Re: linux-next: manual merge of the vhost tree with the dma-mapping tree

[Leon Romanovsky <leon@kernel.org>]

On Fri, Jul 18, 2025 at 06:12:26PM +1000, Stephen Rothwell wrote:
> Hi all,
> 
> Today's linux-next merge of the vhost tree got a conflict in:
> 
>   drivers/virtio/virtio_ring.c
> 
> between commit:
> 
>   b420b31f009f ("kmsan: convert kmsan_handle_dma to use physical addresses")
> 
> from the dma-mapping tree and commit:
> 
>   d1814d4fca2c ("virtio: rename dma helpers")
> 
> from the vhost tree.
> 
> I fixed it up (see below) and can carry the fix as necessary. This
> is now fixed as far as linux-next is concerned, but any non trivial
> conflicts should be mentioned to your upstream maintainer when your tree
> is submitted for merging.  You may also want to consider cooperating
> with the maintainer of the conflicting tree to minimise any particularly
> complex conflicts.
> 
> -- 
> Cheers,
> Stephen Rothwell
> 
> diff --cc drivers/virtio/virtio_ring.c
> index a8421dc802d6,3f86e74dd79f..000000000000
> --- a/drivers/virtio/virtio_ring.c
> +++ b/drivers/virtio/virtio_ring.c
> @@@ -3143,17 -3240,17 +3240,17 @@@ EXPORT_SYMBOL_GPL(virtqueue_unmap_page_
>    * The caller calls this to do dma mapping in advance. The DMA address can be
>    * passed to this _vq when it is in pre-mapped mode.
>    *
> -  * return DMA address. Caller should check that by virtqueue_dma_mapping_error().
> +  * return mapped address. Caller should check that by virtqueue_mapping_error().
>    */
> - dma_addr_t virtqueue_dma_map_single_attrs(struct virtqueue *_vq, void *ptr,
> - 					  size_t size,
> - 					  enum dma_data_direction dir,
> - 					  unsigned long attrs)
> + dma_addr_t virtqueue_map_single_attrs(const struct virtqueue *_vq, void *ptr,
> + 				      size_t size,
> + 				      enum dma_data_direction dir,
> + 				      unsigned long attrs)
>   {
> - 	struct vring_virtqueue *vq = to_vvq(_vq);
> + 	const struct vring_virtqueue *vq = to_vvq(_vq);
>   
> - 	if (!vq->use_dma_api) {
> + 	if (!vq->use_map_api) {
>  -		kmsan_handle_dma(virt_to_page(ptr), offset_in_page(ptr), size, dir);
>  +		kmsan_handle_dma(virt_to_phys(ptr), size, dir);

Thanks, it looks correct to me.

>   		return (dma_addr_t)virt_to_phys(ptr);
>   	}
>