diff --git a/hw/display/xenfb.c b/hw/display/xenfb.c
index 032eb7a9a5..07ddc9deba 100644
--- a/hw/display/xenfb.c
+++ b/hw/display/xenfb.c
@@ -93,10 +93,12 @@ struct XenFB {
 
 static int common_bind(struct common *c)
 {
-    int mfn;
+    uint64_t mfn;
 
-    if (xenstore_read_fe_int(&c->xendev, "page-ref", &mfn) == -1)
+    if (xenstore_read_fe_uint64(&c->xendev, "page-ref", &mfn) == -1)
 	return -1;
+    assert(mfn == (xen_pfn_t)mfn);
+
     if (xenstore_read_fe_int(&c->xendev, "event-channel", &c->xendev.remote_port) == -1)
 	return -1;
 
@@ -107,7 +109,7 @@ static int common_bind(struct common *c)
 	return -1;
 
     xen_be_bind_evtchn(&c->xendev);
-    xen_be_printf(&c->xendev, 1, "ring mfn %d, remote-port %d, local-port %d\n",
+    xen_be_printf(&c->xendev, 1, "ring mfn %"PRIx64", remote-port %d, local-port %d\n",
 		  mfn, c->xendev.remote_port, c->xendev.local_port);
 
     return 0;
@@ -409,7 +411,7 @@ static void input_event(struct XenDevice *xendev)
 
 /* -------------------------------------------------------------------- */
 
-static void xenfb_copy_mfns(int mode, int count, unsigned long *dst, void *src)
+static void xenfb_copy_mfns(int mode, int count, xen_pfn_t *dst, void *src)
 {
     uint32_t *src32 = src;
     uint64_t *src64 = src;
@@ -424,8 +426,8 @@ static int xenfb_map_fb(struct XenFB *xenfb)
     struct xenfb_page *page = xenfb->c.page;
     char *protocol = xenfb->c.xendev.protocol;
     int n_fbdirs;
-    unsigned long *pgmfns = NULL;
-    unsigned long *fbmfns = NULL;
+    xen_pfn_t *pgmfns = NULL;
+    xen_pfn_t *fbmfns = NULL;
     void *map, *pd;
     int mode, ret = -1;
 
@@ -483,8 +485,8 @@ static int xenfb_map_fb(struct XenFB *xenfb)
     n_fbdirs = xenfb->fbpages * mode / 8;
     n_fbdirs = (n_fbdirs + (XC_PAGE_SIZE - 1)) / XC_PAGE_SIZE;
 
-    pgmfns = g_malloc0(sizeof(unsigned long) * n_fbdirs);
-    fbmfns = g_malloc0(sizeof(unsigned long) * xenfb->fbpages);
+    pgmfns = g_malloc0(sizeof(xen_pfn_t) * n_fbdirs);
+    fbmfns = g_malloc0(sizeof(xen_pfn_t) * xenfb->fbpages);
 
     xenfb_copy_mfns(mode, n_fbdirs, pgmfns, pd);
     map = xc_map_foreign_pages(xen_xc, xenfb->c.xendev.dom,
diff --git a/xen-hvm.c b/xen-hvm.c
index bafdf1283f..c928b36a45 100644
--- a/xen-hvm.c
+++ b/xen-hvm.c
@@ -390,7 +390,7 @@ static int xen_remove_from_physmap(XenIOState *state,
     start_addr >>= TARGET_PAGE_BITS;
     phys_offset >>= TARGET_PAGE_BITS;
     for (i = 0; i < size; i++) {
-        unsigned long idx = start_addr + i;
+        xen_pfn_t idx = start_addr + i;
         xen_pfn_t gpfn = phys_offset + i;
 
         rc = xc_domain_add_to_physmap(xen_xc, xen_domid, XENMAPSPACE_gmfn, idx, gpfn);
diff --git a/xen-mapcache.c b/xen-mapcache.c
index eda914a75c..66da1a6d47 100644
--- a/xen-mapcache.c
+++ b/xen-mapcache.c
@@ -33,10 +33,10 @@
 #  define DPRINTF(fmt, ...) do { } while (0)
 #endif
 
-#if defined(__i386__)
+#if HOST_LONG_BITS == 32
 #  define MCACHE_BUCKET_SHIFT 16
 #  define MCACHE_MAX_SIZE     (1UL<<31) /* 2GB Cap */
-#elif defined(__x86_64__)
+#else
 #  define MCACHE_BUCKET_SHIFT 20
 #  define MCACHE_MAX_SIZE     (1UL<<35) /* 32GB Cap */
 #endif