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

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Wed, Jan 23, 2019 at 01:51:29PM -0500, Michael S. Tsirkin wrote:
> 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?

You got mine (SWIOTBL is my area).
> 
> > 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