Re: [PATCH 0/5 v3] Fix virtio-blk issue with SWIOTLB

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, Jan 23, 2019 at 05:30:44PM +0100, Joerg Roedel wrote:
> Hi,
> 
> here is the third version of this patch-set. Previous
> versions can be found here:
> 
> 	V1: https://lore.kernel.org/lkml/20190110134433.15672-1-joro@8bytes.org/
> 
> 	V2: https://lore.kernel.org/lkml/20190115132257.6426-1-joro@8bytes.org/
> 
> The problem solved here is a limitation of the SWIOTLB implementation,
> which does not support allocations larger than 256kb.  When the
> virtio-blk driver tries to read/write a block larger than that, the
> allocation of the dma-handle fails and an IO error is reported.


OK looks good to me.
I will park this in my tree for now this way it will get
testing in linux-next.
Can I get an ack from DMA maintainers on the DMA bits for
merging this in 5.0?

> Changes to v2 are:
> 
> 	* Check if SWIOTLB is active before returning its limit in
> 	  dma_direct_max_mapping_size()
> 
> 	* Only apply the maximum segment limit in virtio-blk when
> 	  DMA-API is used for the vring
> 
> Please review.
> 
> Thanks,
> 
> 	Joerg
> 
> Joerg Roedel (5):
>   swiotlb: Introduce swiotlb_max_mapping_size()
>   swiotlb: Add is_swiotlb_active() function
>   dma: Introduce dma_max_mapping_size()
>   virtio: Introduce virtio_max_dma_size()
>   virtio-blk: Consider virtio_max_dma_size() for maximum segment size
> 
>  drivers/block/virtio_blk.c   | 10 ++++++----
>  drivers/virtio/virtio_ring.c | 10 ++++++++++
>  include/linux/dma-mapping.h  | 16 ++++++++++++++++
>  include/linux/swiotlb.h      | 11 +++++++++++
>  include/linux/virtio.h       |  2 ++
>  kernel/dma/direct.c          | 11 +++++++++++
>  kernel/dma/swiotlb.c         | 10 ++++++++++
>  7 files changed, 66 insertions(+), 4 deletions(-)
> 
> -- 
> 2.17.1