diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 1fcaed0..7b38890 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -3142,10 +3142,10 @@ static long hvm_memory_op(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
 
     switch ( cmd & MEMOP_CMD_MASK )
     {
-    case XENMEM_memory_map:
     case XENMEM_machine_memory_map:
     case XENMEM_machphys_mapping:
         return -ENOSYS;
+    case XENMEM_memory_map:
     case XENMEM_decrease_reservation:
         rc = do_memory_op(cmd, arg);
         current->domain->arch.hvm_domain.qemu_mapcache_invalidate = 1;
@@ -3216,10 +3217,10 @@ static long hvm_memory_op_compat32(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
 
     switch ( cmd & MEMOP_CMD_MASK )
     {
-    case XENMEM_memory_map:
     case XENMEM_machine_memory_map:
     case XENMEM_machphys_mapping:
         return -ENOSYS;
+    case XENMEM_memory_map:
     case XENMEM_decrease_reservation:
         rc = compat_memory_op(cmd, arg);
         current->domain->arch.hvm_domain.qemu_mapcache_invalidate = 1;
diff --git a/tools/firmware/hvmloader/e820.h.orig b/tools/firmware/hvmloader/e820.h
index b2ead7f..2fa700d 100644
--- a/tools/firmware/hvmloader/e820.h.orig
+++ b/tools/firmware/hvmloader/e820.h
@@ -8,6 +8,9 @@
 #define E820_RESERVED     2
 #define E820_ACPI         3
 #define E820_NVS          4
+#define E820_UNUSABLE     5
+
+#define E820MAX         128
 
 struct e820entry {
     uint64_t addr;
diff --git a/tools/firmware/hvmloader/e820.c b/tools/firmware/hvmloader/e820.c
index 2e05e93..86fb20a 100644
--- a/tools/firmware/hvmloader/e820.c
+++ b/tools/firmware/hvmloader/e820.c
@@ -22,6 +22,9 @@
 
 #include "config.h"
 #include "util.h"
+#include "hypercall.h"
+#include <xen/memory.h>
+#include <errno.h>
 
 void dump_e820_table(struct e820entry *e820, unsigned int nr)
 {
@@ -68,16 +68,42 @@ void dump_e820_table(struct e820entry *e820, unsigned int nr)
     }
 }
 
+static const char *e820_names(int type)
+{
+    switch (type) {
+        case E820_RAM: return "RAM";
+        case E820_RESERVED: return "Reserved";
+        case E820_ACPI: return "ACPI";
+        case E820_NVS: return "ACPI NVS";
+        case E820_UNUSABLE: return "Unusable";
+        default: break;
+    }
+    return "Unknown";
+}
+
+
 /* Create an E820 table based on memory parameters provided in hvm_info. */
 int build_e820_table(struct e820entry *e820,
                      unsigned int lowmem_reserved_base,
                      unsigned int bios_image_base)
 {
     unsigned int nr = 0;
+    struct xen_memory_map op;
+    struct e820entry map[E820MAX];
+    int rc;
 
     if ( !lowmem_reserved_base )
             lowmem_reserved_base = 0xA0000;
 
+    set_xen_guest_handle(op.buffer, map);
+
+    rc = hypercall_memory_op ( XENMEM_memory_map, &op);
+    if ( rc != -ENOSYS) { /* It works!? */
+        int i;
+        for ( i = 0; i < op.nr_entries; i++ )
+            printf("    %llx -> %llx %s\n", map[i].addr >> 12,
+                   (map[i].addr + map[i].size) >> 12, e820_names(map[i].type));
+    }
     /* Lowmem must be at least 512K to keep Windows happy) */
     ASSERT ( lowmem_reserved_base > 512<<10 );