diff --git a/docs/devel/vfio-migration.rst b/docs/devel/vfio-migration.rst
index e896b2a673..b433cb5bb2 100644
--- a/docs/devel/vfio-migration.rst
+++ b/docs/devel/vfio-migration.rst
@@ -16,6 +16,13 @@ helps to reduce the total downtime of the VM. VFIO devices opt-in to pre-copy
 support by reporting the VFIO_MIGRATION_PRE_COPY flag in the
 VFIO_DEVICE_FEATURE_MIGRATION ioctl.
 
+When pre-copy is supported, it's possible to further reduce downtime by
+enabling "switchover-ack" migration capability.
+VFIO migration uAPI defines "initial bytes" as part of its pre-copy data stream
+and recommends that the initial bytes are sent and loaded in the destination
+before stopping the source VM. Enabling this migration capability will
+guarantee that and thus, can potentially reduce downtime even further.
+
 Note that currently VFIO migration is supported only for a single device. This
 is due to VFIO migration's lack of P2P support. However, P2P support is planned
 to be added later on.
@@ -45,6 +52,9 @@ VFIO implements the device hooks for the iterative approach as follows:
 * A ``save_live_iterate`` function that reads the VFIO device's data from the
   vendor driver during iterative pre-copy phase.
 
+* A ``switchover_ack_needed`` function that checks if the VFIO device uses
+  "switchover-ack" migration capability when this capability is enabled.
+
 * A ``save_state`` function to save the device config space if it is present.
 
 * A ``save_live_complete_precopy`` function that sets the VFIO device in
diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index 1db901c194..3dc5f2104c 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -69,6 +69,7 @@ typedef struct VFIOMigration {
     uint64_t mig_flags;
     uint64_t precopy_init_size;
     uint64_t precopy_dirty_size;
+    bool initial_data_sent;
 } VFIOMigration;
 
 typedef struct VFIOAddressSpace {
diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
index d8f6a22ae1..acbf0bb7ab 100644
--- a/hw/vfio/migration.c
+++ b/hw/vfio/migration.c
@@ -18,6 +18,8 @@
 #include "sysemu/runstate.h"
 #include "hw/vfio/vfio-common.h"
 #include "migration/migration.h"
+#include "migration/options.h"
+#include "migration/savevm.h"
 #include "migration/vmstate.h"
 #include "migration/qemu-file.h"
 #include "migration/register.h"
@@ -45,6 +47,7 @@
 #define VFIO_MIG_FLAG_DEV_CONFIG_STATE  (0xffffffffef100002ULL)
 #define VFIO_MIG_FLAG_DEV_SETUP_STATE   (0xffffffffef100003ULL)
 #define VFIO_MIG_FLAG_DEV_DATA_STATE    (0xffffffffef100004ULL)
+#define VFIO_MIG_FLAG_DEV_INIT_DATA_SENT (0xffffffffef100005ULL)
 
 /*
  * This is an arbitrary size based on migration of mlx5 devices, where typically
@@ -384,6 +387,7 @@ static void vfio_save_cleanup(void *opaque)
     migration->data_buffer = NULL;
     migration->precopy_init_size = 0;
     migration->precopy_dirty_size = 0;
+    migration->initial_data_sent = false;
     vfio_migration_cleanup(vbasedev);
     trace_vfio_save_cleanup(vbasedev->name);
 }
@@ -457,10 +461,17 @@ static int vfio_save_iterate(QEMUFile *f, void *opaque)
     if (data_size < 0) {
         return data_size;
     }
-    qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE);
 
     vfio_update_estimated_pending_data(migration, data_size);
 
+    if (migrate_switchover_ack() && !migration->precopy_init_size &&
+        !migration->initial_data_sent) {
+        qemu_put_be64(f, VFIO_MIG_FLAG_DEV_INIT_DATA_SENT);
+        migration->initial_data_sent = true;
+    } else {
+        qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE);
+    }
+
     trace_vfio_save_iterate(vbasedev->name, migration->precopy_init_size,
                             migration->precopy_dirty_size);
 
@@ -579,6 +590,24 @@ static int vfio_load_state(QEMUFile *f, void *opaque, int version_id)
             }
             break;
         }
+        case VFIO_MIG_FLAG_DEV_INIT_DATA_SENT:
+        {
+            if (!vfio_precopy_supported(vbasedev) ||
+                !migrate_switchover_ack()) {
+                error_report("%s: Received INIT_DATA_SENT but switchover ack "
+                             "is not used", vbasedev->name);
+                return -EINVAL;
+            }
+
+            ret = qemu_loadvm_approve_switchover();
+            if (ret) {
+                error_report(
+                    "%s: qemu_loadvm_approve_switchover failed, err=%d (%s)",
+                    vbasedev->name, ret, strerror(-ret));
+            }
+
+            return ret;
+        }
         default:
             error_report("%s: Unknown tag 0x%"PRIx64, vbasedev->name, data);
             return -EINVAL;
@@ -593,6 +622,13 @@ static int vfio_load_state(QEMUFile *f, void *opaque, int version_id)
     return ret;
 }
 
+static bool vfio_switchover_ack_needed(void *opaque)
+{
+    VFIODevice *vbasedev = opaque;
+
+    return vfio_precopy_supported(vbasedev);
+}
+
 static const SaveVMHandlers savevm_vfio_handlers = {
     .save_setup = vfio_save_setup,
     .save_cleanup = vfio_save_cleanup,
@@ -605,6 +641,7 @@ static const SaveVMHandlers savevm_vfio_handlers = {
     .load_setup = vfio_load_setup,
     .load_cleanup = vfio_load_cleanup,
     .load_state = vfio_load_state,
+    .switchover_ack_needed = vfio_switchover_ack_needed,
 };
 
 /* ---------------------------------------------------------------------- */
