[PATCH v5 23/36] vfio/migration: Multifd device state transfer support - VFIOStateBuffer(s)

[Maciej S. Szmigiero]

From: "Maciej S. Szmigiero" <maciej.szmigi...@oracle.com>

Add VFIOStateBuffer(s) types and the associated methods.

These store received device state buffers and config state waiting to get
loaded into the device.

Signed-off-by: Maciej S. Szmigiero <maciej.szmigi...@oracle.com>
---
 hw/vfio/migration-multifd.c | 54 +++++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/hw/vfio/migration-multifd.c b/hw/vfio/migration-multifd.c
index 0c3185a26242..760b110a39b9 100644
--- a/hw/vfio/migration-multifd.c
+++ b/hw/vfio/migration-multifd.c
@@ -29,3 +29,57 @@ typedef struct VFIODeviceStatePacket {
     uint32_t flags;
     uint8_t data[0];
 } QEMU_PACKED VFIODeviceStatePacket;
+
+/* type safety */
+typedef struct VFIOStateBuffers {
+    GArray *array;
+} VFIOStateBuffers;
+
+typedef struct VFIOStateBuffer {
+    bool is_present;
+    char *data;
+    size_t len;
+} VFIOStateBuffer;
+
+static void vfio_state_buffer_clear(gpointer data)
+{
+    VFIOStateBuffer *lb = data;
+
+    if (!lb->is_present) {
+        return;
+    }
+
+    g_clear_pointer(&lb->data, g_free);
+    lb->is_present = false;
+}
+
+static void vfio_state_buffers_init(VFIOStateBuffers *bufs)
+{
+    bufs->array = g_array_new(FALSE, TRUE, sizeof(VFIOStateBuffer));
+    g_array_set_clear_func(bufs->array, vfio_state_buffer_clear);
+}
+
+static void vfio_state_buffers_destroy(VFIOStateBuffers *bufs)
+{
+    g_clear_pointer(&bufs->array, g_array_unref);
+}
+
+static void vfio_state_buffers_assert_init(VFIOStateBuffers *bufs)
+{
+    assert(bufs->array);
+}
+
+static guint vfio_state_buffers_size_get(VFIOStateBuffers *bufs)
+{
+    return bufs->array->len;
+}
+
+static void vfio_state_buffers_size_set(VFIOStateBuffers *bufs, guint size)
+{
+    g_array_set_size(bufs->array, size);
+}
+
+static VFIOStateBuffer *vfio_state_buffers_at(VFIOStateBuffers *bufs, guint 
idx)
+{
+    return &g_array_index(bufs->array, VFIOStateBuffer, idx);
+}