diff --git a/docs/memory-hotplug.txt b/docs/memory-hotplug.txt
index f70571d..56bdd0a 100644
--- a/docs/memory-hotplug.txt
+++ b/docs/memory-hotplug.txt
@@ -4,9 +4,7 @@
 This document explains how to use the memory hotplug feature in QEMU,
 which is present since v2.1.0.
 
-Please, note that memory hotunplug is not supported yet. This means
-that you're able to add memory, but you're not able to remove it.
-Also, proper guest support is required for memory hotplug to work.
+Guest support is required for memory hotplug to work.
 
 Basic RAM hotplug
 -----------------
@@ -74,3 +72,22 @@
    -device pc-dimm,id=dimm1,memdev=mem1 \
    -object memory-backend-file,id=mem2,size=256M,mem-path=/mnt/hugepages-2MB \
    -device pc-dimm,id=dimm2,memdev=mem2
+
+
+RAM hot-unplug
+---------------
+
+In order to be able to hot unplug pc-dimm device, QEMU has to be told the ids
+of pc-dimm device and memory backend object. The ids were assigned when you hot
+plugged memory.
+
+Two monitor commands are used to hot unplug memory:
+
+ - "device_del": deletes a front-end pc-dimm device
+ - "object_del": deletes a memory backend object
+
+For example, assuming that the pc-dimm device with id "dimm1" exists, and its memory
+backend is "mem1", the following commands tries to remove it.
+
+  (qemu) device_del dimm1
+  (qemu) object_del mem1
diff --git a/docs/qmp/qmp-events.txt b/docs/qmp/qmp-events.txt
index 64ba46c..6dc2cca 100644
--- a/docs/qmp/qmp-events.txt
+++ b/docs/qmp/qmp-events.txt
@@ -232,6 +232,23 @@
 { "event": "GUEST_PANICKED",
      "data": { "action": "pause" } }
 
+MEM_HOT_UNPLUG_ERROR
+--------------------
+Emitted when memory hot unplug error occurs.
+
+Data:
+
+- "device": device name (json-string)
+- "msg": Informative message (e.g., reason for the error) (json-string)
+
+Example:
+
+{ "event": "MEM_HOT_UNPLUG_ERROR"
+  "data": { "device": "dimm1",
+            "msg": "acpi: device unplug for unsupported device"
+  },
+  "timestamp": { "seconds": 1265044230, "microseconds": 450486 } }
+
 NIC_RX_FILTER_CHANGED
 ---------------------
 
diff --git a/docs/specs/acpi_mem_hotplug.txt b/docs/specs/acpi_mem_hotplug.txt
index 1290994..3df3620 100644
--- a/docs/specs/acpi_mem_hotplug.txt
+++ b/docs/specs/acpi_mem_hotplug.txt
@@ -2,7 +2,7 @@
 --------------------------------------
 
 ACPI BIOS GPE.3 handler is dedicated for notifying OS about memory hot-add
-events.
+and hot-remove events.
 
 Memory hot-plug interface (IO port 0xa00-0xa17, 1-4 byte access):
 ---------------------------------------------------------------
@@ -19,7 +19,9 @@
               1: Device insert event, used to distinguish device for which
                  no device check event to OSPM was issued.
                  It's valid only when bit 1 is set.
-              2-7: reserved and should be ignored by OSPM
+              2: Device remove event, used to distinguish device for which
+                 no device eject request to OSPM was issued.
+              3-7: reserved and should be ignored by OSPM
       [0x15-0x17] reserved
 
   write access:
@@ -31,14 +33,62 @@
       [0xc-0x13] reserved, writes into it are ignored
       [0x14] Memory device control fields
           bits:
-              0: reserved, OSPM must clear it before writing to register
+              0: reserved, OSPM must clear it before writing to register.
+                 Due to BUG in versions prior 2.4 that field isn't cleared
+                 when other fields are written. Keep it reserved and don't
+                 try to reuse it.
               1: if set to 1 clears device insert event, set by OSPM
                  after it has emitted device check event for the
                  selected memory device
-              2-7: reserved, OSPM must clear them before writing to register
+              2: if set to 1 clears device remove event, set by OSPM
+                 after it has emitted device eject request for the
+                 selected memory device
+              3: if set to 1 initiates device eject, set by OSPM when it
+                 triggers memory device removal and calls _EJ0 method
+              4-7: reserved, OSPM must clear them before writing to register
 
 Selecting memory device slot beyond present range has no effect on platform:
    - write accesses to memory hot-plug registers not documented above are
      ignored
    - read accesses to memory hot-plug registers not documented above return
      all bits set to 1.
+
+Memory hot remove process diagram:
+----------------------------------
+ +-------------+     +-----------------------+      +------------------+     
+ |  1. QEMU    |     | 2. QEMU               |      |3. QEMU           |     
+ |  device_del +---->+ device unplug request +----->+Send SCI to guest,|     
+ |             |     |         cb            |      |return control to |     
+ +-------------+     +-----------------------+      |management        |     
+                                                    +------------------+     
+                                                                             
+ +---------------------------------------------------------------------+     
+                                                                             
+ +---------------------+              +-------------------------+            
+ | OSPM:               | remove event | OSPM:                   |            
+ | send Eject Request, |              | Scan memory devices     |            
+ | clear remove event  +<-------------+ for event flags         |            
+ |                     |              |                         |            
+ +---------------------+              +-------------------------+            
+           |                                                                 
+           |                                                                 
+ +---------v--------+            +-----------------------+                   
+ | Guest OS:        |  success   | OSPM:                 |                   
+ | process Ejection +----------->+ Execute _EJ0 method,  |                   
+ | request          |            | set eject bit in flags|                   
+ +------------------+            +-----------------------+                   
+           |failure                         |                                
+           v                                v                                
+ +------------------------+      +-----------------------+                   
+ | OSPM:                  |      | QEMU:                 |                   
+ | set OST event & status |      | call device unplug cb |                   
+ | fields                 |      |                       |                   
+ +------------------------+      +-----------------------+                   
+          |                                  |                               
+          v                                  v                               
+ +------------------+              +-------------------+                     
+ |QEMU:             |              |QEMU:              |                     
+ |Send OST QMP event|              |Send device deleted|                     
+ |                  |              |QMP event          |                     
+ +------------------+              |                   |                     
+                                   +-------------------+
diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c
index d7945f6..77ce00b 100644
--- a/hw/acpi/aml-build.c
+++ b/hw/acpi/aml-build.c
@@ -26,6 +26,7 @@
 #include <string.h>
 #include "hw/acpi/aml-build.h"
 #include "qemu/bswap.h"
+#include "hw/acpi/bios-linker-loader.h"
 
 static GArray *build_alloc_array(void)
 {
@@ -635,9 +636,11 @@
 }
 
 /* ACPI 1.0b: 16.2.5.2 Named Objects Encoding: DefField */
-Aml *aml_field(const char *name, AmlFieldFlags flags)
+Aml *aml_field(const char *name, AmlAccessType type, AmlUpdateRule rule)
 {
     Aml *var = aml_bundle(0x81 /* FieldOp */, AML_EXT_PACKAGE);
+    uint8_t flags = rule << 5 | type;
+
     build_append_namestring(var->buf, "%s", name);
     build_append_byte(var->buf, flags);
     return var;
@@ -891,3 +894,60 @@
                              dec, addr_gran, addr_min, addr_max,
                              addr_trans, len, flags);
 }
+
+void
+build_header(GArray *linker, GArray *table_data,
+             AcpiTableHeader *h, const char *sig, int len, uint8_t rev)
+{
+    memcpy(&h->signature, sig, 4);
+    h->length = cpu_to_le32(len);
+    h->revision = rev;
+    memcpy(h->oem_id, ACPI_BUILD_APPNAME6, 6);
+    memcpy(h->oem_table_id, ACPI_BUILD_APPNAME4, 4);
+    memcpy(h->oem_table_id + 4, sig, 4);
+    h->oem_revision = cpu_to_le32(1);
+    memcpy(h->asl_compiler_id, ACPI_BUILD_APPNAME4, 4);
+    h->asl_compiler_revision = cpu_to_le32(1);
+    h->checksum = 0;
+    /* Checksum to be filled in by Guest linker */
+    bios_linker_loader_add_checksum(linker, ACPI_BUILD_TABLE_FILE,
+                                    table_data->data, h, len, &h->checksum);
+}
+
+void *acpi_data_push(GArray *table_data, unsigned size)
+{
+    unsigned off = table_data->len;
+    g_array_set_size(table_data, off + size);
+    return table_data->data + off;
+}
+
+unsigned acpi_data_len(GArray *table)
+{
+#if GLIB_CHECK_VERSION(2, 22, 0)
+    assert(g_array_get_element_size(table) == 1);
+#endif
+    return table->len;
+}
+
+void acpi_add_table(GArray *table_offsets, GArray *table_data)
+{
+    uint32_t offset = cpu_to_le32(table_data->len);
+    g_array_append_val(table_offsets, offset);
+}
+
+void acpi_build_tables_init(AcpiBuildTables *tables)
+{
+    tables->rsdp = g_array_new(false, true /* clear */, 1);
+    tables->table_data = g_array_new(false, true /* clear */, 1);
+    tables->tcpalog = g_array_new(false, true /* clear */, 1);
+    tables->linker = bios_linker_loader_init();
+}
+
+void acpi_build_tables_cleanup(AcpiBuildTables *tables, bool mfre)
+{
+    void *linker_data = bios_linker_loader_cleanup(tables->linker);
+    g_free(linker_data);
+    g_array_free(tables->rsdp, true);
+    g_array_free(tables->table_data, true);
+    g_array_free(tables->tcpalog, mfre);
+}
diff --git a/hw/acpi/ich9.c b/hw/acpi/ich9.c
index 5352e19..84e5bb8 100644
--- a/hw/acpi/ich9.c
+++ b/hw/acpi/ich9.c
@@ -400,15 +400,26 @@
 void ich9_pm_device_unplug_request_cb(ICH9LPCPMRegs *pm, DeviceState *dev,
                                       Error **errp)
 {
-    error_setg(errp, "acpi: device unplug request for not supported device"
-               " type: %s", object_get_typename(OBJECT(dev)));
+    if (pm->acpi_memory_hotplug.is_enabled &&
+        object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
+        acpi_memory_unplug_request_cb(&pm->acpi_regs, pm->irq,
+                                      &pm->acpi_memory_hotplug, dev, errp);
+    } else {
+        error_setg(errp, "acpi: device unplug request for not supported device"
+                   " type: %s", object_get_typename(OBJECT(dev)));
+    }
 }
 
 void ich9_pm_device_unplug_cb(ICH9LPCPMRegs *pm, DeviceState *dev,
                               Error **errp)
 {
-    error_setg(errp, "acpi: device unplug for not supported device"
-               " type: %s", object_get_typename(OBJECT(dev)));
+    if (pm->acpi_memory_hotplug.is_enabled &&
+        object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
+        acpi_memory_unplug_cb(&pm->acpi_memory_hotplug, dev, errp);
+    } else {
+        error_setg(errp, "acpi: device unplug for not supported device"
+                   " type: %s", object_get_typename(OBJECT(dev)));
+    }
 }
 
 void ich9_pm_ospm_status(AcpiDeviceIf *adev, ACPIOSTInfoList ***list)
diff --git a/hw/acpi/memory_hotplug.c b/hw/acpi/memory_hotplug.c
index c6580da..34cef1e 100644
--- a/hw/acpi/memory_hotplug.c
+++ b/hw/acpi/memory_hotplug.c
@@ -2,6 +2,7 @@
 #include "hw/acpi/pc-hotplug.h"
 #include "hw/mem/pc-dimm.h"
 #include "hw/boards.h"
+#include "hw/qdev-core.h"
 #include "trace.h"
 #include "qapi-event.h"
 
@@ -75,6 +76,7 @@
     case 0x14: /* pack and return is_* fields */
         val |= mdev->is_enabled   ? 1 : 0;
         val |= mdev->is_inserting ? 2 : 0;
+        val |= mdev->is_removing  ? 4 : 0;
         trace_mhp_acpi_read_flags(mem_st->selector, val);
         break;
     default:
@@ -90,6 +92,9 @@
     MemHotplugState *mem_st = opaque;
     MemStatus *mdev;
     ACPIOSTInfo *info;
+    DeviceState *dev = NULL;
+    HotplugHandler *hotplug_ctrl = NULL;
+    Error *local_err = NULL;
 
     if (!mem_st->dev_count) {
         return;
@@ -127,13 +132,36 @@
         qapi_event_send_acpi_device_ost(info, &error_abort);
         qapi_free_ACPIOSTInfo(info);
         break;
-    case 0x14:
+    case 0x14: /* set is_* fields  */
         mdev = &mem_st->devs[mem_st->selector];
         if (data & 2) { /* clear insert event */
             mdev->is_inserting  = false;
             trace_mhp_acpi_clear_insert_evt(mem_st->selector);
+        } else if (data & 4) {
+            mdev->is_removing = false;
+            trace_mhp_acpi_clear_remove_evt(mem_st->selector);
+        } else if (data & 8) {
+            if (!mdev->is_enabled) {
+                trace_mhp_acpi_ejecting_invalid_slot(mem_st->selector);
+                break;
+            }
+
+            dev = DEVICE(mdev->dimm);
+            hotplug_ctrl = qdev_get_hotplug_handler(dev);
+            /* call pc-dimm unplug cb */
+            hotplug_handler_unplug(hotplug_ctrl, dev, &local_err);
+            if (local_err) {
+                trace_mhp_acpi_pc_dimm_delete_failed(mem_st->selector);
+                qapi_event_send_mem_unplug_error(dev->id,
+                                                 error_get_pretty(local_err),
+                                                 &error_abort);
+                break;
+            }
+            trace_mhp_acpi_pc_dimm_deleted(mem_st->selector);
         }
         break;
+    default:
+        break;
     }
 
 }
@@ -163,29 +191,51 @@
     memory_region_add_subregion(as, ACPI_MEMORY_HOTPLUG_BASE, &state->io);
 }
 
-void acpi_memory_plug_cb(ACPIREGS *ar, qemu_irq irq, MemHotplugState *mem_st,
-                         DeviceState *dev, Error **errp)
+/**
+ * acpi_memory_slot_status:
+ * @mem_st: memory hotplug state
+ * @dev: device
+ * @errp: set in case of an error
+ *
+ * Obtain a single memory slot status.
+ *
+ * This function will be called by memory unplug request cb and unplug cb.
+ */
+static MemStatus *
+acpi_memory_slot_status(MemHotplugState *mem_st,
+                        DeviceState *dev, Error **errp)
 {
-    MemStatus *mdev;
     Error *local_err = NULL;
     int slot = object_property_get_int(OBJECT(dev), PC_DIMM_SLOT_PROP,
                                        &local_err);
 
     if (local_err) {
         error_propagate(errp, local_err);
-        return;
+        return NULL;
     }
 
     if (slot >= mem_st->dev_count) {
         char *dev_path = object_get_canonical_path(OBJECT(dev));
-        error_setg(errp, "acpi_memory_plug_cb: "
+        error_setg(errp, "acpi_memory_slot_status: "
                    "device [%s] returned invalid memory slot[%d]",
                     dev_path, slot);
         g_free(dev_path);
+        return NULL;
+    }
+
+    return &mem_st->devs[slot];
+}
+
+void acpi_memory_plug_cb(ACPIREGS *ar, qemu_irq irq, MemHotplugState *mem_st,
+                         DeviceState *dev, Error **errp)
+{
+    MemStatus *mdev;
+
+    mdev = acpi_memory_slot_status(mem_st, dev, errp);
+    if (!mdev) {
         return;
     }
 
-    mdev = &mem_st->devs[slot];
     mdev->dimm = dev;
     mdev->is_enabled = true;
     mdev->is_inserting = true;
@@ -196,6 +246,38 @@
     return;
 }
 
+void acpi_memory_unplug_request_cb(ACPIREGS *ar, qemu_irq irq,
+                                   MemHotplugState *mem_st,
+                                   DeviceState *dev, Error **errp)
+{
+    MemStatus *mdev;
+
+    mdev = acpi_memory_slot_status(mem_st, dev, errp);
+    if (!mdev) {
+        return;
+    }
+
+    mdev->is_removing = true;
+
+    /* Do ACPI magic */
+    ar->gpe.sts[0] |= ACPI_MEMORY_HOTPLUG_STATUS;
+    acpi_update_sci(ar, irq);
+}
+
+void acpi_memory_unplug_cb(MemHotplugState *mem_st,
+                           DeviceState *dev, Error **errp)
+{
+    MemStatus *mdev;
+
+    mdev = acpi_memory_slot_status(mem_st, dev, errp);
+    if (!mdev) {
+        return;
+    }
+
+    mdev->is_enabled = false;
+    mdev->dimm = NULL;
+}
+
 static const VMStateDescription vmstate_memhp_sts = {
     .name = "memory hotplug device state",
     .version_id = 1,
diff --git a/hw/acpi/piix4.c b/hw/acpi/piix4.c
index d1f1179..1b28481 100644
--- a/hw/acpi/piix4.c
+++ b/hw/acpi/piix4.c
@@ -361,7 +361,11 @@
 {
     PIIX4PMState *s = PIIX4_PM(hotplug_dev);
 
-    if (object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) {
+    if (s->acpi_memory_hotplug.is_enabled &&
+        object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
+        acpi_memory_unplug_request_cb(&s->ar, s->irq, &s->acpi_memory_hotplug,
+                                      dev, errp);
+    } else if (object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) {
         acpi_pcihp_device_unplug_cb(&s->ar, s->irq, &s->acpi_pci_hotplug, dev,
                                     errp);
     } else {
@@ -373,8 +377,15 @@
 static void piix4_device_unplug_cb(HotplugHandler *hotplug_dev,
                                    DeviceState *dev, Error **errp)
 {
-    error_setg(errp, "acpi: device unplug for not supported device"
-               " type: %s", object_get_typename(OBJECT(dev)));
+    PIIX4PMState *s = PIIX4_PM(hotplug_dev);
+
+    if (s->acpi_memory_hotplug.is_enabled &&
+        object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
+        acpi_memory_unplug_cb(&s->acpi_memory_hotplug, dev, errp);
+    } else {
+        error_setg(errp, "acpi: device unplug for not supported device"
+                   " type: %s", object_get_typename(OBJECT(dev)));
+    }
 }
 
 static void piix4_update_bus_hotplug(PCIBus *pci_bus, void *opaque)
diff --git a/hw/core/qdev.c b/hw/core/qdev.c
index 6e6a65d..b0f0f84 100644
--- a/hw/core/qdev.c
+++ b/hw/core/qdev.c
@@ -273,7 +273,7 @@
     dev->alias_required_for_version = required_for_version;
 }
 
-static HotplugHandler *qdev_get_hotplug_handler(DeviceState *dev)
+HotplugHandler *qdev_get_hotplug_handler(DeviceState *dev)
 {
     HotplugHandler *hotplug_ctrl = NULL;
 
diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index a361357..73259e7 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -32,7 +32,7 @@
 #include "hw/i386/pc.h"
 #include "target-i386/cpu.h"
 #include "hw/timer/hpet.h"
-#include "hw/i386/acpi-defs.h"
+#include "hw/acpi/acpi-defs.h"
 #include "hw/acpi/acpi.h"
 #include "hw/nvram/fw_cfg.h"
 #include "hw/acpi/bios-linker-loader.h"
@@ -68,9 +68,6 @@
 
 #define ACPI_BUILD_TABLE_SIZE             0x20000
 
-/* Reserve RAM space for tables: add another order of magnitude. */
-#define ACPI_BUILD_TABLE_MAX_SIZE         0x200000
-
 /* #define DEBUG_ACPI_BUILD */
 #ifdef DEBUG_ACPI_BUILD
 #define ACPI_BUILD_DPRINTF(fmt, ...)        \
@@ -265,51 +262,8 @@
                                             NULL);
 }
 
-#define ACPI_BUILD_APPNAME  "Bochs"
-#define ACPI_BUILD_APPNAME6 "BOCHS "
-#define ACPI_BUILD_APPNAME4 "BXPC"
-
-#define ACPI_BUILD_TABLE_FILE "etc/acpi/tables"
-#define ACPI_BUILD_RSDP_FILE "etc/acpi/rsdp"
-#define ACPI_BUILD_TPMLOG_FILE "etc/tpm/log"
-
-static void
-build_header(GArray *linker, GArray *table_data,
-             AcpiTableHeader *h, const char *sig, int len, uint8_t rev)
-{
-    memcpy(&h->signature, sig, 4);
-    h->length = cpu_to_le32(len);
-    h->revision = rev;
-    memcpy(h->oem_id, ACPI_BUILD_APPNAME6, 6);
-    memcpy(h->oem_table_id, ACPI_BUILD_APPNAME4, 4);
-    memcpy(h->oem_table_id + 4, sig, 4);
-    h->oem_revision = cpu_to_le32(1);
-    memcpy(h->asl_compiler_id, ACPI_BUILD_APPNAME4, 4);
-    h->asl_compiler_revision = cpu_to_le32(1);
-    h->checksum = 0;
-    /* Checksum to be filled in by Guest linker */
-    bios_linker_loader_add_checksum(linker, ACPI_BUILD_TABLE_FILE,
-                                    table_data->data, h, len, &h->checksum);
-}
-
-/* End here */
 #define ACPI_PORT_SMI_CMD           0x00b2 /* TODO: this is APM_CNT_IOPORT */
 
-static inline void *acpi_data_push(GArray *table_data, unsigned size)
-{
-    unsigned off = table_data->len;
-    g_array_set_size(table_data, off + size);
-    return table_data->data + off;
-}
-
-static unsigned acpi_data_len(GArray *table)
-{
-#if GLIB_CHECK_VERSION(2, 22, 0)
-    assert(g_array_get_element_size(table) == 1);
-#endif
-    return table->len;
-}
-
 static void acpi_align_size(GArray *blob, unsigned align)
 {
     /* Align size to multiple of given size. This reduces the chance
@@ -318,12 +272,6 @@
     g_array_set_size(blob, ROUND_UP(acpi_data_len(blob), align));
 }
 
-static inline void acpi_add_table(GArray *table_offsets, GArray *table_data)
-{
-    uint32_t offset = cpu_to_le32(table_data->len);
-    g_array_append_val(table_offsets, offset);
-}
-
 /* FACS */
 static void
 build_facs(GArray *table_data, GArray *linker, PcGuestInfo *guest_info)
@@ -796,7 +744,7 @@
 
         aml_append(dev, aml_operation_region("PEOR", aml_system_io,
                                               misc->pvpanic_port, 1));
-        field = aml_field("PEOR", aml_byte_acc);
+        field = aml_field("PEOR", aml_byte_acc, aml_preserve);
         aml_append(field, aml_named_field("PEPT", 8));
         aml_append(dev, field);
 
@@ -813,7 +761,7 @@
         aml_append(ssdt, scope);
     }
 
-    sb_scope = aml_scope("_SB");
+    sb_scope = aml_scope("\\_SB");
     {
         /* create PCI0.PRES device and its _CRS to reserve CPU hotplug MMIO */
         dev = aml_device("PCI0." stringify(CPU_HOTPLUG_RESOURCE_DEVICE));
@@ -833,7 +781,7 @@
         /* declare CPU hotplug MMIO region and PRS field to access it */
         aml_append(sb_scope, aml_operation_region(
             "PRST", aml_system_io, pm->cpu_hp_io_base, pm->cpu_hp_io_len));
-        field = aml_field("PRST", aml_byte_acc);
+        field = aml_field("PRST", aml_byte_acc, aml_preserve);
         aml_append(field, aml_named_field("PRS", 256));
         aml_append(sb_scope, field);
 
@@ -907,7 +855,8 @@
             pm->mem_hp_io_base, pm->mem_hp_io_len)
         );
 
-        field = aml_field(stringify(MEMORY_HOTPLUG_IO_REGION), aml_dword_acc);
+        field = aml_field(stringify(MEMORY_HOTPLUG_IO_REGION), aml_dword_acc,
+                          aml_preserve);
         aml_append(field, /* read only */
             aml_named_field(stringify(MEMORY_SLOT_ADDR_LOW), 32));
         aml_append(field, /* read only */
@@ -920,16 +869,24 @@
             aml_named_field(stringify(MEMORY_SLOT_PROXIMITY), 32));
         aml_append(scope, field);
 
-        field = aml_field(stringify(MEMORY_HOTPLUG_IO_REGION), aml_byte_acc);
+        field = aml_field(stringify(MEMORY_HOTPLUG_IO_REGION), aml_byte_acc,
+                          aml_write_as_zeros);
         aml_append(field, aml_reserved_field(160 /* bits, Offset(20) */));
         aml_append(field, /* 1 if enabled, read only */
             aml_named_field(stringify(MEMORY_SLOT_ENABLED), 1));
         aml_append(field,
             /*(read) 1 if has a insert event. (write) 1 to clear event */
             aml_named_field(stringify(MEMORY_SLOT_INSERT_EVENT), 1));
+        aml_append(field,
+            /* (read) 1 if has a remove event. (write) 1 to clear event */
+            aml_named_field(stringify(MEMORY_SLOT_REMOVE_EVENT), 1));
+        aml_append(field,
+            /* initiates device eject, write only */
+            aml_named_field(stringify(MEMORY_SLOT_EJECT), 1));
         aml_append(scope, field);
 
-        field = aml_field(stringify(MEMORY_HOTPLUG_IO_REGION), aml_dword_acc);
+        field = aml_field(stringify(MEMORY_HOTPLUG_IO_REGION), aml_dword_acc,
+                          aml_preserve);
         aml_append(field, /* DIMM selector, write only */
             aml_named_field(stringify(MEMORY_SLOT_SLECTOR), 32));
         aml_append(field, /* _OST event code, write only */
@@ -970,11 +927,17 @@
             )));
             aml_append(dev, method);
 
+            method = aml_method("_EJ0", 1);
+            s = BASEPATH stringify(MEMORY_SLOT_EJECT_METHOD);
+            aml_append(method, aml_return(aml_call2(
+                       s, aml_name("_UID"), aml_arg(0))));
+            aml_append(dev, method);
+
             aml_append(sb_scope, dev);
         }
 
         /* build Method(MEMORY_SLOT_NOTIFY_METHOD, 2) {
-         *     If (LEqual(Arg0, 0x00)) {Notify(MP00, Arg1)} ...
+         *     If (LEqual(Arg0, 0x00)) {Notify(MP00, Arg1)} ... }
          */
         method = aml_method(stringify(MEMORY_SLOT_NOTIFY_METHOD), 2);
         for (i = 0; i < nr_mem; i++) {
@@ -1294,31 +1257,6 @@
 }
 
 typedef
-struct AcpiBuildTables {
-    GArray *table_data;
-    GArray *rsdp;
-    GArray *tcpalog;
-    GArray *linker;
-} AcpiBuildTables;
-
-static inline void acpi_build_tables_init(AcpiBuildTables *tables)
-{
-    tables->rsdp = g_array_new(false, true /* clear */, 1);
-    tables->table_data = g_array_new(false, true /* clear */, 1);
-    tables->tcpalog = g_array_new(false, true /* clear */, 1);
-    tables->linker = bios_linker_loader_init();
-}
-
-static inline void acpi_build_tables_cleanup(AcpiBuildTables *tables, bool mfre)
-{
-    void *linker_data = bios_linker_loader_cleanup(tables->linker);
-    g_free(linker_data);
-    g_array_free(tables->rsdp, true);
-    g_array_free(tables->table_data, true);
-    g_array_free(tables->tcpalog, mfre);
-}
-
-typedef
 struct AcpiBuildState {
     /* Copy of table in RAM (for patching). */
     MemoryRegion *table_mr;
diff --git a/hw/i386/acpi-dsdt-mem-hotplug.dsl b/hw/i386/acpi-dsdt-mem-hotplug.dsl
index 1e9ec39..c2bb6a1 100644
--- a/hw/i386/acpi-dsdt-mem-hotplug.dsl
+++ b/hw/i386/acpi-dsdt-mem-hotplug.dsl
@@ -29,6 +29,8 @@
             External(MEMORY_SLOT_PROXIMITY, FieldUnitObj) // read only
             External(MEMORY_SLOT_ENABLED, FieldUnitObj) // 1 if enabled, read only
             External(MEMORY_SLOT_INSERT_EVENT, FieldUnitObj) // (read) 1 if has a insert event. (write) 1 to clear event
+            External(MEMORY_SLOT_REMOVE_EVENT, FieldUnitObj) // (read) 1 if has a remove event. (write) 1 to clear event
+            External(MEMORY_SLOT_EJECT, FieldUnitObj) // initiates device eject, write only
             External(MEMORY_SLOT_SLECTOR, FieldUnitObj) // DIMM selector, write only
             External(MEMORY_SLOT_OST_EVENT, FieldUnitObj) // _OST event code, write only
             External(MEMORY_SLOT_OST_STATUS, FieldUnitObj) // _OST status code, write only
@@ -55,8 +57,10 @@
                     If (LEqual(MEMORY_SLOT_INSERT_EVENT, One)) { // Memory device needs check
                         MEMORY_SLOT_NOTIFY_METHOD(Local0, 1)
                         Store(1, MEMORY_SLOT_INSERT_EVENT)
+                    } Elseif (LEqual(MEMORY_SLOT_REMOVE_EVENT, One)) { // Ejection request
+                        MEMORY_SLOT_NOTIFY_METHOD(Local0, 3)
+                        Store(1, MEMORY_SLOT_REMOVE_EVENT)
                     }
-                    // TODO: handle memory eject request
                     Add(Local0, One, Local0) // goto next DIMM
                 }
                 Release(MEMORY_SLOT_LOCK)
@@ -156,5 +160,12 @@
                 Store(Arg2, MEMORY_SLOT_OST_STATUS)
                 Release(MEMORY_SLOT_LOCK)
             }
+
+            Method(MEMORY_SLOT_EJECT_METHOD, 2) {
+                Acquire(MEMORY_SLOT_LOCK, 0xFFFF)
+                Store(ToInteger(Arg0), MEMORY_SLOT_SLECTOR) // select DIMM
+                Store(1, MEMORY_SLOT_EJECT)
+                Release(MEMORY_SLOT_LOCK)
+            }
         } // Device()
     } // Scope()
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index a8e6be1..769eb25 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -1677,6 +1677,52 @@
     error_propagate(errp, local_err);
 }
 
+static void pc_dimm_unplug_request(HotplugHandler *hotplug_dev,
+                                   DeviceState *dev, Error **errp)
+{
+    HotplugHandlerClass *hhc;
+    Error *local_err = NULL;
+    PCMachineState *pcms = PC_MACHINE(hotplug_dev);
+
+    if (!pcms->acpi_dev) {
+        error_setg(&local_err,
+                   "memory hotplug is not enabled: missing acpi device");
+        goto out;
+    }
+
+    hhc = HOTPLUG_HANDLER_GET_CLASS(pcms->acpi_dev);
+    hhc->unplug_request(HOTPLUG_HANDLER(pcms->acpi_dev), dev, &local_err);
+
+out:
+    error_propagate(errp, local_err);
+}
+
+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 = ddc->get_memory_region(dimm);
+    HotplugHandlerClass *hhc;
+    Error *local_err = NULL;
+
+    hhc = HOTPLUG_HANDLER_GET_CLASS(pcms->acpi_dev);
+    hhc->unplug(HOTPLUG_HANDLER(pcms->acpi_dev), dev, &local_err);
+
+    if (local_err) {
+        goto out;
+    }
+
+    memory_region_del_subregion(&pcms->hotplug_memory, mr);
+    vmstate_unregister_ram(mr, dev);
+
+    object_unparent(OBJECT(dev));
+
+ out:
+    error_propagate(errp, local_err);
+}
+
 static void pc_cpu_plug(HotplugHandler *hotplug_dev,
                         DeviceState *dev, Error **errp)
 {
@@ -1719,15 +1765,23 @@
 static void pc_machine_device_unplug_request_cb(HotplugHandler *hotplug_dev,
                                                 DeviceState *dev, Error **errp)
 {
-    error_setg(errp, "acpi: device unplug request for not supported device"
-               " type: %s", object_get_typename(OBJECT(dev)));
+    if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
+        pc_dimm_unplug_request(hotplug_dev, dev, errp);
+    } else {
+        error_setg(errp, "acpi: device unplug request for not supported device"
+                   " type: %s", object_get_typename(OBJECT(dev)));
+    }
 }
 
 static void pc_machine_device_unplug_cb(HotplugHandler *hotplug_dev,
                                         DeviceState *dev, Error **errp)
 {
-    error_setg(errp, "acpi: device unplug for not supported device"
-               " type: %s", object_get_typename(OBJECT(dev)));
+    if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM)) {
+        pc_dimm_unplug(hotplug_dev, dev, errp);
+    } else {
+        error_setg(errp, "acpi: device unplug for not supported device"
+                   " type: %s", object_get_typename(OBJECT(dev)));
+    }
 }
 
 static HotplugHandler *pc_get_hotpug_handler(MachineState *machine,
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 1fe7bfb..212e263 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -310,8 +310,13 @@
     pc_init1(machine, 1, 1);
 }
 
+static void pc_compat_2_3(MachineState *machine)
+{
+}
+
 static void pc_compat_2_2(MachineState *machine)
 {
+    pc_compat_2_3(machine);
     rsdp_in_ram = false;
     x86_cpu_compat_set_features("kvm64", FEAT_1_EDX, 0, CPUID_VME);
     x86_cpu_compat_set_features("kvm32", FEAT_1_EDX, 0, CPUID_VME);
@@ -413,6 +418,12 @@
     x86_cpu_compat_kvm_no_autoenable(FEAT_KVM, 1 << KVM_FEATURE_PV_EOI);
 }
 
+static void pc_init_pci_2_3(MachineState *machine)
+{
+    pc_compat_2_3(machine);
+    pc_init_pci(machine);
+}
+
 static void pc_init_pci_2_2(MachineState *machine)
 {
     pc_compat_2_2(machine);
@@ -512,19 +523,28 @@
     .desc = "Standard PC (i440FX + PIIX, 1996)", \
     .hot_add_cpu = pc_hot_add_cpu
 
-#define PC_I440FX_2_3_MACHINE_OPTIONS                           \
+#define PC_I440FX_2_4_MACHINE_OPTIONS                           \
     PC_I440FX_MACHINE_OPTIONS,                                  \
     .default_machine_opts = "firmware=bios-256k.bin",           \
     .default_display = "std"
 
-static QEMUMachine pc_i440fx_machine_v2_3 = {
-    PC_I440FX_2_3_MACHINE_OPTIONS,
-    .name = "pc-i440fx-2.3",
+
+static QEMUMachine pc_i440fx_machine_v2_4 = {
+    PC_I440FX_2_4_MACHINE_OPTIONS,
+    .name = "pc-i440fx-2.4",
     .alias = "pc",
     .init = pc_init_pci,
     .is_default = 1,
 };
 
+#define PC_I440FX_2_3_MACHINE_OPTIONS PC_I440FX_2_4_MACHINE_OPTIONS
+
+static QEMUMachine pc_i440fx_machine_v2_3 = {
+    PC_I440FX_2_3_MACHINE_OPTIONS,
+    .name = "pc-i440fx-2.3",
+    .init = pc_init_pci_2_3,
+};
+
 #define PC_I440FX_2_2_MACHINE_OPTIONS PC_I440FX_2_3_MACHINE_OPTIONS
 
 static QEMUMachine pc_i440fx_machine_v2_2 = {
@@ -970,6 +990,7 @@
 
 static void pc_machine_init(void)
 {
+    qemu_register_pc_machine(&pc_i440fx_machine_v2_4);
     qemu_register_pc_machine(&pc_i440fx_machine_v2_3);
     qemu_register_pc_machine(&pc_i440fx_machine_v2_2);
     qemu_register_pc_machine(&pc_i440fx_machine_v2_1);
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index dcc17c0..e67f2de 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -289,8 +289,13 @@
     }
 }
 
+static void pc_compat_2_3(MachineState *machine)
+{
+}
+
 static void pc_compat_2_2(MachineState *machine)
 {
+    pc_compat_2_3(machine);
     rsdp_in_ram = false;
     x86_cpu_compat_set_features("kvm64", FEAT_1_EDX, 0, CPUID_VME);
     x86_cpu_compat_set_features("kvm32", FEAT_1_EDX, 0, CPUID_VME);
@@ -361,6 +366,12 @@
     x86_cpu_compat_set_features("Westmere", FEAT_1_ECX, 0, CPUID_EXT_PCLMULQDQ);
 }
 
+static void pc_q35_init_2_3(MachineState *machine)
+{
+    pc_compat_2_3(machine);
+    pc_q35_init(machine);
+}
+
 static void pc_q35_init_2_2(MachineState *machine)
 {
     pc_compat_2_2(machine);
@@ -410,16 +421,24 @@
     .hot_add_cpu = pc_hot_add_cpu, \
     .units_per_default_bus = 1
 
-#define PC_Q35_2_3_MACHINE_OPTIONS                      \
+#define PC_Q35_2_4_MACHINE_OPTIONS                      \
     PC_Q35_MACHINE_OPTIONS,                             \
     .default_machine_opts = "firmware=bios-256k.bin",   \
     .default_display = "std"
 
+static QEMUMachine pc_q35_machine_v2_4 = {
+    PC_Q35_2_4_MACHINE_OPTIONS,
+    .name = "pc-q35-2.4",
+    .alias = "q35",
+    .init = pc_q35_init,
+};
+
+#define PC_Q35_2_3_MACHINE_OPTIONS PC_Q35_2_4_MACHINE_OPTIONS
+
 static QEMUMachine pc_q35_machine_v2_3 = {
     PC_Q35_2_3_MACHINE_OPTIONS,
     .name = "pc-q35-2.3",
-    .alias = "q35",
-    .init = pc_q35_init,
+    .init = pc_q35_init_2_3,
 };
 
 #define PC_Q35_2_2_MACHINE_OPTIONS PC_Q35_2_3_MACHINE_OPTIONS
@@ -506,6 +525,7 @@
 
 static void pc_q35_machine_init(void)
 {
+    qemu_register_pc_machine(&pc_q35_machine_v2_4);
     qemu_register_pc_machine(&pc_q35_machine_v2_3);
     qemu_register_pc_machine(&pc_q35_machine_v2_2);
     qemu_register_pc_machine(&pc_q35_machine_v2_1);
diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index cf23335..47f8b89 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -263,6 +263,13 @@
                                           &file);
             assert(r >= 0);
         }
+    } else if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER) {
+        for (file.index = 0; file.index < net->dev.nvqs; ++file.index) {
+            const VhostOps *vhost_ops = net->dev.vhost_ops;
+            int r = vhost_ops->vhost_call(&net->dev, VHOST_RESET_OWNER,
+                                          NULL);
+            assert(r >= 0);
+        }
     }
     if (net->nc->info->poll) {
         net->nc->info->poll(net->nc, true);
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 67ab228..cc252ed 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -446,6 +446,9 @@
     VirtIONet *n = VIRTIO_NET(vdev);
     NetClientState *nc = qemu_get_queue(n->nic);
 
+    /* Firstly sync all virtio-net possible supported features */
+    features |= n->host_features;
+
     virtio_add_feature(&features, VIRTIO_NET_F_MAC);
 
     if (!peer_has_vnet_hdr(n)) {
@@ -1309,7 +1312,7 @@
 
     n->multiqueue = multiqueue;
 
-    for (i = 2; i <= n->max_queues * 2 + 1; i++) {
+    for (i = 2; i < n->max_queues * 2 + 1; i++) {
         virtio_del_queue(vdev, i);
     }
 
@@ -1552,7 +1555,7 @@
                              vdev, idx, mask);
 }
 
-void virtio_net_set_config_size(VirtIONet *n, uint32_t host_features)
+static void virtio_net_set_config_size(VirtIONet *n, uint32_t host_features)
 {
     int i, config_size = 0;
     virtio_add_feature(&host_features, VIRTIO_NET_F_MAC);
@@ -1585,6 +1588,7 @@
     NetClientState *nc;
     int i;
 
+    virtio_net_set_config_size(n, n->host_features);
     virtio_init(vdev, "virtio-net", VIRTIO_ID_NET, n->config_size);
 
     n->max_queues = MAX(n->nic_conf.peers.queues, 1);
@@ -1721,6 +1725,7 @@
 }
 
 static Property virtio_net_properties[] = {
+    DEFINE_VIRTIO_NET_FEATURES(VirtIONet, host_features),
     DEFINE_NIC_PROPERTIES(VirtIONet, nic_conf),
     DEFINE_PROP_UINT32("x-txtimer", VirtIONet, net_conf.txtimer,
                                                TX_TIMER_INTERVAL),
diff --git a/hw/pci/msix.c b/hw/pci/msix.c
index 031eaab..9935f98 100644
--- a/hw/pci/msix.c
+++ b/hw/pci/msix.c
@@ -295,29 +295,37 @@
 {
     int ret;
     char *name;
+    uint32_t bar_size = 4096;
+    uint32_t bar_pba_offset = bar_size / 2;
+    uint32_t bar_pba_size = (nentries / 8 + 1) * 8;
 
     /*
      * Migration compatibility dictates that this remains a 4k
      * BAR with the vector table in the lower half and PBA in
-     * the upper half.  Do not use these elsewhere!
+     * the upper half for nentries which is lower or equal to 128.
+     * No need to care about using more than 65 entries for legacy
+     * machine types who has at most 64 queues.
      */
-#define MSIX_EXCLUSIVE_BAR_SIZE 4096
-#define MSIX_EXCLUSIVE_BAR_TABLE_OFFSET 0
-#define MSIX_EXCLUSIVE_BAR_PBA_OFFSET (MSIX_EXCLUSIVE_BAR_SIZE / 2)
-#define MSIX_EXCLUSIVE_CAP_OFFSET 0
+    if (nentries * PCI_MSIX_ENTRY_SIZE > bar_pba_offset) {
+        bar_pba_offset = nentries * PCI_MSIX_ENTRY_SIZE;
+    }
 
-    if (nentries * PCI_MSIX_ENTRY_SIZE > MSIX_EXCLUSIVE_BAR_PBA_OFFSET) {
-        return -EINVAL;
+    if (bar_pba_offset + bar_pba_size > 4096) {
+        bar_size = bar_pba_offset + bar_pba_size;
+    }
+
+    if (bar_size & (bar_size - 1)) {
+        bar_size = 1 << qemu_fls(bar_size);
     }
 
     name = g_strdup_printf("%s-msix", dev->name);
-    memory_region_init(&dev->msix_exclusive_bar, OBJECT(dev), name, MSIX_EXCLUSIVE_BAR_SIZE);
+    memory_region_init(&dev->msix_exclusive_bar, OBJECT(dev), name, bar_size);
     g_free(name);
 
     ret = msix_init(dev, nentries, &dev->msix_exclusive_bar, bar_nr,
-                    MSIX_EXCLUSIVE_BAR_TABLE_OFFSET, &dev->msix_exclusive_bar,
-                    bar_nr, MSIX_EXCLUSIVE_BAR_PBA_OFFSET,
-                    MSIX_EXCLUSIVE_CAP_OFFSET);
+                    0, &dev->msix_exclusive_bar,
+                    bar_nr, bar_pba_offset,
+                    0);
     if (ret) {
         return ret;
     }
diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index f5c7a99..48f19a3 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -1615,28 +1615,32 @@
 };
 
 /* Initialize a PCI NIC.  */
-static PCIDevice *pci_nic_init(NICInfo *nd, PCIBus *rootbus,
+PCIDevice *pci_nic_init_nofail(NICInfo *nd, PCIBus *rootbus,
                                const char *default_model,
-                               const char *default_devaddr,
-                               Error **errp)
+                               const char *default_devaddr)
 {
     const char *devaddr = nd->devaddr ? nd->devaddr : default_devaddr;
     Error *err = NULL;
     PCIBus *bus;
-    int devfn;
     PCIDevice *pci_dev;
     DeviceState *dev;
+    int devfn;
     int i;
 
+    if (qemu_show_nic_models(nd->model, pci_nic_models)) {
+        exit(0);
+    }
+
     i = qemu_find_nic_model(nd, pci_nic_models, default_model);
-    if (i < 0)
-        return NULL;
+    if (i < 0) {
+        exit(1);
+    }
 
     bus = pci_get_bus_devfn(&devfn, rootbus, devaddr);
     if (!bus) {
         error_report("Invalid PCI device address %s for device %s",
                      devaddr, pci_nic_names[i]);
-        return NULL;
+        exit(1);
     }
 
     pci_dev = pci_create(bus, devfn, pci_nic_names[i]);
@@ -1645,31 +1649,12 @@
 
     object_property_set_bool(OBJECT(dev), true, "realized", &err);
     if (err) {
-        error_propagate(errp, err);
+        error_report_err(err);
         object_unparent(OBJECT(dev));
-        return NULL;
-    }
-    return pci_dev;
-}
-
-PCIDevice *pci_nic_init_nofail(NICInfo *nd, PCIBus *rootbus,
-                               const char *default_model,
-                               const char *default_devaddr)
-{
-    Error *err = NULL;
-    PCIDevice *res;
-
-    if (qemu_show_nic_models(nd->model, pci_nic_models))
-        exit(0);
-
-    res = pci_nic_init(nd, rootbus, default_model, default_devaddr, &err);
-    if (!res) {
-        if (err) {
-            error_report_err(err);
-        }
         exit(1);
     }
-    return res;
+
+    return pci_dev;
 }
 
 PCIDevice *pci_vga_init(PCIBus *bus)
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 644689a..ac261ef 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -1825,6 +1825,38 @@
 #define SPAPR_COMPAT_2_1 \
         SPAPR_COMPAT_2_2
 
+static void spapr_compat_2_3(Object *obj)
+{
+}
+
+static void spapr_compat_2_2(Object *obj)
+{
+    spapr_compat_2_3(obj);
+}
+
+static void spapr_compat_2_1(Object *obj)
+{
+    spapr_compat_2_2(obj);
+}
+
+static void spapr_machine_2_3_instance_init(Object *obj)
+{
+    spapr_compat_2_3(obj);
+    spapr_machine_initfn(obj);
+}
+
+static void spapr_machine_2_2_instance_init(Object *obj)
+{
+    spapr_compat_2_2(obj);
+    spapr_machine_initfn(obj);
+}
+
+static void spapr_machine_2_1_instance_init(Object *obj)
+{
+    spapr_compat_2_1(obj);
+    spapr_machine_initfn(obj);
+}
+
 static void spapr_machine_2_1_class_init(ObjectClass *oc, void *data)
 {
     MachineClass *mc = MACHINE_CLASS(oc);
@@ -1843,6 +1875,7 @@
     .name          = TYPE_SPAPR_MACHINE "2.1",
     .parent        = TYPE_SPAPR_MACHINE,
     .class_init    = spapr_machine_2_1_class_init,
+    .instance_init = spapr_machine_2_1_instance_init,
 };
 
 static void spapr_machine_2_2_class_init(ObjectClass *oc, void *data)
@@ -1862,6 +1895,7 @@
     .name          = TYPE_SPAPR_MACHINE "2.2",
     .parent        = TYPE_SPAPR_MACHINE,
     .class_init    = spapr_machine_2_2_class_init,
+    .instance_init = spapr_machine_2_2_instance_init,
 };
 
 static void spapr_machine_2_3_class_init(ObjectClass *oc, void *data)
@@ -1870,14 +1904,29 @@
 
     mc->name = "pseries-2.3";
     mc->desc = "pSeries Logical Partition (PAPR compliant) v2.3";
-    mc->alias = "pseries";
-    mc->is_default = 1;
 }
 
 static const TypeInfo spapr_machine_2_3_info = {
     .name          = TYPE_SPAPR_MACHINE "2.3",
     .parent        = TYPE_SPAPR_MACHINE,
     .class_init    = spapr_machine_2_3_class_init,
+    .instance_init = spapr_machine_2_3_instance_init,
+};
+
+static void spapr_machine_2_4_class_init(ObjectClass *oc, void *data)
+{
+    MachineClass *mc = MACHINE_CLASS(oc);
+
+    mc->name = "pseries-2.4";
+    mc->desc = "pSeries Logical Partition (PAPR compliant) v2.4";
+    mc->alias = "pseries";
+    mc->is_default = 1;
+}
+
+static const TypeInfo spapr_machine_2_4_info = {
+    .name          = TYPE_SPAPR_MACHINE "2.4",
+    .parent        = TYPE_SPAPR_MACHINE,
+    .class_init    = spapr_machine_2_4_class_init,
 };
 
 static void spapr_machine_register_types(void)
@@ -1886,6 +1935,7 @@
     type_register_static(&spapr_machine_2_1_info);
     type_register_static(&spapr_machine_2_2_info);
     type_register_static(&spapr_machine_2_3_info);
+    type_register_static(&spapr_machine_2_4_info);
 }
 
 type_init(spapr_machine_register_types)
diff --git a/hw/s390x/s390-virtio-bus.c b/hw/s390x/s390-virtio-bus.c
index 4f69cbb..0e35ac9 100644
--- a/hw/s390x/s390-virtio-bus.c
+++ b/hw/s390x/s390-virtio-bus.c
@@ -155,7 +155,6 @@
     DeviceState *vdev = DEVICE(&dev->vdev);
     Error *err = NULL;
 
-    virtio_net_set_config_size(&dev->vdev, s390_dev->host_features);
     virtio_net_set_netclient_name(&dev->vdev, qdev->id,
                                   object_get_typename(OBJECT(qdev)));
     qdev_set_parent_bus(vdev, BUS(&s390_dev->bus));
@@ -537,18 +536,12 @@
 
 /**************** S390 Virtio Bus Device Descriptions *******************/
 
-static Property s390_virtio_net_properties[] = {
-    DEFINE_VIRTIO_NET_FEATURES(VirtIOS390Device, host_features),
-    DEFINE_PROP_END_OF_LIST(),
-};
-
 static void s390_virtio_net_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     VirtIOS390DeviceClass *k = VIRTIO_S390_DEVICE_CLASS(klass);
 
     k->realize = s390_virtio_net_realize;
-    dc->props = s390_virtio_net_properties;
     set_bit(DEVICE_CATEGORY_NETWORK, dc->categories);
 }
 
@@ -657,18 +650,12 @@
     .abstract = true,
 };
 
-static Property s390_virtio_scsi_properties[] = {
-    DEFINE_VIRTIO_SCSI_FEATURES(VirtIOS390Device, host_features),
-    DEFINE_PROP_END_OF_LIST(),
-};
-
 static void s390_virtio_scsi_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     VirtIOS390DeviceClass *k = VIRTIO_S390_DEVICE_CLASS(klass);
 
     k->realize = s390_virtio_scsi_realize;
-    dc->props = s390_virtio_scsi_properties;
     set_bit(DEVICE_CATEGORY_STORAGE, dc->categories);
 }
 
diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
index 430cc6f..c96101a 100644
--- a/hw/s390x/virtio-ccw.c
+++ b/hw/s390x/virtio-ccw.c
@@ -281,7 +281,7 @@
 
     virtio_queue_set_addr(vdev, index, addr);
     if (!addr) {
-        virtio_queue_set_vector(vdev, index, 0);
+        virtio_queue_set_vector(vdev, index, VIRTIO_NO_VECTOR);
     } else {
         /* Fail if we don't have a big enough queue. */
         /* TODO: Add interface to handle vring.num changing */
@@ -805,7 +805,6 @@
     DeviceState *vdev = DEVICE(&dev->vdev);
     Error *err = NULL;
 
-    virtio_net_set_config_size(&dev->vdev, ccw_dev->host_features[0]);
     virtio_net_set_netclient_name(&dev->vdev, qdev->id,
                                   object_get_typename(OBJECT(qdev)));
     qdev_set_parent_bus(vdev, BUS(&ccw_dev->bus));
@@ -1441,7 +1440,6 @@
 
 static Property virtio_ccw_net_properties[] = {
     DEFINE_PROP_STRING("devno", VirtioCcwDevice, bus_id),
-    DEFINE_VIRTIO_NET_FEATURES(VirtioCcwDevice, host_features[0]),
     DEFINE_PROP_BIT("ioeventfd", VirtioCcwDevice, flags,
                     VIRTIO_CCW_FLAG_USE_IOEVENTFD_BIT, true),
     DEFINE_PROP_END_OF_LIST(),
@@ -1550,7 +1548,6 @@
 
 static Property virtio_ccw_scsi_properties[] = {
     DEFINE_PROP_STRING("devno", VirtioCcwDevice, bus_id),
-    DEFINE_VIRTIO_SCSI_FEATURES(VirtioCcwDevice, host_features[0]),
     DEFINE_PROP_BIT("ioeventfd", VirtioCcwDevice, flags,
                     VIRTIO_CCW_FLAG_USE_IOEVENTFD_BIT, true),
     DEFINE_PROP_END_OF_LIST(),
diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
index c9bea06..e242fef 100644
--- a/hw/scsi/virtio-scsi.c
+++ b/hw/scsi/virtio-scsi.c
@@ -631,6 +631,10 @@
 static uint32_t virtio_scsi_get_features(VirtIODevice *vdev,
                                          uint32_t requested_features)
 {
+    VirtIOSCSI *s = VIRTIO_SCSI(vdev);
+
+    /* Firstly sync all virtio-scsi possible supported features */
+    requested_features |= s->host_features;
     return requested_features;
 }
 
@@ -945,6 +949,7 @@
 
 static Property virtio_scsi_properties[] = {
     DEFINE_VIRTIO_SCSI_PROPERTIES(VirtIOSCSI, parent_obj.conf),
+    DEFINE_VIRTIO_SCSI_FEATURES(VirtIOSCSI, host_features),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index c7c3f72..867c9d1 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -630,28 +630,30 @@
 {
     VirtIOPCIProxy *proxy = container_of(dev, VirtIOPCIProxy, pci_dev);
     VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
-    int ret, queue_no;
+    VirtQueue *vq = virtio_vector_first_queue(vdev, vector);
+    int ret, index, unmasked = 0;
 
-    for (queue_no = 0; queue_no < proxy->nvqs_with_notifiers; queue_no++) {
-        if (!virtio_queue_get_num(vdev, queue_no)) {
+    while (vq) {
+        index = virtio_get_queue_index(vq);
+        if (!virtio_queue_get_num(vdev, index)) {
             break;
         }
-        if (virtio_queue_vector(vdev, queue_no) != vector) {
-            continue;
-        }
-        ret = virtio_pci_vq_vector_unmask(proxy, queue_no, vector, msg);
+        ret = virtio_pci_vq_vector_unmask(proxy, index, vector, msg);
         if (ret < 0) {
             goto undo;
         }
+        vq = virtio_vector_next_queue(vq);
+        ++unmasked;
     }
+
     return 0;
 
 undo:
-    while (--queue_no >= 0) {
-        if (virtio_queue_vector(vdev, queue_no) != vector) {
-            continue;
-        }
-        virtio_pci_vq_vector_mask(proxy, queue_no, vector);
+    vq = virtio_vector_first_queue(vdev, vector);
+    while (vq && --unmasked >= 0) {
+        index = virtio_get_queue_index(vq);
+        virtio_pci_vq_vector_mask(proxy, index, vector);
+        vq = virtio_vector_next_queue(vq);
     }
     return ret;
 }
@@ -660,16 +662,16 @@
 {
     VirtIOPCIProxy *proxy = container_of(dev, VirtIOPCIProxy, pci_dev);
     VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
-    int queue_no;
+    VirtQueue *vq = virtio_vector_first_queue(vdev, vector);
+    int index;
 
-    for (queue_no = 0; queue_no < proxy->nvqs_with_notifiers; queue_no++) {
-        if (!virtio_queue_get_num(vdev, queue_no)) {
+    while (vq) {
+        index = virtio_get_queue_index(vq);
+        if (!virtio_queue_get_num(vdev, index)) {
             break;
         }
-        if (virtio_queue_vector(vdev, queue_no) != vector) {
-            continue;
-        }
-        virtio_pci_vq_vector_mask(proxy, queue_no, vector);
+        virtio_pci_vq_vector_mask(proxy, index, vector);
+        vq = virtio_vector_next_queue(vq);
     }
 }
 
@@ -908,6 +910,13 @@
  * virtio-pci: This is the PCIDevice which has a virtio-pci-bus.
  */
 
+static int virtio_pci_query_nvectors(DeviceState *d)
+{
+    VirtIOPCIProxy *proxy = VIRTIO_PCI(d);
+
+    return proxy->nvectors;
+}
+
 /* This is called by virtio-bus just after the device is plugged. */
 static void virtio_pci_device_plugged(DeviceState *d)
 {
@@ -1078,7 +1087,6 @@
                     VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT, true),
     DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors,
                        DEV_NVECTORS_UNSPECIFIED),
-    DEFINE_VIRTIO_SCSI_FEATURES(VirtIOPCIProxy, host_features),
     DEFINE_PROP_END_OF_LIST(),
 };
 
@@ -1360,7 +1368,6 @@
     DEFINE_PROP_BIT("ioeventfd", VirtIOPCIProxy, flags,
                     VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT, false),
     DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors, 3),
-    DEFINE_VIRTIO_NET_FEATURES(VirtIOPCIProxy, host_features),
     DEFINE_PROP_END_OF_LIST(),
 };
 
@@ -1370,7 +1377,6 @@
     VirtIONetPCI *dev = VIRTIO_NET_PCI(vpci_dev);
     DeviceState *vdev = DEVICE(&dev->vdev);
 
-    virtio_net_set_config_size(&dev->vdev, vpci_dev->host_features);
     virtio_net_set_netclient_name(&dev->vdev, qdev->id,
                                   object_get_typename(OBJECT(qdev)));
     qdev_set_parent_bus(vdev, BUS(&vpci_dev->bus));
@@ -1498,6 +1504,7 @@
     k->vmstate_change = virtio_pci_vmstate_change;
     k->device_plugged = virtio_pci_device_plugged;
     k->device_unplugged = virtio_pci_device_unplugged;
+    k->query_nvectors = virtio_pci_query_nvectors;
 }
 
 static const TypeInfo virtio_pci_bus_info = {
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 17c1260..6985e76 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -89,6 +89,7 @@
     VirtIODevice *vdev;
     EventNotifier guest_notifier;
     EventNotifier host_notifier;
+    QLIST_ENTRY(VirtQueue) node;
 };
 
 /* virt queue functions */
@@ -605,7 +606,7 @@
         vdev->vq[i].vring.used = 0;
         vdev->vq[i].last_avail_idx = 0;
         vdev->vq[i].pa = 0;
-        vdev->vq[i].vector = VIRTIO_NO_VECTOR;
+        virtio_queue_set_vector(vdev, i, VIRTIO_NO_VECTOR);
         vdev->vq[i].signalled_used = 0;
         vdev->vq[i].signalled_used_valid = false;
         vdev->vq[i].notification = true;
@@ -730,6 +731,16 @@
     virtqueue_init(&vdev->vq[n]);
 }
 
+VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector)
+{
+    return QLIST_FIRST(&vdev->vector_queues[vector]);
+}
+
+VirtQueue *virtio_vector_next_queue(VirtQueue *vq)
+{
+    return QLIST_NEXT(vq, node);
+}
+
 int virtio_queue_get_num(VirtIODevice *vdev, int n)
 {
     return vdev->vq[n].vring.num;
@@ -780,8 +791,19 @@
 
 void virtio_queue_set_vector(VirtIODevice *vdev, int n, uint16_t vector)
 {
-    if (n < VIRTIO_PCI_QUEUE_MAX)
+    VirtQueue *vq = &vdev->vq[n];
+
+    if (n < VIRTIO_PCI_QUEUE_MAX) {
+        if (vdev->vector_queues &&
+            vdev->vq[n].vector != VIRTIO_NO_VECTOR) {
+            QLIST_REMOVE(vq, node);
+        }
         vdev->vq[n].vector = vector;
+        if (vdev->vector_queues &&
+            vector != VIRTIO_NO_VECTOR) {
+            QLIST_INSERT_HEAD(&vdev->vector_queues[vector], vq, node);
+        }
+    }
 }
 
 VirtQueue *virtio_add_queue(VirtIODevice *vdev, int queue_size,
@@ -1088,6 +1110,7 @@
     qemu_del_vm_change_state_handler(vdev->vmstate);
     g_free(vdev->config);
     g_free(vdev->vq);
+    g_free(vdev->vector_queues);
 }
 
 static void virtio_vmstate_change(void *opaque, int running, RunState state)
@@ -1125,7 +1148,16 @@
 void virtio_init(VirtIODevice *vdev, const char *name,
                  uint16_t device_id, size_t config_size)
 {
+    BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
+    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
     int i;
+    int nvectors = k->query_nvectors ? k->query_nvectors(qbus->parent) : 0;
+
+    if (nvectors) {
+        vdev->vector_queues =
+            g_malloc0(sizeof(*vdev->vector_queues) * nvectors);
+    }
+
     vdev->device_id = device_id;
     vdev->status = 0;
     vdev->isr = 0;
diff --git a/hw/i386/acpi-defs.h b/include/hw/acpi/acpi-defs.h
similarity index 100%
rename from hw/i386/acpi-defs.h
rename to include/hw/acpi/acpi-defs.h
diff --git a/include/hw/acpi/aml-build.h b/include/hw/acpi/aml-build.h
index 17d3beb..3947201 100644
--- a/include/hw/acpi/aml-build.h
+++ b/include/hw/acpi/aml-build.h
@@ -4,6 +4,18 @@
 #include <stdint.h>
 #include <glib.h>
 #include "qemu/compiler.h"
+#include "hw/acpi/acpi-defs.h"
+
+/* Reserve RAM space for tables: add another order of magnitude. */
+#define ACPI_BUILD_TABLE_MAX_SIZE         0x200000
+
+#define ACPI_BUILD_APPNAME  "Bochs"
+#define ACPI_BUILD_APPNAME6 "BOCHS "
+#define ACPI_BUILD_APPNAME4 "BXPC"
+
+#define ACPI_BUILD_TABLE_FILE "etc/acpi/tables"
+#define ACPI_BUILD_RSDP_FILE "etc/acpi/rsdp"
+#define ACPI_BUILD_TPMLOG_FILE "etc/tpm/log"
 
 typedef enum {
     AML_NO_OPCODE = 0,/* has only data */
@@ -35,7 +47,13 @@
     aml_dword_acc = 3,
     aml_qword_acc = 4,
     aml_buffer_acc = 5,
-} AmlFieldFlags;
+} AmlAccessType;
+
+typedef enum {
+    aml_preserve = 0,
+    aml_write_as_ones = 1,
+    aml_write_as_zeros = 2,
+} AmlUpdateRule;
 
 typedef enum {
     aml_system_memory = 0x00,
@@ -93,6 +111,14 @@
     aml_ReadWrite = 1,
 } AmlReadAndWrite;
 
+typedef
+struct AcpiBuildTables {
+    GArray *table_data;
+    GArray *rsdp;
+    GArray *tcpalog;
+    GArray *linker;
+} AcpiBuildTables;
+
 /**
  * init_aml_allocator:
  *
@@ -120,7 +146,7 @@
  * Joins Aml elements together and helps to construct AML tables
  * Examle of usage:
  *   Aml *table = aml_def_block("SSDT", ...);
- *   Aml *sb = aml_scope("\_SB");
+ *   Aml *sb = aml_scope("\\_SB");
  *   Aml *dev = aml_device("PCI0");
  *
  *   aml_append(dev, aml_name_decl("HID", aml_eisaid("PNP0A03")));
@@ -185,7 +211,16 @@
 Aml *aml_package(uint8_t num_elements);
 Aml *aml_buffer(void);
 Aml *aml_resource_template(void);
-Aml *aml_field(const char *name, AmlFieldFlags flags);
+Aml *aml_field(const char *name, AmlAccessType type, AmlUpdateRule rule);
 Aml *aml_varpackage(uint32_t num_elements);
 
+void
+build_header(GArray *linker, GArray *table_data,
+             AcpiTableHeader *h, const char *sig, int len, uint8_t rev);
+void *acpi_data_push(GArray *table_data, unsigned size);
+unsigned acpi_data_len(GArray *table);
+void acpi_add_table(GArray *table_offsets, GArray *table_data);
+void acpi_build_tables_init(AcpiBuildTables *tables);
+void acpi_build_tables_cleanup(AcpiBuildTables *tables, bool mfre);
+
 #endif
diff --git a/include/hw/acpi/memory_hotplug.h b/include/hw/acpi/memory_hotplug.h
index 7bbf8a0..986223b 100644
--- a/include/hw/acpi/memory_hotplug.h
+++ b/include/hw/acpi/memory_hotplug.h
@@ -7,10 +7,17 @@
 
 #define ACPI_MEMORY_HOTPLUG_STATUS 8
 
+/**
+ * MemStatus:
+ * @is_removing: the memory device in slot has been requested to be ejected.
+ *
+ * This structure stores memory device's status.
+ */
 typedef struct MemStatus {
     DeviceState *dimm;
     bool is_enabled;
     bool is_inserting;
+    bool is_removing;
     uint32_t ost_event;
     uint32_t ost_status;
 } MemStatus;
@@ -28,6 +35,11 @@
 
 void acpi_memory_plug_cb(ACPIREGS *ar, qemu_irq irq, MemHotplugState *mem_st,
                          DeviceState *dev, Error **errp);
+void acpi_memory_unplug_request_cb(ACPIREGS *ar, qemu_irq irq,
+                                   MemHotplugState *mem_st,
+                                   DeviceState *dev, Error **errp);
+void acpi_memory_unplug_cb(MemHotplugState *mem_st,
+                           DeviceState *dev, Error **errp);
 
 extern const VMStateDescription vmstate_memory_hotplug;
 #define VMSTATE_MEMORY_HOTPLUG(memhp, state) \
diff --git a/include/hw/acpi/pc-hotplug.h b/include/hw/acpi/pc-hotplug.h
index efa6ed7..0513c1c 100644
--- a/include/hw/acpi/pc-hotplug.h
+++ b/include/hw/acpi/pc-hotplug.h
@@ -43,6 +43,8 @@
 #define MEMORY_SLOT_PROXIMITY        MPX
 #define MEMORY_SLOT_ENABLED          MES
 #define MEMORY_SLOT_INSERT_EVENT     MINS
+#define MEMORY_SLOT_REMOVE_EVENT     MRMV
+#define MEMORY_SLOT_EJECT            MEJ
 #define MEMORY_SLOT_SLECTOR          MSEL
 #define MEMORY_SLOT_OST_EVENT        MOEV
 #define MEMORY_SLOT_OST_STATUS       MOSC
@@ -51,6 +53,7 @@
 #define MEMORY_SLOT_CRS_METHOD       MCRS
 #define MEMORY_SLOT_OST_METHOD       MOST
 #define MEMORY_SLOT_PROXIMITY_METHOD MPXM
+#define MEMORY_SLOT_EJECT_METHOD     MEJ0
 #define MEMORY_SLOT_NOTIFY_METHOD    MTFY
 #define MEMORY_SLOT_SCAN_METHOD      MSCN
 
diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
index 4e673f9..5b7acf1 100644
--- a/include/hw/qdev-core.h
+++ b/include/hw/qdev-core.h
@@ -266,6 +266,7 @@
 void qdev_init_nofail(DeviceState *dev);
 void qdev_set_legacy_instance_id(DeviceState *dev, int alias_id,
                                  int required_for_version);
+HotplugHandler *qdev_get_hotplug_handler(DeviceState *dev);
 void qdev_unplug(DeviceState *dev, Error **errp);
 void qdev_simple_device_unplug_cb(HotplugHandler *hotplug_dev,
                                   DeviceState *dev, Error **errp);
diff --git a/include/hw/virtio/virtio-bus.h b/include/hw/virtio/virtio-bus.h
index 0d2e7b4..a4588ca 100644
--- a/include/hw/virtio/virtio-bus.h
+++ b/include/hw/virtio/virtio-bus.h
@@ -62,6 +62,7 @@
      * This is called by virtio-bus just before the device is unplugged.
      */
     void (*device_unplugged)(DeviceState *d);
+    int (*query_nvectors)(DeviceState *d);
     /*
      * Does the transport have variable vring alignment?
      * (ie can it ever call virtio_queue_set_align()?)
diff --git a/include/hw/virtio/virtio-net.h b/include/hw/virtio/virtio-net.h
index 4c2fe83..e0dbb41 100644
--- a/include/hw/virtio/virtio-net.h
+++ b/include/hw/virtio/virtio-net.h
@@ -68,6 +68,7 @@
     uint32_t has_vnet_hdr;
     size_t host_hdr_len;
     size_t guest_hdr_len;
+    uint32_t host_features;
     uint8_t has_ufo;
     int mergeable_rx_bufs;
     uint8_t promisc;
@@ -137,7 +138,6 @@
     DEFINE_PROP_INT32("x-txburst", _state, _field.txburst, TX_BURST),          \
     DEFINE_PROP_STRING("tx", _state, _field.tx)
 
-void virtio_net_set_config_size(VirtIONet *n, uint32_t host_features);
 void virtio_net_set_netclient_name(VirtIONet *n, const char *name,
                                    const char *type);
 
diff --git a/include/hw/virtio/virtio-scsi.h b/include/hw/virtio/virtio-scsi.h
index f93b57d..b42e7f1 100644
--- a/include/hw/virtio/virtio-scsi.h
+++ b/include/hw/virtio/virtio-scsi.h
@@ -98,6 +98,7 @@
     bool dataplane_fenced;
     Error *blocker;
     Notifier migration_state_notifier;
+    uint32_t host_features;
 } VirtIOSCSI;
 
 typedef struct VirtIOSCSIReq {
diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index d95f8b6..8210cb3 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -84,6 +84,7 @@
     VMChangeStateEntry *vmstate;
     char *bus_name;
     uint8_t device_endian;
+    QLIST_HEAD(, VirtQueue) *vector_queues;
 };
 
 typedef struct VirtioDeviceClass {
@@ -218,6 +219,8 @@
                                                bool set_handler);
 void virtio_queue_notify_vq(VirtQueue *vq);
 void virtio_irq(VirtQueue *vq);
+VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector);
+VirtQueue *virtio_vector_next_queue(VirtQueue *vq);
 
 static inline void virtio_add_feature(uint32_t *features, unsigned int fbit)
 {
diff --git a/monitor.c b/monitor.c
index 3952d64..b2561e1 100644
--- a/monitor.c
+++ b/monitor.c
@@ -4471,11 +4471,12 @@
     len = strlen(str);
     readline_set_completion_index(rs, len);
     if (nb_args == 2) {
-        NetClientState *ncs[255];
+        NetClientState *ncs[MAX_QUEUE_NUM];
         int count, i;
         count = qemu_find_net_clients_except(NULL, ncs,
-                                             NET_CLIENT_OPTIONS_KIND_NONE, 255);
-        for (i = 0; i < count; i++) {
+                                             NET_CLIENT_OPTIONS_KIND_NONE,
+                                             MAX_QUEUE_NUM);
+        for (i = 0; i < MIN(count, MAX_QUEUE_NUM); i++) {
             const char *name = ncs[i]->name;
             if (!strncmp(str, name, len)) {
                 readline_add_completion(rs, name);
@@ -4490,7 +4491,7 @@
 void netdev_del_completion(ReadLineState *rs, int nb_args, const char *str)
 {
     int len, count, i;
-    NetClientState *ncs[255];
+    NetClientState *ncs[MAX_QUEUE_NUM];
 
     if (nb_args != 2) {
         return;
@@ -4499,8 +4500,8 @@
     len = strlen(str);
     readline_set_completion_index(rs, len);
     count = qemu_find_net_clients_except(NULL, ncs, NET_CLIENT_OPTIONS_KIND_NIC,
-                                         255);
-    for (i = 0; i < count; i++) {
+                                         MAX_QUEUE_NUM);
+    for (i = 0; i < MIN(count, MAX_QUEUE_NUM); i++) {
         QemuOpts *opts;
         const char *name = ncs[i]->name;
         if (strncmp(str, name, len)) {
@@ -4583,15 +4584,16 @@
 
 void host_net_remove_completion(ReadLineState *rs, int nb_args, const char *str)
 {
-    NetClientState *ncs[255];
+    NetClientState *ncs[MAX_QUEUE_NUM];
     int count, i, len;
 
     len = strlen(str);
     readline_set_completion_index(rs, len);
     if (nb_args == 2) {
         count = qemu_find_net_clients_except(NULL, ncs,
-                                             NET_CLIENT_OPTIONS_KIND_NONE, 255);
-        for (i = 0; i < count; i++) {
+                                             NET_CLIENT_OPTIONS_KIND_NONE,
+                                             MAX_QUEUE_NUM);
+        for (i = 0; i < MIN(count, MAX_QUEUE_NUM); i++) {
             int id;
             char name[16];
 
@@ -4606,8 +4608,9 @@
         return;
     } else if (nb_args == 3) {
         count = qemu_find_net_clients_except(NULL, ncs,
-                                             NET_CLIENT_OPTIONS_KIND_NIC, 255);
-        for (i = 0; i < count; i++) {
+                                             NET_CLIENT_OPTIONS_KIND_NIC,
+                                             MAX_QUEUE_NUM);
+        for (i = 0; i < MIN(count, MAX_QUEUE_NUM); i++) {
             int id;
             const char *name;
 
diff --git a/qapi/event.json b/qapi/event.json
index c51dc49..378dda5 100644
--- a/qapi/event.json
+++ b/qapi/event.json
@@ -330,3 +330,17 @@
 ##
 { 'event': 'VSERPORT_CHANGE',
   'data': { 'id': 'str', 'open': 'bool' } }
+
+##
+# @MEM_UNPLUG_ERROR
+#
+# Emitted when memory hot unplug error occurs.
+#
+# @device: device name
+#
+# @msg: Informative message
+#
+# Since: 2.4
+##
+{ 'event': 'MEM_UNPLUG_ERROR',
+  'data': { 'device': 'str', 'msg': 'str' } }
diff --git a/tests/acpi-test-data/pc/DSDT b/tests/acpi-test-data/pc/DSDT
index 1693c37..c658203 100644
--- a/tests/acpi-test-data/pc/DSDT
+++ b/tests/acpi-test-data/pc/DSDT
Binary files differ
diff --git a/tests/acpi-test-data/pc/SSDT b/tests/acpi-test-data/pc/SSDT
index 59be315..210d6a7 100644
--- a/tests/acpi-test-data/pc/SSDT
+++ b/tests/acpi-test-data/pc/SSDT
Binary files differ
diff --git a/tests/acpi-test-data/pc/SSDT.bridge b/tests/acpi-test-data/pc/SSDT.bridge
index fa61369..6e6660b 100644
--- a/tests/acpi-test-data/pc/SSDT.bridge
+++ b/tests/acpi-test-data/pc/SSDT.bridge
Binary files differ
diff --git a/tests/acpi-test-data/q35/DSDT b/tests/acpi-test-data/q35/DSDT
index e9ac11c..4723e59 100644
--- a/tests/acpi-test-data/q35/DSDT
+++ b/tests/acpi-test-data/q35/DSDT
Binary files differ
diff --git a/tests/acpi-test-data/q35/SSDT b/tests/acpi-test-data/q35/SSDT
index e87f5a3..0970c67 100644
--- a/tests/acpi-test-data/q35/SSDT
+++ b/tests/acpi-test-data/q35/SSDT
Binary files differ
diff --git a/tests/acpi-test-data/q35/SSDT.bridge b/tests/acpi-test-data/q35/SSDT.bridge
index b3cac34..a778688 100644
--- a/tests/acpi-test-data/q35/SSDT.bridge
+++ b/tests/acpi-test-data/q35/SSDT.bridge
Binary files differ
diff --git a/tests/bios-tables-test.c b/tests/bios-tables-test.c
index 735ac61..7e85dc4 100644
--- a/tests/bios-tables-test.c
+++ b/tests/bios-tables-test.c
@@ -17,7 +17,7 @@
 #include "qemu-common.h"
 #include "libqtest.h"
 #include "qemu/compiler.h"
-#include "hw/i386/acpi-defs.h"
+#include "hw/acpi/acpi-defs.h"
 #include "hw/i386/smbios.h"
 #include "qemu/bitmap.h"
 
diff --git a/trace-events b/trace-events
index 30eba92..11387c3 100644
--- a/trace-events
+++ b/trace-events
@@ -1562,6 +1562,7 @@
 
 #hw/acpi/memory_hotplug.c
 mhp_acpi_invalid_slot_selected(uint32_t slot) "0x%"PRIx32
+mhp_acpi_ejecting_invalid_slot(uint32_t slot) "0x%"PRIx32
 mhp_acpi_read_addr_lo(uint32_t slot, uint32_t addr) "slot[0x%"PRIx32"] addr lo: 0x%"PRIx32
 mhp_acpi_read_addr_hi(uint32_t slot, uint32_t addr) "slot[0x%"PRIx32"] addr hi: 0x%"PRIx32
 mhp_acpi_read_size_lo(uint32_t slot, uint32_t size) "slot[0x%"PRIx32"] size lo: 0x%"PRIx32
@@ -1572,6 +1573,9 @@
 mhp_acpi_write_ost_ev(uint32_t slot, uint32_t ev) "slot[0x%"PRIx32"] OST EVENT: 0x%"PRIx32
 mhp_acpi_write_ost_status(uint32_t slot, uint32_t st) "slot[0x%"PRIx32"] OST STATUS: 0x%"PRIx32
 mhp_acpi_clear_insert_evt(uint32_t slot) "slot[0x%"PRIx32"] clear insert event"
+mhp_acpi_clear_remove_evt(uint32_t slot) "slot[0x%"PRIx32"] clear remove event"
+mhp_acpi_pc_dimm_deleted(uint32_t slot) "slot[0x%"PRIx32"] pc-dimm deleted"
+mhp_acpi_pc_dimm_delete_failed(uint32_t slot) "slot[0x%"PRIx32"] pc-dimm delete failed"
 
 # hw/i386/pc.c
 mhp_pc_dimm_assigned_slot(int slot) "0x%d"