Re: [PATCH v2 3/3] PCI: endpoint: pci-epf-vntb: Implement .get_dma_dev()

On 3/5/26 8:14 PM, Koichiro Den wrote:
> When vNTB is used as a PCI endpoint function, the NTB device is backed
> by a virtual PCI function. For DMA API allocations and mappings, NTB
> clients must use the device that is associated with the IOMMU domain.
> 
> Implement ntb_dev_ops->get_dma_dev() for pci-epf-vntb and return the EPC
> parent device.
> 
> Suggested-by: Frank Li <[email protected]>
> Signed-off-by: Koichiro Den <[email protected]>

Reviewed-by: Dave Jiang <[email protected]>

> ---
>  drivers/pci/endpoint/functions/pci-epf-vntb.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/pci/endpoint/functions/pci-epf-vntb.c b/drivers/pci/endpoint/functions/pci-epf-vntb.c
> index 20a400e83439..e5433404f573 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-vntb.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-vntb.c
> @@ -1436,6 +1436,14 @@ static int vntb_epf_link_disable(struct ntb_dev *ntb)
>  	return 0;
>  }
>  
> +static struct device *vntb_epf_get_dma_dev(struct ntb_dev *ndev)
> +{
> +	struct epf_ntb *ntb = ntb_ndev(ndev);
> +	struct pci_epc *epc = ntb->epf->epc;
> +
> +	return epc->dev.parent;
> +}
> +
>  static const struct ntb_dev_ops vntb_epf_ops = {
>  	.mw_count		= vntb_epf_mw_count,
>  	.spad_count		= vntb_epf_spad_count,
> @@ -1457,6 +1465,7 @@ static const struct ntb_dev_ops vntb_epf_ops = {
>  	.db_clear_mask		= vntb_epf_db_clear_mask,
>  	.db_clear		= vntb_epf_db_clear,
>  	.link_disable		= vntb_epf_link_disable,
> +	.get_dma_dev		= vntb_epf_get_dma_dev,
>  };
>  
>  static int pci_vntb_probe(struct pci_dev *pdev, const struct pci_device_id *id)