Re: [PATCH v3 0/7] PCI: endpoint: Remote DMA support via vNTB

[Koichiro Den]

On Thu, Sep 03, 2026 at 01:43:45PM +0200, Manivannan Sadhasivam wrote:
> On Tue, Sep 01, 2026 at 03:26:50AM +0900, Koichiro Den wrote:
> > Hi,
> > 
> > This series lets an RC use endpoint-local DesignWare eDMA read channels
> > through vNTB. It keeps the export within pci-epf-vntb and ntb_hw_epf
> > rather than defining a generic remote-DMA ABI or using a separate PCI
> > DMA function.
> > 
> > On the endpoint, pci-epf-vntb reserves the complete eDMA read direction
> > and exposes those channels as a group. HDMA is not yet supported,
> > keeping the series minimal.
> > 
> > The DMA feature is opt-in through the pci-epf-vntb configfs attribute
> > 'dma_bar', which is -1 by default. Without it, no DMA extension is
> > exported. pci-epf-ntb is unchanged.
> > 
> > Base and dependency
> > ===================
> > 
> > This series is based on next-20260827 (3d83758432b5) plus:
> > 
> >   [PATCH v2 0/3] dmaengine: dw-edma: Prepare channels for remote use
> >   https://lore.kernel.org/r/20260828163611.2691264-1-den@xxxxxxxxxxxxx/
> > 
> > The prerequisite is for the dmaengine tree and is not part of
> > pci/endpoint. linux-next provides a common buildable base for both
> > series. Once the prerequisite lands, this series can be rebased onto
> > pci/endpoint.
> > 
> 
> Just to make it clear. This series has to build time dependency with the above
> mentioned dmaengine series, right? The above statement is not very clear.

Yes, this series strictly depends on the prereq series, and as you pointed out,
it's a built-time dependency as well. Sorry for the ambiguity.

> 
> EPF patches LGTM! I'm waiting for an Ack from NTB maintainer for patch 6.

Thanks for taking a look. Note that I have already sent v4:
https://lore.kernel.org/r/20260903082327.2345602-1-den@xxxxxxxxxxxxx/
(One more dependency is added as noted in v4 cover letter..)

Best regards,
Koichiro

> 
> - Mani
> 
> -- 
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