Re: [PATCH 0/5 v5] Fix virtio-blk issue with SWIOTLB

From: Lendacky, Thomas
Date: Wed Jan 30 2019 - 13:11:53 EST


On 1/30/19 10:40 AM, Joerg Roedel wrote:
> Hi,
>
> here is the next version of this patch-set. Previous
> versions can be found here:
>
> V1: https://lore.kernel.org/lkml/20190110134433.15672-1-joro@xxxxxxxxxx/
>
> V2: https://lore.kernel.org/lkml/20190115132257.6426-1-joro@xxxxxxxxxx/
>
> V3: https://lore.kernel.org/lkml/20190123163049.24863-1-joro@xxxxxxxxxx/
>
> V4: https://lore.kernel.org/lkml/20190129084342.26030-1-joro@xxxxxxxxxx/
>
> 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.
>
> Changes to v4 are:
>
> - Added Reviewed-by tags from Christoph
>
> - Added missing EXPORT_SYMBOL(_GPL) lines
>
> Please review.

Looks good. Booted and tested using an SEV guest without any issues.

Tested-by: Tom Lendacky <thomas.lendacky@xxxxxxx>

Thanks,
Tom

>
> 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
>
> Documentation/DMA-API.txt | 8 ++++++++
> drivers/block/virtio_blk.c | 10 ++++++----
> drivers/virtio/virtio_ring.c | 11 +++++++++++
> include/linux/dma-mapping.h | 16 ++++++++++++++++
> include/linux/swiotlb.h | 11 +++++++++++
> include/linux/virtio.h | 2 ++
> kernel/dma/direct.c | 12 ++++++++++++
> kernel/dma/swiotlb.c | 14 ++++++++++++++
> 8 files changed, 80 insertions(+), 4 deletions(-)
>