[Intel-wired-lan] [PATCH net-next v2] ice: Enable configuration of number of qps per VF via devlink

[Samudrala, Sridhar <sridhar.samudrala@intel.com>]

On 5/17/2021 2:49 PM, Creeley, Brett wrote:
>> -----Original Message-----
>> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf Of Sridhar Samudrala
>> Sent: Monday, April 26, 2021 11:20 AM
>> To: intel-wired-lan at lists.osuosl.org; Nguyen, Anthony L <anthony.l.nguyen@intel.com>; Samudrala, Sridhar
>> <sridhar.samudrala@intel.com>
>> Subject: [Intel-wired-lan] [PATCH net-next v2] ice: Enable configuration of number of qps per VF via devlink
>>
>> Introduce a devlink parameter 'num_qps_per_vf' to allow user
>> to configure the maximum number of queue pairs given to SR-IOV
>> VFs before they are created.
>>
>> This is currently determined by the driver based on the number
>> of SR-IOV VFs created. In order to keep this behavior by default
>> the parameter is initialized to 0. To change the default behavior,
>> user can set num_qps_per_vf parameter via devlink and this will
>> be used as the preferred value to determine the queues and vectors
>> assigned per VF.
> What if the host administrator wants to give the VF a different number
> of vectors than queues? For example, if the admin knows the VF
> instance will be exercising VF RDMA and the VF needs more vectors
> for RDMA traffic.
>
> Should we have 2 separate values, i.e. "num_qps_per_vf" and
> "num_msix_per_vf"?

I missed responding to this comment.
Sure. We can add num_msix_pr_vf as a later patch to enable additional 
vectors for RDMA.

Tony,
Can this patch be included in your series when you submit to netdev?
OR do i need to rebase it based on the latest net-next?

Thanks
Sridhar
>
>> USAGE:
>> On a 2 port NIC
>>   # devlink dev param show
>>   pci/0000:42:00.0:
>>     name num_qps_per_vf type driver-specific
>>       values:
>>         cmode runtime value 0
>>   pci/0000:42:00.1:
>>     name num_qps_per_vf type driver-specific
>>       values:
>>         cmode runtime value 0
>>
>>   /* Set num_qps_per_vf to 4 */
>>   # devlink dev param set pci/0000:42:00.0 name num_qps_per_vf value 4 cmode runtime
>>
>>   # devlink dev param show pci/0000:42:00.0 name num_qps_per_vf
>>   pci/0000:42:00.0:
>>     name num_qps_per_vf type driver-specific
>>       values:
>>         cmode runtime value 4
>>
>>   # echo 8 > /sys/class/net/enp66s0f0/device/sriov_numvfs
>>
>> This will create 8 VFs with 4 queue pairs and 5 vectors per VF
>> compared to the default behavior of 16 queue pairs and 17 vectors
>> per VF.
>>
>> v2:
>> Fixed kdoc for ice_devlink_num_qps_per_vf_validate()
>>
>> Signed-off-by: Sridhar Samudrala <sridhar.samudrala@intel.com>
>> ---
>>   Documentation/networking/devlink/ice.rst      |  23 ++++
>>   drivers/net/ethernet/intel/ice/ice_devlink.c  | 110 +++++++++++++++++-
>>   drivers/net/ethernet/intel/ice/ice_main.c     |   3 +
>>   .../net/ethernet/intel/ice/ice_virtchnl_pf.c  |   5 +-
>>   4 files changed, 139 insertions(+), 2 deletions(-)
>>
> <snip>
>