i40evf maximum RSS queues reasoning

[SHegd2]

I was looking through the i40evf source code, and it seems like the maximum number of queues supported is 4. Is there a reasoning for this? Is there a way to use more, such as 16?

I've seen patches proposing removing a few variables (MAX_QUEUES, which sets the max to 16, but doesn't actually serve a purpose since the RX queues limit is set to 4).

[idata]

Hi Brokotiv,

Thank you for posting in Wired Communities. Just to double check if you are referring to the driver at https://downloadcenter.intel.com/download/24693/Intel-Network-Adapter-Virtual-Function-Driver-for-Intel-40-Gigabit-Ethernet-Network-Connections There is an issue stated in our README file regarding increasing the RSS queue may result in code 10 error, you may find the information at https://downloadmirror.intel.com/24693/eng/readme.txt I have posted here for your reference as well:" Code 10 Error in Device Manager When Intel DCB Installed and RSS Queues Changed to 16 or Greater-----------------------------------------------------------------------If the Intel DCB feature is installed, changing the number of Receive Side Scaling (RSS) queues to 16 or greater may result in a Code 10 error in Device Manager. To resolve this issue, reinstall the driver from the Intel installation media. Note that this will reset the RSS queues value to the default of 8. Do not change the RSS queues to 16 or greater, as doing so will result in another Code 10 error. Setting RSS queues to a lower value such as 1, 2, or 4 does not cause error." If this is not the driver you refer to, please provide the link where the driver was posted. Thank you.Regards,Sharon T

[SHegd2]

Hi,

That is indeed the driver used. I was referring to the code here:

https://github.com/torvalds/linux/blob/master/drivers/net/ethernet/intel/i40evf/i40evf.h# L109 linux/i40evf.h at master · torvalds/linux · GitHub

Is this not accurate as to the latest i40evf driver? When I used SR-IOV with the driver, I was only seeing 4 queues enabled by default, and I was not sure how to increase the maximum, to 8 or 16 as mentioned. Using "ethtool -l" showed a maximum of 4 queues. Is there documentation on how to increase this otherwise?

If it helps, I am running this inside an Ubuntu 14.04 VM, running Linux kernel 4.4.0-97-generic. The host the VM is running on is running on Ubuntu 16.04, with Linux Kernel 4.4.0-87-generic.

Thanks for the help.

[idata]

Hi Brokotiv,

Thank you for sharing the information. Can you also share what is the exact model of your network adapter so that I can better assist. Thanks.

Regards,

Sharon T

[SHegd2]

Hi Sharon,

The NIC is a Ethernet Controller X710 for 10GbE SFP+.

[SHegd2]

Hi Sharon,

I just wanted to check if you had any updates on this issue.

[idata]

Hi Brokotiv,

We are still checking and will update in case there is any information to share.Regards,Sharon TIntel Customer SupportAgent under contract to Intel

[idata]

Hi Brokotiv,

Can you confirm how many cores/cpus are assigned to the Virtual machine?Regards,Sharon TIntel Customer SupportAgent under contract to Intel

[SHegd2]

Hi Sharon, 36 cores were assigned to the VM.

[idata]

Hi Brokotiv,

Thank you. We will further check.Regards,Sharon TIntel Customer SupportAgent under contract to Intel

[idata]

Hi Brokotiv,

Hope you don't mind, we need more information below:

1. Linux kernel log from the host OS
2. I40e driver version number from the host.
3. Did customer modified i40e driver?
4. Linux kernel log from the Guest OS.
5. I40ef driver version number from the guest.
6. Did customer modified i40evf driver?
7. Ubuntu 14.4 VM settings. Number of VCPUS assigned, memory amount assigned, network devices attached, PCI devices attached in pass though mode, etc.

Please provide SSU LOG as some information can be found there. You may visit this link for the SSU tool:

https://downloadcenter.intel.com/product/91600/Intel-System-Support-Utility Looking forward to you reply. Thank you.Regards,Sharon TIntel Customer SupportAgent under contract to Intel

[idata]

Hi Brokotiv,

Please fee free to provide the requested information.Looking forward to you reply. Thank you.Regards,Sharon TIntel Customer SupportAgent under contract to Intel