virtio-blk: Consider virtio_max_dma_size() for maximum segment size

Segments can't be larger than the maximum DMA mapping size
supported on the platform. Take that into account when
setting the maximum segment size for a block device.

Cc: stable@vger.kernel.org
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Joerg Roedel 2019-02-07 12:59:17 +01:00 committed by Michael S. Tsirkin
parent e6d6dd6c87
commit fd1068e186
1 changed files with 6 additions and 4 deletions

View File

@ -723,7 +723,7 @@ static int virtblk_probe(struct virtio_device *vdev)
struct request_queue *q;
int err, index;
u32 v, blk_size, sg_elems, opt_io_size;
u32 v, blk_size, max_size, sg_elems, opt_io_size;
u16 min_io_size;
u8 physical_block_exp, alignment_offset;
@ -826,14 +826,16 @@ static int virtblk_probe(struct virtio_device *vdev)
/* No real sector limit. */
blk_queue_max_hw_sectors(q, -1U);
max_size = virtio_max_dma_size(vdev);
/* Host can optionally specify maximum segment size and number of
* segments. */
err = virtio_cread_feature(vdev, VIRTIO_BLK_F_SIZE_MAX,
struct virtio_blk_config, size_max, &v);
if (!err)
blk_queue_max_segment_size(q, v);
else
blk_queue_max_segment_size(q, -1U);
max_size = min(max_size, v);
blk_queue_max_segment_size(q, max_size);
/* Host can optionally specify the block size of the device */
err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE,