Re: [PATCH v4] net/iavf: add lock for vf commands

[David Marchand <david.marchand@redhat.com>]

Hi iavf maintainers,

On Thu, Dec 29, 2022 at 12:00 AM Mike Pattrick <mkp@redhat.com> wrote:
>
> iavf admin queue commands aren't thread-safe. Bugs surrounding this
> issue can manifest in a variety of ways but frequently pend_cmd is
> over written. Simultaneously executing commands can result in a
> misconfigured device or DPDK sleeping in a thread for 2 second.
>
> Despite this limitation, vf commands may be executed from both
> iavf_dev_alarm_handler() in a control thread and the applications main
> thread. This is trivial to simulate in the testpmd application by
> creating a bond of vf's in active backup mode, and then turning the
> bond off and then on again repeatedly.
>
> Previously [1] was proposed as a potential solution, but this commit did
> not resolve all potential issues concerning the admin queue and has been
> reverted from the stable branch. I propose adding locks until a more
> complete solution is available.
>
> [1] commit cb5c1b91f76f ("net/iavf: add thread for event callbacks")
>
> Fixes: 48de41ca11f0 ("net/avf: enable link status update")
> Fixes: 84108425054a ("net/iavf: support asynchronous virtual channel message")
> Cc: stable@dpdk.org
>
> Signed-off-by: Mike Pattrick <mkp@redhat.com>

Review please.


-- 
David Marchand