Re: [PATCH v3 net-next] docs: net: add an explanation of VF (and other) Representors

On 9/5/22 20:55, ecree@xilinx.com wrote:

+Thus, the following should all have representors:
+
+ - VFs belonging to the switchdev function.
+ - Other PFs on the local PCIe controller, and any VFs belonging to them.
+ - PFs and VFs on external PCIe controllers on the device (e.g. for any embedded
+   System-on-Chip within the SmartNIC).
+ - PFs and VFs with other personalities, including network block devices (such
+   as a vDPA virtio-blk PF backed by remote/distributed storage), if (and only
+   if) their network access is implemented through a virtual switch port. [#]_
+   Note that such functions can require a representor despite the representee
+   not having a netdev.
+ - Subfunctions (SFs) belonging to any of the above PFs or VFs, if they have
+   their own port on the switch (as opposed to using their parent PF's port).
+ - Any accelerators or plugins on the device whose interface to the network is
+   through a virtual switch port, even if they do not have a corresponding PCIe
+   PF or VF.
+

<snipped>

+
+.. [#] The concept here is that a hardware IP stack in the device performs the
+   translation between block DMA requests and network packets, so that only
+   network packets pass through the virtual port onto the switch.  The network
+   access that the IP stack "sees" would then be configurable through tc rules;
+   e.g. its traffic might all be wrapped in a specific VLAN or VxLAN.  However,
+   any needed configuration of the block device *qua* block device, not being a
+   networking entity, would not be appropriate for the representor and would
+   thus use some other channel such as devlink.
+   Contrast this with the case of a virtio-blk implementation which forwards the
+   DMA requests unchanged to another PF whose driver then initiates and
+   terminates IP traffic in software; in that case the DMA traffic would *not*
+   run over the virtual switch and the virtio-blk PF should thus *not* have a
+   representor.
+

I think by convention, footnotes should be put on bottom of the doc.

Other than that, LGTM.

Reviewed-by: Bagas Sanjaya <redacted>

-- 
An old man doll... just what I always wanted! - Clara