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>

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 85d79a0..0e2ade6 100644 (file)
--- 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),