On Wed, 25 Mar 2026 11:57:50 -0700
Long Li <[email protected]> wrote:
> When DPDK stops a netvsc device (e.g. on testpmd quit), the data path
> was left pointing to the VF/MANA device. If the kernel netvsc driver
> subsequently reloads the MANA device and opens it, incoming traffic
> arrives on the MANA device immediately, before the queues are fully
> initialized. This causes bogus RX completion events to appear on the
> TX completion queue, triggering a kernel WARNING in mana_poll_tx_cq().
>
> Fix this by switching the data path back to synthetic (via
> NVS_DATAPATH_SYNTHETIC) in hn_vf_stop() before stopping the VF device.
> This tells the host to route traffic through the synthetic path, so
> that when the MANA driver recreates its queues, no unexpected traffic
> arrives until netvsc explicitly switches back to VF.
>
> Also update hn_vf_start() to switch the data path back to VF after the
> VF device is started, enabling correct stop/start cycling.
>
> Both functions now use write locks instead of read locks since they
> modify vf_vsc_switched state.
>
> Fixes: dc7680e8597c ("net/netvsc: support integrated VF")
> Cc: [email protected]
>
> Signed-off-by: Long Li <[email protected]>
> ---
Looks good applied to next-net
