Merge remote-tracking branch 'remotes/ehabkost/tags/machine-next-pull-request' into staging

Machine queue, 2018-05-07

* pc-dimm: factor out MemoryDevice
  (virtio-pmem and virtio-mem will make use of the new abstraction later)
* scripts/device-crash-test: Removed fixed CAN entries

# gpg: Signature made Mon 07 May 2018 18:01:42 BST
# gpg:                using RSA key 2807936F984DC5A6
# gpg: Good signature from "Eduardo Habkost <ehabkost@redhat.com>"
# Primary key fingerprint: 5A32 2FD5 ABC4 D3DB ACCF  D1AA 2807 936F 984D C5A6

* remotes/ehabkost/tags/machine-next-pull-request:
  scripts/device-crash-test: Removed fixed CAN entries
  vl: allow 'maxmem' without 'slot'
  spapr: rename "hotplug memory" terminology to "device memory"
  pc: rename "hotplug memory" terminology to "device memory"
  machine: rename MemoryHotplugState to DeviceMemoryState
  pc-dimm: move actual plug/unplug of a memory region to MemoryDevice
  pc-dimm: factor out capacity and slot checks into MemoryDevice
  pc-dimm: factor out address search into MemoryDevice code
  pc-dimm: pass in the machine and to the MemoryHotplugState
  pc-dimm: no need to pass the memory region
  machine: make MemoryHotplugState accessible via the machine
  pc-dimm: factor out MemoryDevice interface

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

19 files changed, 510 insertions, 358 deletions

diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index c634dcad1d..9bc6d97ea1 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -46,6 +46,7 @@
 #include "hw/acpi/vmgenid.h"
 #include "sysemu/tpm_backend.h"
 #include "hw/timer/mc146818rtc_regs.h"
+#include "hw/mem/memory-device.h"
 #include "sysemu/numa.h"
 
 /* Supported chipsets: */
@@ -2253,7 +2254,7 @@ build_tpm2(GArray *table_data, BIOSLinker *linker, GArray *tcpalog)
 static void build_srat_hotpluggable_memory(GArray *table_data, uint64_t base,
                                            uint64_t len, int default_node)
 {
-    MemoryDeviceInfoList *info_list = qmp_pc_dimm_device_list();
+    MemoryDeviceInfoList *info_list = qmp_memory_device_list();
     MemoryDeviceInfoList *info;
     MemoryDeviceInfo *mi;
     PCDIMMDeviceInfo *di;
@@ -2312,7 +2313,7 @@ build_srat(GArray *table_data, BIOSLinker *linker, MachineState *machine)
     const CPUArchIdList *apic_ids = mc->possible_cpu_arch_ids(machine);
     PCMachineState *pcms = PC_MACHINE(machine);
     ram_addr_t hotplugabble_address_space_size =
-        object_property_get_int(OBJECT(pcms), PC_MACHINE_MEMHP_REGION_SIZE,
+        object_property_get_int(OBJECT(pcms), PC_MACHINE_DEVMEM_REGION_SIZE,
                                 NULL);
 
     srat_start = table_data->len;
@@ -2410,7 +2411,7 @@ build_srat(GArray *table_data, BIOSLinker *linker, MachineState *machine)
      * providing _PXM method if necessary.
      */
     if (hotplugabble_address_space_size) {
-        build_srat_hotpluggable_memory(table_data, pcms->hotplug_memory.base,
+        build_srat_hotpluggable_memory(table_data, machine->device_memory->base,
                                        hotplugabble_address_space_size,
                                        pcms->numa_nodes - 1);
     }
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index b297a5d63b..868893d0a1 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1371,11 +1371,13 @@ void pc_memory_init(PCMachineState *pcms,
         exit(EXIT_FAILURE);
     }
 
-    /* initialize hotplug memory address space */
+    /* always allocate the device memory information */
+    machine->device_memory = g_malloc0(sizeof(*machine->device_memory));
+
+    /* initialize device memory address space */
     if (pcmc->has_reserved_memory &&
         (machine->ram_size < machine->maxram_size)) {
-        ram_addr_t hotplug_mem_size =
-            machine->maxram_size - machine->ram_size;
+        ram_addr_t device_mem_size = machine->maxram_size - machine->ram_size;
 
         if (machine->ram_slots > ACPI_MAX_RAM_SLOTS) {
             error_report("unsupported amount of memory slots: %"PRIu64,
@@ -1390,25 +1392,25 @@ void pc_memory_init(PCMachineState *pcms,
             exit(EXIT_FAILURE);
         }
 
-        pcms->hotplug_memory.base =
+        machine->device_memory->base =
             ROUND_UP(0x100000000ULL + pcms->above_4g_mem_size, 1ULL << 30);
 
         if (pcmc->enforce_aligned_dimm) {
-            /* size hotplug region assuming 1G page max alignment per slot */
-            hotplug_mem_size += (1ULL << 30) * machine->ram_slots;
+            /* size device region assuming 1G page max alignment per slot */
+            device_mem_size += (1ULL << 30) * machine->ram_slots;
         }
 
-        if ((pcms->hotplug_memory.base + hotplug_mem_size) <
-            hotplug_mem_size) {
+        if ((machine->device_memory->base + device_mem_size) <
+            device_mem_size) {
             error_report("unsupported amount of maximum memory: " RAM_ADDR_FMT,
                          machine->maxram_size);
             exit(EXIT_FAILURE);
         }
 
-        memory_region_init(&pcms->hotplug_memory.mr, OBJECT(pcms),
-                           "hotplug-memory", hotplug_mem_size);
-        memory_region_add_subregion(system_memory, pcms->hotplug_memory.base,
-                                    &pcms->hotplug_memory.mr);
+        memory_region_init(&machine->device_memory->mr, OBJECT(pcms),
+                           "device-memory", device_mem_size);
+        memory_region_add_subregion(system_memory, machine->device_memory->base,
+                                    &machine->device_memory->mr);
     }
 
     /* Initialize PC system firmware */
@@ -1429,13 +1431,13 @@ void pc_memory_init(PCMachineState *pcms,
 
     rom_set_fw(fw_cfg);
 
-    if (pcmc->has_reserved_memory && pcms->hotplug_memory.base) {
+    if (pcmc->has_reserved_memory && machine->device_memory->base) {
         uint64_t *val = g_malloc(sizeof(*val));
         PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms);
-        uint64_t res_mem_end = pcms->hotplug_memory.base;
+        uint64_t res_mem_end = machine->device_memory->base;
 
         if (!pcmc->broken_reserved_end) {
-            res_mem_end += memory_region_size(&pcms->hotplug_memory.mr);
+            res_mem_end += memory_region_size(&machine->device_memory->mr);
         }
         *val = cpu_to_le64(ROUND_UP(res_mem_end, 0x1ULL << 30));
         fw_cfg_add_file(fw_cfg, "etc/reserved-memory-end", val, sizeof(*val));
@@ -1462,12 +1464,13 @@ uint64_t pc_pci_hole64_start(void)
 {
     PCMachineState *pcms = PC_MACHINE(qdev_get_machine());
     PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms);
+    MachineState *ms = MACHINE(pcms);
     uint64_t hole64_start = 0;
 
-    if (pcmc->has_reserved_memory && pcms->hotplug_memory.base) {
-        hole64_start = pcms->hotplug_memory.base;
+    if (pcmc->has_reserved_memory && ms->device_memory->base) {
+        hole64_start = ms->device_memory->base;
         if (!pcmc->broken_reserved_end) {
-            hole64_start += memory_region_size(&pcms->hotplug_memory.mr);
+            hole64_start += memory_region_size(&ms->device_memory->mr);
         }
     } else {
         hole64_start = 0x100000000ULL + pcms->above_4g_mem_size;
@@ -1711,7 +1714,7 @@ static void pc_dimm_plug(HotplugHandler *hotplug_dev,
         goto out;
     }
 
-    pc_dimm_memory_plug(dev, &pcms->hotplug_memory, mr, align, &local_err);
+    pc_dimm_memory_plug(dev, MACHINE(pcms), align, &local_err);
     if (local_err) {
         goto out;
     }
@@ -1761,17 +1764,9 @@ static void pc_dimm_unplug(HotplugHandler *hotplug_dev,
                            DeviceState *dev, Error **errp)
 {
     PCMachineState *pcms = PC_MACHINE(hotplug_dev);
-    PCDIMMDevice *dimm = PC_DIMM(dev);
-    PCDIMMDeviceClass *ddc = PC_DIMM_GET_CLASS(dimm);
-    MemoryRegion *mr;
     HotplugHandlerClass *hhc;
     Error *local_err = NULL;
 
-    mr = ddc->get_memory_region(dimm, &local_err);
-    if (local_err) {
-        goto out;
-    }
-
     hhc = HOTPLUG_HANDLER_GET_CLASS(pcms->acpi_dev);
     hhc->unplug(HOTPLUG_HANDLER(pcms->acpi_dev), dev, &local_err);
 
@@ -1779,7 +1774,7 @@ static void pc_dimm_unplug(HotplugHandler *hotplug_dev,
         goto out;
     }
 
-    pc_dimm_memory_unplug(dev, &pcms->hotplug_memory, mr);
+    pc_dimm_memory_unplug(dev, MACHINE(pcms));
     object_unparent(OBJECT(dev));
 
  out:
@@ -2068,12 +2063,12 @@ static HotplugHandler *pc_get_hotpug_handler(MachineState *machine,
 }
 
 static void
-pc_machine_get_hotplug_memory_region_size(Object *obj, Visitor *v,
-                                          const char *name, void *opaque,
-                                          Error **errp)
+pc_machine_get_device_memory_region_size(Object *obj, Visitor *v,
+                                         const char *name, void *opaque,
+                                         Error **errp)
 {
-    PCMachineState *pcms = PC_MACHINE(obj);
-    int64_t value = memory_region_size(&pcms->hotplug_memory.mr);
+    MachineState *ms = MACHINE(obj);
+    int64_t value = memory_region_size(&ms->device_memory->mr);
 
     visit_type_int(v, name, &value, errp);
 }
@@ -2377,8 +2372,8 @@ static void pc_machine_class_init(ObjectClass *oc, void *data)
     nc->nmi_monitor_handler = x86_nmi;
     mc->default_cpu_type = TARGET_DEFAULT_CPU_TYPE;
 
-    object_class_property_add(oc, PC_MACHINE_MEMHP_REGION_SIZE, "int",
-        pc_machine_get_hotplug_memory_region_size, NULL,
+    object_class_property_add(oc, PC_MACHINE_DEVMEM_REGION_SIZE, "int",
+        pc_machine_get_device_memory_region_size, NULL,
         NULL, NULL, &error_abort);
 
     object_class_property_add(oc, PC_MACHINE_MAX_RAM_BELOW_4G, "size",
diff --git a/hw/mem/Makefile.objs b/hw/mem/Makefile.objs
index f12f8b97a2..10be4df2a2 100644
--- a/hw/mem/Makefile.objs
+++ b/hw/mem/Makefile.objs
@@ -1,2 +1,3 @@
 common-obj-$(CONFIG_MEM_HOTPLUG) += pc-dimm.o
+common-obj-$(CONFIG_MEM_HOTPLUG) += memory-device.o
 common-obj-$(CONFIG_NVDIMM) += nvdimm.o
diff --git a/hw/mem/memory-device.c b/hw/mem/memory-device.c
new file mode 100644
index 0000000000..3e04f3954e
--- /dev/null
+++ b/hw/mem/memory-device.c
@@ -0,0 +1,275 @@
+/*
+ * Memory Device Interface
+ *
+ * Copyright ProfitBricks GmbH 2012
+ * Copyright (C) 2014 Red Hat Inc
+ * Copyright (c) 2018 Red Hat Inc
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/mem/memory-device.h"
+#include "hw/qdev.h"
+#include "qapi/error.h"
+#include "hw/boards.h"
+#include "qemu/range.h"
+#include "hw/virtio/vhost.h"
+#include "sysemu/kvm.h"
+
+static gint memory_device_addr_sort(gconstpointer a, gconstpointer b)
+{
+    const MemoryDeviceState *md_a = MEMORY_DEVICE(a);
+    const MemoryDeviceState *md_b = MEMORY_DEVICE(b);
+    const MemoryDeviceClass *mdc_a = MEMORY_DEVICE_GET_CLASS(a);
+    const MemoryDeviceClass *mdc_b = MEMORY_DEVICE_GET_CLASS(b);
+    const uint64_t addr_a = mdc_a->get_addr(md_a);
+    const uint64_t addr_b = mdc_b->get_addr(md_b);
+
+    if (addr_a > addr_b) {
+        return 1;
+    } else if (addr_a < addr_b) {
+        return -1;
+    }
+    return 0;
+}
+
+static int memory_device_build_list(Object *obj, void *opaque)
+{
+    GSList **list = opaque;
+
+    if (object_dynamic_cast(obj, TYPE_MEMORY_DEVICE)) {
+        DeviceState *dev = DEVICE(obj);
+        if (dev->realized) { /* only realized memory devices matter */
+            *list = g_slist_insert_sorted(*list, dev, memory_device_addr_sort);
+        }
+    }
+
+    object_child_foreach(obj, memory_device_build_list, opaque);
+    return 0;
+}
+
+static int memory_device_used_region_size(Object *obj, void *opaque)
+{
+    uint64_t *size = opaque;
+
+    if (object_dynamic_cast(obj, TYPE_MEMORY_DEVICE)) {
+        const DeviceState *dev = DEVICE(obj);
+        const MemoryDeviceState *md = MEMORY_DEVICE(obj);
+        const MemoryDeviceClass *mdc = MEMORY_DEVICE_GET_CLASS(obj);
+
+        if (dev->realized) {
+            *size += mdc->get_region_size(md);
+        }
+    }
+
+    object_child_foreach(obj, memory_device_used_region_size, opaque);
+    return 0;
+}
+
+static void memory_device_check_addable(MachineState *ms, uint64_t size,
+                                        Error **errp)
+{
+    uint64_t used_region_size = 0;
+
+    /* we will need a new memory slot for kvm and vhost */
+    if (kvm_enabled() && !kvm_has_free_slot(ms)) {
+        error_setg(errp, "hypervisor has no free memory slots left");
+        return;
+    }
+    if (!vhost_has_free_slot()) {
+        error_setg(errp, "a used vhost backend has no free memory slots left");
+        return;
+    }
+
+    /* will we exceed the total amount of memory specified */
+    memory_device_used_region_size(OBJECT(ms), &used_region_size);
+    if (used_region_size + size > ms->maxram_size - ms->ram_size) {
+        error_setg(errp, "not enough space, currently 0x%" PRIx64
+                   " in use of total hot pluggable 0x" RAM_ADDR_FMT,
+                   used_region_size, ms->maxram_size - ms->ram_size);
+        return;
+    }
+
+}
+
+uint64_t memory_device_get_free_addr(MachineState *ms, const uint64_t *hint,
+                                     uint64_t align, uint64_t size,
+                                     Error **errp)
+{
+    uint64_t address_space_start, address_space_end;
+    GSList *list = NULL, *item;
+    uint64_t new_addr = 0;
+
+    if (!ms->device_memory) {
+        error_setg(errp, "memory devices (e.g. for memory hotplug) are not "
+                         "supported by the machine");
+        return 0;
+    }
+
+    if (!memory_region_size(&ms->device_memory->mr)) {
+        error_setg(errp, "memory devices (e.g. for memory hotplug) are not "
+                         "enabled, please specify the maxmem option");
+        return 0;
+    }
+    address_space_start = ms->device_memory->base;
+    address_space_end = address_space_start +
+                        memory_region_size(&ms->device_memory->mr);
+    g_assert(QEMU_ALIGN_UP(address_space_start, align) == address_space_start);
+    g_assert(address_space_end >= address_space_start);
+
+    memory_device_check_addable(ms, size, errp);
+    if (*errp) {
+        return 0;
+    }
+
+    if (hint && QEMU_ALIGN_UP(*hint, align) != *hint) {
+        error_setg(errp, "address must be aligned to 0x%" PRIx64 " bytes",
+                   align);
+        return 0;
+    }
+
+    if (QEMU_ALIGN_UP(size, align) != size) {
+        error_setg(errp, "backend memory size must be multiple of 0x%"
+                   PRIx64, align);
+        return 0;
+    }
+
+    if (hint) {
+        new_addr = *hint;
+        if (new_addr < address_space_start) {
+            error_setg(errp, "can't add memory [0x%" PRIx64 ":0x%" PRIx64
+                       "] at 0x%" PRIx64, new_addr, size, address_space_start);
+            return 0;
+        } else if ((new_addr + size) > address_space_end) {
+            error_setg(errp, "can't add memory [0x%" PRIx64 ":0x%" PRIx64
+                       "] beyond 0x%" PRIx64, new_addr, size,
+                       address_space_end);
+            return 0;
+        }
+    } else {
+        new_addr = address_space_start;
+    }
+
+    /* find address range that will fit new memory device */
+    object_child_foreach(OBJECT(ms), memory_device_build_list, &list);
+    for (item = list; item; item = g_slist_next(item)) {
+        const MemoryDeviceState *md = item->data;
+        const MemoryDeviceClass *mdc = MEMORY_DEVICE_GET_CLASS(OBJECT(md));
+        uint64_t md_size, md_addr;
+
+        md_addr = mdc->get_addr(md);
+        md_size = mdc->get_region_size(md);
+        if (*errp) {
+            goto out;
+        }
+
+        if (ranges_overlap(md_addr, md_size, new_addr, size)) {
+            if (hint) {
+                const DeviceState *d = DEVICE(md);
+                error_setg(errp, "address range conflicts with '%s'", d->id);
+                goto out;
+            }
+            new_addr = QEMU_ALIGN_UP(md_addr + md_size, align);
+        }
+    }
+
+    if (new_addr + size > address_space_end) {
+        error_setg(errp, "could not find position in guest address space for "
+                   "memory device - memory fragmented due to alignments");
+        goto out;
+    }
+out:
+    g_slist_free(list);
+    return new_addr;
+}
+
+MemoryDeviceInfoList *qmp_memory_device_list(void)
+{
+    GSList *devices = NULL, *item;
+    MemoryDeviceInfoList *list = NULL, *prev = NULL;
+
+    object_child_foreach(qdev_get_machine(), memory_device_build_list,
+                         &devices);
+
+    for (item = devices; item; item = g_slist_next(item)) {
+        const MemoryDeviceState *md = MEMORY_DEVICE(item->data);
+        const MemoryDeviceClass *mdc = MEMORY_DEVICE_GET_CLASS(item->data);
+        MemoryDeviceInfoList *elem = g_new0(MemoryDeviceInfoList, 1);
+        MemoryDeviceInfo *info = g_new0(MemoryDeviceInfo, 1);
+
+        mdc->fill_device_info(md, info);
+
+        elem->value = info;
+        elem->next = NULL;
+        if (prev) {
+            prev->next = elem;
+        } else {
+            list = elem;
+        }
+        prev = elem;
+    }
+
+    g_slist_free(devices);
+
+    return list;
+}
+
+static int memory_device_plugged_size(Object *obj, void *opaque)
+{
+    uint64_t *size = opaque;
+
+    if (object_dynamic_cast(obj, TYPE_MEMORY_DEVICE)) {
+        const DeviceState *dev = DEVICE(obj);
+        const MemoryDeviceState *md = MEMORY_DEVICE(obj);
+        const MemoryDeviceClass *mdc = MEMORY_DEVICE_GET_CLASS(obj);
+
+        if (dev->realized) {
+            *size += mdc->get_plugged_size(md);
+        }
+    }
+
+    object_child_foreach(obj, memory_device_plugged_size, opaque);
+    return 0;
+}
+
+uint64_t get_plugged_memory_size(void)
+{
+    uint64_t size = 0;
+
+    memory_device_plugged_size(qdev_get_machine(), &size);
+
+    return size;
+}
+
+void memory_device_plug_region(MachineState *ms, MemoryRegion *mr,
+                               uint64_t addr)
+{
+    /* we expect a previous call to memory_device_get_free_addr() */
+    g_assert(ms->device_memory);
+
+    memory_region_add_subregion(&ms->device_memory->mr,
+                                addr - ms->device_memory->base, mr);
+}
+
+void memory_device_unplug_region(MachineState *ms, MemoryRegion *mr)
+{
+    /* we expect a previous call to memory_device_get_free_addr() */
+    g_assert(ms->device_memory);
+
+    memory_region_del_subregion(&ms->device_memory->mr, mr);
+}
+
+static const TypeInfo memory_device_info = {
+    .name          = TYPE_MEMORY_DEVICE,
+    .parent        = TYPE_INTERFACE,
+    .class_size = sizeof(MemoryDeviceClass),
+};
+
+static void memory_device_register_types(void)
+{
+    type_register_static(&memory_device_info);
+}
+
+type_init(memory_device_register_types)
diff --git a/hw/mem/pc-dimm.c b/hw/mem/pc-dimm.c
index 51350d9c2d..0119c68e01 100644
--- a/hw/mem/pc-dimm.c
+++ b/hw/mem/pc-dimm.c
@@ -21,60 +21,45 @@
 #include "qemu/osdep.h"
 #include "hw/mem/pc-dimm.h"
 #include "hw/mem/nvdimm.h"
+#include "hw/mem/memory-device.h"
 #include "qapi/error.h"
-#include "qemu/config-file.h"
 #include "qapi/visitor.h"
-#include "qemu/range.h"
 #include "sysemu/numa.h"
-#include "sysemu/kvm.h"
 #include "trace.h"
-#include "hw/virtio/vhost.h"
 
 typedef struct pc_dimms_capacity {
      uint64_t size;
      Error    **errp;
 } pc_dimms_capacity;
 
-void pc_dimm_memory_plug(DeviceState *dev, MemoryHotplugState *hpms,
-                         MemoryRegion *mr, uint64_t align, Error **errp)
+void pc_dimm_memory_plug(DeviceState *dev, MachineState *machine,
+                         uint64_t align, Error **errp)
 {
     int slot;
-    MachineState *machine = MACHINE(qdev_get_machine());
     PCDIMMDevice *dimm = PC_DIMM(dev);
     PCDIMMDeviceClass *ddc = PC_DIMM_GET_CLASS(dimm);
     MemoryRegion *vmstate_mr = ddc->get_vmstate_memory_region(dimm);
     Error *local_err = NULL;
-    uint64_t existing_dimms_capacity = 0;
+    MemoryRegion *mr;
     uint64_t addr;
 
-    addr = object_property_get_uint(OBJECT(dimm),
-                                    PC_DIMM_ADDR_PROP, &local_err);
+    mr = ddc->get_memory_region(dimm, &local_err);
     if (local_err) {
         goto out;
     }
 
-    addr = pc_dimm_get_free_addr(hpms->base,
-                                 memory_region_size(&hpms->mr),
-                                 !addr ? NULL : &addr, align,
-                                 memory_region_size(mr), &local_err);
+    addr = object_property_get_uint(OBJECT(dimm),
+                                    PC_DIMM_ADDR_PROP, &local_err);
     if (local_err) {
         goto out;
     }
 
-    existing_dimms_capacity = pc_existing_dimms_capacity(&local_err);
+    addr = memory_device_get_free_addr(machine, !addr ? NULL : &addr, align,
+                                       memory_region_size(mr), &local_err);
     if (local_err) {
         goto out;
     }
 
-    if (existing_dimms_capacity + memory_region_size(mr) >
-        machine->maxram_size - machine->ram_size) {
-        error_setg(&local_err, "not enough space, currently 0x%" PRIx64
-                   " in use of total hot pluggable 0x" RAM_ADDR_FMT,
-                   existing_dimms_capacity,
-                   machine->maxram_size - machine->ram_size);
-        goto out;
-    }
-
     object_property_set_uint(OBJECT(dev), addr, PC_DIMM_ADDR_PROP, &local_err);
     if (local_err) {
         goto out;
@@ -97,72 +82,24 @@ void pc_dimm_memory_plug(DeviceState *dev, MemoryHotplugState *hpms,
     }
     trace_mhp_pc_dimm_assigned_slot(slot);
 
-    if (kvm_enabled() && !kvm_has_free_slot(machine)) {
-        error_setg(&local_err, "hypervisor has no free memory slots left");
-        goto out;
-    }
-
-    if (!vhost_has_free_slot()) {
-        error_setg(&local_err, "a used vhost backend has no free"
-                               " memory slots left");
-        goto out;
-    }
-
-    memory_region_add_subregion(&hpms->mr, addr - hpms->base, mr);
+    memory_device_plug_region(machine, mr, addr);
     vmstate_register_ram(vmstate_mr, dev);
 
 out:
     error_propagate(errp, local_err);
 }
 
-void pc_dimm_memory_unplug(DeviceState *dev, MemoryHotplugState *hpms,
-                           MemoryRegion *mr)
+void pc_dimm_memory_unplug(DeviceState *dev, MachineState *machine)
 {
     PCDIMMDevice *dimm = PC_DIMM(dev);
     PCDIMMDeviceClass *ddc = PC_DIMM_GET_CLASS(dimm);
     MemoryRegion *vmstate_mr = ddc->get_vmstate_memory_region(dimm);
+    MemoryRegion *mr = ddc->get_memory_region(dimm, &error_abort);
 
-    memory_region_del_subregion(&hpms->mr, mr);
+    memory_device_unplug_region(machine, mr);
     vmstate_unregister_ram(vmstate_mr, dev);
 }
 
-static int pc_existing_dimms_capacity_internal(Object *obj, void *opaque)
-{
-    pc_dimms_capacity *cap = opaque;
-    uint64_t *size = &cap->size;
-
-    if (object_dynamic_cast(obj, TYPE_PC_DIMM)) {
-        DeviceState *dev = DEVICE(obj);
-
-        if (dev->realized) {
-            (*size) += object_property_get_uint(obj, PC_DIMM_SIZE_PROP,
-                cap->errp);
-        }
-
-        if (cap->errp && *cap->errp) {
-            return 1;
-        }
-    }
-    object_child_foreach(obj, pc_existing_dimms_capacity_internal, opaque);
-    return 0;
-}
-
-uint64_t pc_existing_dimms_capacity(Error **errp)
-{
-    pc_dimms_capacity cap;
-
-    cap.size = 0;
-    cap.errp = errp;
-
-    pc_existing_dimms_capacity_internal(qdev_get_machine(), &cap);
-    return cap.size;
-}
-
-uint64_t get_plugged_memory_size(void)
-{
-    return pc_existing_dimms_capacity(&error_abort);
-}
-
 static int pc_dimm_slot2bitmap(Object *obj, void *opaque)
 {
     unsigned long *bitmap = opaque;
@@ -209,158 +146,6 @@ out:
     return slot;
 }
 
-static gint pc_dimm_addr_sort(gconstpointer a, gconstpointer b)
-{
-    PCDIMMDevice *x = PC_DIMM(a);
-    PCDIMMDevice *y = PC_DIMM(b);
-    Int128 diff = int128_sub(int128_make64(x->addr), int128_make64(y->addr));
-
-    if (int128_lt(diff, int128_zero())) {
-        return -1;
-    } else if (int128_gt(diff, int128_zero())) {
-        return 1;
-    }
-    return 0;
-}
-
-static int pc_dimm_built_list(Object *obj, void *opaque)
-{
-    GSList **list = opaque;
-
-    if (object_dynamic_cast(obj, TYPE_PC_DIMM)) {
-        DeviceState *dev = DEVICE(obj);
-        if (dev->realized) { /* only realized DIMMs matter */
-            *list = g_slist_insert_sorted(*list, dev, pc_dimm_addr_sort);
-        }
-    }
-
-    object_child_foreach(obj, pc_dimm_built_list, opaque);
-    return 0;
-}
-
-MemoryDeviceInfoList *qmp_pc_dimm_device_list(void)
-{
-    GSList *dimms = NULL, *item;
-    MemoryDeviceInfoList *list = NULL, *prev = NULL;
-
-    object_child_foreach(qdev_get_machine(), pc_dimm_built_list, &dimms);
-
-    for (item = dimms; item; item = g_slist_next(item)) {
-        PCDIMMDevice *dimm = PC_DIMM(item->data);
-        Object *obj = OBJECT(dimm);
-        MemoryDeviceInfoList *elem = g_new0(MemoryDeviceInfoList, 1);
-        MemoryDeviceInfo *info = g_new0(MemoryDeviceInfo, 1);
-        PCDIMMDeviceInfo *di = g_new0(PCDIMMDeviceInfo, 1);
-        bool is_nvdimm = object_dynamic_cast(obj, TYPE_NVDIMM);
-        DeviceClass *dc = DEVICE_GET_CLASS(obj);
-        DeviceState *dev = DEVICE(obj);
-
-        if (dev->id) {
-            di->has_id = true;
-            di->id = g_strdup(dev->id);
-        }
-        di->hotplugged = dev->hotplugged;
-        di->hotpluggable = dc->hotpluggable;
-        di->addr = dimm->addr;
-        di->slot = dimm->slot;
-        di->node = dimm->node;
-        di->size = object_property_get_uint(obj, PC_DIMM_SIZE_PROP, NULL);
-        di->memdev = object_get_canonical_path(OBJECT(dimm->hostmem));
-
-        if (!is_nvdimm) {
-            info->u.dimm.data = di;
-            info->type = MEMORY_DEVICE_INFO_KIND_DIMM;
-        } else {
-            info->u.nvdimm.data = di;
-            info->type = MEMORY_DEVICE_INFO_KIND_NVDIMM;
-        }
-        elem->value = info;
-        elem->next = NULL;
-        if (prev) {
-            prev->next = elem;
-        } else {
-            list = elem;
-        }
-        prev = elem;
-    }
-
-    g_slist_free(dimms);
-
-    return list;
-}
-
-uint64_t pc_dimm_get_free_addr(uint64_t address_space_start,
-                               uint64_t address_space_size,
-                               uint64_t *hint, uint64_t align, uint64_t size,
-                               Error **errp)
-{
-    GSList *list = NULL, *item;
-    uint64_t new_addr, ret = 0;
-    uint64_t address_space_end = address_space_start + address_space_size;
-
-    g_assert(QEMU_ALIGN_UP(address_space_start, align) == address_space_start);
-
-    if (!address_space_size) {
-        error_setg(errp, "memory hotplug is not enabled, "
-                         "please add maxmem option");
-        goto out;
-    }
-
-    if (hint && QEMU_ALIGN_UP(*hint, align) != *hint) {
-        error_setg(errp, "address must be aligned to 0x%" PRIx64 " bytes",
-                   align);
-        goto out;
-    }
-
-    if (QEMU_ALIGN_UP(size, align) != size) {
-        error_setg(errp, "backend memory size must be multiple of 0x%"
-                   PRIx64, align);
-        goto out;
-    }
-
-    assert(address_space_end > address_space_start);
-    object_child_foreach(qdev_get_machine(), pc_dimm_built_list, &list);
-
-    if (hint) {
-        new_addr = *hint;
-    } else {
-        new_addr = address_space_start;
-    }
-
-    /* find address range that will fit new DIMM */
-    for (item = list; item; item = g_slist_next(item)) {
-        PCDIMMDevice *dimm = item->data;
-        uint64_t dimm_size = object_property_get_uint(OBJECT(dimm),
-                                                      PC_DIMM_SIZE_PROP,
-                                                      errp);
-        if (errp && *errp) {
-            goto out;
-        }
-
-        if (ranges_overlap(dimm->addr, dimm_size, new_addr, size)) {
-            if (hint) {
-                DeviceState *d = DEVICE(dimm);
-                error_setg(errp, "address range conflicts with '%s'", d->id);
-                goto out;
-            }
-            new_addr = QEMU_ALIGN_UP(dimm->addr + dimm_size, align);
-        }
-    }
-    ret = new_addr;
-
-    if (new_addr < address_space_start) {
-        error_setg(errp, "can't add memory [0x%" PRIx64 ":0x%" PRIx64
-                   "] at 0x%" PRIx64, new_addr, size, address_space_start);
-    } else if ((new_addr + size) > address_space_end) {
-        error_setg(errp, "can't add memory [0x%" PRIx64 ":0x%" PRIx64
-                   "] beyond 0x%" PRIx64, new_addr, size, address_space_end);
-    }
-
-out:
-    g_slist_free(list);
-    return ret;
-}
-
 static Property pc_dimm_properties[] = {
     DEFINE_PROP_UINT64(PC_DIMM_ADDR_PROP, PCDIMMDevice, addr, 0),
     DEFINE_PROP_UINT32(PC_DIMM_NODE_PROP, PCDIMMDevice, node, 0),
@@ -445,10 +230,63 @@ static MemoryRegion *pc_dimm_get_vmstate_memory_region(PCDIMMDevice *dimm)
     return host_memory_backend_get_memory(dimm->hostmem, &error_abort);
 }
 
+static uint64_t pc_dimm_md_get_addr(const MemoryDeviceState *md)
+{
+    const PCDIMMDevice *dimm = PC_DIMM(md);
+
+    return dimm->addr;
+}
+
+static uint64_t pc_dimm_md_get_region_size(const MemoryDeviceState *md)
+{
+    /* dropping const here is fine as we don't touch the memory region */
+    PCDIMMDevice *dimm = PC_DIMM(md);
+    const PCDIMMDeviceClass *ddc = PC_DIMM_GET_CLASS(md);
+    MemoryRegion *mr;
+
+    mr = ddc->get_memory_region(dimm, &error_abort);
+    if (!mr) {
+        return 0;
+    }
+
+    return memory_region_size(mr);
+}
+
+static void pc_dimm_md_fill_device_info(const MemoryDeviceState *md,
+                                        MemoryDeviceInfo *info)
+{
+    PCDIMMDeviceInfo *di = g_new0(PCDIMMDeviceInfo, 1);
+    const DeviceClass *dc = DEVICE_GET_CLASS(md);
+    const PCDIMMDevice *dimm = PC_DIMM(md);
+    const DeviceState *dev = DEVICE(md);
+
+    if (dev->id) {
+        di->has_id = true;
+        di->id = g_strdup(dev->id);
+    }
+    di->hotplugged = dev->hotplugged;
+    di->hotpluggable = dc->hotpluggable;
+    di->addr = dimm->addr;
+    di->slot = dimm->slot;
+    di->node = dimm->node;
+    di->size = object_property_get_uint(OBJECT(dimm), PC_DIMM_SIZE_PROP,
+                                        NULL);
+    di->memdev = object_get_canonical_path(OBJECT(dimm->hostmem));
+
+    if (object_dynamic_cast(OBJECT(dev), TYPE_NVDIMM)) {
+        info->u.nvdimm.data = di;
+        info->type = MEMORY_DEVICE_INFO_KIND_NVDIMM;
+    } else {
+        info->u.dimm.data = di;
+        info->type = MEMORY_DEVICE_INFO_KIND_DIMM;
+    }
+}
+
 static void pc_dimm_class_init(ObjectClass *oc, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(oc);
     PCDIMMDeviceClass *ddc = PC_DIMM_CLASS(oc);
+    MemoryDeviceClass *mdc = MEMORY_DEVICE_CLASS(oc);
 
     dc->realize = pc_dimm_realize;
     dc->unrealize = pc_dimm_unrealize;
@@ -457,6 +295,12 @@ static void pc_dimm_class_init(ObjectClass *oc, void *data)
 
     ddc->get_memory_region = pc_dimm_get_memory_region;
     ddc->get_vmstate_memory_region = pc_dimm_get_vmstate_memory_region;
+
+    mdc->get_addr = pc_dimm_md_get_addr;
+    /* for a dimm plugged_size == region_size */
+    mdc->get_plugged_size = pc_dimm_md_get_region_size;
+    mdc->get_region_size = pc_dimm_md_get_region_size;
+    mdc->fill_device_info = pc_dimm_md_fill_device_info;
 }
 
 static TypeInfo pc_dimm_info = {
@@ -466,6 +310,10 @@ static TypeInfo pc_dimm_info = {
     .instance_init = pc_dimm_init,
     .class_init    = pc_dimm_class_init,
     .class_size    = sizeof(PCDIMMDeviceClass),
+    .interfaces = (InterfaceInfo[]) {
+        { TYPE_MEMORY_DEVICE },
+        { }
+    },
 };
 
 static void pc_dimm_register_types(void)
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 32ab3c43b6..a1abcba6ad 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -74,6 +74,7 @@
 #include "hw/compat.h"
 #include "qemu/cutils.h"
 #include "hw/ppc/spapr_cpu_core.h"
+#include "hw/mem/memory-device.h"
 
 #include <libfdt.h>
 
@@ -702,13 +703,14 @@ spapr_get_drconf_cell(uint32_t seq_lmbs, uint64_t base_addr,
 static int spapr_populate_drmem_v2(sPAPRMachineState *spapr, void *fdt,
                                    int offset, MemoryDeviceInfoList *dimms)
 {
+    MachineState *machine = MACHINE(spapr);
     uint8_t *int_buf, *cur_index, buf_len;
     int ret;
     uint64_t lmb_size = SPAPR_MEMORY_BLOCK_SIZE;
     uint64_t addr, cur_addr, size;
-    uint32_t nr_boot_lmbs = (spapr->hotplug_memory.base / lmb_size);
-    uint64_t mem_end = spapr->hotplug_memory.base +
-                       memory_region_size(&spapr->hotplug_memory.mr);
+    uint32_t nr_boot_lmbs = (machine->device_memory->base / lmb_size);
+    uint64_t mem_end = machine->device_memory->base +
+                       memory_region_size(&machine->device_memory->mr);
     uint32_t node, nr_entries = 0;
     sPAPRDRConnector *drc;
     DrconfCellQueue *elem, *next;
@@ -723,7 +725,7 @@ static int spapr_populate_drmem_v2(sPAPRMachineState *spapr, void *fdt,
     QSIMPLEQ_INSERT_TAIL(&drconf_queue, elem, entry);
     nr_entries++;
 
-    cur_addr = spapr->hotplug_memory.base;
+    cur_addr = machine->device_memory->base;
     for (info = dimms; info; info = info->next) {
         PCDIMMDeviceInfo *di = info->value->u.dimm.data;
 
@@ -786,11 +788,12 @@ static int spapr_populate_drmem_v2(sPAPRMachineState *spapr, void *fdt,
 static int spapr_populate_drmem_v1(sPAPRMachineState *spapr, void *fdt,
                                    int offset, MemoryDeviceInfoList *dimms)
 {
+    MachineState *machine = MACHINE(spapr);
     int i, ret;
     uint64_t lmb_size = SPAPR_MEMORY_BLOCK_SIZE;
-    uint32_t hotplug_lmb_start = spapr->hotplug_memory.base / lmb_size;
-    uint32_t nr_lmbs = (spapr->hotplug_memory.base +
-                       memory_region_size(&spapr->hotplug_memory.mr)) /
+    uint32_t device_lmb_start = machine->device_memory->base / lmb_size;
+    uint32_t nr_lmbs = (machine->device_memory->base +
+                       memory_region_size(&machine->device_memory->mr)) /
                        lmb_size;
     uint32_t *int_buf, *cur_index, buf_len;
 
@@ -805,7 +808,7 @@ static int spapr_populate_drmem_v1(sPAPRMachineState *spapr, void *fdt,
         uint64_t addr = i * lmb_size;
         uint32_t *dynamic_memory = cur_index;
 
-        if (i >= hotplug_lmb_start) {
+        if (i >= device_lmb_start) {
             sPAPRDRConnector *drc;
 
             drc = spapr_drc_by_id(TYPE_SPAPR_DRC_LMB, i);
@@ -824,7 +827,7 @@ static int spapr_populate_drmem_v1(sPAPRMachineState *spapr, void *fdt,
         } else {
             /*
              * LMB information for RMA, boot time RAM and gap b/n RAM and
-             * hotplug memory region -- all these are marked as reserved
+             * device memory region -- all these are marked as reserved
              * and as having no valid DRC.
              */
             dynamic_memory[0] = cpu_to_be32(addr >> 32);
@@ -862,7 +865,7 @@ static int spapr_populate_drconf_memory(sPAPRMachineState *spapr, void *fdt)
     MemoryDeviceInfoList *dimms = NULL;
 
     /*
-     * Don't create the node if there is no hotpluggable memory
+     * Don't create the node if there is no device memory
      */
     if (machine->ram_size == machine->maxram_size) {
         return 0;
@@ -887,7 +890,7 @@ static int spapr_populate_drconf_memory(sPAPRMachineState *spapr, void *fdt)
     }
 
     /* ibm,dynamic-memory or ibm,dynamic-memory-v2 */
-    dimms = qmp_pc_dimm_device_list();
+    dimms = qmp_memory_device_list();
     if (spapr_ovec_test(spapr->ov5_cas, OV5_DRMEM_V2)) {
         ret = spapr_populate_drmem_v2(spapr, fdt, offset, dimms);
     } else {
@@ -1033,11 +1036,11 @@ static void spapr_dt_rtas(sPAPRMachineState *spapr, void *fdt)
     GString *hypertas = g_string_sized_new(256);
     GString *qemu_hypertas = g_string_sized_new(256);
     uint32_t refpoints[] = { cpu_to_be32(0x4), cpu_to_be32(0x4) };
-    uint64_t max_hotplug_addr = spapr->hotplug_memory.base +
-        memory_region_size(&spapr->hotplug_memory.mr);
+    uint64_t max_device_addr = MACHINE(spapr)->device_memory->base +
+        memory_region_size(&MACHINE(spapr)->device_memory->mr);
     uint32_t lrdr_capacity[] = {
-        cpu_to_be32(max_hotplug_addr >> 32),
-        cpu_to_be32(max_hotplug_addr & 0xffffffff),
+        cpu_to_be32(max_device_addr >> 32),
+        cpu_to_be32(max_device_addr & 0xffffffff),
         0, cpu_to_be32(SPAPR_MEMORY_BLOCK_SIZE),
         cpu_to_be32(max_cpus / smp_threads),
     };
@@ -2296,7 +2299,7 @@ static void spapr_create_lmb_dr_connectors(sPAPRMachineState *spapr)
     for (i = 0; i < nr_lmbs; i++) {
         uint64_t addr;
 
-        addr = i * lmb_size + spapr->hotplug_memory.base;
+        addr = i * lmb_size + machine->device_memory->base;
         spapr_dr_connector_new(OBJECT(spapr), TYPE_SPAPR_DRC_LMB,
                                addr / lmb_size);
     }
@@ -2633,9 +2636,12 @@ static void spapr_machine_init(MachineState *machine)
                                          machine->ram_size);
     memory_region_add_subregion(sysmem, 0, ram);
 
+    /* always allocate the device memory information */
+    machine->device_memory = g_malloc0(sizeof(*machine->device_memory));
+
     /* initialize hotplug memory address space */
     if (machine->ram_size < machine->maxram_size) {
-        ram_addr_t hotplug_mem_size = machine->maxram_size - machine->ram_size;
+        ram_addr_t device_mem_size = machine->maxram_size - machine->ram_size;
         /*
          * Limit the number of hotpluggable memory slots to half the number
          * slots that KVM supports, leaving the other half for PCI and other
@@ -2654,12 +2660,12 @@ static void spapr_machine_init(MachineState *machine)
             exit(1);
         }
 
-        spapr->hotplug_memory.base = ROUND_UP(machine->ram_size,
-                                              SPAPR_HOTPLUG_MEM_ALIGN);
-        memory_region_init(&spapr->hotplug_memory.mr, OBJECT(spapr),
-                           "hotplug-memory", hotplug_mem_size);
-        memory_region_add_subregion(sysmem, spapr->hotplug_memory.base,
-                                    &spapr->hotplug_memory.mr);
+        machine->device_memory->base = ROUND_UP(machine->ram_size,
+                                                SPAPR_DEVICE_MEM_ALIGN);
+        memory_region_init(&machine->device_memory->mr, OBJECT(spapr),
+                           "device-memory", device_mem_size);
+        memory_region_add_subregion(sysmem, machine->device_memory->base,
+                                    &machine->device_memory->mr);
     }
 
     if (smc->dr_lmb_enabled) {
@@ -3147,7 +3153,7 @@ static void spapr_memory_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
     align = memory_region_get_alignment(mr);
     size = memory_region_size(mr);
 
-    pc_dimm_memory_plug(dev, &ms->hotplug_memory, mr, align, &local_err);
+    pc_dimm_memory_plug(dev, MACHINE(ms), align, &local_err);
     if (local_err) {
         goto out;
     }
@@ -3168,7 +3174,7 @@ static void spapr_memory_plug(HotplugHandler *hotplug_dev, DeviceState *dev,
     return;
 
 out_unplug:
-    pc_dimm_memory_unplug(dev, &ms->hotplug_memory, mr);
+    pc_dimm_memory_unplug(dev, MACHINE(ms));
 out:
     error_propagate(errp, local_err);
 }
@@ -3286,9 +3292,6 @@ static sPAPRDIMMState *spapr_recover_pending_dimm_state(sPAPRMachineState *ms,
 void spapr_lmb_release(DeviceState *dev)
 {
     sPAPRMachineState *spapr = SPAPR_MACHINE(qdev_get_hotplug_handler(dev));
-    PCDIMMDevice *dimm = PC_DIMM(dev);
-    PCDIMMDeviceClass *ddc = PC_DIMM_GET_CLASS(dimm);
-    MemoryRegion *mr = ddc->get_memory_region(dimm, &error_abort);
     sPAPRDIMMState *ds = spapr_pending_dimm_unplugs_find(spapr, PC_DIMM(dev));
 
     /* This information will get lost if a migration occurs
@@ -3308,7 +3311,7 @@ void spapr_lmb_release(DeviceState *dev)
      * Now that all the LMBs have been removed by the guest, call the
      * pc-dimm unplug handler to cleanup up the pc-dimm device.
      */
-    pc_dimm_memory_unplug(dev, &spapr->hotplug_memory, mr);
+    pc_dimm_memory_unplug(dev, MACHINE(spapr));
     object_unparent(OBJECT(dev));
     spapr_pending_dimm_unplugs_remove(spapr, ds);
 }
@@ -4259,13 +4262,13 @@ static void phb_placement_2_7(sPAPRMachineState *spapr, uint32_t index,
     hwaddr phb0_base, phb_base;
     int i;
 
-    /* Do we have hotpluggable memory? */
+    /* Do we have device memory? */
     if (MACHINE(spapr)->maxram_size > ram_top) {
         /* Can't just use maxram_size, because there may be an
-         * alignment gap between normal and hotpluggable memory
-         * regions */
-        ram_top = spapr->hotplug_memory.base +
-            memory_region_size(&spapr->hotplug_memory.mr);
+         * alignment gap between normal and device memory regions
+         */
+        ram_top = MACHINE(spapr)->device_memory->base +
+            memory_region_size(&MACHINE(spapr)->device_memory->mr);
     }
 
     phb0_base = QEMU_ALIGN_UP(ram_top, phb0_alignment);
diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
index ca9702e667..022f6d8101 100644
--- a/hw/ppc/spapr_hcall.c
+++ b/hw/ppc/spapr_hcall.c
@@ -14,6 +14,7 @@
 #include "kvm_ppc.h"
 #include "hw/ppc/spapr_ovec.h"
 #include "mmu-book3s-v3.h"
+#include "hw/mem/memory-device.h"
 
 struct LPCRSyncState {
     target_ulong value;
@@ -66,13 +67,13 @@ static inline bool valid_ptex(PowerPCCPU *cpu, target_ulong ptex)
 static bool is_ram_address(sPAPRMachineState *spapr, hwaddr addr)
 {
     MachineState *machine = MACHINE(spapr);
-    MemoryHotplugState *hpms = &spapr->hotplug_memory;
+    DeviceMemoryState *dms = machine->device_memory;
 
     if (addr < machine->ram_size) {
         return true;
     }
-    if ((addr >= hpms->base)
-        && ((addr - hpms->base) < memory_region_size(&hpms->mr))) {
+    if ((addr >= dms->base)
+        && ((addr - dms->base) < memory_region_size(&dms->mr))) {
         return true;
     }
 
diff --git a/hw/ppc/spapr_rtas_ddw.c b/hw/ppc/spapr_rtas_ddw.c
index 177dcffc9b..329feb148f 100644
--- a/hw/ppc/spapr_rtas_ddw.c
+++ b/hw/ppc/spapr_rtas_ddw.c
@@ -122,9 +122,8 @@ static void rtas_ibm_query_pe_dma_window(PowerPCCPU *cpu,
     if (machine->ram_size == machine->maxram_size) {
         max_window_size = machine->ram_size;
     } else {
-        MemoryHotplugState *hpms = &spapr->hotplug_memory;
-
-        max_window_size = hpms->base + memory_region_size(&hpms->mr);
+        max_window_size = machine->device_memory->base +
+                          memory_region_size(&machine->device_memory->mr);
     }
 
     avail = SPAPR_PCI_DMA_MAX_WINDOWS - spapr_phb_get_active_win_num(sphb);
diff --git a/include/hw/boards.h b/include/hw/boards.h
index 5c5eee55e6..ef7457f5dd 100644
--- a/include/hw/boards.h
+++ b/include/hw/boards.h
@@ -214,6 +214,17 @@ struct MachineClass {
 };
 
 /**
+ * DeviceMemoryState:
+ * @base: address in guest physical address space where the memory
+ * address space for memory devices starts
+ * @mr: address space container for memory devices
+ */
+typedef struct DeviceMemoryState {
+    hwaddr base;
+    MemoryRegion mr;
+} DeviceMemoryState;
+
+/**
  * MachineState:
  */
 struct MachineState {
@@ -243,6 +254,7 @@ struct MachineState {
     bool enforce_config_section;
     bool enable_graphics;
     char *memory_encryption;
+    DeviceMemoryState *device_memory;
 
     ram_addr_t ram_size;
     ram_addr_t maxram_size;
diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index ffee8413f0..2e834e6ded 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -32,7 +32,6 @@ struct PCMachineState {
     /* <public> */
 
     /* State for other subsystems/APIs: */
-    MemoryHotplugState hotplug_memory;
     Notifier machine_done;
 
     /* Pointers to devices and objects: */
@@ -72,7 +71,7 @@ struct PCMachineState {
 };
 
 #define PC_MACHINE_ACPI_DEVICE_PROP "acpi-device"
-#define PC_MACHINE_MEMHP_REGION_SIZE "hotplug-memory-region-size"
+#define PC_MACHINE_DEVMEM_REGION_SIZE "device-memory-region-size"
 #define PC_MACHINE_MAX_RAM_BELOW_4G "max-ram-below-4g"
 #define PC_MACHINE_VMPORT           "vmport"
 #define PC_MACHINE_SMM              "smm"
diff --git a/include/hw/mem/memory-device.h b/include/hw/mem/memory-device.h
new file mode 100644
index 0000000000..2853b084b5
--- /dev/null
+++ b/include/hw/mem/memory-device.h
@@ -0,0 +1,51 @@
+/*
+ * Memory Device Interface
+ *
+ * Copyright (c) 2018 Red Hat, Inc.
+ *
+ * Authors:
+ *  David Hildenbrand <david@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef MEMORY_DEVICE_H
+#define MEMORY_DEVICE_H
+
+#include "qom/object.h"
+#include "hw/qdev.h"
+
+#define TYPE_MEMORY_DEVICE "memory-device"
+
+#define MEMORY_DEVICE_CLASS(klass) \
+     OBJECT_CLASS_CHECK(MemoryDeviceClass, (klass), TYPE_MEMORY_DEVICE)
+#define MEMORY_DEVICE_GET_CLASS(obj) \
+    OBJECT_GET_CLASS(MemoryDeviceClass, (obj), TYPE_MEMORY_DEVICE)
+#define MEMORY_DEVICE(obj) \
+     INTERFACE_CHECK(MemoryDeviceState, (obj), TYPE_MEMORY_DEVICE)
+
+typedef struct MemoryDeviceState {
+    Object parent_obj;
+} MemoryDeviceState;
+
+typedef struct MemoryDeviceClass {
+    InterfaceClass parent_class;
+
+    uint64_t (*get_addr)(const MemoryDeviceState *md);
+    uint64_t (*get_plugged_size)(const MemoryDeviceState *md);
+    uint64_t (*get_region_size)(const MemoryDeviceState *md);
+    void (*fill_device_info)(const MemoryDeviceState *md,
+                             MemoryDeviceInfo *info);
+} MemoryDeviceClass;
+
+MemoryDeviceInfoList *qmp_memory_device_list(void);
+uint64_t get_plugged_memory_size(void);
+uint64_t memory_device_get_free_addr(MachineState *ms, const uint64_t *hint,
+                                     uint64_t align, uint64_t size,
+                                     Error **errp);
+void memory_device_plug_region(MachineState *ms, MemoryRegion *mr,
+                               uint64_t addr);
+void memory_device_unplug_region(MachineState *ms, MemoryRegion *mr);
+
+#endif
diff --git a/include/hw/mem/pc-dimm.h b/include/hw/mem/pc-dimm.h
index 1fc479281c..627c8601d9 100644
--- a/include/hw/mem/pc-dimm.h
+++ b/include/hw/mem/pc-dimm.h
@@ -19,6 +19,7 @@
 #include "exec/memory.h"
 #include "sysemu/hostmem.h"
 #include "hw/qdev.h"
+#include "hw/boards.h"
 
 #define TYPE_PC_DIMM "pc-dimm"
 #define PC_DIMM(obj) \
@@ -75,29 +76,9 @@ typedef struct PCDIMMDeviceClass {
     MemoryRegion *(*get_vmstate_memory_region)(PCDIMMDevice *dimm);
 } PCDIMMDeviceClass;
 
-/**
- * MemoryHotplugState:
- * @base: address in guest physical address space where hotplug memory
- * address space begins.
- * @mr: hotplug memory address space container
- */
-typedef struct MemoryHotplugState {
-    hwaddr base;
-    MemoryRegion mr;
-} MemoryHotplugState;
-
-uint64_t pc_dimm_get_free_addr(uint64_t address_space_start,
-                               uint64_t address_space_size,
-                               uint64_t *hint, uint64_t align, uint64_t size,
-                               Error **errp);
-
 int pc_dimm_get_free_slot(const int *hint, int max_slots, Error **errp);
 
-MemoryDeviceInfoList *qmp_pc_dimm_device_list(void);
-uint64_t pc_existing_dimms_capacity(Error **errp);
-uint64_t get_plugged_memory_size(void);
-void pc_dimm_memory_plug(DeviceState *dev, MemoryHotplugState *hpms,
-                         MemoryRegion *mr, uint64_t align, Error **errp);
-void pc_dimm_memory_unplug(DeviceState *dev, MemoryHotplugState *hpms,
-                           MemoryRegion *mr);
+void pc_dimm_memory_plug(DeviceState *dev, MachineState *machine,
+                         uint64_t align, Error **errp);
+void pc_dimm_memory_unplug(DeviceState *dev, MachineState *machine);
 #endif
diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index d60b7c6d7a..3388750fc7 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -162,7 +162,6 @@ struct sPAPRMachineState {
 
     /*< public >*/
     char *kvm_type;
-    MemoryHotplugState hotplug_memory;
 
     const char *icp_type;
 
@@ -748,8 +747,8 @@ int spapr_rng_populate_dt(void *fdt);
  */
 #define SPAPR_MAX_RAM_SLOTS     32
 
-/* 1GB alignment for hotplug memory region */
-#define SPAPR_HOTPLUG_MEM_ALIGN (1ULL << 30)
+/* 1GB alignment for device memory region */
+#define SPAPR_DEVICE_MEM_ALIGN (1ULL << 30)
 
 /*
  * Number of 32 bit words in each LMB list entry in ibm,dynamic-memory
diff --git a/numa.c b/numa.c
index 78a869e598..70b150e73a 100644
--- a/numa.c
+++ b/numa.c
@@ -36,6 +36,7 @@
 #include "hw/boards.h"
 #include "sysemu/hostmem.h"
 #include "hw/mem/pc-dimm.h"
+#include "hw/mem/memory-device.h"
 #include "qemu/option.h"
 #include "qemu/config-file.h"
 #include "qemu/cutils.h"
@@ -521,7 +522,7 @@ void memory_region_allocate_system_memory(MemoryRegion *mr, Object *owner,
 
 static void numa_stat_memory_devices(NumaNodeMem node_mem[])
 {
-    MemoryDeviceInfoList *info_list = qmp_pc_dimm_device_list();
+    MemoryDeviceInfoList *info_list = qmp_memory_device_list();
     MemoryDeviceInfoList *info;
     PCDIMMDeviceInfo     *pcdimm_info;
 
diff --git a/qmp.c b/qmp.c
index 9e95b889ff..25fdc9a5b2 100644
--- a/qmp.c
+++ b/qmp.c
@@ -39,7 +39,7 @@
 #include "qapi/qobject-input-visitor.h"
 #include "hw/boards.h"
 #include "qom/object_interfaces.h"
-#include "hw/mem/pc-dimm.h"
+#include "hw/mem/memory-device.h"
 #include "hw/acpi/acpi_dev_interface.h"
 
 NameInfo *qmp_query_name(Error **errp)
@@ -731,7 +731,7 @@ void qmp_object_del(const char *id, Error **errp)
 
 MemoryDeviceInfoList *qmp_query_memory_devices(Error **errp)
 {
-    return qmp_pc_dimm_device_list();
+    return qmp_memory_device_list();
 }
 
 ACPIOSTInfoList *qmp_query_acpi_ospm_status(Error **errp)
diff --git a/scripts/device-crash-test b/scripts/device-crash-test
index 5d17dc68dd..b3ce72069f 100755
--- a/scripts/device-crash-test
+++ b/scripts/device-crash-test
@@ -218,9 +218,6 @@ ERROR_WHITELIST = [
     {'exitcode':-6, 'log':r"Object .* is not an instance of type e500-ccsr", 'loglevel':logging.ERROR},
     {'exitcode':-6, 'log':r"vmstate_register_with_alias_id: Assertion `!se->compat \|\| se->instance_id == 0' failed", 'loglevel':logging.ERROR},
     {'exitcode':-11, 'device':'isa-serial', 'loglevel':logging.ERROR, 'expected':True},
-    {'exitcode':-11, 'device':'mioe3680_pci', 'loglevel':logging.ERROR, 'expected':True},
-    {'exitcode':-11, 'device':'pcm3680_pci', 'loglevel':logging.ERROR, 'expected':True},
-    {'exitcode':-11, 'device':'kvaser_pci', 'loglevel':logging.ERROR, 'expected':True},
 
     # everything else (including SIGABRT and SIGSEGV) will be a fatal error:
     {'exitcode':None, 'fatal':True, 'loglevel':logging.FATAL},
diff --git a/stubs/Makefile.objs b/stubs/Makefile.objs
index 2d59d84091..53d3f32cb2 100644
--- a/stubs/Makefile.objs
+++ b/stubs/Makefile.objs
@@ -34,7 +34,7 @@ stub-obj-y += uuid.o
 stub-obj-y += vm-stop.o
 stub-obj-y += vmstate.o
 stub-obj-$(CONFIG_WIN32) += fd-register.o
-stub-obj-y += qmp_pc_dimm.o
+stub-obj-y += qmp_memory_device.o
 stub-obj-y += target-monitor-defs.o
 stub-obj-y += target-get-monitor-def.o
 stub-obj-y += pc_madt_cpu_entry.o
diff --git a/stubs/qmp_pc_dimm.c b/stubs/qmp_memory_device.c
index b6b2cca89e..85ff8f2d7e 100644
--- a/stubs/qmp_pc_dimm.c
+++ b/stubs/qmp_memory_device.c
@@ -1,8 +1,8 @@
 #include "qemu/osdep.h"
 #include "qom/object.h"
-#include "hw/mem/pc-dimm.h"
+#include "hw/mem/memory-device.h"
 
-MemoryDeviceInfoList *qmp_pc_dimm_device_list(void)
+MemoryDeviceInfoList *qmp_memory_device_list(void)
 {
    return NULL;
 }
diff --git a/vl.c b/vl.c
index 806eec2ef6..12e31d1aa9 100644
--- a/vl.c
+++ b/vl.c
@@ -2868,7 +2868,6 @@ static void set_memory_options(uint64_t *ram_slots, ram_addr_t *maxram_size,
 {
     uint64_t sz;
     const char *mem_str;
-    const char *maxmem_str, *slots_str;
     const ram_addr_t default_ram_size = mc->default_ram_size;
     QemuOpts *opts = qemu_find_opts_singleton("memory");
     Location loc;
@@ -2914,9 +2913,7 @@ static void set_memory_options(uint64_t *ram_slots, ram_addr_t *maxram_size,
     qemu_opt_set_number(opts, "size", ram_size, &error_abort);
     *maxram_size = ram_size;
 
-    maxmem_str = qemu_opt_get(opts, "maxmem");
-    slots_str = qemu_opt_get(opts, "slots");
-    if (maxmem_str && slots_str) {
+    if (qemu_opt_get(opts, "maxmem")) {
         uint64_t slots;
 
         sz = qemu_opt_get_size(opts, "maxmem", 0);
@@ -2927,13 +2924,7 @@ static void set_memory_options(uint64_t *ram_slots, ram_addr_t *maxram_size,
                          "the initial memory size (0x" RAM_ADDR_FMT ")",
                          sz, ram_size);
             exit(EXIT_FAILURE);
-        } else if (sz > ram_size) {
-            if (!slots) {
-                error_report("invalid value of -m option: maxmem was "
-                             "specified, but no hotplug slots were specified");
-                exit(EXIT_FAILURE);
-            }
-        } else if (slots) {
+        } else if (slots && sz == ram_size) {
             error_report("invalid value of -m option maxmem: "
                          "memory slots were specified but maximum memory size "
                          "(0x%" PRIx64 ") is equal to the initial memory size "
@@ -2943,10 +2934,8 @@ static void set_memory_options(uint64_t *ram_slots, ram_addr_t *maxram_size,
 
         *maxram_size = sz;
         *ram_slots = slots;
-    } else if ((!maxmem_str && slots_str) ||
-            (maxmem_str && !slots_str)) {
-        error_report("invalid -m option value: missing "
-                "'%s' option", slots_str ? "maxmem" : "slots");
+    } else if (qemu_opt_get(opts, "slots")) {
+        error_report("invalid -m option value: missing 'maxmem' option");
         exit(EXIT_FAILURE);
     }