Re: [PATCH 1/3] PCI: endpoint: pci-epf-vntb: Pass PF/VF number when BAR programming

[Bjorn Helgaas <helgaas@kernel.org>]

On Wed, Jul 29, 2026 at 02:23:04AM +0900, Koichiro Den wrote:
> vntb_epf_mw_set_trans() programs the memory-window BAR through
> pci_epc_set_bar() with hardcoded function numbers (0, 0), so the BAR
> lands on the wrong function whenever the vNTB EPF is bound to anything
> but PF0. The other BAR programming sites in the vNTB driver already pass
> the EPF's own numbers.
> 
> Pass the EPF's own func_no/vfunc_no here as well.
> 
> Fixes: e35f56bb0330 ("PCI: endpoint: Support NTB transfer between RC and EP")
> Signed-off-by: Koichiro Den <den@valinux.co.jp>
> ---
>  drivers/pci/endpoint/functions/pci-epf-vntb.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/endpoint/functions/pci-epf-vntb.c b/drivers/pci/endpoint/functions/pci-epf-vntb.c
> index c3caec927d74..fba65abfb6b2 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-vntb.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-vntb.c
> @@ -1427,7 +1427,8 @@ static int vntb_epf_mw_set_trans(struct ntb_dev *ndev, int pidx, int idx,
>  	epf_bar->barno = barno;
>  	epf_bar->size = size;
>  
> -	ret = pci_epc_set_bar(ntb->epf->epc, 0, 0, epf_bar);
> +	ret = pci_epc_set_bar(ntb->epf->epc, ntb->epf->func_no,
> +			      ntb->epf->vfunc_no, epf_bar);

Thanks for this fix!

If anybody is bored, I think this file could be somewhat improved by
adding local "epf = ntb->epf" variables to reduce the repetition of
"ntb->epf", as epf_ntb_config_spad_bar_alloc() does.

Even then there's a lot of repetition, but I think much of it is there
to make room for the PRIMARY_INTERFACE/SECONDARY_INTERFACE stuff for
NTBs.

>  	if (ret) {
>  		dev_err(dev, "failure set mw trans\n");
>  		return ret;
> -- 
> 2.51.0
>