XL710 burst limit with TSCDQUANTA register

[FedeParola]

Hello everybody,

I am using MoonGen packet generator (DPDK based) to run some experiments, leveraging hardware rate limit feature provided by the XL710 NIC. I need to control both the average rate and the maximum burst size. Looking at the datasheet of the NIC there should be a register called TSCDQUANTA allowing to set the size of the burst (quanta), however I'm not able to find a way to program this register and its address is not listed in the datasheet. How can I control the burst size?

Best regards,

Federico Parola

[AlfredoS_Intel]

Hi Fedeparola,

Thank you for posting in our Intel® Ethernet Communities Page.

We have a special support site for DPDK concerns. Please go to this link, https://www.intel.com/content/www/us/en/design/support/ips/training/welcome.html, and click "Access and Log In" to contact the DPDK support.

Please let us know if you have any further questions.

We look forward to hearing from you. If we do not get your reply, we will follow up after 3 business days.

Best Regards,

Alfred S

Intel® Customer Support

[FedeParola]

Hello Alfred,

Unfortunately if I try to follow the procedure I receive the message: "You don't have Access to IPS". However I think my problem is not strictly related to DPDK, how to access the TSCDQUANTA register is not specific to that technology.

Best regards,

Federico Parola

[AlfredoS_Intel]

Hi Fedeparola,

Thank you for your response.

We will try to look into the information that you need from our end. Before that, we would like to ask a few questions:

1. May we know the exact model of the XL710 network card?

2. Would it be okay to ask what will be the purpose why you need the information that you are looking for?

We look forward to your reply. Should we not get your reply, we will follow up after three business days.

Best Regards,

Alfred S

Intel® Customer Support

[FedeParola]

Hello Alfred,

1. The model is "Intel Corporation Ethernet Controller XL710 for 40GbE QSFP+ (rev 02)".
This is the result of "ethtool -i":
driver: i40e
version: 5.9.0-050900-generic
firmware-version: 8.10 0x800093f8 1.2829.0
expansion-rom-version:
bus-info: 0000:65:00.0
supports-statistics: yes
supports-test: yes
supports-eeprom-access: yes
supports-register-dump: yes
supports-priv-flags: yes

2. I need to set the burst size for testing purposes, I'm using the NIC on a machine running a packet generator and I need to test the behavior of another machine with different burst sizes. I'm relying on hardware rate limiting provided by the NIC for maximum precision.

Best regards,
Federico

[AlfredoS_Intel]

Hi Fedeparola,

Thank you for providing that information.

We will continue checking this and the information that provided is invaluable to us.

Please allow us some time to check on this. We hope for your understanding regarding this

We will get back to you no later than 3 business days from now.

Best Regards,

Alfred S

Intel® Customer Support 

[AlfredoS_Intel]

Hi Fedeparola,

Thank you for waiting for our update.

Attached is the Datasheet for XL710. It has TSCDQUANTA information. Please let us know if you were able to get the information that you need from the document.

We look forward to your reply. Should we not get your reply, we will follow up after three business days.

Best Regards,

Alfred S

Intel® Customer Support

[FedeParola]

Hi Alfred,
thanks for your response.

The datasheet is the place where I found out about the existence of the register, however it only mentions the register two times, in pages 891 and 891, and no information is given about how to access it (no address, no read/write policy), the datasheet only specifies that it can be used to set the size of burst sent by the NIC.
In the datasheet there are other register with a name starting with TSCD (e.g. TSCDIFSTATUS, TSCDIFCTRL) and no information on how to access those registers is provided either. I wonder if there is a common way to access TSCD type registers on Intel NICs (specified elsewhere) that I am not aware of.

Best regards,
Federico

[AlfredoS_Intel]

Hi Fedeparola,

Thank you for your response and providing more details regarding the issue,

We will continue checking this and the information that provided is invaluable to us.

Please allow us some time to check on this. We hope for your understanding regarding this

We will get back to you no later than 3 business days from now.

Best Regards,

Alfred S

Intel® Customer Support

[SamanthaCl_D_Intel · Accepted solution]

Hello Fedeparola,

Thank you for contacting Intel Customer Support. We understand you require RDC privileged access. Kindly register through the below link. An inside sales representative will reach out to you regarding your application.

Privileged

https://www.intel.com/content/www/us/en/forms/design/registration-privileged.html

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Some examples:

john.smith@intel.com

j.smith@intelcom

john.smith@intel.de

j.smith@intel.org

john.smith@intel.edu

If you have any issues or questions about this form, please note the “Need Help” option on the right-hand side of the page. If you have any concerns or questions for us, please reply to us within 14 days to have this case reopened. Thank you and have a great week ahead. Stay safe!

Best Regards,

Samantha

Intel Customer Support Associate