Small MSS in vmxnet3

Naruto Nguyen narutonguyen2018 at
Mon Sep 25 06:57:11 EDT 2023

could you please let me know any ideas?

Thank you,
Kind regards,

On Sat, 23 Sept 2023 at 12:12, Naruto Nguyen <narutonguyen2018 at> wrote:
> Hello everyone,
> Recently I found that packets sent from vmxnet3 driver on guest have
> MSS value set to very small size, some 10 bytes, some 25 bytes MSS.
> The vmxnet3 NIC enables TSO. Could you let me know any possible reason
> that the packets are fragmented with very small MSS.and is it normal?.
> Any way to avoid this small MSS or it's just normal.
> In addition, when enabling debug for vmxnet3, in function
> vmxnet3_tq_xmit, it has a printout
> netdev_dbg(adapter->netdev,
> "txd[%u]: SOP 0x%Lx 0x%x 0x%x\n",
> (u32)(ctx.sop_txd -
> tq->tx_ring.base), le64_to_cpu(gdesc->txd.addr),
> le32_to_cpu(gdesc->dword[2]), le32_to_cpu(gdesc->dword[3]));
> could you suggest an easier way to extract the MSS value from this output?
> Thanks,
> Kind regards, Naruto

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