Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging

vhost, virtio, pci, pc

Fixes all over the place.
virtio dataplane migration support.
Old q35 machine types removed.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

# gpg: Signature made Thu 25 Feb 2016 11:16:46 GMT using RSA key ID D28D5469
# gpg: Good signature from "Michael S. Tsirkin <mst@kernel.org>"
# gpg:                 aka "Michael S. Tsirkin <mst@redhat.com>"

* remotes/mst/tags/for_upstream: (21 commits)
  q35: No need to check gigabyte_align
  q35: Remove unused q35-acpi-dsdt.aml file
  ich9: Remove enable_tco arguments from init functions
  machine: Remove no_tco field
  q35: Remove old machine versions
  tests/vhost-user-bridge: fix build on 32 bit systems
  vring: remove
  virtio-scsi: do not use vring in dataplane
  virtio-blk: do not use vring in dataplane
  virtio-blk: fix "disabled data plane" mode
  virtio: export vring_notify as virtio_should_notify
  virtio: add AioContext-specific function for host notifiers
  vring: make vring_enable_notification return void
  block-migration: acquire AioContext as necessary
  pci core: function pci_bus_init() cleanup
  pci core: function pci_host_bus_register() cleanup
  balloon: Use only 'pc-dimm' type dimm for ballooning
  virtio-balloon: rewrite get_current_ram_size()
  move get_current_ram_size to virtio-balloon.c
  vhost-user: don't merge regions with different fds
  ...

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

38 files changed, 314 insertions, 1327 deletions

diff --git a/Makefile b/Makefile
index 16db398..70e3ebc 100644
--- a/Makefile
+++ b/Makefile
@@ -391,7 +391,7 @@ bepo    cz
 ifdef INSTALL_BLOBS
 BLOBS=bios.bin bios-256k.bin sgabios.bin vgabios.bin vgabios-cirrus.bin \
 vgabios-stdvga.bin vgabios-vmware.bin vgabios-qxl.bin vgabios-virtio.bin \
-acpi-dsdt.aml q35-acpi-dsdt.aml \
+acpi-dsdt.aml \
 ppc_rom.bin openbios-sparc32 openbios-sparc64 openbios-ppc QEMU,tcx.bin QEMU,cgthree.bin \
 pxe-e1000.rom pxe-eepro100.rom pxe-ne2k_pci.rom \
 pxe-pcnet.rom pxe-rtl8139.rom pxe-virtio.rom \
diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c
index 603068b..6675535 100644
--- a/hw/acpi/aml-build.c
+++ b/hw/acpi/aml-build.c
@@ -1451,7 +1451,7 @@ build_header(GArray *linker, GArray *table_data,
     h->checksum = 0;
     /* Checksum to be filled in by Guest linker */
     bios_linker_loader_add_checksum(linker, ACPI_BUILD_TABLE_FILE,
-                                    table_data->data, h, len, &h->checksum);
+                                    table_data, h, len, &h->checksum);
 }
 
 void *acpi_data_push(GArray *table_data, unsigned size)
diff --git a/hw/acpi/bios-linker-loader.c b/hw/acpi/bios-linker-loader.c
index e04d60a..ace9abb 100644
--- a/hw/acpi/bios-linker-loader.c
+++ b/hw/acpi/bios-linker-loader.c
@@ -25,6 +25,13 @@
 
 #include "qemu/bswap.h"
 
+/*
+ * Linker/loader is a paravirtualized interface that passes commands to guest.
+ * The commands can be used to request guest to
+ * - allocate memory chunks and initialize them from QEMU FW CFG files
+ * - link allocated chunks by storing pointer to one chunk into another
+ * - calculate ACPI checksum of part of the chunk and store into same chunk
+ */
 #define BIOS_LINKER_LOADER_FILESZ FW_CFG_MAX_FILE_PATH
 
 struct BiosLinkerLoaderEntry {
@@ -88,6 +95,12 @@ enum {
     BIOS_LINKER_LOADER_ALLOC_ZONE_FSEG = 0x2,
 };
 
+/*
+ * bios_linker_loader_init: allocate a new linker file blob array.
+ *
+ * After initialization, linker commands can be added, and will
+ * be stored in the array.
+ */
 GArray *bios_linker_loader_init(void)
 {
     return g_array_new(false, true /* clear */, 1);
@@ -99,6 +112,16 @@ void *bios_linker_loader_cleanup(GArray *linker)
     return g_array_free(linker, false);
 }
 
+/*
+ * bios_linker_loader_alloc: ask guest to load file into guest memory.
+ *
+ * @linker: linker file blob array
+ * @file: file to be loaded
+ * @alloc_align: required minimal alignment in bytes. Must be a power of 2.
+ * @alloc_fseg: request allocation in FSEG zone (useful for the RSDP ACPI table)
+ *
+ * Note: this command must precede any other linker command using this file.
+ */
 void bios_linker_loader_alloc(GArray *linker,
                               const char *file,
                               uint32_t alloc_align,
@@ -106,6 +129,8 @@ void bios_linker_loader_alloc(GArray *linker,
 {
     BiosLinkerLoaderEntry entry;
 
+    assert(!(alloc_align & (alloc_align - 1)));
+
     memset(&entry, 0, sizeof entry);
     strncpy(entry.alloc.file, file, sizeof entry.alloc.file - 1);
     entry.command = cpu_to_le32(BIOS_LINKER_LOADER_COMMAND_ALLOCATE);
@@ -118,23 +143,77 @@ void bios_linker_loader_alloc(GArray *linker,
     g_array_prepend_vals(linker, &entry, sizeof entry);
 }
 
+/*
+ * bios_linker_loader_add_checksum: ask guest to add checksum of file data
+ * into (same) file at the specified pointer.
+ *
+ * Checksum calculation simply sums -X for each byte X in the range
+ * using 8-bit math (i.e. ACPI checksum).
+ *
+ * @linker: linker file blob array
+ * @file: file that includes the checksum to be calculated
+ *        and the data to be checksummed
+ * @table: @file blob contents
+ * @start, @size: range of data to checksum
+ * @checksum: location of the checksum to be patched within file blob
+ *
+ * Notes:
+ * - checksum byte initial value must have been pushed into @table
+ *   and reside at address @checksum.
+ * - @size bytes must have been pushed into @table and reside at address
+ *   @start.
+ * - Guest calculates checksum of specified range of data, result is added to
+ *   initial value at @checksum into copy of @file in Guest memory.
+ * - Range might include the checksum itself.
+ * - To avoid confusion, caller must always put 0x0 at @checksum.
+ * - @file must be loaded into Guest memory using bios_linker_loader_alloc
+ */
 void bios_linker_loader_add_checksum(GArray *linker, const char *file,
-                                     void *table,
+                                     GArray *table,
                                      void *start, unsigned size,
                                      uint8_t *checksum)
 {
     BiosLinkerLoaderEntry entry;
+    ptrdiff_t checksum_offset = (gchar *)checksum - table->data;
+    ptrdiff_t start_offset = (gchar *)start - table->data;
+
+    assert(checksum_offset >= 0);
+    assert(start_offset >= 0);
+    assert(checksum_offset + 1 <= table->len);
+    assert(start_offset + size <= table->len);
+    assert(*checksum == 0x0);
 
     memset(&entry, 0, sizeof entry);
     strncpy(entry.cksum.file, file, sizeof entry.cksum.file - 1);
     entry.command = cpu_to_le32(BIOS_LINKER_LOADER_COMMAND_ADD_CHECKSUM);
-    entry.cksum.offset = cpu_to_le32(checksum - (uint8_t *)table);
-    entry.cksum.start = cpu_to_le32((uint8_t *)start - (uint8_t *)table);
+    entry.cksum.offset = cpu_to_le32(checksum_offset);
+    entry.cksum.start = cpu_to_le32(start_offset);
     entry.cksum.length = cpu_to_le32(size);
 
     g_array_append_vals(linker, &entry, sizeof entry);
 }
 
+/*
+ * bios_linker_loader_add_pointer: ask guest to add address of source file
+ * into destination file at the specified pointer.
+ *
+ * @linker: linker file blob array
+ * @dest_file: destination file that must be changed
+ * @src_file: source file who's address must be taken
+ * @table: @dest_file blob contents array
+ * @pointer: location of the pointer to be patched within destination file blob
+ * @pointer_size: size of pointer to be patched, in bytes
+ *
+ * Notes:
+ * - @pointer_size bytes must have been pushed into @table
+ *   and reside at address @pointer.
+ * - Guest address is added to initial value at @pointer
+ *   into copy of @dest_file in Guest memory.
+ *   e.g. to get start of src_file in guest memory, put 0x0 there
+ *   to get address of a field at offset 0x10 in src_file, put 0x10 there
+ * - Both @dest_file and @src_file must be
+ *   loaded into Guest memory using bios_linker_loader_alloc
+ */
 void bios_linker_loader_add_pointer(GArray *linker,
                                     const char *dest_file,
                                     const char *src_file,
@@ -142,7 +221,10 @@ void bios_linker_loader_add_pointer(GArray *linker,
                                     uint8_t pointer_size)
 {
     BiosLinkerLoaderEntry entry;
-    size_t offset = (gchar *)pointer - table->data;
+    ptrdiff_t offset = (gchar *)pointer - table->data;
+
+    assert(offset >= 0);
+    assert(offset + pointer_size <= table->len);
 
     memset(&entry, 0, sizeof entry);
     strncpy(entry.pointer.dest_file, dest_file,
@@ -150,7 +232,6 @@ void bios_linker_loader_add_pointer(GArray *linker,
     strncpy(entry.pointer.src_file, src_file,
             sizeof entry.pointer.src_file - 1);
     entry.command = cpu_to_le32(BIOS_LINKER_LOADER_COMMAND_ADD_POINTER);
-    assert(table->len >= offset + pointer_size);
     entry.pointer.offset = cpu_to_le32(offset);
     entry.pointer.size = pointer_size;
     assert(pointer_size == 1 || pointer_size == 2 ||
diff --git a/hw/acpi/ich9.c b/hw/acpi/ich9.c
index 4f9ce05..7220254 100644
--- a/hw/acpi/ich9.c
+++ b/hw/acpi/ich9.c
@@ -240,7 +240,7 @@ static void pm_powerdown_req(Notifier *n, void *opaque)
 }
 
 void ich9_pm_init(PCIDevice *lpc_pci, ICH9LPCPMRegs *pm,
-                  bool smm_enabled, bool enable_tco,
+                  bool smm_enabled,
                   qemu_irq sci_irq)
 {
     memory_region_init(&pm->io, OBJECT(lpc_pci), "ich9-pm", ICH9_PMIO_SIZE);
@@ -264,10 +264,8 @@ void ich9_pm_init(PCIDevice *lpc_pci, ICH9LPCPMRegs *pm,
 
     pm->smm_enabled = smm_enabled;
 
-    pm->enable_tco = enable_tco;
-    if (pm->enable_tco) {
-        acpi_pm_tco_init(&pm->tco_regs, &pm->io);
-    }
+    pm->enable_tco = true;
+    acpi_pm_tco_init(&pm->tco_regs, &pm->io);
 
     pm->irq = sci_irq;
     qemu_register_reset(pm_reset, pm);
diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
index 8cf9a21..b8b3ece 100644
--- a/hw/arm/virt-acpi-build.c
+++ b/hw/arm/virt-acpi-build.c
@@ -359,7 +359,8 @@ build_rsdp(GArray *rsdp_table, GArray *linker, unsigned rsdt)
     rsdp->checksum = 0;
     /* Checksum to be filled by Guest linker */
     bios_linker_loader_add_checksum(linker, ACPI_BUILD_RSDP_FILE,
-                                    rsdp, rsdp, sizeof *rsdp, &rsdp->checksum);
+                                    rsdp_table, rsdp, sizeof *rsdp,
+                                    &rsdp->checksum);
 
     return rsdp_table;
 }
diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c
index 0d99781..36f3d2b 100644
--- a/hw/block/dataplane/virtio-blk.c
+++ b/hw/block/dataplane/virtio-blk.c
@@ -18,8 +18,6 @@
 #include "qemu/thread.h"
 #include "qemu/error-report.h"
 #include "hw/virtio/virtio-access.h"
-#include "hw/virtio/dataplane/vring.h"
-#include "hw/virtio/dataplane/vring-accessors.h"
 #include "sysemu/block-backend.h"
 #include "hw/virtio/virtio-blk.h"
 #include "virtio-blk.h"
@@ -28,7 +26,6 @@
 #include "qom/object_interfaces.h"
 
 struct VirtIOBlockDataPlane {
-    bool started;
     bool starting;
     bool stopping;
     bool disabled;
@@ -36,7 +33,7 @@ struct VirtIOBlockDataPlane {
     VirtIOBlkConf *conf;
 
     VirtIODevice *vdev;
-    Vring vring;                    /* virtqueue vring */
+    VirtQueue *vq;                  /* virtqueue vring */
     EventNotifier *guest_notifier;  /* irq */
     QEMUBH *bh;                     /* bh for guest notification */
 
@@ -49,93 +46,26 @@ struct VirtIOBlockDataPlane {
      */
     IOThread *iothread;
     AioContext *ctx;
-    EventNotifier host_notifier;    /* doorbell */
 
     /* Operation blocker on BDS */
     Error *blocker;
-    void (*saved_complete_request)(struct VirtIOBlockReq *req,
-                                   unsigned char status);
 };
 
 /* Raise an interrupt to signal guest, if necessary */
-static void notify_guest(VirtIOBlockDataPlane *s)
+void virtio_blk_data_plane_notify(VirtIOBlockDataPlane *s)
 {
-    if (!vring_should_notify(s->vdev, &s->vring)) {
-        return;
-    }
-
-    event_notifier_set(s->guest_notifier);
+    qemu_bh_schedule(s->bh);
 }
 
 static void notify_guest_bh(void *opaque)
 {
     VirtIOBlockDataPlane *s = opaque;
 
-    notify_guest(s);
-}
-
-static void complete_request_vring(VirtIOBlockReq *req, unsigned char status)
-{
-    VirtIOBlockDataPlane *s = req->dev->dataplane;
-    stb_p(&req->in->status, status);
-
-    vring_push(s->vdev, &req->dev->dataplane->vring, &req->elem, req->in_len);
-
-    /* Suppress notification to guest by BH and its scheduled
-     * flag because requests are completed as a batch after io
-     * plug & unplug is introduced, and the BH can still be
-     * executed in dataplane aio context even after it is
-     * stopped, so needn't worry about notification loss with BH.
-     */
-    qemu_bh_schedule(s->bh);
-}
-
-static void handle_notify(EventNotifier *e)
-{
-    VirtIOBlockDataPlane *s = container_of(e, VirtIOBlockDataPlane,
-                                           host_notifier);
-    VirtIOBlock *vblk = VIRTIO_BLK(s->vdev);
-
-    event_notifier_test_and_clear(&s->host_notifier);
-    blk_io_plug(s->conf->conf.blk);
-    for (;;) {
-        MultiReqBuffer mrb = {};
-
-        /* Disable guest->host notifies to avoid unnecessary vmexits */
-        vring_disable_notification(s->vdev, &s->vring);
-
-        for (;;) {
-            VirtIOBlockReq *req = vring_pop(s->vdev, &s->vring,
-                                            sizeof(VirtIOBlockReq));
-
-            if (req == NULL) {
-                break; /* no more requests */
-            }
-
-            virtio_blk_init_request(vblk, req);
-            trace_virtio_blk_data_plane_process_request(s, req->elem.out_num,
-                                                        req->elem.in_num,
-                                                        req->elem.index);
-
-            virtio_blk_handle_request(req, &mrb);
-        }
-
-        if (mrb.num_reqs) {
-            virtio_blk_submit_multireq(s->conf->conf.blk, &mrb);
-        }
-
-        if (likely(!vring_more_avail(s->vdev, &s->vring))) { /* vring emptied */
-            /* Re-enable guest->host notifies and stop processing the vring.
-             * But if the guest has snuck in more descriptors, keep processing.
-             */
-            if (vring_enable_notification(s->vdev, &s->vring)) {
-                break;
-            }
-        } else { /* fatal error */
-            break;
-        }
+    if (!virtio_should_notify(s->vdev, s->vq)) {
+        return;
     }
-    blk_io_unplug(s->conf->conf.blk);
+
+    event_notifier_set(s->guest_notifier);
 }
 
 static void data_plane_set_up_op_blockers(VirtIOBlockDataPlane *s)
@@ -260,23 +190,14 @@ void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s)
     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s->vdev)));
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
     VirtIOBlock *vblk = VIRTIO_BLK(s->vdev);
-    VirtQueue *vq;
     int r;
 
-    if (s->started || s->disabled) {
-        return;
-    }
-
-    if (s->starting) {
+    if (vblk->dataplane_started || s->starting) {
         return;
     }
 
     s->starting = true;
-
-    vq = virtio_get_queue(s->vdev, 0);
-    if (!vring_setup(&s->vring, s->vdev, 0)) {
-        goto fail_vring;
-    }
+    s->vq = virtio_get_queue(s->vdev, 0);
 
     /* Set up guest notifier (irq) */
     r = k->set_guest_notifiers(qbus->parent, 1, true);
@@ -285,7 +206,7 @@ void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s)
                 "ensure -enable-kvm is set\n", r);
         goto fail_guest_notifiers;
     }
-    s->guest_notifier = virtio_queue_get_guest_notifier(vq);
+    s->guest_notifier = virtio_queue_get_guest_notifier(s->vq);
 
     /* Set up virtqueue notify */
     r = k->set_host_notifier(qbus->parent, 0, true);
@@ -293,34 +214,28 @@ void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s)
         fprintf(stderr, "virtio-blk failed to set host notifier (%d)\n", r);
         goto fail_host_notifier;
     }
-    s->host_notifier = *virtio_queue_get_host_notifier(vq);
-
-    s->saved_complete_request = vblk->complete_request;
-    vblk->complete_request = complete_request_vring;
 
     s->starting = false;
-    s->started = true;
+    vblk->dataplane_started = true;
     trace_virtio_blk_data_plane_start(s);
 
     blk_set_aio_context(s->conf->conf.blk, s->ctx);
 
     /* Kick right away to begin processing requests already in vring */
-    event_notifier_set(virtio_queue_get_host_notifier(vq));
+    event_notifier_set(virtio_queue_get_host_notifier(s->vq));
 
     /* Get this show started by hooking up our callbacks */
     aio_context_acquire(s->ctx);
-    aio_set_event_notifier(s->ctx, &s->host_notifier, true,
-                           handle_notify);
+    virtio_queue_aio_set_host_notifier_handler(s->vq, s->ctx, true, true);
     aio_context_release(s->ctx);
     return;
 
   fail_host_notifier:
     k->set_guest_notifiers(qbus->parent, 1, false);
   fail_guest_notifiers:
-    vring_teardown(&s->vring, s->vdev, 0);
     s->disabled = true;
-  fail_vring:
     s->starting = false;
+    vblk->dataplane_started = true;
 }
 
 /* Context: QEMU global mutex held */
@@ -330,39 +245,34 @@ void virtio_blk_data_plane_stop(VirtIOBlockDataPlane *s)
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
     VirtIOBlock *vblk = VIRTIO_BLK(s->vdev);
 
+    if (!vblk->dataplane_started || s->stopping) {
+        return;
+    }
 
     /* Better luck next time. */
     if (s->disabled) {
         s->disabled = false;
-        return;
-    }
-    if (!s->started || s->stopping) {
+        vblk->dataplane_started = false;
         return;
     }
     s->stopping = true;
-    vblk->complete_request = s->saved_complete_request;
     trace_virtio_blk_data_plane_stop(s);
 
     aio_context_acquire(s->ctx);
 
     /* Stop notifications for new requests from guest */
-    aio_set_event_notifier(s->ctx, &s->host_notifier, true, NULL);
+    virtio_queue_aio_set_host_notifier_handler(s->vq, s->ctx, false, false);
 
     /* Drain and switch bs back to the QEMU main loop */
     blk_set_aio_context(s->conf->conf.blk, qemu_get_aio_context());
 
     aio_context_release(s->ctx);
 
-    /* Sync vring state back to virtqueue so that non-dataplane request
-     * processing can continue when we disable the host notifier below.
-     */
-    vring_teardown(&s->vring, s->vdev, 0);
-
     k->set_host_notifier(qbus->parent, 0, false);
 
     /* Clean up guest notifier (irq) */
     k->set_guest_notifiers(qbus->parent, 1, false);
 
-    s->started = false;
+    vblk->dataplane_started = false;
     s->stopping = false;
 }
diff --git a/hw/block/dataplane/virtio-blk.h b/hw/block/dataplane/virtio-blk.h
index c88d40e..0714c11 100644
--- a/hw/block/dataplane/virtio-blk.h
+++ b/hw/block/dataplane/virtio-blk.h
@@ -26,5 +26,6 @@ void virtio_blk_data_plane_destroy(VirtIOBlockDataPlane *s);
 void virtio_blk_data_plane_start(VirtIOBlockDataPlane *s);
 void virtio_blk_data_plane_stop(VirtIOBlockDataPlane *s);
 void virtio_blk_data_plane_drain(VirtIOBlockDataPlane *s);
+void virtio_blk_data_plane_notify(VirtIOBlockDataPlane *s);
 
 #endif /* HW_DATAPLANE_VIRTIO_BLK_H */
diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
index c427698..cb710f1 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -21,7 +21,6 @@
 #include "sysemu/blockdev.h"
 #include "hw/virtio/virtio-blk.h"
 #include "dataplane/virtio-blk.h"
-#include "migration/migration.h"
 #include "block/scsi.h"
 #ifdef __linux__
 # include <scsi/sg.h>
@@ -45,8 +44,7 @@ void virtio_blk_free_request(VirtIOBlockReq *req)
     }
 }
 
-static void virtio_blk_complete_request(VirtIOBlockReq *req,
-                                        unsigned char status)
+static void virtio_blk_req_complete(VirtIOBlockReq *req, unsigned char status)
 {
     VirtIOBlock *s = req->dev;
     VirtIODevice *vdev = VIRTIO_DEVICE(s);
@@ -55,12 +53,11 @@ static void virtio_blk_complete_request(VirtIOBlockReq *req,
 
     stb_p(&req->in->status, status);
     virtqueue_push(s->vq, &req->elem, req->in_len);
-    virtio_notify(vdev, s->vq);
-}
-
-static void virtio_blk_req_complete(VirtIOBlockReq *req, unsigned char status)
-{
-    req->dev->complete_request(req, status);
+    if (s->dataplane) {
+        virtio_blk_data_plane_notify(s->dataplane);
+    } else {
+        virtio_notify(vdev, s->vq);
+    }
 }
 
 static int virtio_blk_handle_rw_error(VirtIOBlockReq *req, int error,
@@ -589,7 +586,7 @@ static void virtio_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq)
     /* Some guests kick before setting VIRTIO_CONFIG_S_DRIVER_OK so start
      * dataplane here instead of waiting for .set_status().
      */
-    if (s->dataplane) {
+    if (s->dataplane && !s->dataplane_started) {
         virtio_blk_data_plane_start(s->dataplane);
         return;
     }
@@ -852,36 +849,6 @@ static const BlockDevOps virtio_block_ops = {
     .resize_cb = virtio_blk_resize,
 };
 
-/* Disable dataplane thread during live migration since it does not
- * update the dirty memory bitmap yet.
- */
-static void virtio_blk_migration_state_changed(Notifier *notifier, void *data)
-{
-    VirtIOBlock *s = container_of(notifier, VirtIOBlock,
-                                  migration_state_notifier);
-    MigrationState *mig = data;
-    Error *err = NULL;
-
-    if (migration_in_setup(mig)) {
-        if (!s->dataplane) {
-            return;
-        }
-        virtio_blk_data_plane_destroy(s->dataplane);
-        s->dataplane = NULL;
-    } else if (migration_has_finished(mig) ||
-               migration_has_failed(mig)) {
-        if (s->dataplane) {
-            return;
-        }
-        blk_drain_all(); /* complete in-flight non-dataplane requests */
-        virtio_blk_data_plane_create(VIRTIO_DEVICE(s), &s->conf,
-                                     &s->dataplane, &err);
-        if (err != NULL) {
-            error_report_err(err);
-        }
-    }
-}
-
 static void virtio_blk_device_realize(DeviceState *dev, Error **errp)
 {
     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
@@ -916,15 +883,12 @@ static void virtio_blk_device_realize(DeviceState *dev, Error **errp)
     s->sector_mask = (s->conf.conf.logical_block_size / BDRV_SECTOR_SIZE) - 1;
 
     s->vq = virtio_add_queue(vdev, 128, virtio_blk_handle_output);
-    s->complete_request = virtio_blk_complete_request;
     virtio_blk_data_plane_create(vdev, conf, &s->dataplane, &err);
     if (err != NULL) {
         error_propagate(errp, err);
         virtio_cleanup(vdev);
         return;
     }
-    s->migration_state_notifier.notify = virtio_blk_migration_state_changed;
-    add_migration_state_change_notifier(&s->migration_state_notifier);
 
     s->change = qemu_add_vm_change_state_handler(virtio_blk_dma_restart_cb, s);
     register_savevm(dev, "virtio-blk", virtio_blk_id++, 2,
@@ -940,7 +904,6 @@ static void virtio_blk_device_unrealize(DeviceState *dev, Error **errp)
     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
     VirtIOBlock *s = VIRTIO_BLK(dev);
 
-    remove_migration_state_change_notifier(&s->migration_state_notifier);
     virtio_blk_data_plane_destroy(s->dataplane);
     s->dataplane = NULL;
     qemu_del_vm_change_state_handler(s->change);
diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index 4554eb8..52c9470 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -2532,7 +2532,8 @@ build_rsdp(GArray *rsdp_table, GArray *linker, unsigned rsdt)
     rsdp->checksum = 0;
     /* Checksum to be filled by Guest linker */
     bios_linker_loader_add_checksum(linker, ACPI_BUILD_RSDP_FILE,
-                                    rsdp, rsdp, sizeof *rsdp, &rsdp->checksum);
+                                    rsdp_table, rsdp, sizeof *rsdp,
+                                    &rsdp->checksum);
 
     return rsdp_table;
 }
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index 208a224..46522c9 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -81,11 +81,9 @@ static void pc_q35_init(MachineState *machine)
      * If it doesn't, we need to split it in chunks below and above 4G.
      * In any case, try to make sure that guest addresses aligned at
      * 1G boundaries get mapped to host addresses aligned at 1G boundaries.
-     * For old machine types, use whatever split we used historically to avoid
-     * breaking migration.
      */
     if (machine->ram_size >= 0xb0000000) {
-        lowmem = pcmc->gigabyte_align ? 0x80000000 : 0xb0000000;
+        lowmem = 0x80000000;
     } else {
         lowmem = 0xb0000000;
     }
@@ -116,10 +114,6 @@ static void pc_q35_init(MachineState *machine)
     }
 
     pc_cpus_init(pcms);
-    if (!pcmc->has_acpi_build) {
-        /* only machine types 1.7 & older need this */
-        pc_acpi_init("q35-acpi-dsdt.aml");
-    }
 
     kvmclock_create();
 
@@ -225,7 +219,7 @@ static void pc_q35_init(MachineState *machine)
                          (pcms->vmport != ON_OFF_AUTO_ON), 0xff0104);
 
     /* connect pm stuff to lpc */
-    ich9_lpc_pm_init(lpc, pc_machine_is_smm_enabled(pcms), !mc->no_tco);
+    ich9_lpc_pm_init(lpc, pc_machine_is_smm_enabled(pcms));
 
     /* ahci and SATA device, for q35 1 ahci controller is built-in */
     ahci = pci_create_simple_multifunction(host_bus,
@@ -259,62 +253,6 @@ static void pc_q35_init(MachineState *machine)
     }
 }
 
-/* Looking for a pc_compat_2_4() function? It doesn't exist.
- * pc_compat_*() functions that run on machine-init time and
- * change global QEMU state are deprecated. Please don't create
- * one, and implement any pc-*-2.4 (and newer) compat code in
- * HW_COMPAT_*, PC_COMPAT_*, or * pc_*_machine_options().
- */
-
-static void pc_compat_2_3(MachineState *machine)
-{
-    PCMachineState *pcms = PC_MACHINE(machine);
-    savevm_skip_section_footers();
-    if (kvm_enabled()) {
-        pcms->smm = ON_OFF_AUTO_OFF;
-    }
-    global_state_set_optional();
-    savevm_skip_configuration();
-}
-
-static void pc_compat_2_2(MachineState *machine)
-{
-    pc_compat_2_3(machine);
-    machine->suppress_vmdesc = true;
-}
-
-static void pc_compat_2_1(MachineState *machine)
-{
-    pc_compat_2_2(machine);
-    x86_cpu_change_kvm_default("svm", NULL);
-}
-
-static void pc_compat_2_0(MachineState *machine)
-{
-    pc_compat_2_1(machine);
-}
-
-static void pc_compat_1_7(MachineState *machine)
-{
-    pc_compat_2_0(machine);
-    x86_cpu_change_kvm_default("x2apic", NULL);
-}
-
-static void pc_compat_1_6(MachineState *machine)
-{
-    pc_compat_1_7(machine);
-}
-
-static void pc_compat_1_5(MachineState *machine)
-{
-    pc_compat_1_6(machine);
-}
-
-static void pc_compat_1_4(MachineState *machine)
-{
-    pc_compat_1_5(machine);
-}
-
 #define DEFINE_Q35_MACHINE(suffix, name, compatfn, optionfn) \
     static void pc_init_##suffix(MachineState *machine) \
     { \
@@ -336,7 +274,6 @@ static void pc_q35_machine_options(MachineClass *m)
     m->default_machine_opts = "firmware=bios-256k.bin";
     m->default_display = "std";
     m->no_floppy = 1;
-    m->no_tco = 0;
 }
 
 static void pc_q35_2_6_machine_options(MachineClass *m)
@@ -371,112 +308,3 @@ static void pc_q35_2_4_machine_options(MachineClass *m)
 
 DEFINE_Q35_MACHINE(v2_4, "pc-q35-2.4", NULL,
                    pc_q35_2_4_machine_options);
-
-
-static void pc_q35_2_3_machine_options(MachineClass *m)
-{
-    pc_q35_2_4_machine_options(m);
-    m->hw_version = "2.3.0";
-    m->no_floppy = 0;
-    m->no_tco = 1;
-    SET_MACHINE_COMPAT(m, PC_COMPAT_2_3);
-}
-
-DEFINE_Q35_MACHINE(v2_3, "pc-q35-2.3", pc_compat_2_3,
-                   pc_q35_2_3_machine_options);
-
-
-static void pc_q35_2_2_machine_options(MachineClass *m)
-{
-    PCMachineClass *pcmc = PC_MACHINE_CLASS(m);
-    pc_q35_2_3_machine_options(m);
-    m->hw_version = "2.2.0";
-    SET_MACHINE_COMPAT(m, PC_COMPAT_2_2);
-    pcmc->rsdp_in_ram = false;
-}
-
-DEFINE_Q35_MACHINE(v2_2, "pc-q35-2.2", pc_compat_2_2,
-                   pc_q35_2_2_machine_options);
-
-
-static void pc_q35_2_1_machine_options(MachineClass *m)
-{
-    PCMachineClass *pcmc = PC_MACHINE_CLASS(m);
-    pc_q35_2_2_machine_options(m);
-    m->hw_version = "2.1.0";
-    m->default_display = NULL;
-    SET_MACHINE_COMPAT(m, PC_COMPAT_2_1);
-    pcmc->smbios_uuid_encoded = false;
-    pcmc->enforce_aligned_dimm = false;
-}
-
-DEFINE_Q35_MACHINE(v2_1, "pc-q35-2.1", pc_compat_2_1,
-                   pc_q35_2_1_machine_options);
-
-
-static void pc_q35_2_0_machine_options(MachineClass *m)
-{
-    PCMachineClass *pcmc = PC_MACHINE_CLASS(m);
-    pc_q35_2_1_machine_options(m);
-    m->hw_version = "2.0.0";
-    SET_MACHINE_COMPAT(m, PC_COMPAT_2_0);
-    pcmc->has_reserved_memory = false;
-    pcmc->smbios_legacy_mode = true;
-    pcmc->acpi_data_size = 0x10000;
-}
-
-DEFINE_Q35_MACHINE(v2_0, "pc-q35-2.0", pc_compat_2_0,
-                   pc_q35_2_0_machine_options);
-
-
-static void pc_q35_1_7_machine_options(MachineClass *m)
-{
-    PCMachineClass *pcmc = PC_MACHINE_CLASS(m);
-    pc_q35_2_0_machine_options(m);
-    m->hw_version = "1.7.0";
-    m->default_machine_opts = NULL;
-    m->option_rom_has_mr = true;
-    SET_MACHINE_COMPAT(m, PC_COMPAT_1_7);
-    pcmc->smbios_defaults = false;
-    pcmc->gigabyte_align = false;
-}
-
-DEFINE_Q35_MACHINE(v1_7, "pc-q35-1.7", pc_compat_1_7,
-                   pc_q35_1_7_machine_options);
-
-
-static void pc_q35_1_6_machine_options(MachineClass *m)
-{
-    PCMachineClass *pcmc = PC_MACHINE_CLASS(m);
-    pc_q35_machine_options(m);
-    m->hw_version = "1.6.0";
-    m->rom_file_has_mr = false;
-    SET_MACHINE_COMPAT(m, PC_COMPAT_1_6);
-    pcmc->has_acpi_build = false;
-}
-
-DEFINE_Q35_MACHINE(v1_6, "pc-q35-1.6", pc_compat_1_6,
-                   pc_q35_1_6_machine_options);
-
-
-static void pc_q35_1_5_machine_options(MachineClass *m)
-{
-    pc_q35_1_6_machine_options(m);
-    m->hw_version = "1.5.0";
-    SET_MACHINE_COMPAT(m, PC_COMPAT_1_5);
-}
-
-DEFINE_Q35_MACHINE(v1_5, "pc-q35-1.5", pc_compat_1_5,
-                   pc_q35_1_5_machine_options);
-
-
-static void pc_q35_1_4_machine_options(MachineClass *m)
-{
-    pc_q35_1_5_machine_options(m);
-    m->hw_version = "1.4.0";
-    m->hot_add_cpu = NULL;
-    SET_MACHINE_COMPAT(m, PC_COMPAT_1_4);
-}
-
-DEFINE_Q35_MACHINE(v1_4, "pc-q35-1.4", pc_compat_1_4,
-                   pc_q35_1_4_machine_options);
diff --git a/hw/isa/lpc_ich9.c b/hw/isa/lpc_ich9.c
index 6cf2eb6..4e896b2 100644
--- a/hw/isa/lpc_ich9.c
+++ b/hw/isa/lpc_ich9.c
@@ -369,13 +369,13 @@ static void ich9_set_sci(void *opaque, int irq_num, int level)
     }
 }
 
-void ich9_lpc_pm_init(PCIDevice *lpc_pci, bool smm_enabled, bool enable_tco)
+void ich9_lpc_pm_init(PCIDevice *lpc_pci, bool smm_enabled)
 {
     ICH9LPCState *lpc = ICH9_LPC_DEVICE(lpc_pci);
     qemu_irq sci_irq;
 
     sci_irq = qemu_allocate_irq(ich9_set_sci, lpc, 0);
-    ich9_pm_init(lpc_pci, &lpc->pm, smm_enabled, enable_tco, sci_irq);
+    ich9_pm_init(lpc_pci, &lpc->pm, smm_enabled, sci_irq);
     ich9_lpc_reset(&lpc->d.qdev);
 }
 
diff --git a/hw/mem/pc-dimm.c b/hw/mem/pc-dimm.c
index 1aa12c6..650f0f8 100644
--- a/hw/mem/pc-dimm.c
+++ b/hw/mem/pc-dimm.c
@@ -192,32 +192,6 @@ int qmp_pc_dimm_device_list(Object *obj, void *opaque)
     return 0;
 }
 
-ram_addr_t get_current_ram_size(void)
-{
-    MemoryDeviceInfoList *info_list = NULL;
-    MemoryDeviceInfoList **prev = &info_list;
-    MemoryDeviceInfoList *info;
-    ram_addr_t size = ram_size;
-
-    qmp_pc_dimm_device_list(qdev_get_machine(), &prev);
-    for (info = info_list; info; info = info->next) {
-        MemoryDeviceInfo *value = info->value;
-
-        if (value) {
-            switch (value->type) {
-            case MEMORY_DEVICE_INFO_KIND_DIMM:
-                size += value->u.dimm->size;
-                break;
-            default:
-                break;
-            }
-        }
-    }
-    qapi_free_MemoryDeviceInfoList(info_list);
-
-    return size;
-}
-
 static int pc_dimm_slot2bitmap(Object *obj, void *opaque)
 {
     unsigned long *bitmap = opaque;
diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index b282120..e67664d 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -278,9 +278,9 @@ static void pcibus_reset(BusState *qbus)
     }
 }
 
-static void pci_host_bus_register(PCIBus *bus, DeviceState *parent)
+static void pci_host_bus_register(DeviceState *host)
 {
-    PCIHostState *host_bridge = PCI_HOST_BRIDGE(parent);
+    PCIHostState *host_bridge = PCI_HOST_BRIDGE(host);
 
     QLIST_INSERT_HEAD(&pci_host_bridges, host_bridge, next);
 }
@@ -331,7 +331,6 @@ const char *pci_root_bus_path(PCIDevice *dev)
 }
 
 static void pci_bus_init(PCIBus *bus, DeviceState *parent,
-                         const char *name,
                          MemoryRegion *address_space_mem,
                          MemoryRegion *address_space_io,
                          uint8_t devfn_min)
@@ -344,7 +343,7 @@ static void pci_bus_init(PCIBus *bus, DeviceState *parent,
     /* host bridge */
     QLIST_INIT(&bus->child);
 
-    pci_host_bus_register(bus, parent);
+    pci_host_bus_register(parent);
 }
 
 bool pci_bus_is_express(PCIBus *bus)
@@ -364,8 +363,7 @@ void pci_bus_new_inplace(PCIBus *bus, size_t bus_size, DeviceState *parent,
                          uint8_t devfn_min, const char *typename)
 {
     qbus_create_inplace(bus, bus_size, typename, parent, name);
-    pci_bus_init(bus, parent, name, address_space_mem,
-                 address_space_io, devfn_min);
+    pci_bus_init(bus, parent, address_space_mem, address_space_io, devfn_min);
 }
 
 PCIBus *pci_bus_new(DeviceState *parent, const char *name,
@@ -376,8 +374,7 @@ PCIBus *pci_bus_new(DeviceState *parent, const char *name,
     PCIBus *bus;
 
     bus = PCI_BUS(qbus_create(typename, parent, name));
-    pci_bus_init(bus, parent, name, address_space_mem,
-                 address_space_io, devfn_min);
+    pci_bus_init(bus, parent, address_space_mem, address_space_io, devfn_min);
     return bus;
 }
 
diff --git a/hw/scsi/virtio-scsi-dataplane.c b/hw/scsi/virtio-scsi-dataplane.c
index 8340326..367e476 100644
--- a/hw/scsi/virtio-scsi-dataplane.c
+++ b/hw/scsi/virtio-scsi-dataplane.c
@@ -39,14 +39,10 @@ void virtio_scsi_set_iothread(VirtIOSCSI *s, IOThread *iothread)
     }
 }
 
-static VirtIOSCSIVring *virtio_scsi_vring_init(VirtIOSCSI *s,
-                                               VirtQueue *vq,
-                                               EventNotifierHandler *handler,
-                                               int n)
+static int virtio_scsi_vring_init(VirtIOSCSI *s, VirtQueue *vq, int n)
 {
     BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(s)));
     VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus);
-    VirtIOSCSIVring *r;
     int rc;
 
     /* Set up virtqueue notify */
@@ -55,105 +51,17 @@ static VirtIOSCSIVring *virtio_scsi_vring_init(VirtIOSCSI *s,
         fprintf(stderr, "virtio-scsi: Failed to set host notifier (%d)\n",
                 rc);
         s->dataplane_fenced = true;
-        return NULL;
+        return rc;
     }
 
-    r = g_new(VirtIOSCSIVring, 1);
-    r->host_notifier = *virtio_queue_get_host_notifier(vq);
-    r->guest_notifier = *virtio_queue_get_guest_notifier(vq);
-    aio_set_event_notifier(s->ctx, &r->host_notifier, true, handler);
-
-    r->parent = s;
-
-    if (!vring_setup(&r->vring, VIRTIO_DEVICE(s), n)) {
-        fprintf(stderr, "virtio-scsi: VRing setup failed\n");
-        goto fail_vring;
-    }
-    return r;
-
-fail_vring:
-    aio_set_event_notifier(s->ctx, &r->host_notifier, true, NULL);
-    k->set_host_notifier(qbus->parent, n, false);
-    g_free(r);
-    return NULL;
-}
-
-VirtIOSCSIReq *virtio_scsi_pop_req_vring(VirtIOSCSI *s,
-                                         VirtIOSCSIVring *vring)
-{
-    VirtIOSCSICommon *vs = (VirtIOSCSICommon *)s;
-    VirtIOSCSIReq *req;
-
-    req = vring_pop((VirtIODevice *)s, &vring->vring,
-                    sizeof(VirtIOSCSIReq) + vs->cdb_size);
-    if (!req) {
-        return NULL;
-    }
-    virtio_scsi_init_req(s, NULL, req);
-    req->vring = vring;
-    return req;
-}
-
-void virtio_scsi_vring_push_notify(VirtIOSCSIReq *req)
-{
-    VirtIODevice *vdev = VIRTIO_DEVICE(req->vring->parent);
-
-    vring_push(vdev, &req->vring->vring, &req->elem,
-               req->qsgl.size + req->resp_iov.size);
-
-    if (vring_should_notify(vdev, &req->vring->vring)) {
-        event_notifier_set(&req->vring->guest_notifier);
-    }
+    virtio_queue_aio_set_host_notifier_handler(vq, s->ctx, true, true);
+    return 0;
 }
 
-static void virtio_scsi_iothread_handle_ctrl(EventNotifier *notifier)
+void virtio_scsi_dataplane_notify(VirtIODevice *vdev, VirtIOSCSIReq *req)
 {
-    VirtIOSCSIVring *vring = container_of(notifier,
-                                          VirtIOSCSIVring, host_notifier);
-    VirtIOSCSI *s = VIRTIO_SCSI(vring->parent);
-    VirtIOSCSIReq *req;
-
-    event_notifier_test_and_clear(notifier);
-    while ((req = virtio_scsi_pop_req_vring(s, vring))) {
-        virtio_scsi_handle_ctrl_req(s, req);
-    }
-}
-
-static void virtio_scsi_iothread_handle_event(EventNotifier *notifier)
-{
-    VirtIOSCSIVring *vring = container_of(notifier,
-                                          VirtIOSCSIVring, host_notifier);
-    VirtIOSCSI *s = vring->parent;
-    VirtIODevice *vdev = VIRTIO_DEVICE(s);
-
-    event_notifier_test_and_clear(notifier);
-
-    if (!(vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
-        return;
-    }
-
-    if (s->events_dropped) {
-        virtio_scsi_push_event(s, NULL, VIRTIO_SCSI_T_NO_EVENT, 0);
-    }
-}
-
-static void virtio_scsi_iothread_handle_cmd(EventNotifier *notifier)
-{
-    VirtIOSCSIVring *vring = container_of(notifier,
-                                          VirtIOSCSIVring, host_notifier);
-    VirtIOSCSI *s = (VirtIOSCSI *)vring->parent;
-    VirtIOSCSIReq *req, *next;
-    QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
-
-    event_notifier_test_and_clear(notifier);
-    while ((req = virtio_scsi_pop_req_vring(s, vring))) {
-        if (virtio_scsi_handle_cmd_req_prepare(s, req)) {
-            QTAILQ_INSERT_TAIL(&reqs, req, next);
-        }
-    }
-
-    QTAILQ_FOREACH_SAFE(req, &reqs, next, next) {
-        virtio_scsi_handle_cmd_req_submit(s, req);
+    if (virtio_should_notify(vdev, req->vq)) {
+        event_notifier_set(virtio_queue_get_guest_notifier(req->vq));
     }
 }
 
@@ -163,46 +71,10 @@ static void virtio_scsi_clear_aio(VirtIOSCSI *s)
     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
     int i;
 
-    if (s->ctrl_vring) {
-        aio_set_event_notifier(s->ctx, &s->ctrl_vring->host_notifier,
-                               true, NULL);
-    }
-    if (s->event_vring) {
-        aio_set_event_notifier(s->ctx, &s->event_vring->host_notifier,
-                               true, NULL);
-    }
-    if (s->cmd_vrings) {
-        for (i = 0; i < vs->conf.num_queues && s->cmd_vrings[i]; i++) {
-            aio_set_event_notifier(s->ctx, &s->cmd_vrings[i]->host_notifier,
-                                   true, NULL);
-        }
-    }
-}
-
-static void virtio_scsi_vring_teardown(VirtIOSCSI *s)
-{
-    VirtIODevice *vdev = VIRTIO_DEVICE(s);
-    VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
-    int i;
-
-    if (s->ctrl_vring) {
-        vring_teardown(&s->ctrl_vring->vring, vdev, 0);
-        g_free(s->ctrl_vring);
-        s->ctrl_vring = NULL;
-    }
-    if (s->event_vring) {
-        vring_teardown(&s->event_vring->vring, vdev, 1);
-        g_free(s->event_vring);
-        s->event_vring = NULL;
-    }
-    if (s->cmd_vrings) {
-        for (i = 0; i < vs->conf.num_queues && s->cmd_vrings[i]; i++) {
-            vring_teardown(&s->cmd_vrings[i]->vring, vdev, 2 + i);
-            g_free(s->cmd_vrings[i]);
-            s->cmd_vrings[i] = NULL;
-        }
-        free(s->cmd_vrings);
-        s->cmd_vrings = NULL;
+    virtio_queue_aio_set_host_notifier_handler(vs->ctrl_vq, s->ctx, false, false);
+    virtio_queue_aio_set_host_notifier_handler(vs->event_vq, s->ctx, false, false);
+    for (i = 0; i < vs->conf.num_queues; i++) {
+        virtio_queue_aio_set_host_notifier_handler(vs->cmd_vqs[i], s->ctx, false, false);
     }
 }
 
@@ -229,30 +101,21 @@ void virtio_scsi_dataplane_start(VirtIOSCSI *s)
     if (rc != 0) {
         fprintf(stderr, "virtio-scsi: Failed to set guest notifiers (%d), "
                 "ensure -enable-kvm is set\n", rc);
-        s->dataplane_fenced = true;
         goto fail_guest_notifiers;
     }
 
     aio_context_acquire(s->ctx);
-    s->ctrl_vring = virtio_scsi_vring_init(s, vs->ctrl_vq,
-                                           virtio_scsi_iothread_handle_ctrl,
-                                           0);
-    if (!s->ctrl_vring) {
+    rc = virtio_scsi_vring_init(s, vs->ctrl_vq, 0);
+    if (rc) {
         goto fail_vrings;
     }
-    s->event_vring = virtio_scsi_vring_init(s, vs->event_vq,
-                                            virtio_scsi_iothread_handle_event,
-                                            1);
-    if (!s->event_vring) {
+    rc = virtio_scsi_vring_init(s, vs->event_vq, 1);
+    if (rc) {
         goto fail_vrings;
     }
-    s->cmd_vrings = g_new(VirtIOSCSIVring *, vs->conf.num_queues);
     for (i = 0; i < vs->conf.num_queues; i++) {
-        s->cmd_vrings[i] =
-            virtio_scsi_vring_init(s, vs->cmd_vqs[i],
-                                   virtio_scsi_iothread_handle_cmd,
-                                   i + 2);
-        if (!s->cmd_vrings[i]) {
+        rc = virtio_scsi_vring_init(s, vs->cmd_vqs[i], i + 2);
+        if (rc) {
             goto fail_vrings;
         }
     }
@@ -265,13 +128,14 @@ void virtio_scsi_dataplane_start(VirtIOSCSI *s)
 fail_vrings:
     virtio_scsi_clear_aio(s);
     aio_context_release(s->ctx);
-    virtio_scsi_vring_teardown(s);
     for (i = 0; i < vs->conf.num_queues + 2; i++) {
         k->set_host_notifier(qbus->parent, i, false);
     }
     k->set_guest_notifiers(qbus->parent, vs->conf.num_queues + 2, false);
 fail_guest_notifiers:
+    s->dataplane_fenced = true;
     s->dataplane_starting = false;
+    s->dataplane_started = true;
 }
 
 /* Context: QEMU global mutex held */
@@ -282,12 +146,14 @@ void virtio_scsi_dataplane_stop(VirtIOSCSI *s)
     VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(s);
     int i;
 
+    if (!s->dataplane_started || s->dataplane_stopping) {
+        return;
+    }
+
     /* Better luck next time. */
     if (s->dataplane_fenced) {
         s->dataplane_fenced = false;
-        return;
-    }
-    if (!s->dataplane_started || s->dataplane_stopping) {
+        s->dataplane_started = false;
         return;
     }
     s->dataplane_stopping = true;
@@ -295,24 +161,12 @@ void virtio_scsi_dataplane_stop(VirtIOSCSI *s)
 
     aio_context_acquire(s->ctx);
 
-    aio_set_event_notifier(s->ctx, &s->ctrl_vring->host_notifier,
-                           true, NULL);
-    aio_set_event_notifier(s->ctx, &s->event_vring->host_notifier,
-                           true, NULL);
-    for (i = 0; i < vs->conf.num_queues; i++) {
-        aio_set_event_notifier(s->ctx, &s->cmd_vrings[i]->host_notifier,
-                               true, NULL);
-    }
+    virtio_scsi_clear_aio(s);
 
     blk_drain_all(); /* ensure there are no in-flight requests */
 
     aio_context_release(s->ctx);
 
-    /* Sync vring state back to virtqueue so that non-dataplane request
-     * processing can continue when we disable the host notifier below.
-     */
-    virtio_scsi_vring_teardown(s);
-
     for (i = 0; i < vs->conf.num_queues + 2; i++) {
         k->set_host_notifier(qbus->parent, i, false);
     }
diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
index 5b29bac..0c30d2e 100644
--- a/hw/scsi/virtio-scsi.c
+++ b/hw/scsi/virtio-scsi.c
@@ -23,7 +23,6 @@
 #include <block/scsi.h>
 #include <hw/virtio/virtio-bus.h>
 #include "hw/virtio/virtio-access.h"
-#include "migration/migration.h"
 
 static inline int virtio_scsi_get_lun(uint8_t *lun)
 {
@@ -43,7 +42,8 @@ static inline SCSIDevice *virtio_scsi_device_find(VirtIOSCSI *s, uint8_t *lun)
 
 void virtio_scsi_init_req(VirtIOSCSI *s, VirtQueue *vq, VirtIOSCSIReq *req)
 {
-    const size_t zero_skip = offsetof(VirtIOSCSIReq, vring);
+    const size_t zero_skip =
+        offsetof(VirtIOSCSIReq, resp_iov) + sizeof(req->resp_iov);
 
     req->vq = vq;
     req->dev = s;
@@ -66,11 +66,10 @@ static void virtio_scsi_complete_req(VirtIOSCSIReq *req)
     VirtIODevice *vdev = VIRTIO_DEVICE(s);
 
     qemu_iovec_from_buf(&req->resp_iov, 0, &req->resp, req->resp_size);
-    if (req->vring) {
-        assert(req->vq == NULL);
-        virtio_scsi_vring_push_notify(req);
+    virtqueue_push(vq, &req->elem, req->qsgl.size + req->resp_iov.size);
+    if (s->dataplane_started) {
+        virtio_scsi_dataplane_notify(vdev, req);
     } else {
-        virtqueue_push(vq, &req->elem, req->qsgl.size + req->resp_iov.size);
         virtio_notify(vdev, vq);
     }
 
@@ -417,7 +416,7 @@ static void virtio_scsi_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
     VirtIOSCSI *s = (VirtIOSCSI *)vdev;
     VirtIOSCSIReq *req;
 
-    if (s->ctx && !s->dataplane_disabled) {
+    if (s->ctx && !s->dataplane_started) {
         virtio_scsi_dataplane_start(s);
         return;
     }
@@ -567,7 +566,7 @@ static void virtio_scsi_handle_cmd(VirtIODevice *vdev, VirtQueue *vq)
     VirtIOSCSIReq *req, *next;
     QTAILQ_HEAD(, VirtIOSCSIReq) reqs = QTAILQ_HEAD_INITIALIZER(reqs);
 
-    if (s->ctx && !s->dataplane_disabled) {
+    if (s->ctx && !s->dataplane_started) {
         virtio_scsi_dataplane_start(s);
         return;
     }
@@ -687,11 +686,7 @@ void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
         aio_context_acquire(s->ctx);
     }
 
-    if (s->dataplane_started) {
-        req = virtio_scsi_pop_req_vring(s, s->event_vring);
-    } else {
-        req = virtio_scsi_pop_req(s, vs->event_vq);
-    }
+    req = virtio_scsi_pop_req(s, vs->event_vq);
     if (!req) {
         s->events_dropped = true;
         goto out;
@@ -733,7 +728,7 @@ static void virtio_scsi_handle_event(VirtIODevice *vdev, VirtQueue *vq)
 {
     VirtIOSCSI *s = VIRTIO_SCSI(vdev);
 
-    if (s->ctx && !s->dataplane_disabled) {
+    if (s->ctx && !s->dataplane_started) {
         virtio_scsi_dataplane_start(s);
         return;
     }
@@ -901,31 +896,6 @@ void virtio_scsi_common_realize(DeviceState *dev, Error **errp,
     }
 }
 
-/* Disable dataplane thread during live migration since it does not
- * update the dirty memory bitmap yet.
- */
-static void virtio_scsi_migration_state_changed(Notifier *notifier, void *data)
-{
-    VirtIOSCSI *s = container_of(notifier, VirtIOSCSI,
-                                 migration_state_notifier);
-    MigrationState *mig = data;
-
-    if (migration_in_setup(mig)) {
-        if (!s->dataplane_started) {
-            return;
-        }
-        virtio_scsi_dataplane_stop(s);
-        s->dataplane_disabled = true;
-    } else if (migration_has_finished(mig) ||
-               migration_has_failed(mig)) {
-        if (s->dataplane_started) {
-            return;
-        }
-        blk_drain_all(); /* complete in-flight non-dataplane requests */
-        s->dataplane_disabled = false;
-    }
-}
-
 static void virtio_scsi_device_realize(DeviceState *dev, Error **errp)
 {
     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
@@ -956,8 +926,6 @@ static void virtio_scsi_device_realize(DeviceState *dev, Error **errp)
 
     register_savevm(dev, "virtio-scsi", virtio_scsi_id++, 1,
                     virtio_scsi_save, virtio_scsi_load, s);
-    s->migration_state_notifier.notify = virtio_scsi_migration_state_changed;
-    add_migration_state_change_notifier(&s->migration_state_notifier);
 
     error_setg(&s->blocker, "block device is in use by data plane");
 
@@ -991,8 +959,6 @@ static void virtio_scsi_device_unrealize(DeviceState *dev, Error **errp)
     error_free(s->blocker);
 
     unregister_savevm(dev, "virtio-scsi", s);
-    remove_migration_state_change_notifier(&s->migration_state_notifier);
-
     virtio_scsi_common_unrealize(dev, errp);
 }
 
diff --git a/hw/virtio/Makefile.objs b/hw/virtio/Makefile.objs
index 19b224a..3e2b175 100644
--- a/hw/virtio/Makefile.objs
+++ b/hw/virtio/Makefile.objs
@@ -2,7 +2,6 @@ common-obj-y += virtio-rng.o
 common-obj-$(CONFIG_VIRTIO_PCI) += virtio-pci.o
 common-obj-y += virtio-bus.o
 common-obj-y += virtio-mmio.o
-obj-$(CONFIG_VIRTIO) += dataplane/
 
 obj-y += virtio.o virtio-balloon.o 
 obj-$(CONFIG_LINUX) += vhost.o vhost-backend.o vhost-user.o
diff --git a/hw/virtio/dataplane/Makefile.objs b/hw/virtio/dataplane/Makefile.objs
deleted file mode 100644
index 753a9ca..0000000
--- a/hw/virtio/dataplane/Makefile.objs
+++ /dev/null
@@ -1 +0,0 @@
-obj-y += vring.o
diff --git a/hw/virtio/dataplane/vring.c b/hw/virtio/dataplane/vring.c
deleted file mode 100644
index 4308d9f..0000000
--- a/hw/virtio/dataplane/vring.c
+++ /dev/null
@@ -1,549 +0,0 @@
-/* Copyright 2012 Red Hat, Inc.
- * Copyright IBM, Corp. 2012
- *
- * Based on Linux 2.6.39 vhost code:
- * Copyright (C) 2009 Red Hat, Inc.
- * Copyright (C) 2006 Rusty Russell IBM Corporation
- *
- * Author: Michael S. Tsirkin <mst@redhat.com>
- *         Stefan Hajnoczi <stefanha@redhat.com>
- *
- * Inspiration, some code, and most witty comments come from
- * Documentation/virtual/lguest/lguest.c, by Rusty Russell
- *
- * This work is licensed under the terms of the GNU GPL, version 2.
- */
-
-#include "qemu/osdep.h"
-#include "trace.h"
-#include "hw/hw.h"
-#include "exec/memory.h"
-#include "exec/address-spaces.h"
-#include "hw/virtio/virtio-access.h"
-#include "hw/virtio/dataplane/vring.h"
-#include "hw/virtio/dataplane/vring-accessors.h"
-#include "qemu/error-report.h"
-
-/* vring_map can be coupled with vring_unmap or (if you still have the
- * value returned in *mr) memory_region_unref.
- * Returns NULL on failure.
- * Callers that can handle a partial mapping must supply mapped_len pointer to
- * get the actual length mapped.
- * Passing mapped_len == NULL requires either a full mapping or a failure.
- */
-static void *vring_map(MemoryRegion **mr, hwaddr phys,
-                       hwaddr len, hwaddr *mapped_len,
-                       bool is_write)
-{
-    MemoryRegionSection section = memory_region_find(get_system_memory(), phys, len);
-    uint64_t size;
-
-    if (!section.mr) {
-        goto out;
-    }
-
-    size = int128_get64(section.size);
-    assert(size);
-
-    /* Passing mapped_len == NULL requires either a full mapping or a failure. */
-    if (!mapped_len && size < len) {
-        goto out;
-    }
-
-    if (is_write && section.readonly) {
-        goto out;
-    }
-    if (!memory_region_is_ram(section.mr)) {
-        goto out;
-    }
-
-    /* Ignore regions with dirty logging, we cannot mark them dirty */
-    if (memory_region_get_dirty_log_mask(section.mr)) {
-        goto out;
-    }
-
-    if (mapped_len) {
-        *mapped_len = MIN(size, len);
-    }
-
-    *mr = section.mr;
-    return memory_region_get_ram_ptr(section.mr) + section.offset_within_region;
-
-out:
-    memory_region_unref(section.mr);
-    *mr = NULL;
-    return NULL;
-}
-
-static void vring_unmap(void *buffer, bool is_write)
-{
-    ram_addr_t addr;
-    MemoryRegion *mr;
-
-    mr = qemu_ram_addr_from_host(buffer, &addr);
-    memory_region_unref(mr);
-}
-
-/* Map the guest's vring to host memory */
-bool vring_setup(Vring *vring, VirtIODevice *vdev, int n)
-{
-    struct vring *vr = &vring->vr;
-    hwaddr addr;
-    hwaddr size;
-    void *ptr;
-
-    vring->broken = false;
-    vr->num = virtio_queue_get_num(vdev, n);
-
-    addr = virtio_queue_get_desc_addr(vdev, n);
-    size = virtio_queue_get_desc_size(vdev, n);
-    /* Map the descriptor area as read only */
-    ptr = vring_map(&vring->mr_desc, addr, size, NULL, false);
-    if (!ptr) {
-        error_report("Failed to map 0x%" HWADDR_PRIx " byte for vring desc "
-                     "at 0x%" HWADDR_PRIx,
-                      size, addr);
-        goto out_err_desc;
-    }
-    vr->desc = ptr;
-
-    addr = virtio_queue_get_avail_addr(vdev, n);
-    size = virtio_queue_get_avail_size(vdev, n);
-    /* Add the size of the used_event_idx */
-    size += sizeof(uint16_t);
-    /* Map the driver area as read only */
-    ptr = vring_map(&vring->mr_avail, addr, size, NULL, false);
-    if (!ptr) {
-        error_report("Failed to map 0x%" HWADDR_PRIx " byte for vring avail "
-                     "at 0x%" HWADDR_PRIx,
-                      size, addr);
-        goto out_err_avail;
-    }
-    vr->avail = ptr;
-
-    addr = virtio_queue_get_used_addr(vdev, n);
-    size = virtio_queue_get_used_size(vdev, n);
-    /* Add the size of the avail_event_idx */
-    size += sizeof(uint16_t);
-    /* Map the device area as read-write */
-    ptr = vring_map(&vring->mr_used, addr, size, NULL, true);
-    if (!ptr) {
-        error_report("Failed to map 0x%" HWADDR_PRIx " byte for vring used "
-                     "at 0x%" HWADDR_PRIx,
-                      size, addr);
-        goto out_err_used;
-    }
-    vr->used = ptr;
-
-    vring->last_avail_idx = virtio_queue_get_last_avail_idx(vdev, n);
-    vring->last_used_idx = vring_get_used_idx(vdev, vring);
-    vring->signalled_used = 0;
-    vring->signalled_used_valid = false;
-
-    trace_vring_setup(virtio_queue_get_ring_addr(vdev, n),
-                      vring->vr.desc, vring->vr.avail, vring->vr.used);
-    return true;
-
-out_err_used:
-    memory_region_unref(vring->mr_avail);
-out_err_avail:
-    memory_region_unref(vring->mr_desc);
-out_err_desc:
-    vring->broken = true;
-    return false;
-}
-
-void vring_teardown(Vring *vring, VirtIODevice *vdev, int n)
-{
-    virtio_queue_set_last_avail_idx(vdev, n, vring->last_avail_idx);
-    virtio_queue_invalidate_signalled_used(vdev, n);
-
-    memory_region_unref(vring->mr_desc);
-    memory_region_unref(vring->mr_avail);
-    memory_region_unref(vring->mr_used);
-}
-
-/* Disable guest->host notifies */
-void vring_disable_notification(VirtIODevice *vdev, Vring *vring)
-{
-    if (!virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) {
-        vring_set_used_flags(vdev, vring, VRING_USED_F_NO_NOTIFY);
-    }
-}
-
-/* Enable guest->host notifies
- *
- * Return true if the vring is empty, false if there are more requests.
- */
-bool vring_enable_notification(VirtIODevice *vdev, Vring *vring)
-{
-    if (virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) {
-        vring_avail_event(&vring->vr) = vring->vr.avail->idx;
-    } else {
-        vring_clear_used_flags(vdev, vring, VRING_USED_F_NO_NOTIFY);
-    }
-    smp_mb(); /* ensure update is seen before reading avail_idx */
-    return !vring_more_avail(vdev, vring);
-}
-
-/* This is stolen from linux/drivers/vhost/vhost.c:vhost_notify() */
-bool vring_should_notify(VirtIODevice *vdev, Vring *vring)
-{
-    uint16_t old, new;
-    bool v;
-    /* Flush out used index updates. This is paired
-     * with the barrier that the Guest executes when enabling
-     * interrupts. */
-    smp_mb();
-
-    if (virtio_vdev_has_feature(vdev, VIRTIO_F_NOTIFY_ON_EMPTY) &&
-        unlikely(!vring_more_avail(vdev, vring))) {
-        return true;
-    }
-
-    if (!virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) {
-        return !(vring_get_avail_flags(vdev, vring) &
-                 VRING_AVAIL_F_NO_INTERRUPT);
-    }
-    old = vring->signalled_used;
-    v = vring->signalled_used_valid;
-    new = vring->signalled_used = vring->last_used_idx;
-    vring->signalled_used_valid = true;
-
-    if (unlikely(!v)) {
-        return true;
-    }
-
-    return vring_need_event(virtio_tswap16(vdev, vring_used_event(&vring->vr)),
-                            new, old);
-}
-
-typedef struct VirtQueueCurrentElement {
-    unsigned in_num;
-    unsigned out_num;
-    hwaddr addr[VIRTQUEUE_MAX_SIZE];
-    struct iovec iov[VIRTQUEUE_MAX_SIZE];
-} VirtQueueCurrentElement;
-
-static int get_desc(Vring *vring, VirtQueueCurrentElement *elem,
-                    struct vring_desc *desc)
-{
-    unsigned *num;
-    struct iovec *iov;
-    hwaddr *addr;
-    MemoryRegion *mr;
-    hwaddr len;
-
-    if (desc->flags & VRING_DESC_F_WRITE) {
-        num = &elem->in_num;
-        iov = &elem->iov[elem->out_num + *num];
-        addr = &elem->addr[elem->out_num + *num];
-    } else {
-        num = &elem->out_num;
-        iov = &elem->iov[*num];
-        addr = &elem->addr[*num];
-
-        /* If it's an output descriptor, they're all supposed
-         * to come before any input descriptors. */
-        if (unlikely(elem->in_num)) {
-            error_report("Descriptor has out after in");
-            return -EFAULT;
-        }
-    }
-
-    while (desc->len) {
-        /* Stop for now if there are not enough iovecs available. */
-        if (*num >= VIRTQUEUE_MAX_SIZE) {
-            error_report("Invalid SG num: %u", *num);
-            return -EFAULT;
-        }
-
-        iov->iov_base = vring_map(&mr, desc->addr, desc->len, &len,
-                                  desc->flags & VRING_DESC_F_WRITE);
-        if (!iov->iov_base) {
-            error_report("Failed to map descriptor addr %#" PRIx64 " len %u",
-                         (uint64_t)desc->addr, desc->len);
-            return -EFAULT;
-        }
-
-        /* The MemoryRegion is looked up again and unref'ed later, leave the
-         * ref in place.  */
-        (iov++)->iov_len = len;
-        *addr++ = desc->addr;
-        desc->len -= len;
-        desc->addr += len;
-        *num += 1;
-    }
-
-    return 0;
-}
-
-static void copy_in_vring_desc(VirtIODevice *vdev,
-                               const struct vring_desc *guest,
-                               struct vring_desc *host)
-{
-    host->addr = virtio_ldq_p(vdev, &guest->addr);
-    host->len = virtio_ldl_p(vdev, &guest->len);
-    host->flags = virtio_lduw_p(vdev, &guest->flags);
-    host->next = virtio_lduw_p(vdev, &guest->next);
-}
-
-static bool read_vring_desc(VirtIODevice *vdev,
-                            hwaddr guest,
-                            struct vring_desc *host)
-{
-    if (address_space_read(&address_space_memory, guest, MEMTXATTRS_UNSPECIFIED,
-                           (uint8_t *)host, sizeof *host)) {
-        return false;
-    }
-    host->addr = virtio_tswap64(vdev, host->addr);
-    host->len = virtio_tswap32(vdev, host->len);
-    host->flags = virtio_tswap16(vdev, host->flags);
-    host->next = virtio_tswap16(vdev, host->next);
-    return true;
-}
-
-/* This is stolen from linux/drivers/vhost/vhost.c. */
-static int get_indirect(VirtIODevice *vdev, Vring *vring,
-                        VirtQueueCurrentElement *cur_elem,
-                        struct vring_desc *indirect)
-{
-    struct vring_desc desc;
-    unsigned int i = 0, count, found = 0;
-    int ret;
-
-    /* Sanity check */
-    if (unlikely(indirect->len % sizeof(desc))) {
-        error_report("Invalid length in indirect descriptor: "
-                     "len %#x not multiple of %#zx",
-                     indirect->len, sizeof(desc));
-        vring->broken = true;
-        return -EFAULT;
-    }
-
-    count = indirect->len / sizeof(desc);
-    /* Buffers are chained via a 16 bit next field, so
-     * we can have at most 2^16 of these. */
-    if (unlikely(count > USHRT_MAX + 1)) {
-        error_report("Indirect buffer length too big: %d", indirect->len);
-        vring->broken = true;
-        return -EFAULT;
-    }
-
-    do {
-        /* Translate indirect descriptor */
-        if (!read_vring_desc(vdev, indirect->addr + found * sizeof(desc),
-                             &desc)) {
-            error_report("Failed to read indirect descriptor "
-                         "addr %#" PRIx64 " len %zu",
-                         (uint64_t)indirect->addr + found * sizeof(desc),
-                         sizeof(desc));
-            vring->broken = true;
-            return -EFAULT;
-        }
-
-        /* Ensure descriptor has been loaded before accessing fields */
-        barrier(); /* read_barrier_depends(); */
-
-        if (unlikely(++found > count)) {
-            error_report("Loop detected: last one at %u "
-                         "indirect size %u", i, count);
-            vring->broken = true;
-            return -EFAULT;
-        }
-
-        if (unlikely(desc.flags & VRING_DESC_F_INDIRECT)) {
-            error_report("Nested indirect descriptor");
-            vring->broken = true;
-            return -EFAULT;
-        }
-
-        ret = get_desc(vring, cur_elem, &desc);
-        if (ret < 0) {
-            vring->broken |= (ret == -EFAULT);
-            return ret;
-        }
-        i = desc.next;
-    } while (desc.flags & VRING_DESC_F_NEXT);
-    return 0;
-}
-
-static void vring_unmap_element(VirtQueueElement *elem)
-{
-    int i;
-
-    /* This assumes that the iovecs, if changed, are never moved past
-     * the end of the valid area.  This is true if iovec manipulations
-     * are done with iov_discard_front and iov_discard_back.
-     */
-    for (i = 0; i < elem->out_num; i++) {
-        vring_unmap(elem->out_sg[i].iov_base, false);
-    }
-
-    for (i = 0; i < elem->in_num; i++) {
-        vring_unmap(elem->in_sg[i].iov_base, true);
-    }
-}
-
-/* This looks in the virtqueue and for the first available buffer, and converts
- * it to an iovec for convenient access.  Since descriptors consist of some
- * number of output then some number of input descriptors, it's actually two
- * iovecs, but we pack them into one and note how many of each there were.
- *
- * This function returns the descriptor number found, or vq->num (which is
- * never a valid descriptor number) if none was found.  A negative code is
- * returned on error.
- *
- * Stolen from linux/drivers/vhost/vhost.c.
- */
-void *vring_pop(VirtIODevice *vdev, Vring *vring, size_t sz)
-{
-    struct vring_desc desc;
-    unsigned int i, head, found = 0, num = vring->vr.num;
-    uint16_t avail_idx, last_avail_idx;
-    VirtQueueCurrentElement cur_elem;
-    VirtQueueElement *elem = NULL;
-    int ret;
-
-    /* If there was a fatal error then refuse operation */
-    if (vring->broken) {
-        ret = -EFAULT;
-        goto out;
-    }
-
-    cur_elem.in_num = cur_elem.out_num = 0;
-
-    /* Check it isn't doing very strange things with descriptor numbers. */
-    last_avail_idx = vring->last_avail_idx;
-    avail_idx = vring_get_avail_idx(vdev, vring);
-    barrier(); /* load indices now and not again later */
-
-    if (unlikely((uint16_t)(avail_idx - last_avail_idx) > num)) {
-        error_report("Guest moved used index from %u to %u",
-                     last_avail_idx, avail_idx);
-        ret = -EFAULT;
-        goto out;
-    }
-
-    /* If there's nothing new since last we looked. */
-    if (avail_idx == last_avail_idx) {
-        ret = -EAGAIN;
-        goto out;
-    }
-
-    /* Only get avail ring entries after they have been exposed by guest. */
-    smp_rmb();
-
-    /* Grab the next descriptor number they're advertising, and increment
-     * the index we've seen. */
-    head = vring_get_avail_ring(vdev, vring, last_avail_idx % num);
-
-    /* If their number is silly, that's an error. */
-    if (unlikely(head >= num)) {
-        error_report("Guest says index %u > %u is available", head, num);
-        ret = -EFAULT;
-        goto out;
-    }
-
-    i = head;
-    do {
-        if (unlikely(i >= num)) {
-            error_report("Desc index is %u > %u, head = %u", i, num, head);
-            ret = -EFAULT;
-            goto out;
-        }
-        if (unlikely(++found > num)) {
-            error_report("Loop detected: last one at %u vq size %u head %u",
-                         i, num, head);
-            ret = -EFAULT;
-            goto out;
-        }
-        copy_in_vring_desc(vdev, &vring->vr.desc[i], &desc);
-
-        /* Ensure descriptor is loaded before accessing fields */
-        barrier();
-
-        if (desc.flags & VRING_DESC_F_INDIRECT) {
-            ret = get_indirect(vdev, vring, &cur_elem, &desc);
-            if (ret < 0) {
-                goto out;
-            }
-            continue;
-        }
-
-        ret = get_desc(vring, &cur_elem, &desc);
-        if (ret < 0) {
-            goto out;
-        }
-
-        i = desc.next;
-    } while (desc.flags & VRING_DESC_F_NEXT);
-
-    /* On success, increment avail index. */
-    vring->last_avail_idx++;
-    if (virtio_vdev_has_feature(vdev, VIRTIO_RING_F_EVENT_IDX)) {
-        vring_avail_event(&vring->vr) =
-            virtio_tswap16(vdev, vring->last_avail_idx);
-    }
-
-    /* Now copy what we have collected and mapped */
-    elem = virtqueue_alloc_element(sz, cur_elem.out_num, cur_elem.in_num);
-    elem->index = head;
-    for (i = 0; i < cur_elem.out_num; i++) {
-        elem->out_addr[i] = cur_elem.addr[i];
-        elem->out_sg[i] = cur_elem.iov[i];
-    }
-    for (i = 0; i < cur_elem.in_num; i++) {
-        elem->in_addr[i] = cur_elem.addr[cur_elem.out_num + i];
-        elem->in_sg[i] = cur_elem.iov[cur_elem.out_num + i];
-    }
-
-    return elem;
-
-out:
-    assert(ret < 0);
-    if (ret == -EFAULT) {
-        vring->broken = true;
-    }
-
-    for (i = 0; i < cur_elem.out_num + cur_elem.in_num; i++) {
-        vring_unmap(cur_elem.iov[i].iov_base, false);
-    }
-
-    g_free(elem);
-    return NULL;
-}
-
-/* After we've used one of their buffers, we tell them about it.
- *
- * Stolen from linux/drivers/vhost/vhost.c.
- */
-void vring_push(VirtIODevice *vdev, Vring *vring, VirtQueueElement *elem,
-                int len)
-{
-    unsigned int head = elem->index;
-    uint16_t new;
-
-    vring_unmap_element(elem);
-
-    /* Don't touch vring if a fatal error occurred */
-    if (vring->broken) {
-        return;
-    }
-
-    /* The virtqueue contains a ring of used buffers.  Get a pointer to the
-     * next entry in that used ring. */
-    vring_set_used_ring_id(vdev, vring, vring->last_used_idx % vring->vr.num,
-                           head);
-    vring_set_used_ring_len(vdev, vring, vring->last_used_idx % vring->vr.num,
-                            len);
-
-    /* Make sure buffer is written before we update index. */
-    smp_wmb();
-
-    new = ++vring->last_used_idx;
-    vring_set_used_idx(vdev, vring, new);
-    if (unlikely((int16_t)(new - vring->signalled_used) < (uint16_t)1)) {
-        vring->signalled_used_valid = false;
-    }
-}
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index 7fde137..7ed3dd9 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -611,6 +611,25 @@ static int vhost_user_migration_done(struct vhost_dev *dev, char* mac_addr)
     return -1;
 }
 
+static bool vhost_user_can_merge(struct vhost_dev *dev,
+                                 uint64_t start1, uint64_t size1,
+                                 uint64_t start2, uint64_t size2)
+{
+    ram_addr_t ram_addr;
+    int mfd, rfd;
+    MemoryRegion *mr;
+
+    mr = qemu_ram_addr_from_host((void *)(uintptr_t)start1, &ram_addr);
+    assert(mr);
+    mfd = qemu_get_ram_fd(ram_addr);
+
+    mr = qemu_ram_addr_from_host((void *)(uintptr_t)start2, &ram_addr);
+    assert(mr);
+    rfd = qemu_get_ram_fd(ram_addr);
+
+    return mfd == rfd;
+}
+
 const VhostOps user_ops = {
         .backend_type = VHOST_BACKEND_TYPE_USER,
         .vhost_backend_init = vhost_user_init,
@@ -633,4 +652,5 @@ const VhostOps user_ops = {
         .vhost_set_vring_enable = vhost_user_set_vring_enable,
         .vhost_requires_shm_log = vhost_user_requires_shm_log,
         .vhost_migration_done = vhost_user_migration_done,
+        .vhost_backend_can_merge = vhost_user_can_merge,
 };
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 72d0c9e..392d848 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -260,6 +260,13 @@ static void vhost_dev_assign_memory(struct vhost_dev *dev,
             continue;
         }
 
+        if (dev->vhost_ops->vhost_backend_can_merge &&
+            !dev->vhost_ops->vhost_backend_can_merge(dev, uaddr, size,
+                                                     reg->userspace_addr,
+                                                     reg->memory_size)) {
+            continue;
+        }
+
         if (merged) {
             --to;
             assert(to >= 0);
diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c
index a382f43..e9c30e9 100644
--- a/hw/virtio/virtio-balloon.c
+++ b/hw/virtio/virtio-balloon.c
@@ -305,6 +305,39 @@ static void virtio_balloon_get_config(VirtIODevice *vdev, uint8_t *config_data)
     memcpy(config_data, &config, sizeof(struct virtio_balloon_config));
 }
 
+static int build_dimm_list(Object *obj, void *opaque)
+{
+    GSList **list = opaque;
+
+    if (object_dynamic_cast(obj, TYPE_PC_DIMM)) {
+        DeviceState *dev = DEVICE(obj);
+        if (dev->realized) { /* only realized DIMMs matter */
+            *list = g_slist_prepend(*list, dev);
+        }
+    }
+
+    object_child_foreach(obj, build_dimm_list, opaque);
+    return 0;
+}
+
+static ram_addr_t get_current_ram_size(void)
+{
+    GSList *list = NULL, *item;
+    ram_addr_t size = ram_size;
+
+    build_dimm_list(qdev_get_machine(), &list);
+    for (item = list; item; item = g_slist_next(item)) {
+        Object *obj = OBJECT(item->data);
+        if (!strcmp(object_get_typename(obj), TYPE_PC_DIMM)) {
+            size += object_property_get_int(obj, PC_DIMM_SIZE_PROP,
+                                            &error_abort);
+        }
+    }
+    g_slist_free(list);
+
+    return size;
+}
+
 static void virtio_balloon_set_config(VirtIODevice *vdev,
                                       const uint8_t *config_data)
 {
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index e365960..08275a9 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -1162,7 +1162,7 @@ void virtio_irq(VirtQueue *vq)
     virtio_notify_vector(vq->vdev, vq->vector);
 }
 
-static bool vring_notify(VirtIODevice *vdev, VirtQueue *vq)
+bool virtio_should_notify(VirtIODevice *vdev, VirtQueue *vq)
 {
     uint16_t old, new;
     bool v;
@@ -1187,7 +1187,7 @@ static bool vring_notify(VirtIODevice *vdev, VirtQueue *vq)
 
 void virtio_notify(VirtIODevice *vdev, VirtQueue *vq)
 {
-    if (!vring_notify(vdev, vq)) {
+    if (!virtio_should_notify(vdev, vq)) {
         return;
     }
 
@@ -1786,6 +1786,22 @@ static void virtio_queue_host_notifier_read(EventNotifier *n)
     }
 }
 
+void virtio_queue_aio_set_host_notifier_handler(VirtQueue *vq, AioContext *ctx,
+                                                bool assign, bool set_handler)
+{
+    if (assign && set_handler) {
+        aio_set_event_notifier(ctx, &vq->host_notifier, true,
+                               virtio_queue_host_notifier_read);
+    } else {
+        aio_set_event_notifier(ctx, &vq->host_notifier, true, NULL);
+    }
+    if (!assign) {
+        /* Test and clear notifier before after disabling event,
+         * in case poll callback didn't have time to run. */
+        virtio_queue_host_notifier_read(&vq->host_notifier);
+    }
+}
+
 void virtio_queue_set_host_notifier_fd_handler(VirtQueue *vq, bool assign,
                                                bool set_handler)
 {
diff --git a/include/exec/cpu-common.h b/include/exec/cpu-common.h
index 85aa403..a0ad2ac 100644
--- a/include/exec/cpu-common.h
+++ b/include/exec/cpu-common.h
@@ -54,7 +54,6 @@ typedef uintptr_t ram_addr_t;
 #endif
 
 extern ram_addr_t ram_size;
-ram_addr_t get_current_ram_size(void);
 
 /* memory API */
 
diff --git a/include/hw/acpi/bios-linker-loader.h b/include/hw/acpi/bios-linker-loader.h
index 721b7b9..82f1af6 100644
--- a/include/hw/acpi/bios-linker-loader.h
+++ b/include/hw/acpi/bios-linker-loader.h
@@ -11,7 +11,7 @@ void bios_linker_loader_alloc(GArray *linker,
                               bool alloc_fseg);
 
 void bios_linker_loader_add_checksum(GArray *linker, const char *file,
-                                     void *table,
+                                     GArray *table,
                                      void *start, unsigned size,
                                      uint8_t *checksum);
 
diff --git a/include/hw/acpi/ich9.h b/include/hw/acpi/ich9.h
index 345fd8d..63fa198 100644
--- a/include/hw/acpi/ich9.h
+++ b/include/hw/acpi/ich9.h
@@ -62,7 +62,6 @@ typedef struct ICH9LPCPMRegs {
 
 void ich9_pm_init(PCIDevice *lpc_pci, ICH9LPCPMRegs *pm,
                   bool smm_enabled,
-                  bool enable_tco,
                   qemu_irq sci_irq);
 
 void ich9_pm_iospace_update(ICH9LPCPMRegs *pm, uint32_t pm_io_base);
diff --git a/include/hw/boards.h b/include/hw/boards.h
index 0f30959..de3b3bd 100644
--- a/include/hw/boards.h
+++ b/include/hw/boards.h
@@ -84,7 +84,6 @@ struct MachineClass {
         no_cdrom:1,
         no_sdcard:1,
         has_dynamic_sysbus:1,
-        no_tco:1,
         pci_allow_0_address:1;
     int is_default;
     const char *default_machine_opts;
diff --git a/include/hw/i386/ich9.h b/include/hw/i386/ich9.h
index b9d2b04..b411434 100644
--- a/include/hw/i386/ich9.h
+++ b/include/hw/i386/ich9.h
@@ -17,7 +17,7 @@
 void ich9_lpc_set_irq(void *opaque, int irq_num, int level);
 int ich9_lpc_map_irq(PCIDevice *pci_dev, int intx);
 PCIINTxRoute ich9_route_intx_pin_to_irq(void *opaque, int pirq_pin);
-void ich9_lpc_pm_init(PCIDevice *pci_lpc, bool smm_enabled, bool enable_tco);
+void ich9_lpc_pm_init(PCIDevice *pci_lpc, bool smm_enabled);
 I2CBus *ich9_smb_init(PCIBus *bus, int devfn, uint32_t smb_io_base);
 
 void ich9_generate_smi(void);
diff --git a/include/hw/virtio/dataplane/vring-accessors.h b/include/hw/virtio/dataplane/vring-accessors.h
deleted file mode 100644
index 815c19b..0000000
--- a/include/hw/virtio/dataplane/vring-accessors.h
+++ /dev/null
@@ -1,75 +0,0 @@
-#ifndef VRING_ACCESSORS_H
-#define VRING_ACCESSORS_H
-
-#include "standard-headers/linux/virtio_ring.h"
-#include "hw/virtio/virtio.h"
-#include "hw/virtio/virtio-access.h"
-
-static inline uint16_t vring_get_used_idx(VirtIODevice *vdev, Vring *vring)
-{
-    return virtio_tswap16(vdev, vring->vr.used->idx);
-}
-
-static inline void vring_set_used_idx(VirtIODevice *vdev, Vring *vring,
-                                      uint16_t idx)
-{
-    vring->vr.used->idx = virtio_tswap16(vdev, idx);
-}
-
-static inline uint16_t vring_get_avail_idx(VirtIODevice *vdev, Vring *vring)
-{
-    return virtio_tswap16(vdev, vring->vr.avail->idx);
-}
-
-static inline uint16_t vring_get_avail_ring(VirtIODevice *vdev, Vring *vring,
-                                            int i)
-{
-    return virtio_tswap16(vdev, vring->vr.avail->ring[i]);
-}
-
-static inline void vring_set_used_ring_id(VirtIODevice *vdev, Vring *vring,
-                                          int i, uint32_t id)
-{
-    vring->vr.used->ring[i].id = virtio_tswap32(vdev, id);
-}
-
-static inline void vring_set_used_ring_len(VirtIODevice *vdev, Vring *vring,
-                                          int i, uint32_t len)
-{
-    vring->vr.used->ring[i].len = virtio_tswap32(vdev, len);
-}
-
-static inline uint16_t vring_get_used_flags(VirtIODevice *vdev, Vring *vring)
-{
-    return virtio_tswap16(vdev, vring->vr.used->flags);
-}
-
-static inline uint16_t vring_get_avail_flags(VirtIODevice *vdev, Vring *vring)
-{
-    return virtio_tswap16(vdev, vring->vr.avail->flags);
-}
-
-static inline void vring_set_used_flags(VirtIODevice *vdev, Vring *vring,
-                                        uint16_t flags)
-{
-    vring->vr.used->flags |= virtio_tswap16(vdev, flags);
-}
-
-static inline void vring_clear_used_flags(VirtIODevice *vdev, Vring *vring,
-                                          uint16_t flags)
-{
-    vring->vr.used->flags &= virtio_tswap16(vdev, ~flags);
-}
-
-static inline unsigned int vring_get_num(Vring *vring)
-{
-    return vring->vr.num;
-}
-
-/* Are there more descriptors available? */
-static inline bool vring_more_avail(VirtIODevice *vdev, Vring *vring)
-{
-    return vring_get_avail_idx(vdev, vring) != vring->last_avail_idx;
-}
-
-#endif
diff --git a/include/hw/virtio/dataplane/vring.h b/include/hw/virtio/dataplane/vring.h
deleted file mode 100644
index e80985e..0000000
--- a/include/hw/virtio/dataplane/vring.h
+++ /dev/null
@@ -1,51 +0,0 @@
-/* Copyright 2012 Red Hat, Inc. and/or its affiliates
- * Copyright IBM, Corp. 2012
- *
- * Based on Linux 2.6.39 vhost code:
- * Copyright (C) 2009 Red Hat, Inc.
- * Copyright (C) 2006 Rusty Russell IBM Corporation
- *
- * Author: Michael S. Tsirkin <mst@redhat.com>
- *         Stefan Hajnoczi <stefanha@redhat.com>
- *
- * Inspiration, some code, and most witty comments come from
- * Documentation/virtual/lguest/lguest.c, by Rusty Russell
- *
- * This work is licensed under the terms of the GNU GPL, version 2.
- */
-
-#ifndef VRING_H
-#define VRING_H
-
-#include "qemu-common.h"
-#include "standard-headers/linux/virtio_ring.h"
-#include "hw/virtio/virtio.h"
-
-typedef struct {
-    MemoryRegion *mr_desc;          /* memory region for the vring desc */
-    MemoryRegion *mr_avail;         /* memory region for the vring avail */
-    MemoryRegion *mr_used;          /* memory region for the vring used */
-    struct vring vr;                /* virtqueue vring mapped to host memory */
-    uint16_t last_avail_idx;        /* last processed avail ring index */
-    uint16_t last_used_idx;         /* last processed used ring index */
-    uint16_t signalled_used;        /* EVENT_IDX state */
-    bool signalled_used_valid;
-    bool broken;                    /* was there a fatal error? */
-} Vring;
-
-/* Fail future vring_pop() and vring_push() calls until reset */
-static inline void vring_set_broken(Vring *vring)
-{
-    vring->broken = true;
-}
-
-bool vring_setup(Vring *vring, VirtIODevice *vdev, int n);
-void vring_teardown(Vring *vring, VirtIODevice *vdev, int n);
-void vring_disable_notification(VirtIODevice *vdev, Vring *vring);
-bool vring_enable_notification(VirtIODevice *vdev, Vring *vring);
-bool vring_should_notify(VirtIODevice *vdev, Vring *vring);
-void *vring_pop(VirtIODevice *vdev, Vring *vring, size_t sz);
-void vring_push(VirtIODevice *vdev, Vring *vring, VirtQueueElement *elem,
-                int len);
-
-#endif /* VRING_H */
diff --git a/include/hw/virtio/vhost-backend.h b/include/hw/virtio/vhost-backend.h
index d6b012f..95fcc96 100644
--- a/include/hw/virtio/vhost-backend.h
+++ b/include/hw/virtio/vhost-backend.h
@@ -69,6 +69,9 @@ typedef int (*vhost_set_vring_enable_op)(struct vhost_dev *dev,
 typedef bool (*vhost_requires_shm_log_op)(struct vhost_dev *dev);
 typedef int (*vhost_migration_done_op)(struct vhost_dev *dev,
                                        char *mac_addr);
+typedef bool (*vhost_backend_can_merge_op)(struct vhost_dev *dev,
+                                           uint64_t start1, uint64_t size1,
+                                           uint64_t start2, uint64_t size2);
 
 typedef struct VhostOps {
     VhostBackendType backend_type;
@@ -96,6 +99,7 @@ typedef struct VhostOps {
     vhost_set_vring_enable_op vhost_set_vring_enable;
     vhost_requires_shm_log_op vhost_requires_shm_log;
     vhost_migration_done_op vhost_migration_done;
+    vhost_backend_can_merge_op vhost_backend_can_merge;
 } VhostOps;
 
 extern const VhostOps user_ops;
diff --git a/include/hw/virtio/virtio-blk.h b/include/hw/virtio/virtio-blk.h
index 199bb0e..ae84d92 100644
--- a/include/hw/virtio/virtio-blk.h
+++ b/include/hw/virtio/virtio-blk.h
@@ -53,9 +53,7 @@ typedef struct VirtIOBlock {
     unsigned short sector_mask;
     bool original_wce;
     VMChangeStateEntry *change;
-    /* Function to push to vq and notify guest */
-    void (*complete_request)(struct VirtIOBlockReq *req, unsigned char status);
-    Notifier migration_state_notifier;
+    bool dataplane_started;
     struct VirtIOBlockDataPlane *dataplane;
 } VirtIOBlock;
 
diff --git a/include/hw/virtio/virtio-scsi.h b/include/hw/virtio/virtio-scsi.h
index a8029aa..209eaa4 100644
--- a/include/hw/virtio/virtio-scsi.h
+++ b/include/hw/virtio/virtio-scsi.h
@@ -22,7 +22,6 @@
 #include "hw/pci/pci.h"
 #include "hw/scsi/scsi.h"
 #include "sysemu/iothread.h"
-#include "hw/virtio/dataplane/vring.h"
 
 #define TYPE_VIRTIO_SCSI_COMMON "virtio-scsi-common"
 #define VIRTIO_SCSI_COMMON(obj) \
@@ -58,13 +57,6 @@ struct VirtIOSCSIConf {
 
 struct VirtIOSCSI;
 
-typedef struct {
-    struct VirtIOSCSI *parent;
-    Vring vring;
-    EventNotifier host_notifier;
-    EventNotifier guest_notifier;
-} VirtIOSCSIVring;
-
 typedef struct VirtIOSCSICommon {
     VirtIODevice parent_obj;
     VirtIOSCSIConf conf;
@@ -96,18 +88,12 @@ typedef struct VirtIOSCSI {
     QTAILQ_HEAD(, VirtIOSCSIBlkChangeNotifier) insert_notifiers;
     QTAILQ_HEAD(, VirtIOSCSIBlkChangeNotifier) remove_notifiers;
 
-    /* Vring is used instead of vq in dataplane code, because of the underlying
-     * memory layer thread safety */
-    VirtIOSCSIVring *ctrl_vring;
-    VirtIOSCSIVring *event_vring;
-    VirtIOSCSIVring **cmd_vrings;
     bool dataplane_started;
     bool dataplane_starting;
     bool dataplane_stopping;
     bool dataplane_disabled;
     bool dataplane_fenced;
     Error *blocker;
-    Notifier migration_state_notifier;
     uint32_t host_features;
 } VirtIOSCSI;
 
@@ -123,9 +109,6 @@ typedef struct VirtIOSCSIReq {
     QEMUSGList qsgl;
     QEMUIOVector resp_iov;
 
-    /* Set by dataplane code. */
-    VirtIOSCSIVring *vring;
-
     union {
         /* Used for two-stage request submission */
         QTAILQ_ENTRY(VirtIOSCSIReq) next;
@@ -168,8 +151,6 @@ void virtio_scsi_push_event(VirtIOSCSI *s, SCSIDevice *dev,
 void virtio_scsi_set_iothread(VirtIOSCSI *s, IOThread *iothread);
 void virtio_scsi_dataplane_start(VirtIOSCSI *s);
 void virtio_scsi_dataplane_stop(VirtIOSCSI *s);
-void virtio_scsi_vring_push_notify(VirtIOSCSIReq *req);
-VirtIOSCSIReq *virtio_scsi_pop_req_vring(VirtIOSCSI *s,
-                                         VirtIOSCSIVring *vring);
+void virtio_scsi_dataplane_notify(VirtIODevice *vdev, VirtIOSCSIReq *req);
 
 #endif /* _QEMU_VIRTIO_SCSI_H */
diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index c38a2fe..2b5b248 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -163,6 +163,7 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes,
                                unsigned int *out_bytes,
                                unsigned max_in_bytes, unsigned max_out_bytes);
 
+bool virtio_should_notify(VirtIODevice *vdev, VirtQueue *vq);
 void virtio_notify(VirtIODevice *vdev, VirtQueue *vq);
 
 void virtio_save(VirtIODevice *vdev, QEMUFile *f);
@@ -249,6 +250,8 @@ void virtio_queue_set_guest_notifier_fd_handler(VirtQueue *vq, bool assign,
 EventNotifier *virtio_queue_get_host_notifier(VirtQueue *vq);
 void virtio_queue_set_host_notifier_fd_handler(VirtQueue *vq, bool assign,
                                                bool set_handler);
+void virtio_queue_aio_set_host_notifier_handler(VirtQueue *vq, AioContext *ctx,
+                                                bool assign, bool set_handler);
 void virtio_queue_notify_vq(VirtQueue *vq);
 void virtio_irq(VirtQueue *vq);
 VirtQueue *virtio_vector_first_queue(VirtIODevice *vdev, uint16_t vector);
diff --git a/migration/block.c b/migration/block.c
index 3a8330a..72883d7 100644
--- a/migration/block.c
+++ b/migration/block.c
@@ -54,17 +54,25 @@ typedef struct BlkMigDevState {
     int shared_base;
     int64_t total_sectors;
     QSIMPLEQ_ENTRY(BlkMigDevState) entry;
+    Error *blocker;
 
     /* Only used by migration thread.  Does not need a lock.  */
     int bulk_completed;
     int64_t cur_sector;
     int64_t cur_dirty;
 
-    /* Protected by block migration lock.  */
+    /* Data in the aio_bitmap is protected by block migration lock.
+     * Allocation and free happen during setup and cleanup respectively.
+     */
     unsigned long *aio_bitmap;
+
+    /* Protected by block migration lock.  */
     int64_t completed_sectors;
+
+    /* During migration this is protected by iothread lock / AioContext.
+     * Allocation and free happen during setup and cleanup respectively.
+     */
     BdrvDirtyBitmap *dirty_bitmap;
-    Error *blocker;
 } BlkMigDevState;
 
 typedef struct BlkMigBlock {
@@ -100,7 +108,7 @@ typedef struct BlkMigState {
     int prev_progress;
     int bulk_completed;
 
-    /* Lock must be taken _inside_ the iothread lock.  */
+    /* Lock must be taken _inside_ the iothread lock and any AioContexts.  */
     QemuMutex lock;
 } BlkMigState;
 
@@ -264,11 +272,13 @@ static int mig_save_device_bulk(QEMUFile *f, BlkMigDevState *bmds)
 
     if (bmds->shared_base) {
         qemu_mutex_lock_iothread();
+        aio_context_acquire(bdrv_get_aio_context(bs));
         while (cur_sector < total_sectors &&
                !bdrv_is_allocated(bs, cur_sector, MAX_IS_ALLOCATED_SEARCH,
                                   &nr_sectors)) {
             cur_sector += nr_sectors;
         }
+        aio_context_release(bdrv_get_aio_context(bs));
         qemu_mutex_unlock_iothread();
     }
 
@@ -302,11 +312,21 @@ static int mig_save_device_bulk(QEMUFile *f, BlkMigDevState *bmds)
     block_mig_state.submitted++;
     blk_mig_unlock();
 
+    /* We do not know if bs is under the main thread (and thus does
+     * not acquire the AioContext when doing AIO) or rather under
+     * dataplane.  Thus acquire both the iothread mutex and the
+     * AioContext.
+     *
+     * This is ugly and will disappear when we make bdrv_* thread-safe,
+     * without the need to acquire the AioContext.
+     */
     qemu_mutex_lock_iothread();
+    aio_context_acquire(bdrv_get_aio_context(bmds->bs));
     blk->aiocb = bdrv_aio_readv(bs, cur_sector, &blk->qiov,
                                 nr_sectors, blk_mig_read_cb, blk);
 
     bdrv_reset_dirty_bitmap(bmds->dirty_bitmap, cur_sector, nr_sectors);
+    aio_context_release(bdrv_get_aio_context(bmds->bs));
     qemu_mutex_unlock_iothread();
 
     bmds->cur_sector = cur_sector + nr_sectors;
@@ -321,8 +341,10 @@ static int set_dirty_tracking(void)
     int ret;
 
     QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
+        aio_context_acquire(bdrv_get_aio_context(bmds->bs));
         bmds->dirty_bitmap = bdrv_create_dirty_bitmap(bmds->bs, BLOCK_SIZE,
                                                       NULL, NULL);
+        aio_context_release(bdrv_get_aio_context(bmds->bs));
         if (!bmds->dirty_bitmap) {
             ret = -errno;
             goto fail;
@@ -333,18 +355,24 @@ static int set_dirty_tracking(void)
 fail:
     QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
         if (bmds->dirty_bitmap) {
+            aio_context_acquire(bdrv_get_aio_context(bmds->bs));
             bdrv_release_dirty_bitmap(bmds->bs, bmds->dirty_bitmap);
+            aio_context_release(bdrv_get_aio_context(bmds->bs));
         }
     }
     return ret;
 }
 
+/* Called with iothread lock taken.  */
+
 static void unset_dirty_tracking(void)
 {
     BlkMigDevState *bmds;
 
     QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
+        aio_context_acquire(bdrv_get_aio_context(bmds->bs));
         bdrv_release_dirty_bitmap(bmds->bs, bmds->dirty_bitmap);
+        aio_context_release(bdrv_get_aio_context(bmds->bs));
     }
 }
 
@@ -444,7 +472,7 @@ static void blk_mig_reset_dirty_cursor(void)
     }
 }
 
-/* Called with iothread lock taken.  */
+/* Called with iothread lock and AioContext taken.  */
 
 static int mig_save_device_dirty(QEMUFile *f, BlkMigDevState *bmds,
                                  int is_async)
@@ -527,7 +555,9 @@ static int blk_mig_save_dirty_block(QEMUFile *f, int is_async)
     int ret = 1;
 
     QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
+        aio_context_acquire(bdrv_get_aio_context(bmds->bs));
         ret = mig_save_device_dirty(f, bmds, is_async);
+        aio_context_release(bdrv_get_aio_context(bmds->bs));
         if (ret <= 0) {
             break;
         }
@@ -585,7 +615,9 @@ static int64_t get_remaining_dirty(void)
     int64_t dirty = 0;
 
     QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
+        aio_context_acquire(bdrv_get_aio_context(bmds->bs));
         dirty += bdrv_get_dirty_count(bmds->dirty_bitmap);
+        aio_context_release(bdrv_get_aio_context(bmds->bs));
     }
 
     return dirty << BDRV_SECTOR_BITS;
@@ -597,21 +629,28 @@ static void block_migration_cleanup(void *opaque)
 {
     BlkMigDevState *bmds;
     BlkMigBlock *blk;
+    AioContext *ctx;
 
     bdrv_drain_all();
 
     unset_dirty_tracking();
 
-    blk_mig_lock();
     while ((bmds = QSIMPLEQ_FIRST(&block_mig_state.bmds_list)) != NULL) {
         QSIMPLEQ_REMOVE_HEAD(&block_mig_state.bmds_list, entry);
         bdrv_op_unblock_all(bmds->bs, bmds->blocker);
         error_free(bmds->blocker);
+
+        /* Save ctx, because bmds->bs can disappear during bdrv_unref.  */
+        ctx = bdrv_get_aio_context(bmds->bs);
+        aio_context_acquire(ctx);
         bdrv_unref(bmds->bs);
+        aio_context_release(ctx);
+
         g_free(bmds->aio_bitmap);
         g_free(bmds);
     }
 
+    blk_mig_lock();
     while ((blk = QSIMPLEQ_FIRST(&block_mig_state.blk_list)) != NULL) {
         QSIMPLEQ_REMOVE_HEAD(&block_mig_state.blk_list, entry);
         g_free(blk->buf);
@@ -633,13 +672,12 @@ static int block_save_setup(QEMUFile *f, void *opaque)
     /* start track dirty blocks */
     ret = set_dirty_tracking();
 
+    qemu_mutex_unlock_iothread();
+
     if (ret) {
-        qemu_mutex_unlock_iothread();
         return ret;
     }
 
-    qemu_mutex_unlock_iothread();
-
     ret = flush_blks(f);
     blk_mig_reset_dirty_cursor();
     qemu_put_be64(f, BLK_MIG_FLAG_EOS);
@@ -761,17 +799,18 @@ static void block_save_pending(QEMUFile *f, void *opaque, uint64_t max_size,
     uint64_t pending;
 
     qemu_mutex_lock_iothread();
+    pending = get_remaining_dirty();
+    qemu_mutex_unlock_iothread();
+
     blk_mig_lock();
-    pending = get_remaining_dirty() +
-                       block_mig_state.submitted * BLOCK_SIZE +
-                       block_mig_state.read_done * BLOCK_SIZE;
+    pending += block_mig_state.submitted * BLOCK_SIZE +
+               block_mig_state.read_done * BLOCK_SIZE;
+    blk_mig_unlock();
 
     /* Report at least one block pending during bulk phase */
     if (pending <= max_size && !block_mig_state.bulk_completed) {
         pending = max_size + BLOCK_SIZE;
     }
-    blk_mig_unlock();
-    qemu_mutex_unlock_iothread();
 
     DPRINTF("Enter save live pending  %" PRIu64 "\n", pending);
     /* We don't do postcopy */
diff --git a/pc-bios/q35-acpi-dsdt.aml b/pc-bios/q35-acpi-dsdt.aml
deleted file mode 100644
index d71b3a3..0000000
--- a/pc-bios/q35-acpi-dsdt.aml
+++ /dev/null
diff --git a/stubs/qmp_pc_dimm_device_list.c b/stubs/qmp_pc_dimm_device_list.c
index a4af7fe..def2115 100644
--- a/stubs/qmp_pc_dimm_device_list.c
+++ b/stubs/qmp_pc_dimm_device_list.c
@@ -6,8 +6,3 @@ int qmp_pc_dimm_device_list(Object *obj, void *opaque)
 {
    return 0;
 }
-
-ram_addr_t get_current_ram_size(void)
-{
-    return ram_size;
-}
diff --git a/tests/vhost-user-bridge.c b/tests/vhost-user-bridge.c
index f2b6c67..0779ba26 100644
--- a/tests/vhost-user-bridge.c
+++ b/tests/vhost-user-bridge.c
@@ -414,7 +414,7 @@ vubr_message_read(int conn_fd, VhostUserMsg *vmsg)
     if (vmsg->size > sizeof(vmsg->payload)) {
         fprintf(stderr,
                 "Error: too big message request: %d, size: vmsg->size: %u, "
-                "while sizeof(vmsg->payload) = %lu\n",
+                "while sizeof(vmsg->payload) = %zu\n",
                 vmsg->request, vmsg->size, sizeof(vmsg->payload));
         exit(1);
     }
@@ -578,7 +578,7 @@ vubr_post_buffer(VubrDev *dev, VubrVirtq *vq, uint8_t *buf, int32_t len)
             exit(1);
         }
 
-        void *chunk_start = (void *)gpa_to_va(dev, desc[i].addr);
+        void *chunk_start = (void *)(uintptr_t)gpa_to_va(dev, desc[i].addr);
         uint32_t chunk_len = desc[i].len;
         uint32_t chunk_write_len = MIN(remaining_len, chunk_len);
 
@@ -641,7 +641,7 @@ vubr_process_desc(VubrDev *dev, VubrVirtq *vq)
     DPRINT("Chunks: ");
     i = d_index;
     do {
-        void *chunk_start = (void *)gpa_to_va(dev, desc[i].addr);
+        void *chunk_start = (void *)(uintptr_t)gpa_to_va(dev, desc[i].addr);
         uint32_t chunk_len = desc[i].len;
 
         assert(!(desc[i].flags & VRING_DESC_F_WRITE));
@@ -861,7 +861,7 @@ vubr_set_mem_table_exec(VubrDev *dev, VhostUserMsg *vmsg)
         if (mmap_addr == MAP_FAILED) {
             vubr_die("mmap");
         }
-        dev_region->mmap_addr = (uint64_t) mmap_addr;
+        dev_region->mmap_addr = (uint64_t)(uintptr_t)mmap_addr;
         DPRINT("    mmap_addr:       0x%016"PRIx64"\n", dev_region->mmap_addr);
 
         close(vmsg->fds[i]);
@@ -935,9 +935,9 @@ vubr_set_vring_addr_exec(VubrDev *dev, VhostUserMsg *vmsg)
     DPRINT("    avail_user_addr:  0x%016llx\n", vra->avail_user_addr);
     DPRINT("    log_guest_addr:   0x%016llx\n", vra->log_guest_addr);
 
-    vq->desc = (struct vring_desc *)qva_to_va(dev, vra->desc_user_addr);
-    vq->used = (struct vring_used *)qva_to_va(dev, vra->used_user_addr);
-    vq->avail = (struct vring_avail *)qva_to_va(dev, vra->avail_user_addr);
+    vq->desc = (struct vring_desc *)(uintptr_t)qva_to_va(dev, vra->desc_user_addr);
+    vq->used = (struct vring_used *)(uintptr_t)qva_to_va(dev, vra->used_user_addr);
+    vq->avail = (struct vring_avail *)(uintptr_t)qva_to_va(dev, vra->avail_user_addr);
     vq->log_guest_addr = vra->log_guest_addr;
 
     DPRINT("Setting virtq addresses:\n");
diff --git a/trace-events b/trace-events
index f986c81..61a133f 100644
--- a/trace-events
+++ b/trace-events
@@ -127,9 +127,6 @@ virtio_blk_data_plane_start(void *s) "dataplane %p"
 virtio_blk_data_plane_stop(void *s) "dataplane %p"
 virtio_blk_data_plane_process_request(void *s, unsigned int out_num, unsigned int in_num, unsigned int head) "dataplane %p out_num %u in_num %u head %u"
 
-# hw/virtio/dataplane/vring.c
-vring_setup(uint64_t physical, void *desc, void *avail, void *used) "vring physical %#"PRIx64" desc %p avail %p used %p"
-
 # thread-pool.c
 thread_pool_submit(void *pool, void *req, void *opaque) "pool %p req %p opaque %p"
 thread_pool_complete(void *pool, void *req, void *opaque, int ret) "pool %p req %p opaque %p ret %d"