[Qemu-devel] [PATCH 2/5] vfio/migration: support device of device config capability

[Yan Zhao]

Device config is the default data that every device should have. so
device config capability is by default on, no need to set.

- Currently two type of resources are saved/loaded for device of device
  config capability:
  General PCI config data, and Device config data.
  They are copies as a whole when precopy is stopped.

Migration setup flow:
- Setup device state regions, check its device state version and capabilities.
  Mmap Device Config Region and Dirty Bitmap Region, if available.
- If device state regions are failed to get setup, a migration blocker is
  registered instead.
- Added SaveVMHandlers to register device state save/load handlers.
- Register VM state change handler to set device's running/stop states.
- On migration startup on source machine, set device's state to
  VFIO_DEVICE_STATE_LOGGING

Signed-off-by: Yan Zhao <address@hidden>
Signed-off-by: Yulei Zhang <address@hidden>
---
 hw/vfio/Makefile.objs         |   2 +-
 hw/vfio/migration.c           | 633 ++++++++++++++++++++++++++++++++++++++++++
 hw/vfio/pci.c                 |   1 -
 hw/vfio/pci.h                 |  25 +-
 include/hw/vfio/vfio-common.h |   1 +
 5 files changed, 659 insertions(+), 3 deletions(-)
 create mode 100644 hw/vfio/migration.c

diff --git a/hw/vfio/Makefile.objs b/hw/vfio/Makefile.objs
index 8b3f664..f32ff19 100644
--- a/hw/vfio/Makefile.objs
+++ b/hw/vfio/Makefile.objs
@@ -1,6 +1,6 @@
 ifeq ($(CONFIG_LINUX), y)
 obj-$(CONFIG_SOFTMMU) += common.o
-obj-$(CONFIG_PCI) += pci.o pci-quirks.o display.o
+obj-$(CONFIG_PCI) += pci.o pci-quirks.o display.o migration.o
 obj-$(CONFIG_VFIO_CCW) += ccw.o
 obj-$(CONFIG_SOFTMMU) += platform.o
 obj-$(CONFIG_VFIO_XGMAC) += calxeda-xgmac.o
diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
new file mode 100644
index 0000000..16d6395
--- /dev/null
+++ b/hw/vfio/migration.c
@@ -0,0 +1,633 @@
+#include "qemu/osdep.h"
+
+#include "hw/vfio/vfio-common.h"
+#include "migration/blocker.h"
+#include "migration/register.h"
+#include "qapi/error.h"
+#include "pci.h"
+#include "sysemu/kvm.h"
+#include "exec/ram_addr.h"
+
+#define VFIO_SAVE_FLAG_SETUP 0
+#define VFIO_SAVE_FLAG_PCI 1
+#define VFIO_SAVE_FLAG_DEVCONFIG 2
+#define VFIO_SAVE_FLAG_DEVMEMORY 4
+#define VFIO_SAVE_FLAG_CONTINUE 8
+
+static int vfio_device_state_region_setup(VFIOPCIDevice *vdev,
+        VFIORegion *region, uint32_t subtype, const char *name)
+{
+    VFIODevice *vbasedev = &vdev->vbasedev;
+    struct vfio_region_info *info;
+    int ret;
+
+    ret = vfio_get_dev_region_info(vbasedev, VFIO_REGION_TYPE_DEVICE_STATE,
+            subtype, &info);
+    if (ret) {
+        error_report("Failed to get info of region %s", name);
+        return ret;
+    }
+
+    if (vfio_region_setup(OBJECT(vdev), vbasedev,
+            region, info->index, name)) {
+        error_report("Failed to setup migrtion region %s", name);
+        return ret;
+    }
+
+    if (vfio_region_mmap(region)) {
+        error_report("Failed to mmap migrtion region %s", name);
+    }
+
+    return 0;
+}
+
+bool vfio_device_data_cap_system_memory(VFIOPCIDevice *vdev)
+{
+   return !!(vdev->migration->data_caps & VFIO_DEVICE_DATA_CAP_SYSTEM_MEMORY);
+}
+
+bool vfio_device_data_cap_device_memory(VFIOPCIDevice *vdev)
+{
+   return !!(vdev->migration->data_caps & VFIO_DEVICE_DATA_CAP_DEVICE_MEMORY);
+}
+
+static bool vfio_device_state_region_mmaped(VFIORegion *region)
+{
+    bool mmaped = true;
+    if (region->nr_mmaps != 1 || region->mmaps[0].offset ||
+            (region->size != region->mmaps[0].size) ||
+            (region->mmaps[0].mmap == NULL)) {
+        mmaped = false;
+    }
+
+    return mmaped;
+}
+
+static int vfio_get_device_config_size(VFIOPCIDevice *vdev)
+{
+    VFIODevice *vbasedev = &vdev->vbasedev;
+    VFIORegion *region_ctl =
+        &vdev->migration->region[VFIO_DEVSTATE_REGION_CTL];
+    VFIORegion *region_config =
+        &vdev->migration->region[VFIO_DEVSTATE_REGION_DATA_CONFIG];
+    uint64_t len;
+    int sz;
+
+    sz = sizeof(len);
+    if (pread(vbasedev->fd, &len, sz,
+                region_ctl->fd_offset +
+                offsetof(struct vfio_device_state_ctl, device_config.size))
+            != sz) {
+        error_report("vfio: Failed to get length of device config");
+        return -1;
+    }
+    if (len > region_config->size) {
+        error_report("vfio: Error device config length");
+        return -1;
+    }
+    vdev->migration->devconfig_size = len;
+
+    return 0;
+}
+
+static int vfio_set_device_config_size(VFIOPCIDevice *vdev, uint64_t size)
+{
+    VFIODevice *vbasedev = &vdev->vbasedev;
+    VFIORegion *region_ctl =
+        &vdev->migration->region[VFIO_DEVSTATE_REGION_CTL];
+    VFIORegion *region_config =
+        &vdev->migration->region[VFIO_DEVSTATE_REGION_DATA_CONFIG];
+    int sz;
+
+    if (size > region_config->size) {
+        return -1;
+    }
+
+    sz = sizeof(size);
+    if (pwrite(vbasedev->fd, &size, sz,
+                region_ctl->fd_offset +
+                offsetof(struct vfio_device_state_ctl, device_config.size))
+            != sz) {
+        error_report("vfio: Failed to set length of device config");
+        return -1;
+    }
+    vdev->migration->devconfig_size = size;
+    return 0;
+}
+
+static int vfio_save_data_device_config(VFIOPCIDevice *vdev, QEMUFile *f)
+{
+    VFIODevice *vbasedev = &vdev->vbasedev;
+    VFIORegion *region_ctl =
+        &vdev->migration->region[VFIO_DEVSTATE_REGION_CTL];
+    VFIORegion *region_config =
+        &vdev->migration->region[VFIO_DEVSTATE_REGION_DATA_CONFIG];
+    void *dest;
+    uint32_t sz;
+    uint8_t *buf = NULL;
+    uint32_t action = VFIO_DEVICE_DATA_ACTION_GET_BUFFER;
+    uint64_t len = vdev->migration->devconfig_size;
+
+    qemu_put_be64(f, len);
+
+    sz = sizeof(action);
+    if (pwrite(vbasedev->fd, &action, sz,
+                region_ctl->fd_offset +
+                offsetof(struct vfio_device_state_ctl, device_config.action))
+            != sz) {
+        error_report("vfio: action failure for device config get buffer");
+        return -1;
+    }
+
+    if (!vfio_device_state_region_mmaped(region_config)) {
+        buf = g_malloc(len);
+        if (buf == NULL) {
+            error_report("vfio: Failed to allocate memory for migrate");
+            return -1;
+        }
+        if (pread(vbasedev->fd, buf, len, region_config->fd_offset) != len) {
+            error_report("vfio: Failed read device config buffer");
+            return -1;
+        }
+        qemu_put_buffer(f, buf, len);
+        g_free(buf);
+    } else {
+        dest = region_config->mmaps[0].mmap;
+        qemu_put_buffer(f, dest, len);
+    }
+    return 0;
+}
+
+static int vfio_load_data_device_config(VFIOPCIDevice *vdev,
+                            QEMUFile *f, uint64_t len)
+{
+    VFIODevice *vbasedev = &vdev->vbasedev;
+    VFIORegion *region_ctl =
+        &vdev->migration->region[VFIO_DEVSTATE_REGION_CTL];
+    VFIORegion *region_config =
+        &vdev->migration->region[VFIO_DEVSTATE_REGION_DATA_CONFIG];
+    void *dest;
+    uint32_t sz;
+    uint8_t *buf = NULL;
+    uint32_t action = VFIO_DEVICE_DATA_ACTION_SET_BUFFER;
+
+    vfio_set_device_config_size(vdev, len);
+
+    if (!vfio_device_state_region_mmaped(region_config)) {
+        buf = g_malloc(len);
+        if (buf == NULL) {
+            error_report("vfio: Failed to allocate memory for migrate");
+            return -1;
+        }
+        qemu_get_buffer(f, buf, len);
+        if (pwrite(vbasedev->fd, buf, len,
+                    region_config->fd_offset) != len) {
+            error_report("vfio: Failed to write devie config buffer");
+            return -1;
+        }
+        g_free(buf);
+    } else {
+        dest = region_config->mmaps[0].mmap;
+        qemu_get_buffer(f, dest, len);
+    }
+
+    sz = sizeof(action);
+    if (pwrite(vbasedev->fd, &action, sz,
+                region_ctl->fd_offset +
+                offsetof(struct vfio_device_state_ctl, device_config.action))
+            != sz) {
+        error_report("vfio: action failure for device config set buffer");
+        return -1;
+    }
+
+    return 0;
+}
+
+static int vfio_set_dirty_page_bitmap_chunk(VFIOPCIDevice *vdev,
+        uint64_t start_addr, uint64_t page_nr)
+{
+
+    VFIODevice *vbasedev = &vdev->vbasedev;
+    VFIORegion *region_ctl =
+        &vdev->migration->region[VFIO_DEVSTATE_REGION_CTL];
+    VFIORegion *region_bitmap =
+        &vdev->migration->region[VFIO_DEVSTATE_REGION_DATA_BITMAP];
+    unsigned long bitmap_size =
+                    BITS_TO_LONGS(page_nr) * sizeof(unsigned long);
+    uint32_t sz;
+
+    struct {
+        __u64 start_addr;
+        __u64 page_nr;
+    } system_memory;
+    system_memory.start_addr = start_addr;
+    system_memory.page_nr = page_nr;
+    sz = sizeof(system_memory);
+    if (pwrite(vbasedev->fd, &system_memory, sz,
+                region_ctl->fd_offset +
+                offsetof(struct vfio_device_state_ctl, system_memory))
+            != sz) {
+        error_report("vfio: Failed to set system memory range for dirty 
pages");
+        return -1;
+    }
+
+    if (!vfio_device_state_region_mmaped(region_bitmap)) {
+        void *bitmap = g_malloc0(bitmap_size);
+
+        if (pread(vbasedev->fd, bitmap, bitmap_size,
+                    region_bitmap->fd_offset) != bitmap_size) {
+            error_report("vfio: Failed to read dirty bitmap data");
+            return -1;
+        }
+
+        cpu_physical_memory_set_dirty_lebitmap(bitmap, start_addr, page_nr);
+
+        g_free(bitmap);
+    } else {
+        cpu_physical_memory_set_dirty_lebitmap(
+                    region_bitmap->mmaps[0].mmap,
+                    start_addr, page_nr);
+    }
+   return 0;
+}
+
+int vfio_set_dirty_page_bitmap(VFIOPCIDevice *vdev,
+        uint64_t start_addr, uint64_t page_nr)
+{
+    VFIORegion *region_bitmap =
+        &vdev->migration->region[VFIO_DEVSTATE_REGION_DATA_BITMAP];
+    unsigned long chunk_size = region_bitmap->size;
+    uint64_t chunk_pg_nr = (chunk_size / sizeof(unsigned long)) *
+                                BITS_PER_LONG;
+
+    uint64_t cnt_left;
+    int rc = 0;
+
+    cnt_left = page_nr;
+
+    while (cnt_left >= chunk_pg_nr) {
+        rc = vfio_set_dirty_page_bitmap_chunk(vdev, start_addr, chunk_pg_nr);
+        if (rc) {
+            goto exit;
+        }
+        cnt_left -= chunk_pg_nr;
+        start_addr += start_addr;
+   }
+   rc = vfio_set_dirty_page_bitmap_chunk(vdev, start_addr, cnt_left);
+
+exit:
+   return rc;
+}
+
+static int vfio_set_device_state(VFIOPCIDevice *vdev,
+        uint32_t dev_state)
+{
+    VFIODevice *vbasedev = &vdev->vbasedev;
+    VFIORegion *region =
+        &vdev->migration->region[VFIO_DEVSTATE_REGION_CTL];
+    uint32_t sz = sizeof(dev_state);
+
+    if (!vdev->migration) {
+        return -1;
+    }
+
+    if (pwrite(vbasedev->fd, &dev_state, sz,
+              region->fd_offset +
+              offsetof(struct vfio_device_state_ctl, device_state))
+            != sz) {
+        error_report("vfio: Failed to set device state %d", dev_state);
+        return -1;
+    }
+    vdev->migration->device_state = dev_state;
+    return 0;
+}
+
+static int vfio_get_device_data_caps(VFIOPCIDevice *vdev)
+{
+    VFIODevice *vbasedev = &vdev->vbasedev;
+    VFIORegion *region =
+        &vdev->migration->region[VFIO_DEVSTATE_REGION_CTL];
+
+    uint32_t caps;
+    uint32_t size = sizeof(caps);
+
+    if (pread(vbasedev->fd, &caps, size,
+                region->fd_offset +
+                offsetof(struct vfio_device_state_ctl, caps))
+            != size) {
+        error_report("%s Failed to read data caps of device states",
+                vbasedev->name);
+        return -1;
+    }
+    vdev->migration->data_caps = caps;
+    return 0;
+}
+
+
+static int vfio_check_devstate_version(VFIOPCIDevice *vdev)
+{
+    VFIODevice *vbasedev = &vdev->vbasedev;
+    VFIORegion *region =
+        &vdev->migration->region[VFIO_DEVSTATE_REGION_CTL];
+
+    uint32_t version;
+    uint32_t size = sizeof(version);
+
+    if (pread(vbasedev->fd, &version, size,
+                region->fd_offset +
+                offsetof(struct vfio_device_state_ctl, version))
+            != size) {
+        error_report("%s Failed to read version of device state interfaces",
+                vbasedev->name);
+        return -1;
+    }
+
+    if (version != VFIO_DEVICE_STATE_INTERFACE_VERSION) {
+        error_report("%s migration version mismatch, right version is %d",
+                vbasedev->name, VFIO_DEVICE_STATE_INTERFACE_VERSION);
+        return -1;
+    }
+
+    return 0;
+}
+
+static void vfio_vm_change_state_handler(void *pv, int running, RunState state)
+{
+    VFIOPCIDevice *vdev = pv;
+    uint32_t dev_state = vdev->migration->device_state;
+
+    if (!running) {
+        dev_state |= VFIO_DEVICE_STATE_STOP;
+    } else {
+        dev_state &= ~VFIO_DEVICE_STATE_STOP;
+    }
+
+    vfio_set_device_state(vdev, dev_state);
+}
+
+static void vfio_save_live_pending(QEMUFile *f, void *opaque,
+                                   uint64_t max_size,
+                                   uint64_t *res_precopy_only,
+                                   uint64_t *res_compatible,
+                                   uint64_t *res_post_copy_only)
+{
+    VFIOPCIDevice *vdev = opaque;
+
+    if (!vfio_device_data_cap_device_memory(vdev)) {
+        return;
+    }
+
+    return;
+}
+
+static int vfio_save_iterate(QEMUFile *f, void *opaque)
+{
+    VFIOPCIDevice *vdev = opaque;
+
+    if (!vfio_device_data_cap_device_memory(vdev)) {
+        return 0;
+    }
+
+    return 0;
+}
+
+static void vfio_pci_load_config(VFIOPCIDevice *vdev, QEMUFile *f)
+{
+    PCIDevice *pdev = &vdev->pdev;
+    uint32_t ctl, msi_lo, msi_hi, msi_data, bar_cfg, i;
+    bool msi_64bit;
+
+    /* retore pci bar configuration */
+    ctl = pci_default_read_config(pdev, PCI_COMMAND, 2);
+    vfio_pci_write_config(pdev, PCI_COMMAND,
+            ctl & (!(PCI_COMMAND_IO | PCI_COMMAND_MEMORY)), 2);
+    for (i = 0; i < PCI_ROM_SLOT; i++) {
+        bar_cfg = qemu_get_be32(f);
+        vfio_pci_write_config(pdev, PCI_BASE_ADDRESS_0 + i * 4, bar_cfg, 4);
+    }
+    vfio_pci_write_config(pdev, PCI_COMMAND,
+            ctl | PCI_COMMAND_IO | PCI_COMMAND_MEMORY, 2);
+
+    /* restore msi configuration */
+    ctl = pci_default_read_config(pdev, pdev->msi_cap + PCI_MSI_FLAGS, 2);
+    msi_64bit = !!(ctl & PCI_MSI_FLAGS_64BIT);
+
+    vfio_pci_write_config(&vdev->pdev,
+            pdev->msi_cap + PCI_MSI_FLAGS,
+            ctl & (!PCI_MSI_FLAGS_ENABLE), 2);
+
+    msi_lo = qemu_get_be32(f);
+    vfio_pci_write_config(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_LO, msi_lo, 4);
+
+    if (msi_64bit) {
+        msi_hi = qemu_get_be32(f);
+        vfio_pci_write_config(pdev, pdev->msi_cap + PCI_MSI_ADDRESS_HI,
+                msi_hi, 4);
+    }
+    msi_data = qemu_get_be32(f);
+    vfio_pci_write_config(pdev,
+            pdev->msi_cap + (msi_64bit ? PCI_MSI_DATA_64 : PCI_MSI_DATA_32),
+            msi_data, 2);
+
+    vfio_pci_write_config(&vdev->pdev, pdev->msi_cap + PCI_MSI_FLAGS,
+            ctl | PCI_MSI_FLAGS_ENABLE, 2);
+
+}
+
+static int vfio_load_state(QEMUFile *f, void *opaque, int version_id)
+{
+    VFIOPCIDevice *vdev = opaque;
+    int flag;
+    uint64_t len;
+    int ret = 0;
+
+    if (version_id != VFIO_DEVICE_STATE_INTERFACE_VERSION) {
+        return -EINVAL;
+    }
+
+    do {
+        flag = qemu_get_byte(f);
+
+        switch (flag & ~VFIO_SAVE_FLAG_CONTINUE) {
+        case VFIO_SAVE_FLAG_SETUP:
+            break;
+        case VFIO_SAVE_FLAG_PCI:
+            vfio_pci_load_config(vdev, f);
+            break;
+        case VFIO_SAVE_FLAG_DEVCONFIG:
+            len = qemu_get_be64(f);
+            vfio_load_data_device_config(vdev, f, len);
+            break;
+        default:
+            ret = -EINVAL;
+        }
+    } while (flag & VFIO_SAVE_FLAG_CONTINUE);
+
+    return ret;
+}
+
+static void vfio_pci_save_config(VFIOPCIDevice *vdev, QEMUFile *f)
+{
+    PCIDevice *pdev = &vdev->pdev;
+    uint32_t msi_cfg, msi_lo, msi_hi, msi_data, bar_cfg, i;
+    bool msi_64bit;
+
+    for (i = 0; i < PCI_ROM_SLOT; i++) {
+        bar_cfg = pci_default_read_config(pdev, PCI_BASE_ADDRESS_0 + i * 4, 4);
+        qemu_put_be32(f, bar_cfg);
+    }
+
+    msi_cfg = pci_default_read_config(pdev, pdev->msi_cap + PCI_MSI_FLAGS, 2);
+    msi_64bit = !!(msi_cfg & PCI_MSI_FLAGS_64BIT);
+
+    msi_lo = pci_default_read_config(pdev,
+            pdev->msi_cap + PCI_MSI_ADDRESS_LO, 4);
+    qemu_put_be32(f, msi_lo);
+
+    if (msi_64bit) {
+        msi_hi = pci_default_read_config(pdev,
+                pdev->msi_cap + PCI_MSI_ADDRESS_HI,
+                4);
+        qemu_put_be32(f, msi_hi);
+    }
+
+    msi_data = pci_default_read_config(pdev,
+            pdev->msi_cap + (msi_64bit ? PCI_MSI_DATA_64 : PCI_MSI_DATA_32),
+            2);
+    qemu_put_be32(f, msi_data);
+
+}
+
+static int vfio_save_complete_precopy(QEMUFile *f, void *opaque)
+{
+    VFIOPCIDevice *vdev = opaque;
+    int rc = 0;
+
+    qemu_put_byte(f, VFIO_SAVE_FLAG_PCI | VFIO_SAVE_FLAG_CONTINUE);
+    vfio_pci_save_config(vdev, f);
+
+    qemu_put_byte(f, VFIO_SAVE_FLAG_DEVCONFIG);
+    rc += vfio_get_device_config_size(vdev);
+    rc += vfio_save_data_device_config(vdev, f);
+
+    return rc;
+}
+
+static int vfio_save_setup(QEMUFile *f, void *opaque)
+{
+    VFIOPCIDevice *vdev = opaque;
+    qemu_put_byte(f, VFIO_SAVE_FLAG_SETUP);
+
+    vfio_set_device_state(vdev, VFIO_DEVICE_STATE_RUNNING |
+            VFIO_DEVICE_STATE_LOGGING);
+    return 0;
+}
+
+static int vfio_load_setup(QEMUFile *f, void *opaque)
+{
+    return 0;
+}
+
+static void vfio_save_cleanup(void *opaque)
+{
+    VFIOPCIDevice *vdev = opaque;
+    uint32_t dev_state = vdev->migration->device_state;
+
+    dev_state &= ~VFIO_DEVICE_STATE_LOGGING;
+
+    vfio_set_device_state(vdev, dev_state);
+}
+
+static SaveVMHandlers savevm_vfio_handlers = {
+    .save_setup = vfio_save_setup,
+    .save_live_pending = vfio_save_live_pending,
+    .save_live_iterate = vfio_save_iterate,
+    .save_live_complete_precopy = vfio_save_complete_precopy,
+    .save_cleanup = vfio_save_cleanup,
+    .load_setup = vfio_load_setup,
+    .load_state = vfio_load_state,
+};
+
+int vfio_migration_init(VFIOPCIDevice *vdev, Error **errp)
+{
+    int ret;
+    Error *local_err = NULL;
+    vdev->migration = g_new0(VFIOMigration, 1);
+
+    if (vfio_device_state_region_setup(vdev,
+              &vdev->migration->region[VFIO_DEVSTATE_REGION_CTL],
+              VFIO_REGION_SUBTYPE_DEVICE_STATE_CTL,
+              "device-state-ctl")) {
+        goto error;
+    }
+
+    if (vfio_check_devstate_version(vdev)) {
+        goto error;
+    }
+
+    if (vfio_get_device_data_caps(vdev)) {
+        goto error;
+    }
+
+    if (vfio_device_state_region_setup(vdev,
+              &vdev->migration->region[VFIO_DEVSTATE_REGION_DATA_CONFIG],
+              VFIO_REGION_SUBTYPE_DEVICE_STATE_DATA_CONFIG,
+              "device-state-data-device-config")) {
+        goto error;
+    }
+
+    if (vfio_device_data_cap_device_memory(vdev)) {
+        error_report("No suppport of data cap device memory Yet");
+        goto error;
+    }
+
+    if (vfio_device_data_cap_system_memory(vdev) &&
+            vfio_device_state_region_setup(vdev,
+              &vdev->migration->region[VFIO_DEVSTATE_REGION_DATA_BITMAP],
+              VFIO_REGION_SUBTYPE_DEVICE_STATE_DATA_DIRTYBITMAP,
+              "device-state-data-dirtybitmap")) {
+        goto error;
+    }
+
+    vdev->migration->device_state = VFIO_DEVICE_STATE_RUNNING;
+
+    register_savevm_live(NULL, TYPE_VFIO_PCI, -1,
+            VFIO_DEVICE_STATE_INTERFACE_VERSION,
+            &savevm_vfio_handlers,
+            vdev);
+
+    vdev->migration->vm_state =
+        qemu_add_vm_change_state_handler(vfio_vm_change_state_handler, vdev);
+
+    return 0;
+error:
+    error_setg(&vdev->migration_blocker,
+            "VFIO device doesn't support migration");
+    ret = migrate_add_blocker(vdev->migration_blocker, &local_err);
+    if (local_err) {
+        error_propagate(errp, local_err);
+        error_free(vdev->migration_blocker);
+    }
+
+    g_free(vdev->migration);
+    vdev->migration = NULL;
+
+    return ret;
+}
+
+void vfio_migration_finalize(VFIOPCIDevice *vdev)
+{
+    if (vdev->migration) {
+        int i;
+        qemu_del_vm_change_state_handler(vdev->migration->vm_state);
+        unregister_savevm(NULL, TYPE_VFIO_PCI, vdev);
+        for (i = 0; i < VFIO_DEVSTATE_REGION_NUM; i++) {
+            vfio_region_finalize(&vdev->migration->region[i]);
+        }
+        g_free(vdev->migration);
+        vdev->migration = NULL;
+    } else if (vdev->migration_blocker) {
+        migrate_del_blocker(vdev->migration_blocker);
+        error_free(vdev->migration_blocker);
+    }
+}
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index c0cb1ec..b8e006b 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -37,7 +37,6 @@
 
 #define MSIX_CAP_LENGTH 12
 
-#define TYPE_VFIO_PCI "vfio-pci"
 #define PCI_VFIO(obj)    OBJECT_CHECK(VFIOPCIDevice, obj, TYPE_VFIO_PCI)
 
 static void vfio_disable_interrupts(VFIOPCIDevice *vdev);
diff --git a/hw/vfio/pci.h b/hw/vfio/pci.h
index b1ae4c0..4b7b1bb 100644
--- a/hw/vfio/pci.h
+++ b/hw/vfio/pci.h
@@ -19,6 +19,7 @@
 #include "qemu/event_notifier.h"
 #include "qemu/queue.h"
 #include "qemu/timer.h"
+#include "sysemu/sysemu.h"
 
 #define PCI_ANY_ID (~0)
 
@@ -56,6 +57,21 @@ typedef struct VFIOBAR {
     QLIST_HEAD(, VFIOQuirk) quirks;
 } VFIOBAR;
 
+enum {
+    VFIO_DEVSTATE_REGION_CTL = 0,
+    VFIO_DEVSTATE_REGION_DATA_CONFIG,
+    VFIO_DEVSTATE_REGION_DATA_DEVICE_MEMORY,
+    VFIO_DEVSTATE_REGION_DATA_BITMAP,
+    VFIO_DEVSTATE_REGION_NUM,
+};
+typedef struct VFIOMigration {
+    VFIORegion region[VFIO_DEVSTATE_REGION_NUM];
+    uint32_t data_caps;
+    uint32_t device_state;
+    uint64_t devconfig_size;
+    VMChangeStateEntry *vm_state;
+} VFIOMigration;
+
 typedef struct VFIOVGARegion {
     MemoryRegion mem;
     off_t offset;
@@ -132,6 +148,8 @@ typedef struct VFIOPCIDevice {
     VFIOBAR bars[PCI_NUM_REGIONS - 1]; /* No ROM */
     VFIOVGA *vga; /* 0xa0000, 0x3b0, 0x3c0 */
     void *igd_opregion;
+    VFIOMigration *migration;
+    Error *migration_blocker;
     PCIHostDeviceAddress host;
     EventNotifier err_notifier;
     EventNotifier req_notifier;
@@ -198,5 +216,10 @@ int vfio_pci_igd_opregion_init(VFIOPCIDevice *vdev,
 void vfio_display_reset(VFIOPCIDevice *vdev);
 int vfio_display_probe(VFIOPCIDevice *vdev, Error **errp);
 void vfio_display_finalize(VFIOPCIDevice *vdev);
-
+bool vfio_device_data_cap_system_memory(VFIOPCIDevice *vdev);
+bool vfio_device_data_cap_device_memory(VFIOPCIDevice *vdev);
+int vfio_set_dirty_page_bitmap(VFIOPCIDevice *vdev,
+         uint64_t start_addr, uint64_t page_nr);
+int vfio_migration_init(VFIOPCIDevice *vdev, Error **errp);
+void vfio_migration_finalize(VFIOPCIDevice *vdev);
 #endif /* HW_VFIO_VFIO_PCI_H */
diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index 1b434d0..ed43613 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -32,6 +32,7 @@
 #endif
 
 #define VFIO_MSG_PREFIX "vfio %s: "
+#define TYPE_VFIO_PCI "vfio-pci"
 
 enum {
     VFIO_DEVICE_TYPE_PCI = 0,
-- 
2.7.4