Re: [PATCH v7 11/21] RDMA/core: introduce ib_dma_pci_p2p_dma_supported()

From: Christoph Hellwig
Date: Wed Jun 29 2022 - 02:42:43 EST


On Wed, Jun 15, 2022 at 10:12:23AM -0600, Logan Gunthorpe wrote:
> Introduce the helper function ib_dma_pci_p2p_dma_supported() to check
> if a given ib_device can be used in P2PDMA transfers. This ensures
> the ib_device is not using virt_dma and also that the underlying
> dma_device supports P2PDMA.
>
> Use the new helper in nvme-rdma to replace the existing check for
> ib_uses_virt_dma(). Adding the dma_pci_p2pdma_supported() check allows
> switching away from pci_p2pdma_[un]map_sg().
>
> Signed-off-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
> Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
> Reviewed-by: Max Gurtovoy <mgurtovoy@xxxxxxxxxx>

Looks good:

Reviewed-by: Christoph Hellwig <hch@xxxxxx>