[Qemu-devel] [PATCH 4/4] virtio: bump migration version number

[Anthony Liguori <aliguori@us.ibm.com>]

And disable migration on big endian hosts from older versions where
endianness of the device state was ambiguous on the wire.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
---
 hw/virtio-blk.c        | 13 +++++++++++--
 hw/virtio-serial-bus.c |  9 +++++++--
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c
index 7ab174f..837a709 100644
--- a/hw/virtio-blk.c
+++ b/hw/virtio-blk.c
@@ -566,8 +566,17 @@ static int virtio_blk_load(QEMUFile *f, void *opaque, int version_id)
     VirtIOBlock *s = opaque;
     int ret;
 
-    if (version_id != 2)
+#ifdef HOST_WORDS_BIGENDIAN
+    /* Because of the use of native endianness, we can't reliably handle
+     * migration below this version on big endian hosts. */
+    if (version < 3) {
         return -EINVAL;
+    }
+#endif
+
+    if (version_id < 2) {
+        return -EINVAL;
+    }
 
     ret = virtio_load(&s->vdev, f);
     if (ret) {
@@ -633,7 +642,7 @@ VirtIODevice *virtio_blk_init(DeviceState *dev, VirtIOBlkConf *blk)
 
     qemu_add_vm_change_state_handler(virtio_blk_dma_restart_cb, s);
     s->qdev = dev;
-    register_savevm(dev, "virtio-blk", virtio_blk_id++, 2,
+    register_savevm(dev, "virtio-blk", virtio_blk_id++, 3,
                     virtio_blk_save, virtio_blk_load, s);
     bdrv_set_dev_ops(s->bs, &virtio_block_ops, s);
     bdrv_set_buffer_alignment(s->bs, s->conf->logical_block_size);
diff --git a/hw/virtio-serial-bus.c b/hw/virtio-serial-bus.c
index aa1ded0..6aa3b85 100644
--- a/hw/virtio-serial-bus.c
+++ b/hw/virtio-serial-bus.c
@@ -665,9 +665,14 @@ static int virtio_serial_load(QEMUFile *f, void *opaque, int version_id)
     unsigned int i;
     int ret;
 
-    if (version_id > 3) {
+#ifdef HOST_WORDS_BIGENDIAN
+    /* Because of the use of native endianness, we can't reliably handle
+     * migration below this version on big endian hosts. */
+
+    if (version_id < 4) {
         return -EINVAL;
     }
+#endif
 
     /* The virtio device */
     ret = virtio_load(&s->vdev, f);
@@ -987,7 +992,7 @@ VirtIODevice *virtio_serial_init(DeviceState *dev, virtio_serial_conf *conf)
      * Register for the savevm section with the virtio-console name
      * to preserve backward compat
      */
-    register_savevm(dev, "virtio-console", -1, 3, virtio_serial_save,
+    register_savevm(dev, "virtio-console", -1, 4, virtio_serial_save,
                     virtio_serial_load, vser);
 
     vser->post_load.timer = qemu_new_timer_ns(vm_clock,
-- 
1.8.0