; i < req->count; i++) {
-                cpu_physical_memory_read(req->data + (sign * i * req->size),
+                cpu_physical_memory_read(
+                        req->data + (sign * i * (int64_t)req->size),
                         (uint8_t*) &tmp, req->size);
-                cpu_physical_memory_write(req->addr + (sign * i * req->size),
+                cpu_physical_memory_write(
+                        req->addr + (sign * i * (int64_t)req->size),
                         (uint8_t*) &tmp, req->size);
             }
         }
diff --git a/xen-mapcache.c b/xen-mapcache.c
index 59ba085b623d79fec761b659e98e10fd70b3c275..9cd6db3d7b01bcc55782d57d212d07c9dd74dc6c 100644
--- a/xen-mapcache.c
+++ b/xen-mapcache.c
@@ -320,10 +320,6 @@ void xen_invalidate_map_cache_entry(uint8_t *buffer)
     target_phys_addr_t size;
     int found = 0;
 
-    if (mapcache->last_address_vaddr == buffer) {
-        mapcache->last_address_index = -1;
-    }
-
     QTAILQ_FOREACH(reventry, &mapcache->locked_entries, next) {
         if (reventry->vaddr_req == buffer) {
             paddr_index = reventry->paddr_index;
@@ -342,6 +338,11 @@ void xen_invalidate_map_cache_entry(uint8_t *buffer)
     QTAILQ_REMOVE(&mapcache->locked_entries, reventry, next);
     g_free(reventry);
 
+    if (mapcache->last_address_index == paddr_index) {
+        mapcache->last_address_index = -1;
+        mapcache->last_address_vaddr = NULL;
+    }
+
     entry = &mapcache->entry[paddr_index % mapcache->nr_buckets];
     while (entry && (entry->paddr_index != paddr_index || entry->size != size)) {
         pentry = entry;