err = virtio_config_val(vdev, VIRTIO_BLK_F_SEG_MAX,
offsetof(struct virtio_blk_config, seg_max),
&sg_elems);
- if (err)
+
+ /* We need at least one SG element, whatever they say. */
+ if (err || !sg_elems)
sg_elems = 1;
/* We need an extra sg elements at head and tail. */