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Date: Mon, 19 Mar 2018 15:49:13 -0400
From: Joe Buehler <aspam@cox.net>
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To: Vincenzo Maffione <v.maffione@gmail.com>
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Subject: Re: netmap ixgbevf mtu
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Vincenzo Maffione wrote:

> To receive a frame larger than the RX buffer size you need multiple
> netmap slots (as multiple descriptors are
> used by the hardware), looking at the NS_MOREFRAG flag.
> See the example code in utils/functional.c::rx_one().

This works fine -- thanks.

> Also TX may have per-slot limitations (e.g. due to the size of the NIC
> TX fifo), but this is usually > 9K, so using a single descriptor per
> packet should always
> be ok. However, you can also use multiple slots on the TX side (see
> utils/functional.c::tx_one()).

Trying to split TX frames into multiple buffers does not work, the NIC is sending 2048 byte frames (the buf_size I am using).

I will re-check my code.  Do I need a particular version of ixgbevf perhaps?

Joe Buehler