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-rw-r--r--hw/Makefile.objs2
-rw-r--r--hw/arm/virt.c2
-rw-r--r--hw/audio/ac97.c9
-rw-r--r--hw/audio/adlib.c8
-rw-r--r--hw/audio/cs4231a.c8
-rw-r--r--hw/audio/es1370.c9
-rw-r--r--hw/audio/gus.c8
-rw-r--r--hw/audio/intel-hda.c3
-rw-r--r--hw/audio/pcspk.c26
-rw-r--r--hw/audio/sb16.c9
-rw-r--r--hw/audio/soundhw.c24
-rw-r--r--hw/core/numa.c17
-rw-r--r--hw/core/qdev.c6
-rw-r--r--hw/display/Makefile.objs30
-rw-r--r--hw/i386/Kconfig1
-rw-r--r--hw/i386/intel_iommu.c2
-rw-r--r--hw/i386/microvm.c1
-rw-r--r--hw/i386/pc.c80
-rw-r--r--hw/i386/pc_piix.c4
-rw-r--r--hw/i386/pc_q35.c4
-rw-r--r--hw/isa/i82378.c2
-rw-r--r--hw/m68k/mcf5206.c39
-rw-r--r--hw/mips/jazz.c2
-rw-r--r--hw/net/vhost_net-stub.c11
-rw-r--r--hw/net/vhost_net.c44
-rw-r--r--hw/net/virtio-net.c19
-rw-r--r--hw/nvram/fw_cfg.c35
-rw-r--r--hw/s390x/s390-virtio-ccw.c22
-rw-r--r--hw/usb/Makefile.objs13
-rw-r--r--hw/vfio/ap.c8
-rw-r--r--hw/vfio/ccw.c11
-rw-r--r--hw/vfio/common.c53
-rw-r--r--hw/vfio/pci.c6
-rw-r--r--hw/virtio/Kconfig11
-rw-r--r--hw/virtio/Makefile.objs3
-rw-r--r--hw/virtio/trace-events10
-rw-r--r--hw/virtio/vhost-backend.c6
-rw-r--r--hw/virtio/vhost-vdpa.c475
-rw-r--r--hw/virtio/vhost.c52
-rw-r--r--hw/virtio/virtio-balloon.c36
-rw-r--r--hw/virtio/virtio-mem-pci.c157
-rw-r--r--hw/virtio/virtio-mem-pci.h34
-rw-r--r--hw/virtio/virtio-mem.c873
-rw-r--r--hw/virtio/virtio-pci.c13
-rw-r--r--hw/virtio/virtio.c6
45 files changed, 1994 insertions, 200 deletions
diff --git a/hw/Makefile.objs b/hw/Makefile.objs
index 4cbe5e4e57..14b7ea4eb6 100644
--- a/hw/Makefile.objs
+++ b/hw/Makefile.objs
@@ -43,4 +43,6 @@ devices-dirs-y += smbios/
 endif
 
 common-obj-y += $(devices-dirs-y)
+common-obj-m += display/
+common-obj-m += usb/
 obj-y += $(devices-dirs-y)
diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index c78972fb79..7d9f7157da 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -2401,6 +2401,7 @@ static void virt_machine_class_init(ObjectClass *oc, void *data)
     hc->unplug = virt_machine_device_unplug_cb;
     mc->nvdimm_supported = true;
     mc->auto_enable_numa_with_memhp = true;
+    mc->auto_enable_numa_with_memdev = true;
     mc->default_ram_id = "mach-virt.ram";
 
     object_class_property_add(oc, "acpi", "OnOffAuto",
@@ -2516,6 +2517,7 @@ static void virt_machine_5_0_options(MachineClass *mc)
     compat_props_add(mc->compat_props, hw_compat_5_0, hw_compat_5_0_len);
     mc->numa_mem_supported = true;
     vmc->acpi_expose_flash = true;
+    mc->auto_enable_numa_with_memdev = false;
 }
 DEFINE_VIRT_MACHINE(5, 0)
 
diff --git a/hw/audio/ac97.c b/hw/audio/ac97.c
index 8a9b9924c4..38522cf0ba 100644
--- a/hw/audio/ac97.c
+++ b/hw/audio/ac97.c
@@ -1393,12 +1393,6 @@ static void ac97_exit(PCIDevice *dev)
     AUD_remove_card(&s->card);
 }
 
-static int ac97_init (PCIBus *bus)
-{
-    pci_create_simple(bus, -1, TYPE_AC97);
-    return 0;
-}
-
 static Property ac97_properties[] = {
     DEFINE_AUDIO_PROPERTIES(AC97LinkState, card),
     DEFINE_PROP_END_OF_LIST (),
@@ -1436,7 +1430,8 @@ static const TypeInfo ac97_info = {
 static void ac97_register_types (void)
 {
     type_register_static (&ac97_info);
-    pci_register_soundhw("ac97", "Intel 82801AA AC97 Audio", ac97_init);
+    deprecated_register_soundhw("ac97", "Intel 82801AA AC97 Audio",
+                                0, TYPE_AC97);
 }
 
 type_init (ac97_register_types)
diff --git a/hw/audio/adlib.c b/hw/audio/adlib.c
index 7c3b67dcfb..65dff5b6fc 100644
--- a/hw/audio/adlib.c
+++ b/hw/audio/adlib.c
@@ -319,16 +319,10 @@ static const TypeInfo adlib_info = {
     .class_init    = adlib_class_initfn,
 };
 
-static int Adlib_init (ISABus *bus)
-{
-    isa_create_simple (bus, TYPE_ADLIB);
-    return 0;
-}
-
 static void adlib_register_types (void)
 {
     type_register_static (&adlib_info);
-    isa_register_soundhw("adlib", ADLIB_DESC, Adlib_init);
+    deprecated_register_soundhw("adlib", ADLIB_DESC, 1, TYPE_ADLIB);
 }
 
 type_init (adlib_register_types)
diff --git a/hw/audio/cs4231a.c b/hw/audio/cs4231a.c
index ffdbb58d6a..59705a8d47 100644
--- a/hw/audio/cs4231a.c
+++ b/hw/audio/cs4231a.c
@@ -683,12 +683,6 @@ static void cs4231a_realizefn (DeviceState *dev, Error **errp)
     AUD_register_card ("cs4231a", &s->card);
 }
 
-static int cs4231a_init (ISABus *bus)
-{
-    isa_create_simple (bus, TYPE_CS4231A);
-    return 0;
-}
-
 static Property cs4231a_properties[] = {
     DEFINE_AUDIO_PROPERTIES(CSState, card),
     DEFINE_PROP_UINT32 ("iobase",  CSState, port, 0x534),
@@ -720,7 +714,7 @@ static const TypeInfo cs4231a_info = {
 static void cs4231a_register_types (void)
 {
     type_register_static (&cs4231a_info);
-    isa_register_soundhw("cs4231a", "CS4231A", cs4231a_init);
+    deprecated_register_soundhw("cs4231a", "CS4231A", 1, TYPE_CS4231A);
 }
 
 type_init (cs4231a_register_types)
diff --git a/hw/audio/es1370.c b/hw/audio/es1370.c
index 5f8a83ff56..4255463a49 100644
--- a/hw/audio/es1370.c
+++ b/hw/audio/es1370.c
@@ -884,12 +884,6 @@ static void es1370_exit(PCIDevice *dev)
     AUD_remove_card(&s->card);
 }
 
-static int es1370_init (PCIBus *bus)
-{
-    pci_create_simple (bus, -1, TYPE_ES1370);
-    return 0;
-}
-
 static Property es1370_properties[] = {
     DEFINE_AUDIO_PROPERTIES(ES1370State, card),
     DEFINE_PROP_END_OF_LIST(),
@@ -928,7 +922,8 @@ static const TypeInfo es1370_info = {
 static void es1370_register_types (void)
 {
     type_register_static (&es1370_info);
-    pci_register_soundhw("es1370", "ENSONIQ AudioPCI ES1370", es1370_init);
+    deprecated_register_soundhw("es1370", "ENSONIQ AudioPCI ES1370",
+                                0, TYPE_ES1370);
 }
 
 type_init (es1370_register_types)
diff --git a/hw/audio/gus.c b/hw/audio/gus.c
index c8df2bde6b..7e4a8cadad 100644
--- a/hw/audio/gus.c
+++ b/hw/audio/gus.c
@@ -286,12 +286,6 @@ static void gus_realizefn (DeviceState *dev, Error **errp)
     AUD_set_active_out (s->voice, 1);
 }
 
-static int GUS_init (ISABus *bus)
-{
-    isa_create_simple (bus, TYPE_GUS);
-    return 0;
-}
-
 static Property gus_properties[] = {
     DEFINE_AUDIO_PROPERTIES(GUSState, card),
     DEFINE_PROP_UINT32 ("freq",    GUSState, freq,        44100),
@@ -322,7 +316,7 @@ static const TypeInfo gus_info = {
 static void gus_register_types (void)
 {
     type_register_static (&gus_info);
-    isa_register_soundhw("gus", "Gravis Ultrasound GF1", GUS_init);
+    deprecated_register_soundhw("gus", "Gravis Ultrasound GF1", 1, TYPE_GUS);
 }
 
 type_init (gus_register_types)
diff --git a/hw/audio/intel-hda.c b/hw/audio/intel-hda.c
index f673b8317a..f6cea49686 100644
--- a/hw/audio/intel-hda.c
+++ b/hw/audio/intel-hda.c
@@ -25,6 +25,7 @@
 #include "qemu/bitops.h"
 #include "qemu/log.h"
 #include "qemu/module.h"
+#include "qemu/error-report.h"
 #include "hw/audio/soundhw.h"
 #include "intel-hda.h"
 #include "migration/vmstate.h"
@@ -1307,6 +1308,8 @@ static int intel_hda_and_codec_init(PCIBus *bus)
     BusState *hdabus;
     DeviceState *codec;
 
+    warn_report("'-soundhw hda' is deprecated, "
+                "please use '-device intel-hda -device hda-duplex' instead");
     controller = DEVICE(pci_create_simple(bus, -1, "intel-hda"));
     hdabus = QLIST_FIRST(&controller->child_bus);
     codec = qdev_new("hda-duplex");
diff --git a/hw/audio/pcspk.c b/hw/audio/pcspk.c
index c37a387861..ea539e7605 100644
--- a/hw/audio/pcspk.c
+++ b/hw/audio/pcspk.c
@@ -28,6 +28,7 @@
 #include "audio/audio.h"
 #include "qemu/module.h"
 #include "qemu/timer.h"
+#include "qemu/error-report.h"
 #include "hw/timer/i8254.h"
 #include "migration/vmstate.h"
 #include "hw/audio/pcspk.h"
@@ -112,11 +113,15 @@ static void pcspk_callback(void *opaque, int free)
     }
 }
 
-static int pcspk_audio_init(ISABus *bus)
+static int pcspk_audio_init(PCSpkState *s)
 {
-    PCSpkState *s = pcspk_state;
     struct audsettings as = {PCSPK_SAMPLE_RATE, 1, AUDIO_FORMAT_U8, 0};
 
+    if (s->voice) {
+        /* already initialized */
+        return 0;
+    }
+
     AUD_register_card(s_spk, &s->card);
 
     s->voice = AUD_open_out(&s->card, s->voice, s_spk, s, pcspk_callback, &as);
@@ -185,6 +190,10 @@ static void pcspk_realizefn(DeviceState *dev, Error **errp)
 
     isa_register_ioport(isadev, &s->ioport, s->iobase);
 
+    if (s->card.state) {
+        pcspk_audio_init(s);
+    }
+
     pcspk_state = s;
 }
 
@@ -210,7 +219,7 @@ static const VMStateDescription vmstate_spk = {
 
 static Property pcspk_properties[] = {
     DEFINE_AUDIO_PROPERTIES(PCSpkState, card),
-    DEFINE_PROP_UINT32("iobase", PCSpkState, iobase,  -1),
+    DEFINE_PROP_UINT32("iobase", PCSpkState, iobase,  0x61),
     DEFINE_PROP_BOOL("migrate", PCSpkState, migrate,  true),
     DEFINE_PROP_END_OF_LIST(),
 };
@@ -236,9 +245,18 @@ static const TypeInfo pcspk_info = {
     .class_init     = pcspk_class_initfn,
 };
 
+static int pcspk_audio_init_soundhw(ISABus *bus)
+{
+    PCSpkState *s = pcspk_state;
+
+    warn_report("'-soundhw pcspk' is deprecated, "
+                "please set a backend using '-machine pcspk-audiodev=<name>' instead");
+    return pcspk_audio_init(s);
+}
+
 static void pcspk_register(void)
 {
     type_register_static(&pcspk_info);
-    isa_register_soundhw("pcspk", "PC speaker", pcspk_audio_init);
+    isa_register_soundhw("pcspk", "PC speaker", pcspk_audio_init_soundhw);
 }
 type_init(pcspk_register)
diff --git a/hw/audio/sb16.c b/hw/audio/sb16.c
index df6f755a37..2d9e50f99b 100644
--- a/hw/audio/sb16.c
+++ b/hw/audio/sb16.c
@@ -1415,12 +1415,6 @@ static void sb16_realizefn (DeviceState *dev, Error **errp)
     AUD_register_card ("sb16", &s->card);
 }
 
-static int SB16_init (ISABus *bus)
-{
-    isa_create_simple (bus, TYPE_SB16);
-    return 0;
-}
-
 static Property sb16_properties[] = {
     DEFINE_AUDIO_PROPERTIES(SB16State, card),
     DEFINE_PROP_UINT32 ("version", SB16State, ver,  0x0405), /* 4.5 */
@@ -1453,7 +1447,8 @@ static const TypeInfo sb16_info = {
 static void sb16_register_types (void)
 {
     type_register_static (&sb16_info);
-    isa_register_soundhw("sb16", "Creative Sound Blaster 16", SB16_init);
+    deprecated_register_soundhw("sb16", "Creative Sound Blaster 16",
+                                1, TYPE_SB16);
 }
 
 type_init (sb16_register_types)
diff --git a/hw/audio/soundhw.c b/hw/audio/soundhw.c
index c750473c8f..173b674ff5 100644
--- a/hw/audio/soundhw.c
+++ b/hw/audio/soundhw.c
@@ -22,6 +22,7 @@
  * THE SOFTWARE.
  */
 #include "qemu/osdep.h"
+#include "qemu/option.h"
 #include "qemu/help_option.h"
 #include "qemu/error-report.h"
 #include "qom/object.h"
@@ -32,6 +33,7 @@
 struct soundhw {
     const char *name;
     const char *descr;
+    const char *typename;
     int enabled;
     int isa;
     union {
@@ -65,6 +67,17 @@ void pci_register_soundhw(const char *name, const char *descr,
     soundhw_count++;
 }
 
+void deprecated_register_soundhw(const char *name, const char *descr,
+                                 int isa, const char *typename)
+{
+    assert(soundhw_count < ARRAY_SIZE(soundhw) - 1);
+    soundhw[soundhw_count].name = name;
+    soundhw[soundhw_count].descr = descr;
+    soundhw[soundhw_count].isa = isa;
+    soundhw[soundhw_count].typename = typename;
+    soundhw_count++;
+}
+
 void select_soundhw(const char *optarg)
 {
     struct soundhw *c;
@@ -136,7 +149,16 @@ void soundhw_init(void)
 
     for (c = soundhw; c->name; ++c) {
         if (c->enabled) {
-            if (c->isa) {
+            if (c->typename) {
+                warn_report("'-soundhw %s' is deprecated, "
+                            "please use '-device %s' instead",
+                            c->name, c->typename);
+                if (c->isa) {
+                    isa_create_simple(isa_bus, c->typename);
+                } else {
+                    pci_create_simple(pci_bus, -1, c->typename);
+                }
+            } else if (c->isa) {
                 if (!isa_bus) {
                     error_report("ISA bus not available for %s", c->name);
                     exit(1);
diff --git a/hw/core/numa.c b/hw/core/numa.c
index 2725886d06..6a20ce7cf1 100644
--- a/hw/core/numa.c
+++ b/hw/core/numa.c
@@ -688,8 +688,9 @@ void numa_complete_configuration(MachineState *ms)
     NodeInfo *numa_info = ms->numa_state->nodes;
 
     /*
-     * If memory hotplug is enabled (slots > 0) but without '-numa'
-     * options explicitly on CLI, guestes will break.
+     * If memory hotplug is enabled (slot > 0) or memory devices are enabled
+     * (ms->maxram_size > ram_size) but without '-numa' options explicitly on
+     * CLI, guests will break.
      *
      *   Windows: won't enable memory hotplug without SRAT table at all
      *
@@ -704,9 +705,9 @@ void numa_complete_configuration(MachineState *ms)
      * assume there is just one node with whole RAM.
      */
     if (ms->numa_state->num_nodes == 0 &&
-        ((ms->ram_slots > 0 &&
-        mc->auto_enable_numa_with_memhp) ||
-        mc->auto_enable_numa)) {
+        ((ms->ram_slots && mc->auto_enable_numa_with_memhp) ||
+         (ms->maxram_size > ms->ram_size && mc->auto_enable_numa_with_memdev) ||
+         mc->auto_enable_numa)) {
             NumaNodeOptions node = { };
             parse_numa_node(ms, &node, &error_abort);
             numa_info[0].node_mem = ram_size;
@@ -824,6 +825,7 @@ static void numa_stat_memory_devices(NumaNodeMem node_mem[])
     MemoryDeviceInfoList *info;
     PCDIMMDeviceInfo     *pcdimm_info;
     VirtioPMEMDeviceInfo *vpi;
+    VirtioMEMDeviceInfo *vmi;
 
     for (info = info_list; info; info = info->next) {
         MemoryDeviceInfo *value = info->value;
@@ -844,6 +846,11 @@ static void numa_stat_memory_devices(NumaNodeMem node_mem[])
                 node_mem[0].node_mem += vpi->size;
                 node_mem[0].node_plugged_mem += vpi->size;
                 break;
+            case MEMORY_DEVICE_INFO_KIND_VIRTIO_MEM:
+                vmi = value->u.virtio_mem.data;
+                node_mem[vmi->node].node_mem += vmi->size;
+                node_mem[vmi->node].node_plugged_mem += vmi->size;
+                break;
             default:
                 g_assert_not_reached();
             }
diff --git a/hw/core/qdev.c b/hw/core/qdev.c
index 2131c7f951..9de16eae05 100644
--- a/hw/core/qdev.c
+++ b/hw/core/qdev.c
@@ -137,6 +137,9 @@ void qdev_set_parent_bus(DeviceState *dev, BusState *bus)
  */
 DeviceState *qdev_new(const char *name)
 {
+    if (!object_class_by_name(name)) {
+        module_load_qom_one(name);
+    }
     return DEVICE(object_new(name));
 }
 
@@ -147,10 +150,9 @@ DeviceState *qdev_new(const char *name)
  */
 DeviceState *qdev_try_new(const char *name)
 {
-    if (!object_class_by_name(name)) {
+    if (!module_object_class_by_name(name)) {
         return NULL;
     }
-
     return DEVICE(object_new(name));
 }
 
diff --git a/hw/display/Makefile.objs b/hw/display/Makefile.objs
index 77a7d622bd..e907f3182b 100644
--- a/hw/display/Makefile.objs
+++ b/hw/display/Makefile.objs
@@ -44,18 +44,24 @@ common-obj-$(CONFIG_ARTIST) += artist.o
 
 obj-$(CONFIG_VGA) += vga.o
 
-common-obj-$(CONFIG_QXL) += qxl.o qxl-logger.o qxl-render.o
-
-obj-$(CONFIG_VIRTIO_GPU) += virtio-gpu-base.o virtio-gpu.o virtio-gpu-3d.o
-obj-$(CONFIG_VHOST_USER_GPU) += vhost-user-gpu.o
-obj-$(call land,$(CONFIG_VIRTIO_GPU),$(CONFIG_VIRTIO_PCI)) += virtio-gpu-pci.o
-obj-$(call land,$(CONFIG_VHOST_USER_GPU),$(CONFIG_VIRTIO_PCI)) += vhost-user-gpu-pci.o
-obj-$(CONFIG_VIRTIO_VGA) += virtio-vga.o
-obj-$(CONFIG_VHOST_USER_VGA) += vhost-user-vga.o
-virtio-gpu.o-cflags := $(VIRGL_CFLAGS)
-virtio-gpu.o-libs += $(VIRGL_LIBS)
-virtio-gpu-3d.o-cflags := $(VIRGL_CFLAGS)
-virtio-gpu-3d.o-libs += $(VIRGL_LIBS)
+ifeq ($(CONFIG_QXL),y)
+common-obj-m += qxl.mo
+qxl.mo-objs = qxl.o qxl-logger.o qxl-render.o
+endif
+
+ifeq ($(CONFIG_VIRTIO_GPU),y)
+common-obj-m += virtio-gpu.mo
+virtio-gpu-obj-$(CONFIG_VIRTIO_GPU) += virtio-gpu-base.o virtio-gpu.o virtio-gpu-3d.o
+virtio-gpu-obj-$(CONFIG_VHOST_USER_GPU) += vhost-user-gpu.o
+virtio-gpu-obj-$(call land,$(CONFIG_VIRTIO_GPU),$(CONFIG_VIRTIO_PCI)) += virtio-gpu-pci.o
+virtio-gpu-obj-$(call land,$(CONFIG_VHOST_USER_GPU),$(CONFIG_VIRTIO_PCI)) += vhost-user-gpu-pci.o
+virtio-gpu-obj-$(CONFIG_VIRTIO_VGA) += virtio-vga.o
+virtio-gpu-obj-$(CONFIG_VHOST_USER_VGA) += vhost-user-vga.o
+virtio-gpu.mo-objs := $(virtio-gpu-obj-y)
+virtio-gpu.mo-cflags := $(VIRGL_CFLAGS)
+virtio-gpu.mo-libs := $(VIRGL_LIBS)
+endif
+
 common-obj-$(CONFIG_DPCD) += dpcd.o
 common-obj-$(CONFIG_XLNX_ZYNQMP_ARM) += xlnx_dp.o
 
diff --git a/hw/i386/Kconfig b/hw/i386/Kconfig
index c93f32f657..03e347b207 100644
--- a/hw/i386/Kconfig
+++ b/hw/i386/Kconfig
@@ -35,6 +35,7 @@ config PC
     select ACPI_PCI
     select ACPI_VMGENID
     select VIRTIO_PMEM_SUPPORTED
+    select VIRTIO_MEM_SUPPORTED
 
 config PC_PCI
     bool
diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index df7ad254ac..c56398e991 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -3758,7 +3758,7 @@ static bool vtd_decide_config(IntelIOMMUState *s, Error **errp)
     /* Currently only address widths supported are 39 and 48 bits */
     if ((s->aw_bits != VTD_HOST_AW_39BIT) &&
         (s->aw_bits != VTD_HOST_AW_48BIT)) {
-        error_setg(errp, "Supported values for x-aw-bits are: %d, %d",
+        error_setg(errp, "Supported values for aw-bits are: %d, %d",
                    VTD_HOST_AW_39BIT, VTD_HOST_AW_48BIT);
         return false;
     }
diff --git a/hw/i386/microvm.c b/hw/i386/microvm.c
index 5e931975a0..81d0888930 100644
--- a/hw/i386/microvm.c
+++ b/hw/i386/microvm.c
@@ -464,6 +464,7 @@ static void microvm_class_init(ObjectClass *oc, void *data)
     mc->max_cpus = 288;
     mc->has_hotpluggable_cpus = false;
     mc->auto_enable_numa_with_memhp = false;
+    mc->auto_enable_numa_with_memdev = false;
     mc->default_cpu_type = TARGET_DEFAULT_CPU_TYPE;
     mc->nvdimm_supported = false;
     mc->default_ram_id = "microvm.ram";
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 4af9679d03..d7f27bc16b 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -88,6 +88,7 @@
 #include "hw/net/ne2000-isa.h"
 #include "standard-headers/asm-x86/bootparam.h"
 #include "hw/virtio/virtio-pmem-pci.h"
+#include "hw/virtio/virtio-mem-pci.h"
 #include "hw/mem/memory-device.h"
 #include "sysemu/replay.h"
 #include "qapi/qmp/qerror.h"
@@ -1155,11 +1156,10 @@ static void pc_superio_init(ISABus *isa_bus, bool create_fdctrl, bool no_vmport)
     g_free(a20_line);
 }
 
-void pc_basic_device_init(ISABus *isa_bus, qemu_irq *gsi,
+void pc_basic_device_init(struct PCMachineState *pcms,
+                          ISABus *isa_bus, qemu_irq *gsi,
                           ISADevice **rtc_state,
                           bool create_fdctrl,
-                          bool no_vmport,
-                          bool has_pit,
                           uint32_t hpet_irqs)
 {
     int i;
@@ -1210,7 +1210,7 @@ void pc_basic_device_init(ISABus *isa_bus, qemu_irq *gsi,
 
     qemu_register_boot_set(pc_boot_set, *rtc_state);
 
-    if (!xen_enabled() && has_pit) {
+    if (!xen_enabled() && pcms->pit_enabled) {
         if (kvm_pit_in_kernel()) {
             pit = kvm_pit_init(isa_bus, 0x40);
         } else {
@@ -1220,13 +1220,13 @@ void pc_basic_device_init(ISABus *isa_bus, qemu_irq *gsi,
             /* connect PIT to output control line of the HPET */
             qdev_connect_gpio_out(hpet, 0, qdev_get_gpio_in(DEVICE(pit), 0));
         }
-        pcspk_init(isa_bus, pit);
+        pcspk_init(pcms->pcspk, isa_bus, pit);
     }
 
     i8257_dma_init(isa_bus, 0);
 
     /* Super I/O */
-    pc_superio_init(isa_bus, create_fdctrl, no_vmport);
+    pc_superio_init(isa_bus, create_fdctrl, pcms->vmport != ON_OFF_AUTO_ON);
 }
 
 void pc_nic_init(PCMachineClass *pcmc, ISABus *isa_bus, PCIBus *pci_bus)
@@ -1637,19 +1637,20 @@ static void pc_cpu_pre_plug(HotplugHandler *hotplug_dev,
     numa_cpu_pre_plug(cpu_slot, dev, errp);
 }
 
-static void pc_virtio_pmem_pci_pre_plug(HotplugHandler *hotplug_dev,
-                                        DeviceState *dev, Error **errp)
+static void pc_virtio_md_pci_pre_plug(HotplugHandler *hotplug_dev,
+                                      DeviceState *dev, Error **errp)
 {
     HotplugHandler *hotplug_dev2 = qdev_get_bus_hotplug_handler(dev);
     Error *local_err = NULL;
 
-    if (!hotplug_dev2) {
+    if (!hotplug_dev2 && dev->hotplugged) {
         /*
          * Without a bus hotplug handler, we cannot control the plug/unplug
-         * order. This should never be the case on x86, however better add
-         * a safety net.
+         * order. We should never reach this point when hotplugging on x86,
+         * however, better add a safety net.
          */
-        error_setg(errp, "virtio-pmem-pci not supported on this bus.");
+        error_setg(errp, "hotplug of virtio based memory devices not supported"
+                   " on this bus.");
         return;
     }
     /*
@@ -1658,14 +1659,14 @@ static void pc_virtio_pmem_pci_pre_plug(HotplugHandler *hotplug_dev,
      */
     memory_device_pre_plug(MEMORY_DEVICE(dev), MACHINE(hotplug_dev), NULL,
                            &local_err);
-    if (!local_err) {
+    if (!local_err && hotplug_dev2) {
         hotplug_handler_pre_plug(hotplug_dev2, dev, &local_err);
     }
     error_propagate(errp, local_err);
 }
 
-static void pc_virtio_pmem_pci_plug(HotplugHandler *hotplug_dev,
-                                    DeviceState *dev, Error **errp)
+static void pc_virtio_md_pci_plug(HotplugHandler *hotplug_dev,
+                                  DeviceState *dev, Error **errp)
 {
     HotplugHandler *hotplug_dev2 = qdev_get_bus_hotplug_handler(dev);
     Error *local_err = NULL;
@@ -1676,24 +1677,26 @@ static void pc_virtio_pmem_pci_plug(HotplugHandler *hotplug_dev,
      * device bits.
      */
     memory_device_plug(MEMORY_DEVICE(dev), MACHINE(hotplug_dev));
-    hotplug_handler_plug(hotplug_dev2, dev, &local_err);
-    if (local_err) {
-        memory_device_unplug(MEMORY_DEVICE(dev), MACHINE(hotplug_dev));
+    if (hotplug_dev2) {
+        hotplug_handler_plug(hotplug_dev2, dev, &local_err);
+        if (local_err) {
+            memory_device_unplug(MEMORY_DEVICE(dev), MACHINE(hotplug_dev));
+        }
     }
     error_propagate(errp, local_err);
 }
 
-static void pc_virtio_pmem_pci_unplug_request(HotplugHandler *hotplug_dev,
-                                              DeviceState *dev, Error **errp)
+static void pc_virtio_md_pci_unplug_request(HotplugHandler *hotplug_dev,
+                                            DeviceState *dev, Error **errp)
 {
-    /* We don't support virtio pmem hot unplug */
-    error_setg(errp, "virtio pmem device unplug not supported.");
+    /* We don't support hot unplug of virtio based memory devices */
+    error_setg(errp, "virtio based memory devices cannot be unplugged.");
 }
 
-static void pc_virtio_pmem_pci_unplug(HotplugHandler *hotplug_dev,
-                                      DeviceState *dev, Error **errp)
+static void pc_virtio_md_pci_unplug(HotplugHandler *hotplug_dev,
+                                    DeviceState *dev, Error **errp)
 {
-    /* We don't support virtio pmem hot unplug */
+    /* We don't support hot unplug of virtio based memory devices */
 }
 
 static void pc_machine_device_pre_plug_cb(HotplugHandler *hotplug_dev,
@@ -1703,8 +1706,9 @@ static void pc_machine_device_pre_plug_cb(HotplugHandler *hotplug_dev,
         pc_memory_pre_plug(hotplug_dev, dev, errp);
     } else if (object_dynamic_cast(OBJECT(dev), TYPE_CPU)) {
         pc_cpu_pre_plug(hotplug_dev, dev, errp);
-    } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI)) {
-        pc_virtio_pmem_pci_pre_plug(hotplug_dev, dev, errp);
+    } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI) ||
+               object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MEM_PCI)) {
+        pc_virtio_md_pci_pre_plug(hotplug_dev, dev, errp);
     }
 }
 
@@ -1715,8 +1719,9 @@ static void pc_machine_device_plug_cb(HotplugHandler *hotplug_dev,
         pc_memory_plug(hotplug_dev, dev, errp);
     } else if (object_dynamic_cast(OBJECT(dev), TYPE_CPU)) {
         pc_cpu_plug(hotplug_dev, dev, errp);
-    } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI)) {
-        pc_virtio_pmem_pci_plug(hotplug_dev, dev, errp);
+    } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI) ||
+               object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MEM_PCI)) {
+        pc_virtio_md_pci_plug(hotplug_dev, dev, errp);
     }
 }
 
@@ -1727,8 +1732,9 @@ static void pc_machine_device_unplug_request_cb(HotplugHandler *hotplug_dev,
         pc_memory_unplug_request(hotplug_dev, dev, errp);
     } else if (object_dynamic_cast(OBJECT(dev), TYPE_CPU)) {
         pc_cpu_unplug_request_cb(hotplug_dev, dev, errp);
-    } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI)) {
-        pc_virtio_pmem_pci_unplug_request(hotplug_dev, dev, errp);
+    } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI) ||
+               object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MEM_PCI)) {
+        pc_virtio_md_pci_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)));
@@ -1742,8 +1748,9 @@ static void pc_machine_device_unplug_cb(HotplugHandler *hotplug_dev,
         pc_memory_unplug(hotplug_dev, dev, errp);
     } else if (object_dynamic_cast(OBJECT(dev), TYPE_CPU)) {
         pc_cpu_unplug_cb(hotplug_dev, dev, errp);
-    } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI)) {
-        pc_virtio_pmem_pci_unplug(hotplug_dev, dev, errp);
+    } else if (object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI) ||
+               object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MEM_PCI)) {
+        pc_virtio_md_pci_unplug(hotplug_dev, dev, errp);
     } else {
         error_setg(errp, "acpi: device unplug for not supported device"
                    " type: %s", object_get_typename(OBJECT(dev)));
@@ -1755,7 +1762,8 @@ static HotplugHandler *pc_get_hotplug_handler(MachineState *machine,
 {
     if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM) ||
         object_dynamic_cast(OBJECT(dev), TYPE_CPU) ||
-        object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI)) {
+        object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_PMEM_PCI) ||
+        object_dynamic_cast(OBJECT(dev), TYPE_VIRTIO_MEM_PCI)) {
         return HOTPLUG_HANDLER(machine);
     }
 
@@ -1892,6 +1900,9 @@ static void pc_machine_initfn(Object *obj)
     pcms->pit_enabled = true;
 
     pc_system_flash_create(pcms);
+    pcms->pcspk = isa_new(TYPE_PC_SPEAKER);
+    object_property_add_alias(OBJECT(pcms), "pcspk-audiodev",
+                              OBJECT(pcms->pcspk), "audiodev");
 }
 
 static void pc_machine_reset(MachineState *machine)
@@ -1966,6 +1977,7 @@ static void pc_machine_class_init(ObjectClass *oc, void *data)
     mc->get_default_cpu_node_id = x86_get_default_cpu_node_id;
     mc->possible_cpu_arch_ids = x86_possible_cpu_arch_ids;
     mc->auto_enable_numa_with_memhp = true;
+    mc->auto_enable_numa_with_memdev = true;
     mc->has_hotpluggable_cpus = true;
     mc->default_boot_order = "cad";
     mc->hot_add_cpu = pc_hot_add_cpu;
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 1d832b2878..2bb42a8141 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -235,8 +235,7 @@ static void pc_init1(MachineState *machine,
     }
 
     /* init basic PC hardware */
-    pc_basic_device_init(isa_bus, x86ms->gsi, &rtc_state, true,
-                         (pcms->vmport != ON_OFF_AUTO_ON), pcms->pit_enabled,
+    pc_basic_device_init(pcms, isa_bus, x86ms->gsi, &rtc_state, true,
                          0x4);
 
     pc_nic_init(pcmc, isa_bus, pci_bus);
@@ -444,6 +443,7 @@ static void pc_i440fx_5_0_machine_options(MachineClass *m)
     m->numa_mem_supported = true;
     compat_props_add(m->compat_props, hw_compat_5_0, hw_compat_5_0_len);
     compat_props_add(m->compat_props, pc_compat_5_0, pc_compat_5_0_len);
+    m->auto_enable_numa_with_memdev = false;
 }
 
 DEFINE_I440FX_MACHINE(v5_0, "pc-i440fx-5.0", NULL,
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index 047ea8db28..33163ed18d 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -275,8 +275,7 @@ static void pc_q35_init(MachineState *machine)
     }
 
     /* init basic PC hardware */
-    pc_basic_device_init(isa_bus, x86ms->gsi, &rtc_state, !mc->no_floppy,
-                         (pcms->vmport != ON_OFF_AUTO_ON), pcms->pit_enabled,
+    pc_basic_device_init(pcms, isa_bus, x86ms->gsi, &rtc_state, !mc->no_floppy,
                          0xff0104);
 
     /* connect pm stuff to lpc */
@@ -372,6 +371,7 @@ static void pc_q35_5_0_machine_options(MachineClass *m)
     m->numa_mem_supported = true;
     compat_props_add(m->compat_props, hw_compat_5_0, hw_compat_5_0_len);
     compat_props_add(m->compat_props, pc_compat_5_0, pc_compat_5_0_len);
+    m->auto_enable_numa_with_memhp = false;
 }
 
 DEFINE_Q35_MACHINE(v5_0, "pc-q35-5.0", NULL,
diff --git a/hw/isa/i82378.c b/hw/isa/i82378.c
index d9e6c7fa00..75a2da2881 100644
--- a/hw/isa/i82378.c
+++ b/hw/isa/i82378.c
@@ -102,7 +102,7 @@ static void i82378_realize(PCIDevice *pci, Error **errp)
     pit = i8254_pit_init(isabus, 0x40, 0, NULL);
 
     /* speaker */
-    pcspk_init(isabus, pit);
+    pcspk_init(isa_new(TYPE_PC_SPEAKER), isabus, pit);
 
     /* 2 82C37 (dma) */
     isa_create_simple(isabus, "i82374");
diff --git a/hw/m68k/mcf5206.c b/hw/m68k/mcf5206.c
index a2fef04f8e..94a37a1a46 100644
--- a/hw/m68k/mcf5206.c
+++ b/hw/m68k/mcf5206.c
@@ -10,7 +10,6 @@
 #include "qemu/error-report.h"
 #include "qemu/log.h"
 #include "cpu.h"
-#include "hw/hw.h"
 #include "hw/irq.h"
 #include "hw/m68k/mcf.h"
 #include "qemu/timer.h"
@@ -69,10 +68,16 @@ static void m5206_timer_recalibrate(m5206_timer_state *s)
     if (mode == 2)
         prescale *= 16;
 
-    if (mode == 3 || mode == 0)
-        hw_error("m5206_timer: mode %d not implemented\n", mode);
-    if ((s->tmr & TMR_FRR) == 0)
-        hw_error("m5206_timer: free running mode not implemented\n");
+    if (mode == 3 || mode == 0) {
+        qemu_log_mask(LOG_UNIMP, "m5206_timer: mode %d not implemented\n",
+                      mode);
+        goto exit;
+    }
+    if ((s->tmr & TMR_FRR) == 0) {
+        qemu_log_mask(LOG_UNIMP,
+                      "m5206_timer: free running mode not implemented\n");
+        goto exit;
+    }
 
     /* Assume 66MHz system clock.  */
     ptimer_set_freq(s->timer, 66000000 / prescale);
@@ -391,7 +396,9 @@ static uint32_t m5206_mbar_readb(void *opaque, hwaddr offset)
     m5206_mbar_state *s = (m5206_mbar_state *)opaque;
     offset &= 0x3ff;
     if (offset >= 0x200) {
-        hw_error("Bad MBAR read offset 0x%x", (int)offset);
+        qemu_log_mask(LOG_GUEST_ERROR, "Bad MBAR read offset 0x%" HWADDR_PRIX,
+                      offset);
+        return 0;
     }
     if (m5206_mbar_width[offset >> 2] > 1) {
         uint16_t val;
@@ -410,7 +417,9 @@ static uint32_t m5206_mbar_readw(void *opaque, hwaddr offset)
     int width;
     offset &= 0x3ff;
     if (offset >= 0x200) {
-        hw_error("Bad MBAR read offset 0x%x", (int)offset);
+        qemu_log_mask(LOG_GUEST_ERROR, "Bad MBAR read offset 0x%" HWADDR_PRIX,
+                      offset);
+        return 0;
     }
     width = m5206_mbar_width[offset >> 2];
     if (width > 2) {
@@ -434,7 +443,9 @@ static uint32_t m5206_mbar_readl(void *opaque, hwaddr offset)
     int width;
     offset &= 0x3ff;
     if (offset >= 0x200) {
-        hw_error("Bad MBAR read offset 0x%x", (int)offset);
+        qemu_log_mask(LOG_GUEST_ERROR, "Bad MBAR read offset 0x%" HWADDR_PRIX,
+                      offset);
+        return 0;
     }
     width = m5206_mbar_width[offset >> 2];
     if (width < 4) {
@@ -458,7 +469,9 @@ static void m5206_mbar_writeb(void *opaque, hwaddr offset,
     int width;
     offset &= 0x3ff;
     if (offset >= 0x200) {
-        hw_error("Bad MBAR write offset 0x%x", (int)offset);
+        qemu_log_mask(LOG_GUEST_ERROR, "Bad MBAR write offset 0x%" HWADDR_PRIX,
+                      offset);
+        return;
     }
     width = m5206_mbar_width[offset >> 2];
     if (width > 1) {
@@ -482,7 +495,9 @@ static void m5206_mbar_writew(void *opaque, hwaddr offset,
     int width;
     offset &= 0x3ff;
     if (offset >= 0x200) {
-        hw_error("Bad MBAR write offset 0x%x", (int)offset);
+        qemu_log_mask(LOG_GUEST_ERROR, "Bad MBAR write offset 0x%" HWADDR_PRIX,
+                      offset);
+        return;
     }
     width = m5206_mbar_width[offset >> 2];
     if (width > 2) {
@@ -510,7 +525,9 @@ static void m5206_mbar_writel(void *opaque, hwaddr offset,
     int width;
     offset &= 0x3ff;
     if (offset >= 0x200) {
-        hw_error("Bad MBAR write offset 0x%x", (int)offset);
+        qemu_log_mask(LOG_GUEST_ERROR, "Bad MBAR write offset 0x%" HWADDR_PRIX,
+                      offset);
+        return;
     }
     width = m5206_mbar_width[offset >> 2];
     if (width < 4) {
diff --git a/hw/mips/jazz.c b/hw/mips/jazz.c
index c3b0da60cc..0002bff695 100644
--- a/hw/mips/jazz.c
+++ b/hw/mips/jazz.c
@@ -250,7 +250,7 @@ static void mips_jazz_init(MachineState *machine,
     isa_bus_irqs(isa_bus, i8259);
     i8257_dma_init(isa_bus, 0);
     pit = i8254_pit_init(isa_bus, 0x40, 0, NULL);
-    pcspk_init(isa_bus, pit);
+    pcspk_init(isa_new(TYPE_PC_SPEAKER), isa_bus, pit);
 
     /* Video card */
     switch (jazz_model) {
diff --git a/hw/net/vhost_net-stub.c b/hw/net/vhost_net-stub.c
index aac0e98228..a7f4252630 100644
--- a/hw/net/vhost_net-stub.c
+++ b/hw/net/vhost_net-stub.c
@@ -52,6 +52,17 @@ uint64_t vhost_net_get_features(struct vhost_net *net, uint64_t features)
     return features;
 }
 
+int vhost_net_get_config(struct vhost_net *net,  uint8_t *config,
+                         uint32_t config_len)
+{
+    return 0;
+}
+int vhost_net_set_config(struct vhost_net *net, const uint8_t *data,
+                         uint32_t offset, uint32_t size, uint32_t flags)
+{
+    return 0;
+}
+
 void vhost_net_ack_features(struct vhost_net *net, uint64_t features)
 {
 }
diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index 6b82803fa7..24d555e764 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -17,6 +17,7 @@
 #include "net/net.h"
 #include "net/tap.h"
 #include "net/vhost-user.h"
+#include "net/vhost-vdpa.h"
 
 #include "standard-headers/linux/vhost_types.h"
 #include "hw/virtio/virtio-net.h"
@@ -33,12 +34,6 @@
 #include "hw/virtio/vhost.h"
 #include "hw/virtio/virtio-bus.h"
 
-struct vhost_net {
-    struct vhost_dev dev;
-    struct vhost_virtqueue vqs[2];
-    int backend;
-    NetClientState *nc;
-};
 
 /* Features supported by host kernel. */
 static const int kernel_feature_bits[] = {
@@ -96,6 +91,11 @@ static const int *vhost_net_get_feature_bits(struct vhost_net *net)
     case NET_CLIENT_DRIVER_VHOST_USER:
         feature_bits = user_feature_bits;
         break;
+#ifdef CONFIG_VHOST_NET_VDPA
+    case NET_CLIENT_DRIVER_VHOST_VDPA:
+        feature_bits = vdpa_feature_bits;
+        break;
+#endif
     default:
         error_report("Feature bits not defined for this type: %d",
                 net->nc->info->type);
@@ -110,6 +110,16 @@ uint64_t vhost_net_get_features(struct vhost_net *net, uint64_t features)
     return vhost_get_features(&net->dev, vhost_net_get_feature_bits(net),
             features);
 }
+int vhost_net_get_config(struct vhost_net *net,  uint8_t *config,
+                         uint32_t config_len)
+{
+    return vhost_dev_get_config(&net->dev, config, config_len);
+}
+int vhost_net_set_config(struct vhost_net *net, const uint8_t *data,
+                         uint32_t offset, uint32_t size, uint32_t flags)
+{
+    return vhost_dev_set_config(&net->dev, data, offset, size, flags);
+}
 
 void vhost_net_ack_features(struct vhost_net *net, uint64_t features)
 {
@@ -306,7 +316,9 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
     VirtioBusState *vbus = VIRTIO_BUS(qbus);
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
+    struct vhost_net *net;
     int r, e, i;
+    NetClientState *peer;
 
     if (!k->set_guest_notifiers) {
         error_report("binding does not support guest notifiers");
@@ -314,9 +326,9 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
     }
 
     for (i = 0; i < total_queues; i++) {
-        struct vhost_net *net;
 
-        net = get_vhost_net(ncs[i].peer);
+        peer = qemu_get_peer(ncs, i);
+        net = get_vhost_net(peer);
         vhost_net_set_vq_index(net, i * 2);
 
         /* Suppress the masking guest notifiers on vhost user
@@ -335,15 +347,16 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
     }
 
     for (i = 0; i < total_queues; i++) {
-        r = vhost_net_start_one(get_vhost_net(ncs[i].peer), dev);
+        peer = qemu_get_peer(ncs, i);
+        r = vhost_net_start_one(get_vhost_net(peer), dev);
 
         if (r < 0) {
             goto err_start;
         }
 
-        if (ncs[i].peer->vring_enable) {
+        if (peer->vring_enable) {
             /* restore vring enable state */
-            r = vhost_set_vring_enable(ncs[i].peer, ncs[i].peer->vring_enable);
+            r = vhost_set_vring_enable(peer, peer->vring_enable);
 
             if (r < 0) {
                 goto err_start;
@@ -355,7 +368,8 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
 
 err_start:
     while (--i >= 0) {
-        vhost_net_stop_one(get_vhost_net(ncs[i].peer), dev);
+        peer = qemu_get_peer(ncs , i);
+        vhost_net_stop_one(get_vhost_net(peer), dev);
     }
     e = k->set_guest_notifiers(qbus->parent, total_queues * 2, false);
     if (e < 0) {
@@ -430,6 +444,12 @@ VHostNetState *get_vhost_net(NetClientState *nc)
         assert(vhost_net);
         break;
 #endif
+#ifdef CONFIG_VHOST_NET_VDPA
+    case NET_CLIENT_DRIVER_VHOST_VDPA:
+        vhost_net = vhost_vdpa_get_vhost_net(nc);
+        assert(vhost_net);
+        break;
+#endif
     default:
         break;
     }
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 9bb5578e5d..1596cb1397 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -43,6 +43,7 @@
 #include "monitor/qdev.h"
 #include "hw/pci/pci.h"
 #include "net_rx_pkt.h"
+#include "hw/virtio/vhost.h"
 
 #define VIRTIO_NET_VM_VERSION    11
 
@@ -125,6 +126,8 @@ static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
     VirtIONet *n = VIRTIO_NET(vdev);
     struct virtio_net_config netcfg;
 
+    int ret = 0;
+    memset(&netcfg, 0 , sizeof(struct virtio_net_config));
     virtio_stw_p(vdev, &netcfg.status, n->status);
     virtio_stw_p(vdev, &netcfg.max_virtqueue_pairs, n->max_queues);
     virtio_stw_p(vdev, &netcfg.mtu, n->net_conf.mtu);
@@ -138,6 +141,15 @@ static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config)
     virtio_stl_p(vdev, &netcfg.supported_hash_types,
                  VIRTIO_NET_RSS_SUPPORTED_HASHES);
     memcpy(config, &netcfg, n->config_size);
+
+    NetClientState *nc = qemu_get_queue(n->nic);
+    if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
+        ret = vhost_net_get_config(get_vhost_net(nc->peer), (uint8_t *)&netcfg,
+                             n->config_size);
+    if (ret != -1) {
+        memcpy(config, &netcfg, n->config_size);
+    }
+    }
 }
 
 static void virtio_net_set_config(VirtIODevice *vdev, const uint8_t *config)
@@ -153,6 +165,13 @@ static void virtio_net_set_config(VirtIODevice *vdev, const uint8_t *config)
         memcpy(n->mac, netcfg.mac, ETH_ALEN);
         qemu_format_nic_info_str(qemu_get_queue(n->nic), n->mac);
     }
+
+    NetClientState *nc = qemu_get_queue(n->nic);
+    if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
+        vhost_net_set_config(get_vhost_net(nc->peer), (uint8_t *)&netcfg,
+                               0, n->config_size,
+                        VHOST_SET_CONFIG_TYPE_MASTER);
+      }
 }
 
 static bool virtio_net_started(VirtIONet *n, uint8_t status)
diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c
index 0408a31f8e..694722b212 100644
--- a/hw/nvram/fw_cfg.c
+++ b/hw/nvram/fw_cfg.c
@@ -1032,6 +1032,35 @@ void *fw_cfg_modify_file(FWCfgState *s, const char *filename,
     return NULL;
 }
 
+void fw_cfg_add_from_generator(FWCfgState *s, const char *filename,
+                               const char *gen_id, Error **errp)
+{
+    FWCfgDataGeneratorClass *klass;
+    Error *local_err = NULL;
+    GByteArray *array;
+    Object *obj;
+    gsize size;
+
+    obj = object_resolve_path_component(object_get_objects_root(), gen_id);
+    if (!obj) {
+        error_setg(errp, "Cannot find object ID '%s'", gen_id);
+        return;
+    }
+    if (!object_dynamic_cast(obj, TYPE_FW_CFG_DATA_GENERATOR_INTERFACE)) {
+        error_setg(errp, "Object ID '%s' is not a '%s' subclass",
+                   gen_id, TYPE_FW_CFG_DATA_GENERATOR_INTERFACE);
+        return;
+    }
+    klass = FW_CFG_DATA_GENERATOR_GET_CLASS(obj);
+    array = klass->get_data(obj, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        return;
+    }
+    size = array->len;
+    fw_cfg_add_file(s, filename, g_byte_array_free(array, TRUE), size);
+}
+
 static void fw_cfg_machine_reset(void *opaque)
 {
     MachineClass *mc = MACHINE_GET_CLASS(qdev_get_machine());
@@ -1333,12 +1362,18 @@ static const TypeInfo fw_cfg_mem_info = {
     .class_init    = fw_cfg_mem_class_init,
 };
 
+static const TypeInfo fw_cfg_data_generator_interface_info = {
+    .parent = TYPE_INTERFACE,
+    .name = TYPE_FW_CFG_DATA_GENERATOR_INTERFACE,
+    .class_size = sizeof(FWCfgDataGeneratorClass),
+};
 
 static void fw_cfg_register_types(void)
 {
     type_register_static(&fw_cfg_info);
     type_register_static(&fw_cfg_io_info);
     type_register_static(&fw_cfg_mem_info);
+    type_register_static(&fw_cfg_data_generator_interface_info);
 }
 
 type_init(fw_cfg_register_types)
diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
index b111406d56..023fd25f2b 100644
--- a/hw/s390x/s390-virtio-ccw.c
+++ b/hw/s390x/s390-virtio-ccw.c
@@ -43,7 +43,6 @@
 #include "hw/qdev-properties.h"
 #include "hw/s390x/tod.h"
 #include "sysemu/sysemu.h"
-#include "sysemu/balloon.h"
 #include "hw/s390x/pv.h"
 #include "migration/blocker.h"
 
@@ -329,7 +328,7 @@ static void s390_machine_unprotect(S390CcwMachineState *ms)
     ms->pv = false;
     migrate_del_blocker(pv_mig_blocker);
     error_free_or_abort(&pv_mig_blocker);
-    qemu_balloon_inhibit(false);
+    ram_block_discard_disable(false);
 }
 
 static int s390_machine_protect(S390CcwMachineState *ms)
@@ -338,17 +337,22 @@ static int s390_machine_protect(S390CcwMachineState *ms)
     int rc;
 
    /*
-    * Ballooning on protected VMs needs support in the guest for
-    * sharing and unsharing balloon pages. Block ballooning for
-    * now, until we have a solution to make at least Linux guests
-    * either support it or fail gracefully.
+    * Discarding of memory in RAM blocks does not work as expected with
+    * protected VMs. Sharing and unsharing pages would be required. Disable
+    * it for now, until until we have a solution to make at least Linux
+    * guests either support it (e.g., virtio-balloon) or fail gracefully.
     */
-    qemu_balloon_inhibit(true);
+    rc = ram_block_discard_disable(true);
+    if (rc) {
+        error_report("protected VMs: cannot disable RAM discard");
+        return rc;
+    }
+
     error_setg(&pv_mig_blocker,
                "protected VMs are currently not migrateable.");
     rc = migrate_add_blocker(pv_mig_blocker, &local_err);
     if (rc) {
-        qemu_balloon_inhibit(false);
+        ram_block_discard_disable(false);
         error_report_err(local_err);
         error_free_or_abort(&pv_mig_blocker);
         return rc;
@@ -357,7 +361,7 @@ static int s390_machine_protect(S390CcwMachineState *ms)
     /* Create SE VM */
     rc = s390_pv_vm_enable();
     if (rc) {
-        qemu_balloon_inhibit(false);
+        ram_block_discard_disable(false);
         migrate_del_blocker(pv_mig_blocker);
         error_free_or_abort(&pv_mig_blocker);
         return rc;
diff --git a/hw/usb/Makefile.objs b/hw/usb/Makefile.objs
index fa5c3fa1b8..e342ff59fa 100644
--- a/hw/usb/Makefile.objs
+++ b/hw/usb/Makefile.objs
@@ -29,11 +29,13 @@ common-obj-$(CONFIG_USB_NETWORK)      += dev-network.o
 
 ifeq ($(CONFIG_USB_SMARTCARD),y)
 common-obj-y                          += dev-smartcard-reader.o
-common-obj-$(CONFIG_SMARTCARD)        += smartcard.mo
+ifeq ($(CONFIG_SMARTCARD),y)
+common-obj-m                          += smartcard.mo
 smartcard.mo-objs := ccid-card-passthru.o ccid-card-emulated.o
 smartcard.mo-cflags := $(SMARTCARD_CFLAGS)
 smartcard.mo-libs := $(SMARTCARD_LIBS)
 endif
+endif
 
 ifeq ($(CONFIG_POSIX),y)
 common-obj-$(CONFIG_USB_STORAGE_MTP)  += dev-mtp.o
@@ -41,9 +43,12 @@ endif
 
 # usb redirection
 ifeq ($(CONFIG_USB),y)
-common-obj-$(CONFIG_USB_REDIR) += redirect.o quirks.o
-redirect.o-cflags = $(USB_REDIR_CFLAGS)
-redirect.o-libs = $(USB_REDIR_LIBS)
+ifeq ($(CONFIG_USB_REDIR),y)
+common-obj-m += redirect.mo
+redirect.mo-objs = redirect.o quirks.o
+redirect.mo-cflags = $(USB_REDIR_CFLAGS)
+redirect.mo-libs = $(USB_REDIR_LIBS)
+endif
 endif
 
 # usb pass-through
diff --git a/hw/vfio/ap.c b/hw/vfio/ap.c
index 95564c17ed..b9330a8e6f 100644
--- a/hw/vfio/ap.c
+++ b/hw/vfio/ap.c
@@ -105,12 +105,12 @@ static void vfio_ap_realize(DeviceState *dev, Error **errp)
     vapdev->vdev.dev = dev;
 
     /*
-     * vfio-ap devices operate in a way compatible with
-     * memory ballooning, as no pages are pinned in the host.
+     * vfio-ap devices operate in a way compatible with discarding of
+     * memory in RAM blocks, as no pages are pinned in the host.
      * This needs to be set before vfio_get_device() for vfio common to
-     * handle the balloon inhibitor.
+     * handle ram_block_discard_disable().
      */
-    vapdev->vdev.balloon_allowed = true;
+    vapdev->vdev.ram_block_discard_allowed = true;
 
     ret = vfio_get_device(vfio_group, mdevid, &vapdev->vdev, errp);
     if (ret) {
diff --git a/hw/vfio/ccw.c b/hw/vfio/ccw.c
index 06e69d7066..ff7f369779 100644
--- a/hw/vfio/ccw.c
+++ b/hw/vfio/ccw.c
@@ -574,12 +574,13 @@ static void vfio_ccw_get_device(VFIOGroup *group, VFIOCCWDevice *vcdev,
 
     /*
      * All vfio-ccw devices are believed to operate in a way compatible with
-     * memory ballooning, ie. pages pinned in the host are in the current
-     * working set of the guest driver and therefore never overlap with pages
-     * available to the guest balloon driver.  This needs to be set before
-     * vfio_get_device() for vfio common to handle the balloon inhibitor.
+     * discarding of memory in RAM blocks, ie. pages pinned in the host are
+     * in the current working set of the guest driver and therefore never
+     * overlap e.g., with pages available to the guest balloon driver.  This
+     * needs to be set before vfio_get_device() for vfio common to handle
+     * ram_block_discard_disable().
      */
-    vcdev->vdev.balloon_allowed = true;
+    vcdev->vdev.ram_block_discard_allowed = true;
 
     if (vfio_get_device(group, vcdev->cdev.mdevid, &vcdev->vdev, errp)) {
         goto out_err;
diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 0b3593b3c0..33357140b8 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -33,7 +33,6 @@
 #include "qemu/error-report.h"
 #include "qemu/main-loop.h"
 #include "qemu/range.h"
-#include "sysemu/balloon.h"
 #include "sysemu/kvm.h"
 #include "sysemu/reset.h"
 #include "trace.h"
@@ -1215,31 +1214,36 @@ static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,
     space = vfio_get_address_space(as);
 
     /*
-     * VFIO is currently incompatible with memory ballooning insofar as the
+     * VFIO is currently incompatible with discarding of RAM insofar as the
      * madvise to purge (zap) the page from QEMU's address space does not
      * interact with the memory API and therefore leaves stale virtual to
      * physical mappings in the IOMMU if the page was previously pinned.  We
-     * therefore add a balloon inhibit for each group added to a container,
+     * therefore set discarding broken for each group added to a container,
      * whether the container is used individually or shared.  This provides
      * us with options to allow devices within a group to opt-in and allow
-     * ballooning, so long as it is done consistently for a group (for instance
+     * discarding, so long as it is done consistently for a group (for instance
      * if the device is an mdev device where it is known that the host vendor
      * driver will never pin pages outside of the working set of the guest
-     * driver, which would thus not be ballooning candidates).
+     * driver, which would thus not be discarding candidates).
      *
      * The first opportunity to induce pinning occurs here where we attempt to
      * attach the group to existing containers within the AddressSpace.  If any
-     * pages are already zapped from the virtual address space, such as from a
-     * previous ballooning opt-in, new pinning will cause valid mappings to be
+     * pages are already zapped from the virtual address space, such as from
+     * previous discards, new pinning will cause valid mappings to be
      * re-established.  Likewise, when the overall MemoryListener for a new
      * container is registered, a replay of mappings within the AddressSpace
      * will occur, re-establishing any previously zapped pages as well.
      *
-     * NB. Balloon inhibiting does not currently block operation of the
-     * balloon driver or revoke previously pinned pages, it only prevents
-     * calling madvise to modify the virtual mapping of ballooned pages.
+     * Especially virtio-balloon is currently only prevented from discarding
+     * new memory, it will not yet set ram_block_discard_set_required() and
+     * therefore, neither stops us here or deals with the sudden memory
+     * consumption of inflated memory.
      */
-    qemu_balloon_inhibit(true);
+    ret = ram_block_discard_disable(true);
+    if (ret) {
+        error_setg_errno(errp, -ret, "Cannot set discarding of RAM broken");
+        return ret;
+    }
 
     QLIST_FOREACH(container, &space->containers, next) {
         if (!ioctl(group->fd, VFIO_GROUP_SET_CONTAINER, &container->fd)) {
@@ -1405,7 +1409,7 @@ close_fd_exit:
     close(fd);
 
 put_space_exit:
-    qemu_balloon_inhibit(false);
+    ram_block_discard_disable(false);
     vfio_put_address_space(space);
 
     return ret;
@@ -1526,8 +1530,8 @@ void vfio_put_group(VFIOGroup *group)
         return;
     }
 
-    if (!group->balloon_allowed) {
-        qemu_balloon_inhibit(false);
+    if (!group->ram_block_discard_allowed) {
+        ram_block_discard_disable(false);
     }
     vfio_kvm_device_del_group(group);
     vfio_disconnect_container(group);
@@ -1565,22 +1569,23 @@ int vfio_get_device(VFIOGroup *group, const char *name,
     }
 
     /*
-     * Clear the balloon inhibitor for this group if the driver knows the
-     * device operates compatibly with ballooning.  Setting must be consistent
-     * per group, but since compatibility is really only possible with mdev
-     * currently, we expect singleton groups.
+     * Set discarding of RAM as not broken for this group if the driver knows
+     * the device operates compatibly with discarding.  Setting must be
+     * consistent per group, but since compatibility is really only possible
+     * with mdev currently, we expect singleton groups.
      */
-    if (vbasedev->balloon_allowed != group->balloon_allowed) {
+    if (vbasedev->ram_block_discard_allowed !=
+        group->ram_block_discard_allowed) {
         if (!QLIST_EMPTY(&group->device_list)) {
-            error_setg(errp,
-                       "Inconsistent device balloon setting within group");
+            error_setg(errp, "Inconsistent setting of support for discarding "
+                       "RAM (e.g., balloon) within group");
             close(fd);
             return -1;
         }
 
-        if (!group->balloon_allowed) {
-            group->balloon_allowed = true;
-            qemu_balloon_inhibit(false);
+        if (!group->ram_block_discard_allowed) {
+            group->ram_block_discard_allowed = true;
+            ram_block_discard_disable(false);
         }
     }
 
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 6838bcc4b3..d020ea9f82 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -2789,7 +2789,7 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
     }
 
     /*
-     * Mediated devices *might* operate compatibly with memory ballooning, but
+     * Mediated devices *might* operate compatibly with discarding of RAM, but
      * we cannot know for certain, it depends on whether the mdev vendor driver
      * stays in sync with the active working set of the guest driver.  Prevent
      * the x-balloon-allowed option unless this is minimally an mdev device.
@@ -2802,7 +2802,7 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
 
     trace_vfio_mdev(vdev->vbasedev.name, is_mdev);
 
-    if (vdev->vbasedev.balloon_allowed && !is_mdev) {
+    if (vdev->vbasedev.ram_block_discard_allowed && !is_mdev) {
         error_setg(errp, "x-balloon-allowed only potentially compatible "
                    "with mdev devices");
         vfio_put_group(group);
@@ -3156,7 +3156,7 @@ static Property vfio_pci_dev_properties[] = {
                     VFIO_FEATURE_ENABLE_IGD_OPREGION_BIT, false),
     DEFINE_PROP_BOOL("x-no-mmap", VFIOPCIDevice, vbasedev.no_mmap, false),
     DEFINE_PROP_BOOL("x-balloon-allowed", VFIOPCIDevice,
-                     vbasedev.balloon_allowed, false),
+                     vbasedev.ram_block_discard_allowed, false),
     DEFINE_PROP_BOOL("x-no-kvm-intx", VFIOPCIDevice, no_kvm_intx, false),
     DEFINE_PROP_BOOL("x-no-kvm-msi", VFIOPCIDevice, no_kvm_msi, false),
     DEFINE_PROP_BOOL("x-no-kvm-msix", VFIOPCIDevice, no_kvm_msix, false),
diff --git a/hw/virtio/Kconfig b/hw/virtio/Kconfig
index 83122424fa..0eda25c4e1 100644
--- a/hw/virtio/Kconfig
+++ b/hw/virtio/Kconfig
@@ -47,3 +47,14 @@ config VIRTIO_PMEM
     depends on VIRTIO
     depends on VIRTIO_PMEM_SUPPORTED
     select MEM_DEVICE
+
+config VIRTIO_MEM_SUPPORTED
+    bool
+
+config VIRTIO_MEM
+    bool
+    default y
+    depends on VIRTIO
+    depends on LINUX
+    depends on VIRTIO_MEM_SUPPORTED
+    select MEM_DEVICE
diff --git a/hw/virtio/Makefile.objs b/hw/virtio/Makefile.objs
index 13e75f171f..fc91719b4a 100644
--- a/hw/virtio/Makefile.objs
+++ b/hw/virtio/Makefile.objs
@@ -5,6 +5,7 @@ obj-y += virtio.o
 obj-$(CONFIG_VHOST) += vhost.o vhost-backend.o
 common-obj-$(call lnot,$(CONFIG_VHOST)) += vhost-stub.o
 obj-$(CONFIG_VHOST_USER) += vhost-user.o
+obj-$(CONFIG_VHOST_VDPA) += vhost-vdpa.o
 
 common-obj-$(CONFIG_VIRTIO_RNG) += virtio-rng.o
 common-obj-$(CONFIG_VIRTIO_PCI) += virtio-pci.o
@@ -19,6 +20,8 @@ obj-$(call land,$(CONFIG_VHOST_USER_FS),$(CONFIG_VIRTIO_PCI)) += vhost-user-fs-p
 obj-$(CONFIG_VIRTIO_IOMMU) += virtio-iommu.o
 obj-$(CONFIG_VHOST_VSOCK) += vhost-vsock-common.o vhost-vsock.o
 obj-$(CONFIG_VHOST_USER_VSOCK) += vhost-vsock-common.o vhost-user-vsock.o
+obj-$(CONFIG_VIRTIO_MEM) += virtio-mem.o
+common-obj-$(call land,$(CONFIG_VIRTIO_MEM),$(CONFIG_VIRTIO_PCI)) += virtio-mem-pci.o
 
 ifeq ($(CONFIG_VIRTIO_PCI),y)
 obj-$(CONFIG_VHOST_VSOCK) += vhost-vsock-pci.o
diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events
index 23109f69bb..045e89cae6 100644
--- a/hw/virtio/trace-events
+++ b/hw/virtio/trace-events
@@ -75,3 +75,13 @@ virtio_iommu_put_domain(uint32_t domain_id) "Free domain=%d"
 virtio_iommu_translate_out(uint64_t virt_addr, uint64_t phys_addr, uint32_t sid) "0x%"PRIx64" -> 0x%"PRIx64 " for sid=%d"
 virtio_iommu_report_fault(uint8_t reason, uint32_t flags, uint32_t endpoint, uint64_t addr) "FAULT reason=%d flags=%d endpoint=%d address =0x%"PRIx64
 virtio_iommu_fill_resv_property(uint32_t devid, uint8_t subtype, uint64_t start, uint64_t end) "dev= %d, type=%d start=0x%"PRIx64" end=0x%"PRIx64
+
+# virtio-mem.c
+virtio_mem_send_response(uint16_t type) "type=%" PRIu16
+virtio_mem_plug_request(uint64_t addr, uint16_t nb_blocks) "addr=0x%" PRIx64 " nb_blocks=%" PRIu16
+virtio_mem_unplug_request(uint64_t addr, uint16_t nb_blocks) "addr=0x%" PRIx64 " nb_blocks=%" PRIu16
+virtio_mem_unplugged_all(void) ""
+virtio_mem_unplug_all_request(void) ""
+virtio_mem_resized_usable_region(uint64_t old_size, uint64_t new_size) "old_size=0x%" PRIx64 "new_size=0x%" PRIx64
+virtio_mem_state_request(uint64_t addr, uint16_t nb_blocks) "addr=0x%" PRIx64 " nb_blocks=%" PRIu16
+virtio_mem_state_response(uint16_t state) "state=%" PRIu16
diff --git a/hw/virtio/vhost-backend.c b/hw/virtio/vhost-backend.c
index 48905383f8..782b1d67d9 100644
--- a/hw/virtio/vhost-backend.c
+++ b/hw/virtio/vhost-backend.c
@@ -15,6 +15,7 @@
 #include "qemu/main-loop.h"
 #include "standard-headers/linux/vhost_types.h"
 
+#include "hw/virtio/vhost-vdpa.h"
 #ifdef CONFIG_VHOST_KERNEL
 #include <linux/vhost.h>
 #include <sys/ioctl.h>
@@ -286,6 +287,11 @@ int vhost_set_backend_type(struct vhost_dev *dev, VhostBackendType backend_type)
         dev->vhost_ops = &user_ops;
         break;
 #endif
+#ifdef CONFIG_VHOST_VDPA
+    case VHOST_BACKEND_TYPE_VDPA:
+        dev->vhost_ops = &vdpa_ops;
+        break;
+#endif
     default:
         error_report("Unknown vhost backend type");
         r = -1;
diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
new file mode 100644
index 0000000000..a3d17fe0f9
--- /dev/null
+++ b/hw/virtio/vhost-vdpa.c
@@ -0,0 +1,475 @@
+/*
+ * vhost-vdpa
+ *
+ *  Copyright(c) 2017-2018 Intel Corporation.
+ *  Copyright(c) 2020 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 <linux/vhost.h>
+#include <linux/vfio.h>
+#include <sys/eventfd.h>
+#include <sys/ioctl.h>
+#include "hw/virtio/vhost.h"
+#include "hw/virtio/vhost-backend.h"
+#include "hw/virtio/virtio-net.h"
+#include "hw/virtio/vhost-vdpa.h"
+#include "qemu/main-loop.h"
+#include <linux/kvm.h>
+#include "sysemu/kvm.h"
+
+static bool vhost_vdpa_listener_skipped_section(MemoryRegionSection *section)
+{
+    return (!memory_region_is_ram(section->mr) &&
+            !memory_region_is_iommu(section->mr)) ||
+           /*
+            * Sizing an enabled 64-bit BAR can cause spurious mappings to
+            * addresses in the upper part of the 64-bit address space.  These
+            * are never accessed by the CPU and beyond the address width of
+            * some IOMMU hardware.  TODO: VDPA should tell us the IOMMU width.
+            */
+           section->offset_within_address_space & (1ULL << 63);
+}
+
+static int vhost_vdpa_dma_map(struct vhost_vdpa *v, hwaddr iova, hwaddr size,
+                              void *vaddr, bool readonly)
+{
+    struct vhost_msg_v2 msg;
+    int fd = v->device_fd;
+    int ret = 0;
+
+    msg.type = v->msg_type;
+    msg.iotlb.iova = iova;
+    msg.iotlb.size = size;
+    msg.iotlb.uaddr = (uint64_t)(uintptr_t)vaddr;
+    msg.iotlb.perm = readonly ? VHOST_ACCESS_RO : VHOST_ACCESS_RW;
+    msg.iotlb.type = VHOST_IOTLB_UPDATE;
+
+    if (write(fd, &msg, sizeof(msg)) != sizeof(msg)) {
+        error_report("failed to write, fd=%d, errno=%d (%s)",
+            fd, errno, strerror(errno));
+        return -EIO ;
+    }
+
+    return ret;
+}
+
+static int vhost_vdpa_dma_unmap(struct vhost_vdpa *v, hwaddr iova,
+                                hwaddr size)
+{
+    struct vhost_msg_v2 msg;
+    int fd = v->device_fd;
+    int ret = 0;
+
+    msg.type = v->msg_type;
+    msg.iotlb.iova = iova;
+    msg.iotlb.size = size;
+    msg.iotlb.type = VHOST_IOTLB_INVALIDATE;
+
+    if (write(fd, &msg, sizeof(msg)) != sizeof(msg)) {
+        error_report("failed to write, fd=%d, errno=%d (%s)",
+            fd, errno, strerror(errno));
+        return -EIO ;
+    }
+
+    return ret;
+}
+
+static void vhost_vdpa_listener_region_add(MemoryListener *listener,
+                                           MemoryRegionSection *section)
+{
+    struct vhost_vdpa *v = container_of(listener, struct vhost_vdpa, listener);
+    hwaddr iova;
+    Int128 llend, llsize;
+    void *vaddr;
+    int ret;
+
+    if (vhost_vdpa_listener_skipped_section(section)) {
+        return;
+    }
+
+    if (unlikely((section->offset_within_address_space & ~TARGET_PAGE_MASK) !=
+                 (section->offset_within_region & ~TARGET_PAGE_MASK))) {
+        error_report("%s received unaligned region", __func__);
+        return;
+    }
+
+    iova = TARGET_PAGE_ALIGN(section->offset_within_address_space);
+    llend = int128_make64(section->offset_within_address_space);
+    llend = int128_add(llend, section->size);
+    llend = int128_and(llend, int128_exts64(TARGET_PAGE_MASK));
+
+    if (int128_ge(int128_make64(iova), llend)) {
+        return;
+    }
+
+    memory_region_ref(section->mr);
+
+    /* Here we assume that memory_region_is_ram(section->mr)==true */
+
+    vaddr = memory_region_get_ram_ptr(section->mr) +
+            section->offset_within_region +
+            (iova - section->offset_within_address_space);
+
+    llsize = int128_sub(llend, int128_make64(iova));
+
+    ret = vhost_vdpa_dma_map(v, iova, int128_get64(llsize),
+                             vaddr, section->readonly);
+    if (ret) {
+        error_report("vhost vdpa map fail!");
+        if (memory_region_is_ram_device(section->mr)) {
+            /* Allow unexpected mappings not to be fatal for RAM devices */
+            error_report("map ram fail!");
+          return ;
+        }
+        goto fail;
+    }
+
+    return;
+
+fail:
+    if (memory_region_is_ram_device(section->mr)) {
+        error_report("failed to vdpa_dma_map. pci p2p may not work");
+        return;
+
+    }
+    /*
+     * On the initfn path, store the first error in the container so we
+     * can gracefully fail.  Runtime, there's not much we can do other
+     * than throw a hardware error.
+     */
+    error_report("vhost-vdpa: DMA mapping failed, unable to continue");
+    return;
+
+}
+
+static void vhost_vdpa_listener_region_del(MemoryListener *listener,
+                                           MemoryRegionSection *section)
+{
+    struct vhost_vdpa *v = container_of(listener, struct vhost_vdpa, listener);
+    hwaddr iova;
+    Int128 llend, llsize;
+    int ret;
+    bool try_unmap = true;
+
+    if (vhost_vdpa_listener_skipped_section(section)) {
+        return;
+    }
+
+    if (unlikely((section->offset_within_address_space & ~TARGET_PAGE_MASK) !=
+                 (section->offset_within_region & ~TARGET_PAGE_MASK))) {
+        error_report("%s received unaligned region", __func__);
+        return;
+    }
+
+    iova = TARGET_PAGE_ALIGN(section->offset_within_address_space);
+    llend = int128_make64(section->offset_within_address_space);
+    llend = int128_add(llend, section->size);
+    llend = int128_and(llend, int128_exts64(TARGET_PAGE_MASK));
+
+    if (int128_ge(int128_make64(iova), llend)) {
+        return;
+    }
+
+    llsize = int128_sub(llend, int128_make64(iova));
+
+    if (try_unmap) {
+        ret = vhost_vdpa_dma_unmap(v, iova, int128_get64(llsize));
+        if (ret) {
+            error_report("vhost_vdpa dma unmap error!");
+        }
+    }
+
+    memory_region_unref(section->mr);
+}
+/*
+ * IOTLB API is used by vhost-vpda which requires incremental updating
+ * of the mapping. So we can not use generic vhost memory listener which
+ * depends on the addnop().
+ */
+static const MemoryListener vhost_vdpa_memory_listener = {
+    .region_add = vhost_vdpa_listener_region_add,
+    .region_del = vhost_vdpa_listener_region_del,
+};
+
+static int vhost_vdpa_call(struct vhost_dev *dev, unsigned long int request,
+                             void *arg)
+{
+    struct vhost_vdpa *v = dev->opaque;
+    int fd = v->device_fd;
+
+    assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA);
+
+    return ioctl(fd, request, arg);
+}
+
+static void vhost_vdpa_add_status(struct vhost_dev *dev, uint8_t status)
+{
+    uint8_t s;
+
+    if (vhost_vdpa_call(dev, VHOST_VDPA_GET_STATUS, &s)) {
+        return;
+    }
+
+    s |= status;
+
+    vhost_vdpa_call(dev, VHOST_VDPA_SET_STATUS, &s);
+}
+
+static int vhost_vdpa_init(struct vhost_dev *dev, void *opaque)
+{
+    struct vhost_vdpa *v;
+    uint64_t features;
+    assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA);
+
+    v = opaque;
+    dev->opaque =  opaque ;
+    vhost_vdpa_call(dev, VHOST_GET_FEATURES, &features);
+    dev->backend_features = features;
+    v->listener = vhost_vdpa_memory_listener;
+    v->msg_type = VHOST_IOTLB_MSG_V2;
+
+    vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
+                               VIRTIO_CONFIG_S_DRIVER);
+
+    return 0;
+}
+
+static int vhost_vdpa_cleanup(struct vhost_dev *dev)
+{
+    struct vhost_vdpa *v;
+    assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA);
+    v = dev->opaque;
+    memory_listener_unregister(&v->listener);
+
+    dev->opaque = NULL;
+    return 0;
+}
+
+static int vhost_vdpa_memslots_limit(struct vhost_dev *dev)
+{
+    return INT_MAX;
+}
+
+static int vhost_vdpa_set_mem_table(struct vhost_dev *dev,
+                                    struct vhost_memory *mem)
+{
+
+    if (mem->padding) {
+        return -1;
+    }
+
+    return 0;
+}
+
+static int vhost_vdpa_set_features(struct vhost_dev *dev,
+                                   uint64_t features)
+{
+    int ret;
+    ret = vhost_vdpa_call(dev, VHOST_SET_FEATURES, &features);
+    uint8_t status = 0;
+    if (ret) {
+        return ret;
+    }
+    vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_FEATURES_OK);
+    vhost_vdpa_call(dev, VHOST_VDPA_GET_STATUS, &status);
+
+    return !(status & VIRTIO_CONFIG_S_FEATURES_OK);
+}
+
+int vhost_vdpa_get_device_id(struct vhost_dev *dev,
+                                   uint32_t *device_id)
+{
+    return vhost_vdpa_call(dev, VHOST_VDPA_GET_DEVICE_ID, device_id);
+}
+
+static int vhost_vdpa_reset_device(struct vhost_dev *dev)
+{
+    uint8_t status = 0;
+
+    return vhost_vdpa_call(dev, VHOST_VDPA_SET_STATUS, &status);
+}
+
+static int vhost_vdpa_get_vq_index(struct vhost_dev *dev, int idx)
+{
+    assert(idx >= dev->vq_index && idx < dev->vq_index + dev->nvqs);
+
+    return idx - dev->vq_index;
+}
+
+static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev)
+{
+    int i;
+    for (i = 0; i < dev->nvqs; ++i) {
+        struct vhost_vring_state state = {
+            .index = dev->vq_index + i,
+            .num = 1,
+        };
+        vhost_vdpa_call(dev, VHOST_VDPA_SET_VRING_ENABLE, &state);
+    }
+    return 0;
+}
+
+static int vhost_vdpa_set_config(struct vhost_dev *dev, const uint8_t *data,
+                                   uint32_t offset, uint32_t size,
+                                   uint32_t flags)
+{
+    struct vhost_vdpa_config *config;
+    int ret;
+    unsigned long config_size = offsetof(struct vhost_vdpa_config, buf);
+    config = g_malloc(size + config_size);
+    if (config == NULL) {
+        return -1;
+    }
+    config->off = offset;
+    config->len = size;
+    memcpy(config->buf, data, size);
+    ret = vhost_vdpa_call(dev, VHOST_VDPA_SET_CONFIG, config);
+    g_free(config);
+    return ret;
+}
+
+static int vhost_vdpa_get_config(struct vhost_dev *dev, uint8_t *config,
+                                   uint32_t config_len)
+{
+    struct vhost_vdpa_config *v_config;
+    unsigned long config_size = offsetof(struct vhost_vdpa_config, buf);
+    int ret;
+
+    v_config = g_malloc(config_len + config_size);
+    if (v_config == NULL) {
+        return -1;
+    }
+    v_config->len = config_len;
+    v_config->off = 0;
+    ret = vhost_vdpa_call(dev, VHOST_VDPA_GET_CONFIG, v_config);
+    memcpy(config, v_config->buf, config_len);
+    g_free(v_config);
+    return ret;
+ }
+
+static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
+{
+    struct vhost_vdpa *v = dev->opaque;
+    if (started) {
+        uint8_t status = 0;
+        memory_listener_register(&v->listener, &address_space_memory);
+        vhost_vdpa_set_vring_ready(dev);
+        vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
+        vhost_vdpa_call(dev, VHOST_VDPA_GET_STATUS, &status);
+
+        return !(status & VIRTIO_CONFIG_S_DRIVER_OK);
+    } else {
+        vhost_vdpa_reset_device(dev);
+        vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
+                                   VIRTIO_CONFIG_S_DRIVER);
+        memory_listener_unregister(&v->listener);
+
+        return 0;
+    }
+}
+
+static int vhost_vdpa_set_log_base(struct vhost_dev *dev, uint64_t base,
+                                     struct vhost_log *log)
+{
+    return vhost_vdpa_call(dev, VHOST_SET_LOG_BASE, &base);
+}
+
+static int vhost_vdpa_set_vring_addr(struct vhost_dev *dev,
+                                       struct vhost_vring_addr *addr)
+{
+    return vhost_vdpa_call(dev, VHOST_SET_VRING_ADDR, addr);
+}
+
+static int vhost_vdpa_set_vring_num(struct vhost_dev *dev,
+                                      struct vhost_vring_state *ring)
+{
+    return vhost_vdpa_call(dev, VHOST_SET_VRING_NUM, ring);
+}
+
+static int vhost_vdpa_set_vring_base(struct vhost_dev *dev,
+                                       struct vhost_vring_state *ring)
+{
+    return vhost_vdpa_call(dev, VHOST_SET_VRING_BASE, ring);
+}
+
+static int vhost_vdpa_get_vring_base(struct vhost_dev *dev,
+                                       struct vhost_vring_state *ring)
+{
+    return vhost_vdpa_call(dev, VHOST_GET_VRING_BASE, ring);
+}
+
+static int vhost_vdpa_set_vring_kick(struct vhost_dev *dev,
+                                       struct vhost_vring_file *file)
+{
+    return vhost_vdpa_call(dev, VHOST_SET_VRING_KICK, file);
+}
+
+static int vhost_vdpa_set_vring_call(struct vhost_dev *dev,
+                                       struct vhost_vring_file *file)
+{
+    return vhost_vdpa_call(dev, VHOST_SET_VRING_CALL, file);
+}
+
+static int vhost_vdpa_get_features(struct vhost_dev *dev,
+                                     uint64_t *features)
+{
+    return vhost_vdpa_call(dev, VHOST_GET_FEATURES, features);
+}
+
+static int vhost_vdpa_set_owner(struct vhost_dev *dev)
+{
+    return vhost_vdpa_call(dev, VHOST_SET_OWNER, NULL);
+}
+
+static int vhost_vdpa_vq_get_addr(struct vhost_dev *dev,
+                    struct vhost_vring_addr *addr, struct vhost_virtqueue *vq)
+{
+    assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA);
+    addr->desc_user_addr = (uint64_t)(unsigned long)vq->desc_phys;
+    addr->avail_user_addr = (uint64_t)(unsigned long)vq->avail_phys;
+    addr->used_user_addr = (uint64_t)(unsigned long)vq->used_phys;
+    return 0;
+}
+
+static bool  vhost_vdpa_force_iommu(struct vhost_dev *dev)
+{
+    return true;
+}
+
+const VhostOps vdpa_ops = {
+        .backend_type = VHOST_BACKEND_TYPE_VDPA,
+        .vhost_backend_init = vhost_vdpa_init,
+        .vhost_backend_cleanup = vhost_vdpa_cleanup,
+        .vhost_set_log_base = vhost_vdpa_set_log_base,
+        .vhost_set_vring_addr = vhost_vdpa_set_vring_addr,
+        .vhost_set_vring_num = vhost_vdpa_set_vring_num,
+        .vhost_set_vring_base = vhost_vdpa_set_vring_base,
+        .vhost_get_vring_base = vhost_vdpa_get_vring_base,
+        .vhost_set_vring_kick = vhost_vdpa_set_vring_kick,
+        .vhost_set_vring_call = vhost_vdpa_set_vring_call,
+        .vhost_get_features = vhost_vdpa_get_features,
+        .vhost_set_owner = vhost_vdpa_set_owner,
+        .vhost_set_vring_endian = NULL,
+        .vhost_backend_memslots_limit = vhost_vdpa_memslots_limit,
+        .vhost_set_mem_table = vhost_vdpa_set_mem_table,
+        .vhost_set_features = vhost_vdpa_set_features,
+        .vhost_reset_device = vhost_vdpa_reset_device,
+        .vhost_get_vq_index = vhost_vdpa_get_vq_index,
+        .vhost_get_config  = vhost_vdpa_get_config,
+        .vhost_set_config = vhost_vdpa_set_config,
+        .vhost_requires_shm_log = NULL,
+        .vhost_migration_done = NULL,
+        .vhost_backend_can_merge = NULL,
+        .vhost_net_set_mtu = NULL,
+        .vhost_set_iotlb_callback = NULL,
+        .vhost_send_device_iotlb_msg = NULL,
+        .vhost_dev_start = vhost_vdpa_dev_start,
+        .vhost_get_device_id = vhost_vdpa_get_device_id,
+         .vhost_vq_get_addr = vhost_vdpa_vq_get_addr,
+         .vhost_force_iommu = vhost_vdpa_force_iommu,
+};
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 5fd25fe520..1a1384e7a6 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -773,15 +773,25 @@ static int vhost_virtqueue_set_addr(struct vhost_dev *dev,
                                     struct vhost_virtqueue *vq,
                                     unsigned idx, bool enable_log)
 {
-    struct vhost_vring_addr addr = {
-        .index = idx,
-        .desc_user_addr = (uint64_t)(unsigned long)vq->desc,
-        .avail_user_addr = (uint64_t)(unsigned long)vq->avail,
-        .used_user_addr = (uint64_t)(unsigned long)vq->used,
-        .log_guest_addr = vq->used_phys,
-        .flags = enable_log ? (1 << VHOST_VRING_F_LOG) : 0,
-    };
-    int r = dev->vhost_ops->vhost_set_vring_addr(dev, &addr);
+    struct vhost_vring_addr addr;
+    int r;
+    memset(&addr, 0, sizeof(struct vhost_vring_addr));
+
+    if (dev->vhost_ops->vhost_vq_get_addr) {
+        r = dev->vhost_ops->vhost_vq_get_addr(dev, &addr, vq);
+        if (r < 0) {
+            VHOST_OPS_DEBUG("vhost_vq_get_addr failed");
+            return -errno;
+        }
+    } else {
+        addr.desc_user_addr = (uint64_t)(unsigned long)vq->desc;
+        addr.avail_user_addr = (uint64_t)(unsigned long)vq->avail;
+        addr.used_user_addr = (uint64_t)(unsigned long)vq->used;
+    }
+    addr.index = idx;
+    addr.log_guest_addr = vq->used_phys;
+    addr.flags = enable_log ? (1 << VHOST_VRING_F_LOG) : 0;
+    r = dev->vhost_ops->vhost_set_vring_addr(dev, &addr);
     if (r < 0) {
         VHOST_OPS_DEBUG("vhost_set_vring_addr failed");
         return -errno;
@@ -800,6 +810,11 @@ static int vhost_dev_set_features(struct vhost_dev *dev,
     if (!vhost_dev_has_iommu(dev)) {
         features &= ~(0x1ULL << VIRTIO_F_IOMMU_PLATFORM);
     }
+    if (dev->vhost_ops->vhost_force_iommu) {
+        if (dev->vhost_ops->vhost_force_iommu(dev) == true) {
+            features |= 0x1ULL << VIRTIO_F_IOMMU_PLATFORM;
+       }
+    }
     r = dev->vhost_ops->vhost_set_features(dev, features);
     if (r < 0) {
         VHOST_OPS_DEBUG("vhost_set_features failed");
@@ -1685,9 +1700,15 @@ int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev)
             goto fail_log;
         }
     }
-
-    if (vhost_dev_has_iommu(hdev)) {
-        hdev->vhost_ops->vhost_set_iotlb_callback(hdev, true);
+    if (hdev->vhost_ops->vhost_dev_start) {
+        r = hdev->vhost_ops->vhost_dev_start(hdev, true);
+        if (r) {
+            goto fail_log;
+        }
+    }
+    if (vhost_dev_has_iommu(hdev) &&
+        hdev->vhost_ops->vhost_set_iotlb_callback) {
+            hdev->vhost_ops->vhost_set_iotlb_callback(hdev, true);
 
         /* Update used ring information for IOTLB to work correctly,
          * vhost-kernel code requires for this.*/
@@ -1722,6 +1743,9 @@ void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev)
     /* should only be called after backend is connected */
     assert(hdev->vhost_ops);
 
+    if (hdev->vhost_ops->vhost_dev_start) {
+        hdev->vhost_ops->vhost_dev_start(hdev, false);
+    }
     for (i = 0; i < hdev->nvqs; ++i) {
         vhost_virtqueue_stop(hdev,
                              vdev,
@@ -1730,7 +1754,9 @@ void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev)
     }
 
     if (vhost_dev_has_iommu(hdev)) {
-        hdev->vhost_ops->vhost_set_iotlb_callback(hdev, false);
+        if (hdev->vhost_ops->vhost_set_iotlb_callback) {
+            hdev->vhost_ops->vhost_set_iotlb_callback(hdev, false);
+        }
         memory_listener_unregister(&hdev->iommu_listener);
     }
     vhost_log_put(hdev, true);
diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c
index 10507b2a43..ae31f0817a 100644
--- a/hw/virtio/virtio-balloon.c
+++ b/hw/virtio/virtio-balloon.c
@@ -63,6 +63,12 @@ static bool virtio_balloon_pbp_matches(PartiallyBalloonedPage *pbp,
     return pbp->base_gpa == base_gpa;
 }
 
+static bool virtio_balloon_inhibited(void)
+{
+    /* Postcopy cannot deal with concurrent discards, so it's special. */
+    return ram_block_discard_is_disabled() || migration_in_incoming_postcopy();
+}
+
 static void balloon_inflate_page(VirtIOBalloon *balloon,
                                  MemoryRegion *mr, hwaddr mr_offset,
                                  PartiallyBalloonedPage *pbp)
@@ -336,7 +342,7 @@ static void virtio_balloon_handle_report(VirtIODevice *vdev, VirtQueue *vq)
          * accessible by another device or process, or if the guest is
          * expecting it to retain a non-zero value.
          */
-        if (qemu_balloon_is_inhibited() || dev->poison_val) {
+        if (virtio_balloon_inhibited() || dev->poison_val) {
             goto skip_element;
         }
 
@@ -421,7 +427,7 @@ static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq)
 
             trace_virtio_balloon_handle_output(memory_region_name(section.mr),
                                                pa);
-            if (!qemu_balloon_is_inhibited()) {
+            if (!virtio_balloon_inhibited()) {
                 if (vq == s->ivq) {
                     balloon_inflate_page(s, section.mr,
                                          section.offset_within_region, &pbp);
@@ -628,8 +634,13 @@ static void virtio_balloon_free_page_done(VirtIOBalloon *s)
 {
     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 
-    s->free_page_report_status = FREE_PAGE_REPORT_S_DONE;
-    virtio_notify_config(vdev);
+    if (s->free_page_report_status != FREE_PAGE_REPORT_S_DONE) {
+        /* See virtio_balloon_free_page_stop() */
+        qemu_mutex_lock(&s->free_page_lock);
+        s->free_page_report_status = FREE_PAGE_REPORT_S_DONE;
+        qemu_mutex_unlock(&s->free_page_lock);
+        virtio_notify_config(vdev);
+    }
 }
 
 static int
@@ -653,17 +664,26 @@ virtio_balloon_free_page_report_notify(NotifierWithReturn *n, void *data)
     case PRECOPY_NOTIFY_SETUP:
         precopy_enable_free_page_optimization();
         break;
-    case PRECOPY_NOTIFY_COMPLETE:
-    case PRECOPY_NOTIFY_CLEANUP:
     case PRECOPY_NOTIFY_BEFORE_BITMAP_SYNC:
         virtio_balloon_free_page_stop(dev);
         break;
     case PRECOPY_NOTIFY_AFTER_BITMAP_SYNC:
         if (vdev->vm_running) {
             virtio_balloon_free_page_start(dev);
-        } else {
-            virtio_balloon_free_page_done(dev);
+            break;
         }
+        /*
+         * Set S_DONE before migrating the vmstate, so the guest will reuse
+         * all hinted pages once running on the destination. Fall through.
+         */
+    case PRECOPY_NOTIFY_CLEANUP:
+        /*
+         * Especially, if something goes wrong during precopy or if migration
+         * is canceled, we have to properly communicate S_DONE to the VM.
+         */
+        virtio_balloon_free_page_done(dev);
+        break;
+    case PRECOPY_NOTIFY_COMPLETE:
         break;
     default:
         virtio_error(vdev, "%s: %d reason unknown", __func__, pnd->reason);
diff --git a/hw/virtio/virtio-mem-pci.c b/hw/virtio/virtio-mem-pci.c
new file mode 100644
index 0000000000..1a8e854123
--- /dev/null
+++ b/hw/virtio/virtio-mem-pci.c
@@ -0,0 +1,157 @@
+/*
+ * Virtio MEM PCI device
+ *
+ * Copyright (C) 2020 Red Hat, Inc.
+ *
+ * Authors:
+ *  David Hildenbrand <david@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "virtio-mem-pci.h"
+#include "hw/mem/memory-device.h"
+#include "qapi/error.h"
+#include "qapi/qapi-events-misc.h"
+
+static void virtio_mem_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp)
+{
+    VirtIOMEMPCI *mem_pci = VIRTIO_MEM_PCI(vpci_dev);
+    DeviceState *vdev = DEVICE(&mem_pci->vdev);
+
+    qdev_set_parent_bus(vdev, BUS(&vpci_dev->bus));
+    object_property_set_bool(OBJECT(vdev), true, "realized", errp);
+}
+
+static void virtio_mem_pci_set_addr(MemoryDeviceState *md, uint64_t addr,
+                                    Error **errp)
+{
+    object_property_set_uint(OBJECT(md), addr, VIRTIO_MEM_ADDR_PROP, errp);
+}
+
+static uint64_t virtio_mem_pci_get_addr(const MemoryDeviceState *md)
+{
+    return object_property_get_uint(OBJECT(md), VIRTIO_MEM_ADDR_PROP,
+                                    &error_abort);
+}
+
+static MemoryRegion *virtio_mem_pci_get_memory_region(MemoryDeviceState *md,
+                                                      Error **errp)
+{
+    VirtIOMEMPCI *pci_mem = VIRTIO_MEM_PCI(md);
+    VirtIOMEM *vmem = VIRTIO_MEM(&pci_mem->vdev);
+    VirtIOMEMClass *vmc = VIRTIO_MEM_GET_CLASS(vmem);
+
+    return vmc->get_memory_region(vmem, errp);
+}
+
+static uint64_t virtio_mem_pci_get_plugged_size(const MemoryDeviceState *md,
+                                                Error **errp)
+{
+    return object_property_get_uint(OBJECT(md), VIRTIO_MEM_SIZE_PROP,
+                                    errp);
+}
+
+static void virtio_mem_pci_fill_device_info(const MemoryDeviceState *md,
+                                            MemoryDeviceInfo *info)
+{
+    VirtioMEMDeviceInfo *vi = g_new0(VirtioMEMDeviceInfo, 1);
+    VirtIOMEMPCI *pci_mem = VIRTIO_MEM_PCI(md);
+    VirtIOMEM *vmem = VIRTIO_MEM(&pci_mem->vdev);
+    VirtIOMEMClass *vpc = VIRTIO_MEM_GET_CLASS(vmem);
+    DeviceState *dev = DEVICE(md);
+
+    if (dev->id) {
+        vi->has_id = true;
+        vi->id = g_strdup(dev->id);
+    }
+
+    /* let the real device handle everything else */
+    vpc->fill_device_info(vmem, vi);
+
+    info->u.virtio_mem.data = vi;
+    info->type = MEMORY_DEVICE_INFO_KIND_VIRTIO_MEM;
+}
+
+static void virtio_mem_pci_size_change_notify(Notifier *notifier, void *data)
+{
+    VirtIOMEMPCI *pci_mem = container_of(notifier, VirtIOMEMPCI,
+                                         size_change_notifier);
+    DeviceState *dev = DEVICE(pci_mem);
+    const uint64_t * const size_p = data;
+    const char *id = NULL;
+
+    if (dev->id) {
+        id = g_strdup(dev->id);
+    }
+
+    qapi_event_send_memory_device_size_change(!!id, id, *size_p);
+}
+
+static void virtio_mem_pci_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    VirtioPCIClass *k = VIRTIO_PCI_CLASS(klass);
+    PCIDeviceClass *pcidev_k = PCI_DEVICE_CLASS(klass);
+    MemoryDeviceClass *mdc = MEMORY_DEVICE_CLASS(klass);
+
+    k->realize = virtio_mem_pci_realize;
+    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
+    pcidev_k->vendor_id = PCI_VENDOR_ID_REDHAT_QUMRANET;
+    pcidev_k->device_id = PCI_DEVICE_ID_VIRTIO_MEM;
+    pcidev_k->revision = VIRTIO_PCI_ABI_VERSION;
+    pcidev_k->class_id = PCI_CLASS_OTHERS;
+
+    mdc->get_addr = virtio_mem_pci_get_addr;
+    mdc->set_addr = virtio_mem_pci_set_addr;
+    mdc->get_plugged_size = virtio_mem_pci_get_plugged_size;
+    mdc->get_memory_region = virtio_mem_pci_get_memory_region;
+    mdc->fill_device_info = virtio_mem_pci_fill_device_info;
+}
+
+static void virtio_mem_pci_instance_init(Object *obj)
+{
+    VirtIOMEMPCI *dev = VIRTIO_MEM_PCI(obj);
+    VirtIOMEMClass *vmc;
+    VirtIOMEM *vmem;
+
+    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
+                                TYPE_VIRTIO_MEM);
+
+    dev->size_change_notifier.notify = virtio_mem_pci_size_change_notify;
+    vmem = VIRTIO_MEM(&dev->vdev);
+    vmc = VIRTIO_MEM_GET_CLASS(vmem);
+    /*
+     * We never remove the notifier again, as we expect both devices to
+     * disappear at the same time.
+     */
+    vmc->add_size_change_notifier(vmem, &dev->size_change_notifier);
+
+    object_property_add_alias(obj, VIRTIO_MEM_BLOCK_SIZE_PROP,
+                              OBJECT(&dev->vdev), VIRTIO_MEM_BLOCK_SIZE_PROP);
+    object_property_add_alias(obj, VIRTIO_MEM_SIZE_PROP, OBJECT(&dev->vdev),
+                              VIRTIO_MEM_SIZE_PROP);
+    object_property_add_alias(obj, VIRTIO_MEM_REQUESTED_SIZE_PROP,
+                              OBJECT(&dev->vdev),
+                              VIRTIO_MEM_REQUESTED_SIZE_PROP);
+}
+
+static const VirtioPCIDeviceTypeInfo virtio_mem_pci_info = {
+    .base_name = TYPE_VIRTIO_MEM_PCI,
+    .generic_name = "virtio-mem-pci",
+    .instance_size = sizeof(VirtIOMEMPCI),
+    .instance_init = virtio_mem_pci_instance_init,
+    .class_init = virtio_mem_pci_class_init,
+    .interfaces = (InterfaceInfo[]) {
+        { TYPE_MEMORY_DEVICE },
+        { }
+    },
+};
+
+static void virtio_mem_pci_register_types(void)
+{
+    virtio_pci_types_register(&virtio_mem_pci_info);
+}
+type_init(virtio_mem_pci_register_types)
diff --git a/hw/virtio/virtio-mem-pci.h b/hw/virtio/virtio-mem-pci.h
new file mode 100644
index 0000000000..b51a28b275
--- /dev/null
+++ b/hw/virtio/virtio-mem-pci.h
@@ -0,0 +1,34 @@
+/*
+ * Virtio MEM PCI device
+ *
+ * Copyright (C) 2020 Red Hat, Inc.
+ *
+ * Authors:
+ *  David Hildenbrand <david@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef QEMU_VIRTIO_MEM_PCI_H
+#define QEMU_VIRTIO_MEM_PCI_H
+
+#include "hw/virtio/virtio-pci.h"
+#include "hw/virtio/virtio-mem.h"
+
+typedef struct VirtIOMEMPCI VirtIOMEMPCI;
+
+/*
+ * virtio-mem-pci: This extends VirtioPCIProxy.
+ */
+#define TYPE_VIRTIO_MEM_PCI "virtio-mem-pci-base"
+#define VIRTIO_MEM_PCI(obj) \
+        OBJECT_CHECK(VirtIOMEMPCI, (obj), TYPE_VIRTIO_MEM_PCI)
+
+struct VirtIOMEMPCI {
+    VirtIOPCIProxy parent_obj;
+    VirtIOMEM vdev;
+    Notifier size_change_notifier;
+};
+
+#endif /* QEMU_VIRTIO_MEM_PCI_H */
diff --git a/hw/virtio/virtio-mem.c b/hw/virtio/virtio-mem.c
new file mode 100644
index 0000000000..65850530e7
--- /dev/null
+++ b/hw/virtio/virtio-mem.c
@@ -0,0 +1,873 @@
+/*
+ * Virtio MEM device
+ *
+ * Copyright (C) 2020 Red Hat, Inc.
+ *
+ * Authors:
+ *  David Hildenbrand <david@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+#include "qemu/iov.h"
+#include "qemu/cutils.h"
+#include "qemu/error-report.h"
+#include "qemu/units.h"
+#include "sysemu/numa.h"
+#include "sysemu/sysemu.h"
+#include "sysemu/reset.h"
+#include "hw/virtio/virtio.h"
+#include "hw/virtio/virtio-bus.h"
+#include "hw/virtio/virtio-access.h"
+#include "hw/virtio/virtio-mem.h"
+#include "qapi/error.h"
+#include "qapi/visitor.h"
+#include "exec/ram_addr.h"
+#include "migration/misc.h"
+#include "hw/boards.h"
+#include "hw/qdev-properties.h"
+#include "config-devices.h"
+#include "trace.h"
+
+/*
+ * Use QEMU_VMALLOC_ALIGN, so no THP will have to be split when unplugging
+ * memory (e.g., 2MB on x86_64).
+ */
+#define VIRTIO_MEM_MIN_BLOCK_SIZE QEMU_VMALLOC_ALIGN
+/*
+ * Size the usable region bigger than the requested size if possible. Esp.
+ * Linux guests will only add (aligned) memory blocks in case they fully
+ * fit into the usable region, but plug+online only a subset of the pages.
+ * The memory block size corresponds mostly to the section size.
+ *
+ * This allows e.g., to add 20MB with a section size of 128MB on x86_64, and
+ * a section size of 1GB on arm64 (as long as the start address is properly
+ * aligned, similar to ordinary DIMMs).
+ *
+ * We can change this at any time and maybe even make it configurable if
+ * necessary (as the section size can change). But it's more likely that the
+ * section size will rather get smaller and not bigger over time.
+ */
+#if defined(TARGET_X86_64) || defined(TARGET_I386)
+#define VIRTIO_MEM_USABLE_EXTENT (2 * (128 * MiB))
+#else
+#error VIRTIO_MEM_USABLE_EXTENT not defined
+#endif
+
+static bool virtio_mem_is_busy(void)
+{
+    /*
+     * Postcopy cannot handle concurrent discards and we don't want to migrate
+     * pages on-demand with stale content when plugging new blocks.
+     *
+     * For precopy, we don't want unplugged blocks in our migration stream, and
+     * when plugging new blocks, the page content might differ between source
+     * and destination (observable by the guest when not initializing pages
+     * after plugging them) until we're running on the destination (as we didn't
+     * migrate these blocks when they were unplugged).
+     */
+    return migration_in_incoming_postcopy() || !migration_is_idle();
+}
+
+static bool virtio_mem_test_bitmap(VirtIOMEM *vmem, uint64_t start_gpa,
+                                   uint64_t size, bool plugged)
+{
+    const unsigned long first_bit = (start_gpa - vmem->addr) / vmem->block_size;
+    const unsigned long last_bit = first_bit + (size / vmem->block_size) - 1;
+    unsigned long found_bit;
+
+    /* We fake a shorter bitmap to avoid searching too far. */
+    if (plugged) {
+        found_bit = find_next_zero_bit(vmem->bitmap, last_bit + 1, first_bit);
+    } else {
+        found_bit = find_next_bit(vmem->bitmap, last_bit + 1, first_bit);
+    }
+    return found_bit > last_bit;
+}
+
+static void virtio_mem_set_bitmap(VirtIOMEM *vmem, uint64_t start_gpa,
+                                  uint64_t size, bool plugged)
+{
+    const unsigned long bit = (start_gpa - vmem->addr) / vmem->block_size;
+    const unsigned long nbits = size / vmem->block_size;
+
+    if (plugged) {
+        bitmap_set(vmem->bitmap, bit, nbits);
+    } else {
+        bitmap_clear(vmem->bitmap, bit, nbits);
+    }
+}
+
+static void virtio_mem_send_response(VirtIOMEM *vmem, VirtQueueElement *elem,
+                                     struct virtio_mem_resp *resp)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(vmem);
+    VirtQueue *vq = vmem->vq;
+
+    trace_virtio_mem_send_response(le16_to_cpu(resp->type));
+    iov_from_buf(elem->in_sg, elem->in_num, 0, resp, sizeof(*resp));
+
+    virtqueue_push(vq, elem, sizeof(*resp));
+    virtio_notify(vdev, vq);
+}
+
+static void virtio_mem_send_response_simple(VirtIOMEM *vmem,
+                                            VirtQueueElement *elem,
+                                            uint16_t type)
+{
+    struct virtio_mem_resp resp = {
+        .type = cpu_to_le16(type),
+    };
+
+    virtio_mem_send_response(vmem, elem, &resp);
+}
+
+static bool virtio_mem_valid_range(VirtIOMEM *vmem, uint64_t gpa, uint64_t size)
+{
+    if (!QEMU_IS_ALIGNED(gpa, vmem->block_size)) {
+        return false;
+    }
+    if (gpa + size < gpa || !size) {
+        return false;
+    }
+    if (gpa < vmem->addr || gpa >= vmem->addr + vmem->usable_region_size) {
+        return false;
+    }
+    if (gpa + size > vmem->addr + vmem->usable_region_size) {
+        return false;
+    }
+    return true;
+}
+
+static int virtio_mem_set_block_state(VirtIOMEM *vmem, uint64_t start_gpa,
+                                      uint64_t size, bool plug)
+{
+    const uint64_t offset = start_gpa - vmem->addr;
+    int ret;
+
+    if (virtio_mem_is_busy()) {
+        return -EBUSY;
+    }
+
+    if (!plug) {
+        ret = ram_block_discard_range(vmem->memdev->mr.ram_block, offset, size);
+        if (ret) {
+            error_report("Unexpected error discarding RAM: %s",
+                         strerror(-ret));
+            return -EBUSY;
+        }
+    }
+    virtio_mem_set_bitmap(vmem, start_gpa, size, plug);
+    return 0;
+}
+
+static int virtio_mem_state_change_request(VirtIOMEM *vmem, uint64_t gpa,
+                                           uint16_t nb_blocks, bool plug)
+{
+    const uint64_t size = nb_blocks * vmem->block_size;
+    int ret;
+
+    if (!virtio_mem_valid_range(vmem, gpa, size)) {
+        return VIRTIO_MEM_RESP_ERROR;
+    }
+
+    if (plug && (vmem->size + size > vmem->requested_size)) {
+        return VIRTIO_MEM_RESP_NACK;
+    }
+
+    /* test if really all blocks are in the opposite state */
+    if (!virtio_mem_test_bitmap(vmem, gpa, size, !plug)) {
+        return VIRTIO_MEM_RESP_ERROR;
+    }
+
+    ret = virtio_mem_set_block_state(vmem, gpa, size, plug);
+    if (ret) {
+        return VIRTIO_MEM_RESP_BUSY;
+    }
+    if (plug) {
+        vmem->size += size;
+    } else {
+        vmem->size -= size;
+    }
+    notifier_list_notify(&vmem->size_change_notifiers, &vmem->size);
+    return VIRTIO_MEM_RESP_ACK;
+}
+
+static void virtio_mem_plug_request(VirtIOMEM *vmem, VirtQueueElement *elem,
+                                    struct virtio_mem_req *req)
+{
+    const uint64_t gpa = le64_to_cpu(req->u.plug.addr);
+    const uint16_t nb_blocks = le16_to_cpu(req->u.plug.nb_blocks);
+    uint16_t type;
+
+    trace_virtio_mem_plug_request(gpa, nb_blocks);
+    type = virtio_mem_state_change_request(vmem, gpa, nb_blocks, true);
+    virtio_mem_send_response_simple(vmem, elem, type);
+}
+
+static void virtio_mem_unplug_request(VirtIOMEM *vmem, VirtQueueElement *elem,
+                                      struct virtio_mem_req *req)
+{
+    const uint64_t gpa = le64_to_cpu(req->u.unplug.addr);
+    const uint16_t nb_blocks = le16_to_cpu(req->u.unplug.nb_blocks);
+    uint16_t type;
+
+    trace_virtio_mem_unplug_request(gpa, nb_blocks);
+    type = virtio_mem_state_change_request(vmem, gpa, nb_blocks, false);
+    virtio_mem_send_response_simple(vmem, elem, type);
+}
+
+static void virtio_mem_resize_usable_region(VirtIOMEM *vmem,
+                                            uint64_t requested_size,
+                                            bool can_shrink)
+{
+    uint64_t newsize = MIN(memory_region_size(&vmem->memdev->mr),
+                           requested_size + VIRTIO_MEM_USABLE_EXTENT);
+
+    if (!requested_size) {
+        newsize = 0;
+    }
+
+    if (newsize < vmem->usable_region_size && !can_shrink) {
+        return;
+    }
+
+    trace_virtio_mem_resized_usable_region(vmem->usable_region_size, newsize);
+    vmem->usable_region_size = newsize;
+}
+
+static int virtio_mem_unplug_all(VirtIOMEM *vmem)
+{
+    RAMBlock *rb = vmem->memdev->mr.ram_block;
+    int ret;
+
+    if (virtio_mem_is_busy()) {
+        return -EBUSY;
+    }
+
+    ret = ram_block_discard_range(rb, 0, qemu_ram_get_used_length(rb));
+    if (ret) {
+        error_report("Unexpected error discarding RAM: %s", strerror(-ret));
+        return -EBUSY;
+    }
+    bitmap_clear(vmem->bitmap, 0, vmem->bitmap_size);
+    if (vmem->size) {
+        vmem->size = 0;
+        notifier_list_notify(&vmem->size_change_notifiers, &vmem->size);
+    }
+    trace_virtio_mem_unplugged_all();
+    virtio_mem_resize_usable_region(vmem, vmem->requested_size, true);
+    return 0;
+}
+
+static void virtio_mem_unplug_all_request(VirtIOMEM *vmem,
+                                          VirtQueueElement *elem)
+{
+    trace_virtio_mem_unplug_all_request();
+    if (virtio_mem_unplug_all(vmem)) {
+        virtio_mem_send_response_simple(vmem, elem, VIRTIO_MEM_RESP_BUSY);
+    } else {
+        virtio_mem_send_response_simple(vmem, elem, VIRTIO_MEM_RESP_ACK);
+    }
+}
+
+static void virtio_mem_state_request(VirtIOMEM *vmem, VirtQueueElement *elem,
+                                     struct virtio_mem_req *req)
+{
+    const uint16_t nb_blocks = le16_to_cpu(req->u.state.nb_blocks);
+    const uint64_t gpa = le64_to_cpu(req->u.state.addr);
+    const uint64_t size = nb_blocks * vmem->block_size;
+    struct virtio_mem_resp resp = {
+        .type = cpu_to_le16(VIRTIO_MEM_RESP_ACK),
+    };
+
+    trace_virtio_mem_state_request(gpa, nb_blocks);
+    if (!virtio_mem_valid_range(vmem, gpa, size)) {
+        virtio_mem_send_response_simple(vmem, elem, VIRTIO_MEM_RESP_ERROR);
+        return;
+    }
+
+    if (virtio_mem_test_bitmap(vmem, gpa, size, true)) {
+        resp.u.state.state = cpu_to_le16(VIRTIO_MEM_STATE_PLUGGED);
+    } else if (virtio_mem_test_bitmap(vmem, gpa, size, false)) {
+        resp.u.state.state = cpu_to_le16(VIRTIO_MEM_STATE_UNPLUGGED);
+    } else {
+        resp.u.state.state = cpu_to_le16(VIRTIO_MEM_STATE_MIXED);
+    }
+    trace_virtio_mem_state_response(le16_to_cpu(resp.u.state.state));
+    virtio_mem_send_response(vmem, elem, &resp);
+}
+
+static void virtio_mem_handle_request(VirtIODevice *vdev, VirtQueue *vq)
+{
+    const int len = sizeof(struct virtio_mem_req);
+    VirtIOMEM *vmem = VIRTIO_MEM(vdev);
+    VirtQueueElement *elem;
+    struct virtio_mem_req req;
+    uint16_t type;
+
+    while (true) {
+        elem = virtqueue_pop(vq, sizeof(VirtQueueElement));
+        if (!elem) {
+            return;
+        }
+
+        if (iov_to_buf(elem->out_sg, elem->out_num, 0, &req, len) < len) {
+            virtio_error(vdev, "virtio-mem protocol violation: invalid request"
+                         " size: %d", len);
+            g_free(elem);
+            return;
+        }
+
+        if (iov_size(elem->in_sg, elem->in_num) <
+            sizeof(struct virtio_mem_resp)) {
+            virtio_error(vdev, "virtio-mem protocol violation: not enough space"
+                         " for response: %zu",
+                         iov_size(elem->in_sg, elem->in_num));
+            g_free(elem);
+            return;
+        }
+
+        type = le16_to_cpu(req.type);
+        switch (type) {
+        case VIRTIO_MEM_REQ_PLUG:
+            virtio_mem_plug_request(vmem, elem, &req);
+            break;
+        case VIRTIO_MEM_REQ_UNPLUG:
+            virtio_mem_unplug_request(vmem, elem, &req);
+            break;
+        case VIRTIO_MEM_REQ_UNPLUG_ALL:
+            virtio_mem_unplug_all_request(vmem, elem);
+            break;
+        case VIRTIO_MEM_REQ_STATE:
+            virtio_mem_state_request(vmem, elem, &req);
+            break;
+        default:
+            virtio_error(vdev, "virtio-mem protocol violation: unknown request"
+                         " type: %d", type);
+            g_free(elem);
+            return;
+        }
+
+        g_free(elem);
+    }
+}
+
+static void virtio_mem_get_config(VirtIODevice *vdev, uint8_t *config_data)
+{
+    VirtIOMEM *vmem = VIRTIO_MEM(vdev);
+    struct virtio_mem_config *config = (void *) config_data;
+
+    config->block_size = cpu_to_le64(vmem->block_size);
+    config->node_id = cpu_to_le16(vmem->node);
+    config->requested_size = cpu_to_le64(vmem->requested_size);
+    config->plugged_size = cpu_to_le64(vmem->size);
+    config->addr = cpu_to_le64(vmem->addr);
+    config->region_size = cpu_to_le64(memory_region_size(&vmem->memdev->mr));
+    config->usable_region_size = cpu_to_le64(vmem->usable_region_size);
+}
+
+static uint64_t virtio_mem_get_features(VirtIODevice *vdev, uint64_t features,
+                                        Error **errp)
+{
+    MachineState *ms = MACHINE(qdev_get_machine());
+
+    if (ms->numa_state) {
+#if defined(CONFIG_ACPI)
+        virtio_add_feature(&features, VIRTIO_MEM_F_ACPI_PXM);
+#endif
+    }
+    return features;
+}
+
+static void virtio_mem_system_reset(void *opaque)
+{
+    VirtIOMEM *vmem = VIRTIO_MEM(opaque);
+
+    /*
+     * During usual resets, we will unplug all memory and shrink the usable
+     * region size. This is, however, not possible in all scenarios. Then,
+     * the guest has to deal with this manually (VIRTIO_MEM_REQ_UNPLUG_ALL).
+     */
+    virtio_mem_unplug_all(vmem);
+}
+
+static void virtio_mem_device_realize(DeviceState *dev, Error **errp)
+{
+    MachineState *ms = MACHINE(qdev_get_machine());
+    int nb_numa_nodes = ms->numa_state ? ms->numa_state->num_nodes : 0;
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VirtIOMEM *vmem = VIRTIO_MEM(dev);
+    uint64_t page_size;
+    RAMBlock *rb;
+    int ret;
+
+    if (!vmem->memdev) {
+        error_setg(errp, "'%s' property is not set", VIRTIO_MEM_MEMDEV_PROP);
+        return;
+    } else if (host_memory_backend_is_mapped(vmem->memdev)) {
+        char *path = object_get_canonical_path_component(OBJECT(vmem->memdev));
+
+        error_setg(errp, "'%s' property specifies a busy memdev: %s",
+                   VIRTIO_MEM_MEMDEV_PROP, path);
+        g_free(path);
+        return;
+    } else if (!memory_region_is_ram(&vmem->memdev->mr) ||
+        memory_region_is_rom(&vmem->memdev->mr) ||
+        !vmem->memdev->mr.ram_block) {
+        error_setg(errp, "'%s' property specifies an unsupported memdev",
+                   VIRTIO_MEM_MEMDEV_PROP);
+        return;
+    }
+
+    if ((nb_numa_nodes && vmem->node >= nb_numa_nodes) ||
+        (!nb_numa_nodes && vmem->node)) {
+        error_setg(errp, "'%s' property has value '%" PRIu32 "', which exceeds"
+                   "the number of numa nodes: %d", VIRTIO_MEM_NODE_PROP,
+                   vmem->node, nb_numa_nodes ? nb_numa_nodes : 1);
+        return;
+    }
+
+    if (enable_mlock) {
+        error_setg(errp, "Incompatible with mlock");
+        return;
+    }
+
+    rb = vmem->memdev->mr.ram_block;
+    page_size = qemu_ram_pagesize(rb);
+
+    if (vmem->block_size < page_size) {
+        error_setg(errp, "'%s' property has to be at least the page size (0x%"
+                   PRIx64 ")", VIRTIO_MEM_BLOCK_SIZE_PROP, page_size);
+        return;
+    } else if (!QEMU_IS_ALIGNED(vmem->requested_size, vmem->block_size)) {
+        error_setg(errp, "'%s' property has to be multiples of '%s' (0x%" PRIx64
+                   ")", VIRTIO_MEM_REQUESTED_SIZE_PROP,
+                   VIRTIO_MEM_BLOCK_SIZE_PROP, vmem->block_size);
+        return;
+    } else if (!QEMU_IS_ALIGNED(memory_region_size(&vmem->memdev->mr),
+                                vmem->block_size)) {
+        error_setg(errp, "'%s' property memdev size has to be multiples of"
+                   "'%s' (0x%" PRIx64 ")", VIRTIO_MEM_MEMDEV_PROP,
+                   VIRTIO_MEM_BLOCK_SIZE_PROP, vmem->block_size);
+        return;
+    }
+
+    if (ram_block_discard_require(true)) {
+        error_setg(errp, "Discarding RAM is disabled");
+        return;
+    }
+
+    ret = ram_block_discard_range(rb, 0, qemu_ram_get_used_length(rb));
+    if (ret) {
+        error_setg_errno(errp, -ret, "Unexpected error discarding RAM");
+        ram_block_discard_require(false);
+        return;
+    }
+
+    virtio_mem_resize_usable_region(vmem, vmem->requested_size, true);
+
+    vmem->bitmap_size = memory_region_size(&vmem->memdev->mr) /
+                        vmem->block_size;
+    vmem->bitmap = bitmap_new(vmem->bitmap_size);
+
+    virtio_init(vdev, TYPE_VIRTIO_MEM, VIRTIO_ID_MEM,
+                sizeof(struct virtio_mem_config));
+    vmem->vq = virtio_add_queue(vdev, 128, virtio_mem_handle_request);
+
+    host_memory_backend_set_mapped(vmem->memdev, true);
+    vmstate_register_ram(&vmem->memdev->mr, DEVICE(vmem));
+    qemu_register_reset(virtio_mem_system_reset, vmem);
+    precopy_add_notifier(&vmem->precopy_notifier);
+}
+
+static void virtio_mem_device_unrealize(DeviceState *dev)
+{
+    VirtIODevice *vdev = VIRTIO_DEVICE(dev);
+    VirtIOMEM *vmem = VIRTIO_MEM(dev);
+
+    precopy_remove_notifier(&vmem->precopy_notifier);
+    qemu_unregister_reset(virtio_mem_system_reset, vmem);
+    vmstate_unregister_ram(&vmem->memdev->mr, DEVICE(vmem));
+    host_memory_backend_set_mapped(vmem->memdev, false);
+    virtio_del_queue(vdev, 0);
+    virtio_cleanup(vdev);
+    g_free(vmem->bitmap);
+    ram_block_discard_require(false);
+}
+
+static int virtio_mem_restore_unplugged(VirtIOMEM *vmem)
+{
+    RAMBlock *rb = vmem->memdev->mr.ram_block;
+    unsigned long first_zero_bit, last_zero_bit;
+    uint64_t offset, length;
+    int ret;
+
+    /* Find consecutive unplugged blocks and discard the consecutive range. */
+    first_zero_bit = find_first_zero_bit(vmem->bitmap, vmem->bitmap_size);
+    while (first_zero_bit < vmem->bitmap_size) {
+        offset = first_zero_bit * vmem->block_size;
+        last_zero_bit = find_next_bit(vmem->bitmap, vmem->bitmap_size,
+                                      first_zero_bit + 1) - 1;
+        length = (last_zero_bit - first_zero_bit + 1) * vmem->block_size;
+
+        ret = ram_block_discard_range(rb, offset, length);
+        if (ret) {
+            error_report("Unexpected error discarding RAM: %s",
+                         strerror(-ret));
+            return -EINVAL;
+        }
+        first_zero_bit = find_next_zero_bit(vmem->bitmap, vmem->bitmap_size,
+                                            last_zero_bit + 2);
+    }
+    return 0;
+}
+
+static int virtio_mem_post_load(void *opaque, int version_id)
+{
+    if (migration_in_incoming_postcopy()) {
+        return 0;
+    }
+
+    return virtio_mem_restore_unplugged(VIRTIO_MEM(opaque));
+}
+
+typedef struct VirtIOMEMMigSanityChecks {
+    VirtIOMEM *parent;
+    uint64_t addr;
+    uint64_t region_size;
+    uint64_t block_size;
+    uint32_t node;
+} VirtIOMEMMigSanityChecks;
+
+static int virtio_mem_mig_sanity_checks_pre_save(void *opaque)
+{
+    VirtIOMEMMigSanityChecks *tmp = opaque;
+    VirtIOMEM *vmem = tmp->parent;
+
+    tmp->addr = vmem->addr;
+    tmp->region_size = memory_region_size(&vmem->memdev->mr);
+    tmp->block_size = vmem->block_size;
+    tmp->node = vmem->node;
+    return 0;
+}
+
+static int virtio_mem_mig_sanity_checks_post_load(void *opaque, int version_id)
+{
+    VirtIOMEMMigSanityChecks *tmp = opaque;
+    VirtIOMEM *vmem = tmp->parent;
+    const uint64_t new_region_size = memory_region_size(&vmem->memdev->mr);
+
+    if (tmp->addr != vmem->addr) {
+        error_report("Property '%s' changed from 0x%" PRIx64 " to 0x%" PRIx64,
+                     VIRTIO_MEM_ADDR_PROP, tmp->addr, vmem->addr);
+        return -EINVAL;
+    }
+    /*
+     * Note: Preparation for resizeable memory regions. The maximum size
+     * of the memory region must not change during migration.
+     */
+    if (tmp->region_size != new_region_size) {
+        error_report("Property '%s' size changed from 0x%" PRIx64 " to 0x%"
+                     PRIx64, VIRTIO_MEM_MEMDEV_PROP, tmp->region_size,
+                     new_region_size);
+        return -EINVAL;
+    }
+    if (tmp->block_size != vmem->block_size) {
+        error_report("Property '%s' changed from 0x%" PRIx64 " to 0x%" PRIx64,
+                     VIRTIO_MEM_BLOCK_SIZE_PROP, tmp->block_size,
+                     vmem->block_size);
+        return -EINVAL;
+    }
+    if (tmp->node != vmem->node) {
+        error_report("Property '%s' changed from %" PRIu32 " to %" PRIu32,
+                     VIRTIO_MEM_NODE_PROP, tmp->node, vmem->node);
+        return -EINVAL;
+    }
+    return 0;
+}
+
+static const VMStateDescription vmstate_virtio_mem_sanity_checks = {
+    .name = "virtio-mem-device/sanity-checks",
+    .pre_save = virtio_mem_mig_sanity_checks_pre_save,
+    .post_load = virtio_mem_mig_sanity_checks_post_load,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT64(addr, VirtIOMEMMigSanityChecks),
+        VMSTATE_UINT64(region_size, VirtIOMEMMigSanityChecks),
+        VMSTATE_UINT64(block_size, VirtIOMEMMigSanityChecks),
+        VMSTATE_UINT32(node, VirtIOMEMMigSanityChecks),
+        VMSTATE_END_OF_LIST(),
+    },
+};
+
+static const VMStateDescription vmstate_virtio_mem_device = {
+    .name = "virtio-mem-device",
+    .minimum_version_id = 1,
+    .version_id = 1,
+    .post_load = virtio_mem_post_load,
+    .fields = (VMStateField[]) {
+        VMSTATE_WITH_TMP(VirtIOMEM, VirtIOMEMMigSanityChecks,
+                         vmstate_virtio_mem_sanity_checks),
+        VMSTATE_UINT64(usable_region_size, VirtIOMEM),
+        VMSTATE_UINT64(size, VirtIOMEM),
+        VMSTATE_UINT64(requested_size, VirtIOMEM),
+        VMSTATE_BITMAP(bitmap, VirtIOMEM, 0, bitmap_size),
+        VMSTATE_END_OF_LIST()
+    },
+};
+
+static const VMStateDescription vmstate_virtio_mem = {
+    .name = "virtio-mem",
+    .minimum_version_id = 1,
+    .version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_VIRTIO_DEVICE,
+        VMSTATE_END_OF_LIST()
+    },
+};
+
+static void virtio_mem_fill_device_info(const VirtIOMEM *vmem,
+                                        VirtioMEMDeviceInfo *vi)
+{
+    vi->memaddr = vmem->addr;
+    vi->node = vmem->node;
+    vi->requested_size = vmem->requested_size;
+    vi->size = vmem->size;
+    vi->max_size = memory_region_size(&vmem->memdev->mr);
+    vi->block_size = vmem->block_size;
+    vi->memdev = object_get_canonical_path(OBJECT(vmem->memdev));
+}
+
+static MemoryRegion *virtio_mem_get_memory_region(VirtIOMEM *vmem, Error **errp)
+{
+    if (!vmem->memdev) {
+        error_setg(errp, "'%s' property must be set", VIRTIO_MEM_MEMDEV_PROP);
+        return NULL;
+    }
+
+    return &vmem->memdev->mr;
+}
+
+static void virtio_mem_add_size_change_notifier(VirtIOMEM *vmem,
+                                                Notifier *notifier)
+{
+    notifier_list_add(&vmem->size_change_notifiers, notifier);
+}
+
+static void virtio_mem_remove_size_change_notifier(VirtIOMEM *vmem,
+                                                   Notifier *notifier)
+{
+    notifier_remove(notifier);
+}
+
+static void virtio_mem_get_size(Object *obj, Visitor *v, const char *name,
+                                void *opaque, Error **errp)
+{
+    const VirtIOMEM *vmem = VIRTIO_MEM(obj);
+    uint64_t value = vmem->size;
+
+    visit_type_size(v, name, &value, errp);
+}
+
+static void virtio_mem_get_requested_size(Object *obj, Visitor *v,
+                                          const char *name, void *opaque,
+                                          Error **errp)
+{
+    const VirtIOMEM *vmem = VIRTIO_MEM(obj);
+    uint64_t value = vmem->requested_size;
+
+    visit_type_size(v, name, &value, errp);
+}
+
+static void virtio_mem_set_requested_size(Object *obj, Visitor *v,
+                                          const char *name, void *opaque,
+                                          Error **errp)
+{
+    VirtIOMEM *vmem = VIRTIO_MEM(obj);
+    Error *err = NULL;
+    uint64_t value;
+
+    visit_type_size(v, name, &value, &err);
+    if (err) {
+        error_propagate(errp, err);
+        return;
+    }
+
+    /*
+     * The block size and memory backend are not fixed until the device was
+     * realized. realize() will verify these properties then.
+     */
+    if (DEVICE(obj)->realized) {
+        if (!QEMU_IS_ALIGNED(value, vmem->block_size)) {
+            error_setg(errp, "'%s' has to be multiples of '%s' (0x%" PRIx64
+                       ")", name, VIRTIO_MEM_BLOCK_SIZE_PROP,
+                       vmem->block_size);
+            return;
+        } else if (value > memory_region_size(&vmem->memdev->mr)) {
+            error_setg(errp, "'%s' cannot exceed the memory backend size"
+                       "(0x%" PRIx64 ")", name,
+                       memory_region_size(&vmem->memdev->mr));
+            return;
+        }
+
+        if (value != vmem->requested_size) {
+            virtio_mem_resize_usable_region(vmem, value, false);
+            vmem->requested_size = value;
+        }
+        /*
+         * Trigger a config update so the guest gets notified. We trigger
+         * even if the size didn't change (especially helpful for debugging).
+         */
+        virtio_notify_config(VIRTIO_DEVICE(vmem));
+    } else {
+        vmem->requested_size = value;
+    }
+}
+
+static void virtio_mem_get_block_size(Object *obj, Visitor *v, const char *name,
+                                      void *opaque, Error **errp)
+{
+    const VirtIOMEM *vmem = VIRTIO_MEM(obj);
+    uint64_t value = vmem->block_size;
+
+    visit_type_size(v, name, &value, errp);
+}
+
+static void virtio_mem_set_block_size(Object *obj, Visitor *v, const char *name,
+                                      void *opaque, Error **errp)
+{
+    VirtIOMEM *vmem = VIRTIO_MEM(obj);
+    Error *err = NULL;
+    uint64_t value;
+
+    if (DEVICE(obj)->realized) {
+        error_setg(errp, "'%s' cannot be changed", name);
+        return;
+    }
+
+    visit_type_size(v, name, &value, &err);
+    if (err) {
+        error_propagate(errp, err);
+        return;
+    }
+
+    if (value < VIRTIO_MEM_MIN_BLOCK_SIZE) {
+        error_setg(errp, "'%s' property has to be at least 0x%" PRIx32, name,
+                   VIRTIO_MEM_MIN_BLOCK_SIZE);
+        return;
+    } else if (!is_power_of_2(value)) {
+        error_setg(errp, "'%s' property has to be a power of two", name);
+        return;
+    }
+    vmem->block_size = value;
+}
+
+static void virtio_mem_precopy_exclude_unplugged(VirtIOMEM *vmem)
+{
+    void * const host = qemu_ram_get_host_addr(vmem->memdev->mr.ram_block);
+    unsigned long first_zero_bit, last_zero_bit;
+    uint64_t offset, length;
+
+    /*
+     * Find consecutive unplugged blocks and exclude them from migration.
+     *
+     * Note: Blocks cannot get (un)plugged during precopy, no locking needed.
+     */
+    first_zero_bit = find_first_zero_bit(vmem->bitmap, vmem->bitmap_size);
+    while (first_zero_bit < vmem->bitmap_size) {
+        offset = first_zero_bit * vmem->block_size;
+        last_zero_bit = find_next_bit(vmem->bitmap, vmem->bitmap_size,
+                                      first_zero_bit + 1) - 1;
+        length = (last_zero_bit - first_zero_bit + 1) * vmem->block_size;
+
+        qemu_guest_free_page_hint(host + offset, length);
+        first_zero_bit = find_next_zero_bit(vmem->bitmap, vmem->bitmap_size,
+                                            last_zero_bit + 2);
+    }
+}
+
+static int virtio_mem_precopy_notify(NotifierWithReturn *n, void *data)
+{
+    VirtIOMEM *vmem = container_of(n, VirtIOMEM, precopy_notifier);
+    PrecopyNotifyData *pnd = data;
+
+    switch (pnd->reason) {
+    case PRECOPY_NOTIFY_SETUP:
+        precopy_enable_free_page_optimization();
+        break;
+    case PRECOPY_NOTIFY_AFTER_BITMAP_SYNC:
+        virtio_mem_precopy_exclude_unplugged(vmem);
+        break;
+    default:
+        break;
+    }
+
+    return 0;
+}
+
+static void virtio_mem_instance_init(Object *obj)
+{
+    VirtIOMEM *vmem = VIRTIO_MEM(obj);
+
+    vmem->block_size = VIRTIO_MEM_MIN_BLOCK_SIZE;
+    notifier_list_init(&vmem->size_change_notifiers);
+    vmem->precopy_notifier.notify = virtio_mem_precopy_notify;
+
+    object_property_add(obj, VIRTIO_MEM_SIZE_PROP, "size", virtio_mem_get_size,
+                        NULL, NULL, NULL);
+    object_property_add(obj, VIRTIO_MEM_REQUESTED_SIZE_PROP, "size",
+                        virtio_mem_get_requested_size,
+                        virtio_mem_set_requested_size, NULL, NULL);
+    object_property_add(obj, VIRTIO_MEM_BLOCK_SIZE_PROP, "size",
+                        virtio_mem_get_block_size, virtio_mem_set_block_size,
+                        NULL, NULL);
+}
+
+static Property virtio_mem_properties[] = {
+    DEFINE_PROP_UINT64(VIRTIO_MEM_ADDR_PROP, VirtIOMEM, addr, 0),
+    DEFINE_PROP_UINT32(VIRTIO_MEM_NODE_PROP, VirtIOMEM, node, 0),
+    DEFINE_PROP_LINK(VIRTIO_MEM_MEMDEV_PROP, VirtIOMEM, memdev,
+                     TYPE_MEMORY_BACKEND, HostMemoryBackend *),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void virtio_mem_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
+    VirtIOMEMClass *vmc = VIRTIO_MEM_CLASS(klass);
+
+    device_class_set_props(dc, virtio_mem_properties);
+    dc->vmsd = &vmstate_virtio_mem;
+
+    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
+    vdc->realize = virtio_mem_device_realize;
+    vdc->unrealize = virtio_mem_device_unrealize;
+    vdc->get_config = virtio_mem_get_config;
+    vdc->get_features = virtio_mem_get_features;
+    vdc->vmsd = &vmstate_virtio_mem_device;
+
+    vmc->fill_device_info = virtio_mem_fill_device_info;
+    vmc->get_memory_region = virtio_mem_get_memory_region;
+    vmc->add_size_change_notifier = virtio_mem_add_size_change_notifier;
+    vmc->remove_size_change_notifier = virtio_mem_remove_size_change_notifier;
+}
+
+static const TypeInfo virtio_mem_info = {
+    .name = TYPE_VIRTIO_MEM,
+    .parent = TYPE_VIRTIO_DEVICE,
+    .instance_size = sizeof(VirtIOMEM),
+    .instance_init = virtio_mem_instance_init,
+    .class_init = virtio_mem_class_init,
+    .class_size = sizeof(VirtIOMEMClass),
+};
+
+static void virtio_register_types(void)
+{
+    type_register_static(&virtio_mem_info);
+}
+
+type_init(virtio_register_types)
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index 7bc8c1c056..8554cf2a03 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -1107,6 +1107,18 @@ static AddressSpace *virtio_pci_get_dma_as(DeviceState *d)
     return pci_get_address_space(dev);
 }
 
+static bool virtio_pci_queue_enabled(DeviceState *d, int n)
+{
+    VirtIOPCIProxy *proxy = VIRTIO_PCI(d);
+    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
+
+    if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) {
+        return proxy->vqs[vdev->queue_sel].enabled;
+    }
+
+    return virtio_queue_enabled(vdev, n);
+}
+
 static int virtio_pci_add_mem_cap(VirtIOPCIProxy *proxy,
                                    struct virtio_pci_cap *cap)
 {
@@ -2064,6 +2076,7 @@ static void virtio_pci_bus_class_init(ObjectClass *klass, void *data)
     k->ioeventfd_enabled = virtio_pci_ioeventfd_enabled;
     k->ioeventfd_assign = virtio_pci_ioeventfd_assign;
     k->get_dma_as = virtio_pci_get_dma_as;
+    k->queue_enabled = virtio_pci_queue_enabled;
 }
 
 static const TypeInfo virtio_pci_bus_info = {
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index cc9c9dc162..5bd2a2f621 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -3286,6 +3286,12 @@ hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n)
 
 bool virtio_queue_enabled(VirtIODevice *vdev, int n)
 {
+    BusState *qbus = qdev_get_parent_bus(DEVICE(vdev));
+    VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
+
+    if (k->queue_enabled) {
+        return k->queue_enabled(qbus->parent, n);
+    }
     return virtio_queue_get_desc_addr(vdev, n) != 0;
 }