vfio: Introduce a new header file for internal migration services

Gather all VFIO migration related declarations into
"vfio-migration-internal.h" to reduce exposure of VFIO internals in
"hw/vfio/vfio-common.h".

Cc: Kirti Wankhede <kwankhede@nvidia.com>
Cc: Avihai Horon <avihaih@nvidia.com>
Reviewed-by: Prasad Pandit <pjp@fedoraproject.org>
Reviewed-by: John Levon <john.levon@nutanix.com>
Reviewed-by: Avihai Horon <avihaih@nvidia.com>
Link: https://lore.kernel.org/qemu-devel/20250326075122.1299361-7-clg@redhat.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>

5 files changed, 76 insertions, 1 deletions

diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 679076343a..bef5414dd7 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -43,6 +43,7 @@
 #include "migration/qemu-file.h"
 #include "system/tcg.h"
 #include "system/tpm.h"
+#include "vfio-migration-internal.h"
 
 VFIODeviceList vfio_device_list =
     QLIST_HEAD_INITIALIZER(vfio_device_list);
diff --git a/hw/vfio/migration-multifd.c b/hw/vfio/migration-multifd.c
index 09aa57f5f8..a3005226b9 100644
--- a/hw/vfio/migration-multifd.c
+++ b/hw/vfio/migration-multifd.c
@@ -11,7 +11,6 @@
 
 #include "qemu/osdep.h"
 #include "hw/vfio/vfio-common.h"
-#include "hw/vfio/vfio-migration.h"
 #include "migration/misc.h"
 #include "qapi/error.h"
 #include "qemu/bswap.h"
@@ -22,6 +21,7 @@
 #include "io/channel-buffer.h"
 #include "migration/qemu-file.h"
 #include "migration-multifd.h"
+#include "vfio-migration-internal.h"
 #include "trace.h"
 
 #define VFIO_DEVICE_STATE_CONFIG_STATE (1)
diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
index b5bb0cd092..54f6ca3e7c 100644
--- a/hw/vfio/migration.c
+++ b/hw/vfio/migration.c
@@ -31,6 +31,7 @@
 #include "pci.h"
 #include "trace.h"
 #include "hw/hw.h"
+#include "vfio-migration-internal.h"
 
 /*
  * This is an arbitrary size based on migration of mlx5 devices, where typically
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index f87f3ccbe1..b0aac2f3a0 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -44,6 +44,7 @@
 #include "migration/blocker.h"
 #include "migration/qemu-file.h"
 #include "system/iommufd.h"
+#include "vfio-migration-internal.h"
 
 #define TYPE_VFIO_PCI_NOHOTPLUG "vfio-pci-nohotplug"
 
diff --git a/hw/vfio/vfio-migration-internal.h b/hw/vfio/vfio-migration-internal.h
new file mode 100644
index 0000000000..ab6a1bad9b
--- /dev/null
+++ b/hw/vfio/vfio-migration-internal.h
@@ -0,0 +1,72 @@
+/*
+ * VFIO migration
+ *
+ * Copyright Red Hat, Inc. 2025
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef HW_VFIO_VFIO_MIGRATION_INTERNAL_H
+#define HW_VFIO_VFIO_MIGRATION_INTERNAL_H
+
+#ifdef CONFIG_LINUX
+#include <linux/vfio.h>
+#endif
+
+#include "qemu/typedefs.h"
+#include "qemu/notify.h"
+
+/*
+ * Flags to be used as unique delimiters for VFIO devices in the migration
+ * stream. These flags are composed as:
+ * 0xffffffff => MSB 32-bit all 1s
+ * 0xef10     => Magic ID, represents emulated (virtual) function IO
+ * 0x0000     => 16-bits reserved for flags
+ *
+ * The beginning of state information is marked by _DEV_CONFIG_STATE,
+ * _DEV_SETUP_STATE, or _DEV_DATA_STATE, respectively. The end of a
+ * certain state information is marked by _END_OF_STATE.
+ */
+#define VFIO_MIG_FLAG_END_OF_STATE      (0xffffffffef100001ULL)
+#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)
+
+typedef struct VFIODevice VFIODevice;
+typedef struct VFIOMultifd VFIOMultifd;
+
+typedef struct VFIOMigration {
+    struct VFIODevice *vbasedev;
+    VMChangeStateEntry *vm_state;
+    NotifierWithReturn migration_state;
+    uint32_t device_state;
+    int data_fd;
+    void *data_buffer;
+    size_t data_buffer_size;
+    uint64_t mig_flags;
+    uint64_t precopy_init_size;
+    uint64_t precopy_dirty_size;
+    bool multifd_transfer;
+    VFIOMultifd *multifd;
+    bool initial_data_sent;
+
+    bool event_save_iterate_started;
+    bool event_precopy_empty_hit;
+} VFIOMigration;
+
+bool vfio_migration_realize(VFIODevice *vbasedev, Error **errp);
+void vfio_migration_exit(VFIODevice *vbasedev);
+int vfio_save_device_config_state(QEMUFile *f, void *opaque, Error **errp);
+int vfio_load_device_config_state(QEMUFile *f, void *opaque);
+
+#ifdef CONFIG_LINUX
+int vfio_migration_set_state(VFIODevice *vbasedev,
+                             enum vfio_device_mig_state new_state,
+                             enum vfio_device_mig_state recover_state,
+                             Error **errp);
+#endif
+
+void vfio_migration_add_bytes_transferred(unsigned long val);
+
+#endif /* HW_VFIO_VFIO_MIGRATION_INTERNAL_H */