Re: [PATCH v2 1/5] PCI/P2PDMA: Don't enforce ACS check for functions of same device

[Logan Gunthorpe]

On 2024-10-30 12:46, Bjorn Helgaas wrote:
> On Fri, Oct 25, 2024 at 06:57:37AM +0000, Kasireddy, Vivek wrote:
> In the PCIe world, I don't think a TLP can "loop back" to another
> function on the same device.

I'm not sure if the spec says anything that specifically denies this.
But it seems to me that it would be possible for a multifunction device
to handle a transfer to a neighbouring function internally and not
actually involve the PCIe fabric. This seems like something we'd want to
support if and when such a device were to be created.

Logan