On Tue, Mar 06, 2012 at 01:22:07PM +0100, Paolo Bonzini wrote:
> 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 <pbonz...@redhat.com>
My first reaction is you want a new non guest
visible flag to control whether SG_IO fails on host.
guest visible ones must be consistent across migration.
> ---
> 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
