Re: [RFC PATCH 1/3] net: Pad short frames to minimum size (60 bytes)

[Peter Maydell]

On Fri, 26 Feb 2021 at 10:03, Bin Meng <bmeng.cn@gmail.com> wrote:
>
> From: Bin Meng <bin.meng@windriver.com>
>
> The minimum Ethernet frame length is 60 bytes, and we should pad
> frames whose length is smaller to the minimum size.
>
> This commit fixes the issue as seen with various ethernet models,
> that ARP requests get dropped, preventing the guest from becoming
> visible on the network.
>
> The following 2 commits that attempted to workaround this issue
> in e1000 and vmxenet3 before, should be reverted.
>
>   commit 78aeb23eded2 ("e1000: Pad short frames to minimum size (60 bytes)")
>   commit 40a87c6c9b11 ("vmxnet3: Pad short frames to minimum size (60 bytes)")
>
> Signed-off-by: Bin Meng <bin.meng@windriver.com>
> ---

Is it better to do this here, or in the places which create
network packets? Doing it centrally has the advantage of
being just one place to change which then means senders
and receivers don't need to think about it. On the other
hand it means we don't have any equivalent of really actually
sending a short frame and having the modelled ethernet device
implement the handling of the short frame.

thanks
-- PMM