While checking RSS, I found something strange.

[qweeeee]

While checking RSS, I found something strange.
As a result of checking the distribution of CPU cores when received packets using DPDK 21.11.2, I found that only one core processing the packet.
When a Double Tagging (IEEE 802.1ad) packet with two vlan tags is recieved, one core is processing the packet. I am using XL710 NIC card and i40e driver, and the F/W version is 3.33 0x80000e2c 0.0.0.
I would like to know the following:
1. Does RSS operation support for IEEE 802.1ad packets?
2. If it is possible, how can i set up.

[Irwan_Intel]

Hi qweeeee

Thank you for posting in Intel® Ethernet Community

The IEEE 802.1ad standard, informally known as QinQ, allows for multiple VLAN IDs within a single Ethernet frame.

802.1ad (QinQ) is supported in 3.19 and later kernels.

Receive checksum offloads and VLAN acceleration are not supported for 802.1ad (QinQ) packets.

The following are examples of how to configure 802.1ad (QinQ):

# ip link add link eth0 eth0.24 type vlan proto 802.1ad id 24

# ip link add link eth0.24 eth0.24.371 type vlan proto 802.1Q id 371

Where "24" and "371" are example VLAN IDs.

For RSS, you can refer to the Ethernet Adapter User Guide below:

Intel® Ethernet Adapters and Devices User Guide: https://cdrdv2.intel.com/v1/dl/getContent/705831?explicitVersion=true

Refer to the following sections:

3.20 Max Number of RSS Queues Per Vport

3.22.1.1 General Optimization

3.29 Receive Side Scaling

From an OS perspective, set the maximum number of RSS processors accordingly by your platform capability. 

Refer to the following links for more information:

https://docs.microsoft.com/en-us/windows-hardware/drivers/network/setting-the-number-of-rss-processors

https://docs.microsoft.com/en-us/powershell/module/netadapter/set-netadapterrss

Regards,

Irwan_Intel

[qweeeee]

thank you for your reply.

but i wanna know about Does RSS support for IEEE 802.1ad(Q-in-Q) packets.

there are no information about RSS for 802.1ad packet in here "https://cdrdv2.intel.com/v1/dl/getContent/705831?explicitVersion=true" 

i'm using XL710 NIC card[8086:1583] and i40e driver.

thank you for your help.

[Irwan_Intel]

Hi qweeeee,

The RSS algorithm does not deconstruct the entire packet and does not look for QinQ.

However this may change in future releases of the NVM.

Regards,

Irwan_Intel

[qweeeee]

Thank you for your reply.

I hope it happens soon~~

[Irwan_Intel]

Hello qweeeee,

Thank you for your understanding. I will proceed to close this case. If you have any further questions or require assistance in the future, please don't hesitate to reach out.

Regards,

Irwan_Intel