Re: vmxnet3: possible bug in vmxnet3_isc_rxd_pkt_get

On 19/11/2021 20:46, Andriy Gapon wrote:
> I think that this was the case and that I was able to find the corresponding 
> descriptors in the completion ring.
> 
> Please see https://people.freebsd.org/~avg/vmxnet3-fragment-overrun.txt
> 
> $54 is the SOP, it has qid of 6.
> It is followed by many fragments with qid 14 (there are 8 queues / queue sets) 
> and zero length.
> But not all of them are zero length, some have length of 4096, e.g. $77, $86, etc.
> $124 is the last fragment, its has eop = 1 and error = 1.
> So, there are 71 fragments in total.
> 
> So, it is clear that VMWare produced 71 segments for a single packet before 
> giving up on it.
> 
> I wonder why it did that.
> Perhaps it's a bug, perhaps it does not count zero-length segments against the 
> limit, maybe something else.
> 
> In any case, it happens.


This is what I am currently testing at work: https://reviews.freebsd.org/D33189
So far so good.

> Finally, the packet looks interesting: udp = 0, tcp = 0, ipcsum_ok = 0, ipv6 = 
> 0, ipv4 = 0.  I wonder what kind of a packet it could be -- being rather large 
> and not an IP packet.


-- 
Andriy Gapon