virtio: set max_segment_size and max_sectors to infinite.

Setting max_segment_size allows more than 64k per sg element, unless
the host specified a limit.  Setting max_sectors indicates that our
max_hw_segments is the only limit.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 85d79a02d487..0e2ade648aff 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -277,6 +277,9 @@ static int virtblk_probe(struct virtio_device *vdev)
         }
         set_capacity(vblk->disk, cap);
 
+        /* No real sector limit. */
+        blk_queue_max_sectors(vblk->disk->queue, -1U);
+
         /* Host can optionally specify maximum segment size and number of
          * segments. */
         err = virtio_config_val(vdev, VIRTIO_BLK_F_SIZE_MAX,
@@ -284,6 +287,8 @@ static int virtblk_probe(struct virtio_device *vdev)
                                 &v);
         if (!err)
                 blk_queue_max_segment_size(vblk->disk->queue, v);
+        else
+                blk_queue_max_segment_size(vblk->disk->queue, -1UL);
 
         err = virtio_config_val(vdev, VIRTIO_BLK_F_SEG_MAX,
                                 offsetof(struct virtio_blk_config, seg_max),