netdev - Re: [PATCH net-next RFC WIP] Patch for XDP support for virtio

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Date:   Wed, 26 Oct 2016 15:52:02 +0200
From:   Jesper Dangaard Brouer <brouer@...hat.com>
To:     Shrijeet Mukherjee <shrijeet@...il.com>
Cc:     brouer@...hat.com, mst@...hat.com, tom@...bertland.com,
        netdev@...r.kernel.org, shm@...ulusnetworks.com,
        roopa@...ulusnetworks.com, nikolay@...ulusnetworks.com
Subject: Re: [PATCH net-next RFC WIP] Patch for XDP support for virtio_net

On Sat, 22 Oct 2016 04:07:23 +0000
Shrijeet Mukherjee <shrijeet@...il.com> wrote:

> This patch adds support for xdp ndo and also inserts the xdp program
> call into the merged RX buffers and big buffers paths

I really appreciate you are doing this for virtio_net.

My first question is: Is the (packet) page data writable?
(MST might be able to answer?)

As this is currently an XDP requirement[1].  


> * The small packet skb receive is skipped for now
> * No TX for now

I do see more and more valid use-cases for only implementing XDP_DROP
and not necessarily also implementing XDP_TX.  This does requires that
we implement some kind of feature/capabilities negotiation mechanism[2].


[1] https://prototype-kernel.readthedocs.io/en/latest/networking/XDP/design/requirements.html#write-access-to-packet-data

[2] https://prototype-kernel.readthedocs.io/en/latest/networking/XDP/design/design.html#capabilities-negotiation

-- 
Best regards,
  Jesper Dangaard Brouer
  MSc.CS, Principal Kernel Engineer at Red Hat
  Author of http://www.iptv-analyzer.org
  LinkedIn: http://www.linkedin.com/in/brouer