diff --git a/cpu-common.h b/cpu-common.h
index 4890da4..f430f2d 100644
--- a/cpu-common.h
+++ b/cpu-common.h
@@ -40,8 +40,10 @@ static inline void cpu_register_physical_memory(target_phys_addr_t start_addr,
 }
 
 ram_addr_t cpu_get_physical_page_desc(target_phys_addr_t addr);
-ram_addr_t qemu_ram_map(ram_addr_t size, void *host);
+ram_addr_t qemu_ram_map(DeviceState *dev, const char *name,
+                        ram_addr_t size, void *host);
 ram_addr_t qemu_ram_alloc(DeviceState *dev, const char *name, ram_addr_t size);
+void qemu_ram_unmap(ram_addr_t addr);
 void qemu_ram_free(ram_addr_t addr);
 /* This should only be used for ram local to a device.  */
 void *qemu_get_ram_ptr(ram_addr_t addr);
diff --git a/exec.c b/exec.c
index 7c7e7bc..6347e61 100644
--- a/exec.c
+++ b/exec.c
@@ -2787,33 +2787,6 @@ static void *file_ram_alloc(RAMBlock *block,
 }
 #endif
 
-ram_addr_t qemu_ram_map(ram_addr_t size, void *host)
-{
-    RAMBlock *new_block;
-
-    size = TARGET_PAGE_ALIGN(size);
-    new_block = qemu_malloc(sizeof(*new_block));
-
-    new_block->host = host;
-
-    new_block->offset = ram_list.last_offset;
-    new_block->length = size;
-
-    QLIST_INSERT_HEAD(&ram_list.blocks, new_block, next);
-
-    ram_list.phys_dirty = qemu_realloc(ram_list.phys_dirty,
-        (ram_list.last_offset + size) >> TARGET_PAGE_BITS);
-    memset(ram_list.phys_dirty + (ram_list.last_offset >> TARGET_PAGE_BITS),
-           0xff, size >> TARGET_PAGE_BITS);
-
-    ram_list.last_offset += size;
-
-    if (kvm_enabled())
-        kvm_setup_guest_memory(new_block->host, size);
-
-    return new_block->offset;
-}
-
 static ram_addr_t find_ram_offset(ram_addr_t size)
 {
     RAMBlock *block, *next_block;
@@ -2851,6 +2824,49 @@ static ram_addr_t last_ram_offset(void)
     return last;
 }
 
+ram_addr_t qemu_ram_map(DeviceState *dev, const char *name,
+                        ram_addr_t size, void *host)
+{
+    RAMBlock *new_block, *block;
+
+    size = TARGET_PAGE_ALIGN(size);
+    new_block = qemu_mallocz(sizeof(*new_block));
+
+    if (dev && dev->parent_bus && dev->parent_bus->info->get_dev_path) {
+        char *id = dev->parent_bus->info->get_dev_path(dev);
+        if (id) {
+            snprintf(new_block->idstr, sizeof(new_block->idstr), "%s/", id);
+            qemu_free(id);
+        }
+    }
+    pstrcat(new_block->idstr, sizeof(new_block->idstr), name);
+
+    QLIST_FOREACH(block, &ram_list.blocks, next) {
+        if (!strcmp(block->idstr, new_block->idstr)) {
+            fprintf(stderr, "RAMBlock \"%s\" already registered, abort!\n",
+                    new_block->idstr);
+            abort();
+        }
+    }
+
+    new_block->host = host;
+
+    new_block->offset = find_ram_offset(size);
+    new_block->length = size;
+
+    QLIST_INSERT_HEAD(&ram_list.blocks, new_block, next);
+
+    ram_list.phys_dirty = qemu_realloc(ram_list.phys_dirty,
+                                       last_ram_offset() >> TARGET_PAGE_BITS);
+    memset(ram_list.phys_dirty + (new_block->offset >> TARGET_PAGE_BITS),
+           0xff, size >> TARGET_PAGE_BITS);
+
+    if (kvm_enabled())
+        kvm_setup_guest_memory(new_block->host, size);
+
+    return new_block->offset;
+}
+
 ram_addr_t qemu_ram_alloc(DeviceState *dev, const char *name, ram_addr_t size)
 {
     RAMBlock *new_block, *block;
@@ -2917,6 +2933,19 @@ ram_addr_t qemu_ram_alloc(DeviceState *dev, const char *name, ram_addr_t size)
     return new_block->offset;
 }
 
+void qemu_ram_unmap(ram_addr_t addr)
+{
+    RAMBlock *block;
+
+    QLIST_FOREACH(block, &ram_list.blocks, next) {
+        if (addr == block->offset) {
+            QLIST_REMOVE(block, next);
+            qemu_free(block);
+            return;
+        }
+    }
+}
+
 void qemu_ram_free(ram_addr_t addr)
 {
     RAMBlock *block;
diff --git a/hw/device-assignment.c b/hw/device-assignment.c
index 48ac73c..cbbf37f 100644
--- a/hw/device-assignment.c
+++ b/hw/device-assignment.c
@@ -571,9 +571,13 @@ static int assigned_dev_register_regions(PCIRegion *io_regions,
 
             if (!slow_map) {
                 void *virtbase = pci_dev->v_addrs[i].u.r_virtbase;
-
-                pci_dev->v_addrs[i].memory_index = qemu_ram_map(cur_region->size,
-                                                                virtbase);
+                char name[32];
+                snprintf(name, sizeof(name), "%s.bar%d",
+                         pci_dev->dev.qdev.info->name, i);
+                pci_dev->v_addrs[i].memory_index =
+                                            qemu_ram_map(&pci_dev->dev.qdev,
+                                                         name, cur_region->size,
+                                                         virtbase);
             } else
                 pci_dev->v_addrs[i].memory_index = 0;
 
@@ -779,9 +783,14 @@ static void free_assigned_device(AssignedDevice *dev)
                 continue;
             } else if (pci_region->type & IORESOURCE_MEM) {
                 if (region->u.r_virtbase) {
-                    int ret = munmap(region->u.r_virtbase,
-                                     (pci_region->size + 0xFFF) & 0xFFFFF000);
-                    if (ret != 0)
+                    if (region->memory_index) {
+                        cpu_register_physical_memory(region->e_physbase,
+                                                     region->e_size,
+                                                     IO_MEM_UNASSIGNED);
+                        qemu_ram_unmap(region->memory_index);
+                    }
+                    if (munmap(region->u.r_virtbase,
+                               (pci_region->size + 0xFFF) & 0xFFFFF000))
                         fprintf(stderr,
 				"Failed to unmap assigned device region: %s\n",
 				strerror(errno));
diff --git a/hw/i8254-kvm.c b/hw/i8254-kvm.c
index c62ab6a..6125213 100644
--- a/hw/i8254-kvm.c
+++ b/hw/i8254-kvm.c
@@ -114,7 +114,7 @@ PITState *kvm_pit_init(int base, qemu_irq irq)
     s->irq_timer = qemu_new_timer(vm_clock, dummy_timer, s);
     vmstate_pit.pre_save = kvm_pit_pre_save;
     vmstate_pit.post_load = kvm_pit_post_load;
-    vmstate_register(base, &vmstate_pit, pit);
+    vmstate_register(NULL, base, &vmstate_pit, pit);
     qemu_register_reset(pit_reset, pit);
     pit_reset(pit);
 
diff --git a/hw/i8259.c b/hw/i8259.c
index 70da847..11060d3 100644
--- a/hw/i8259.c
+++ b/hw/i8259.c
@@ -658,7 +658,7 @@ static void kvm_i8259_set_irq(void *opaque, int irq, int level)
 
 static void kvm_pic_init1(int io_addr, PicState *s)
 {
-    vmstate_register(io_addr, &vmstate_pic, s);
+    vmstate_register(NULL, io_addr, &vmstate_pic, s);
     qemu_register_reset(pic_reset, s);
 }
 
diff --git a/kvm-tpr-opt.c b/kvm-tpr-opt.c
index 429c2f4..46890e2 100644
--- a/kvm-tpr-opt.c
+++ b/kvm-tpr-opt.c
@@ -370,7 +370,7 @@ static void vtpr_ioport_write(void *opaque, uint32_t addr, uint32_t val)
 
 static void kvm_tpr_opt_setup(void)
 {
-    register_savevm("kvm-tpr-opt", 0, 1, tpr_save, tpr_load, NULL);
+    register_savevm(NULL, "kvm-tpr-opt", 0, 1, tpr_save, tpr_load, NULL);
     register_ioport_write(0x7e, 1, 1, vtpr_ioport_write, NULL);
     register_ioport_write(0x7e, 2, 2, vtpr_ioport_write16, NULL);
 }
diff --git a/qemu-kvm-x86.c b/qemu-kvm-x86.c
index 403337a..fd426b7 100644
--- a/qemu-kvm-x86.c
+++ b/qemu-kvm-x86.c
@@ -598,7 +598,7 @@ int kvm_arch_qemu_create_context(void)
 
 #ifdef KVM_CAP_ADJUST_CLOCK
     if (kvm_check_extension(kvm_state, KVM_CAP_ADJUST_CLOCK))
-        vmstate_register(0, &vmstate_kvmclock, &kvmclock_data);
+        vmstate_register(NULL, 0, &vmstate_kvmclock, &kvmclock_data);
 #endif
 
     r = kvm_set_boot_cpu_id(0);
