[Qemu-devel] [PATCH 3/3] virtio-blk: note optional features

[Paolo Bonzini <pbonzini@redhat.com>]

The guest must already be prepared to see SG_IO support
disappear from under its feet, for example if migration
refers to a block device on the source and file-based
storage on the destination; or more likely, if the source
kernel allows (gasp) SG_IO on a partition and the destination
does not.  So, we can migrate safely even if the source
had VIRTIO_BLK_F_SCSI and the destination does not.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 hw/virtio-blk.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c
index c95f8fc..9a4158a 100644
--- a/hw/virtio-blk.c
+++ b/hw/virtio-blk.c
@@ -542,7 +542,7 @@ static int virtio_blk_load(QEMUFile *f, void *opaque, int version_id)
     if (version_id != 2)
         return -EINVAL;
 
-    ret = virtio_load(&s->vdev, f, 0);
+    ret = virtio_load(&s->vdev, f, VIRTIO_BLK_F_SCSI);
     if (ret) {
         return ret;
     }
-- 
1.7.7.6