On Tue, Jan 15, 2019 at 02:22:57PM +0100, Joerg Roedel wrote: > From: Joerg Roedel <jroedel@xxxxxxx> > > 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. > > Signed-off-by: Joerg Roedel <jroedel@xxxxxxx> > --- > drivers/block/virtio_blk.c | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) > > diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c > index b16a887bbd02..6193962a7fec 100644 > --- a/drivers/block/virtio_blk.c > +++ b/drivers/block/virtio_blk.c > @@ -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 = dma_max_mapping_size(&vdev->dev); > + Should this be limited to ACCESS_PLATFORM? I see no reason to limit this without as guest can access any memory. I'd like a bit of time to consider this point. > /* 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, > -- > 2.17.1
