Netvsc PMD : Hotplug handling : checksum offloads

Netvsc PMD : Hotplug handling : checksum offloads

[Nandini Rangaswamy]

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 Hi Long/Stephen,
I was going through the hotplug handling code in netvsc PMD and need
clarification.
Earlier with failsafe PMD , my dpdk app used to subscribe to hotplug events
to set the checksum offloads to do software checksum calculation when VF
was removed and switch to H/W checksum calculation when VF was added.
I see even with netvsc PMD , it does not do anything specific to RSS
/checksum offloads in hotplug callbacks but initializes VF port (through
ioctl) during hotplug add and removes VF port in hotplug remove callback.
So my understanding is, the dpdk app should continue to handle the checksum
offloads as part of hotplug callbacks and netvsc will not handle it
automatically.
Can you confirm if this is correct?
Regards,
Nandini

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Re: Netvsc PMD : Hotplug handling : checksum offloads

[Stephen Hemminger]

On Thu, 19 Sep 2024 11:11:44 -0700
Nandini Rangaswamy <nandini.rangaswamy@broadcom.com> wrote:

>  Hi Long/Stephen,
> I was going through the hotplug handling code in netvsc PMD and need
> clarification.
> Earlier with failsafe PMD , my dpdk app used to subscribe to hotplug events
> to set the checksum offloads to do software checksum calculation when VF
> was removed and switch to H/W checksum calculation when VF was added.
> I see even with netvsc PMD , it does not do anything specific to RSS
> /checksum offloads in hotplug callbacks but initializes VF port (through
> ioctl) during hotplug add and removes VF port in hotplug remove callback.
> So my understanding is, the dpdk app should continue to handle the checksum
> offloads as part of hotplug callbacks and netvsc will not handle it
> automatically.
> Can you confirm if this is correct?
> Regards,
> Nandini

The code should look at the checksum flags in each packet, rather
than assuming VF hotplug will change things.