[RFC PATCH for 8.0 09/13] virtio: add vmstate_virtqueue_element_old

["Eugenio Pérez" <eperezma@redhat.com>]

VMStateDescription of an inflight descriptor represented in
VirtQueueElementOld.

TODO: Convert to VirtQueueElement.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
 include/hw/virtio/virtio.h  |  1 +
 include/migration/vmstate.h | 11 +++++++++++
 hw/virtio/virtio.c          | 32 ++++++++++++++++++++++++++++++++
 3 files changed, 44 insertions(+)

diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index b4c5163fb0..f3485e5748 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -105,6 +105,7 @@ void *qemu_get_virtqueue_element_from_old(VirtIODevice *vdev,
                                           size_t sz);
 void qemu_put_virtqueue_element_old(const VirtQueueElement *elem,
                                     VirtQueueElementOld *data);
+extern const VMStateDescription vmstate_virtqueue_element_old;
 
 #define VIRTIO_QUEUE_MAX 1024
 
diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h
index ad24aa1934..9726d2d09e 100644
--- a/include/migration/vmstate.h
+++ b/include/migration/vmstate.h
@@ -448,6 +448,17 @@ extern const VMStateInfo vmstate_info_qlist;
     .offset     = vmstate_offset_varray(_state, _field, _type),      \
 }
 
+#define VMSTATE_VARRAY_UINT32_UNSAFE(_field, _state, _field_num, _version, \
+                                     _info, _type) {\
+    .name       = (stringify(_field)),                               \
+    .version_id = (_version),                                        \
+    .num_offset = vmstate_offset_value(_state, _field_num, uint32_t),\
+    .info       = &(_info),                                          \
+    .size       = sizeof(_type),                                     \
+    .flags      = VMS_VARRAY_UINT32,                                 \
+    .offset     = vmstate_offset_varray(_state, _field, _type),      \
+}
+
 #define VMSTATE_VSTRUCT_TEST(_field, _state, _test, _version, _vmsd, _type, _struct_version) { \
     .name         = (stringify(_field)),                             \
     .version_id   = (_version),                                      \
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 5ddc49610c..7936fcfec2 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -3165,6 +3165,38 @@ static bool virtio_disabled_needed(void *opaque)
     return vdev->disabled;
 }
 
+const VMStateDescription vmstate_virtqueue_element_old = {
+    .name = "virtqueue_element",
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32(index, VirtQueueElementOld),
+        VMSTATE_UINT32(in_num, VirtQueueElementOld),
+        VMSTATE_UINT32(out_num, VirtQueueElementOld),
+        /*
+         * TODO: Needed for packed
+         * VMSTATE_UINT16(ndescs, VirtQueueElement),
+         */
+
+        VMSTATE_VALIDATE("fit", vq_element_in_range),
+        VMSTATE_VARRAY_UINT32_UNSAFE(in_addr, VirtQueueElementOld, in_num, 0,
+                                     vmstate_info_uint64, hwaddr),
+        VMSTATE_VARRAY_UINT32_UNSAFE(out_addr, VirtQueueElementOld, out_num, 0,
+                                     vmstate_info_uint64, hwaddr),
+
+        /*
+         * Assume iovec[n] == uint64_t[n*2]
+         * TODO: Probably need to send each field individually because of
+         * endianess.
+         */
+        VMSTATE_VARRAY_MULTIPLY(in_sg_64, VirtQueueElementOld, in_num,
+                                sizeof(struct iovec) / sizeof(uint64_t),
+                                vmstate_info_uint64, uint64_t),
+        VMSTATE_VARRAY_MULTIPLY(out_sg_64, VirtQueueElementOld, out_num,
+                                sizeof(struct iovec) / sizeof(uint64_t),
+                                vmstate_info_uint64, uint64_t),
+        VMSTATE_END_OF_LIST()
+    },
+};
+
 static const VMStateDescription vmstate_virtqueue = {
     .name = "virtqueue_state",
     .version_id = 1,
-- 
2.31.1