Is it require to blacklist i40evf / iavf from the compute side?

Issue

• We are looking at the baseline recommandation regarding enabling SR=IOV for Openstack computes. Currently, we are seeing computes loading both i40e and i40evf drivers after a fresh deployment.

• While we did not have issues in the past two years of operations, we had some sporadic of libvirt getting hung and forcing a compute reboot .

• What we found out is that disabling the i40evf driver seems to correct our issue and libvirt does not hang.

[stack@overcloud-compute-1 ~]$ lsmod | grep i40
i40evf                103843  0
i40e                  354807  0
ptp                    19231  2 tg3,i40e

• When we spin a VM with SR-IOV ports, we do see the i40e and i40evf driver react:

[Wed Jul  7 10:39:56 2021] i40evf 0000:37:04.3: Reset warning received from the PF
[Wed Jul  7 10:39:56 2021] i40evf 0000:37:04.3: Scheduling reset task
[Wed Jul  7 10:39:56 2021] i40e 0000:37:00.0: VF 19 is now trusted
[Wed Jul  7 10:39:56 2021] i40evf 0000:37:0c.3: Reset warning received from the PF
[Wed Jul  7 10:39:56 2021] i40evf 0000:37:0c.3: Scheduling reset task
[Wed Jul  7 10:39:56 2021] i40e 0000:37:00.1: VF 19 is now trusted
[Wed Jul  7 10:39:56 2021] i40evf 0000:d8:04.3: Reset warning received from the PF
[Wed Jul  7 10:39:56 2021] i40evf 0000:d8:04.3: Scheduling reset task
[Wed Jul  7 10:39:56 2021] i40e 0000:d8:00.0: VF 19 is now trusted
[Wed Jul  7 10:39:57 2021] i40evf 0000:d8:0c.3: Reset warning received from the PF
[Wed Jul  7 10:39:57 2021] i40evf 0000:d8:0c.3: Scheduling reset task
[Wed Jul  7 10:39:57 2021] i40e 0000:d8:00.1: VF 19 is now trusted
[Wed Jul  7 10:39:59 2021] i40e 0000:37:00.0: VF 19 still in reset. Try again.
[Wed Jul  7 10:39:59 2021] i40e 0000:37:00.1: VF 19 still in reset. Try again.
[Wed Jul  7 10:39:59 2021] i40e 0000:37:00.0: VF 19 still in reset. Try again.
[Wed Jul  7 10:39:59 2021] i40e 0000:37:00.1: VF 19 still in reset. Try again.
[Wed Jul  7 10:39:59 2021] i40e 0000:37:00.0: Setting MAC fa:16:3e:53:02:9e on VF 19
[Wed Jul  7 10:39:59 2021] i40e 0000:37:00.0: Reload the VF driver to make this change effective.
[Wed Jul  7 10:39:59 2021] i40e 0000:37:00.0: Setting VLAN 65, QOS 0x0 on VF 19
[Wed Jul  7 10:39:59 2021] i40e 0000:37:00.1: Setting MAC fa:16:3e:38:89:89 on VF 19
[Wed Jul  7 10:39:59 2021] i40e 0000:37:00.1: Reload the VF driver to make this change effective.
[Wed Jul  7 10:39:59 2021] i40e 0000:37:00.1: Setting VLAN 96, QOS 0x0 on VF 19
[Wed Jul  7 10:39:59 2021] i40e 0000:d8:00.0: Setting MAC fa:16:3e:3c:8f:1f on VF 19
[Wed Jul  7 10:39:59 2021] i40e 0000:d8:00.0: Reload the VF driver to make this change effective.
[Wed Jul  7 10:39:59 2021] i40e 0000:d8:00.0: Setting VLAN 58, QOS 0x0 on VF 19
[Wed Jul  7 10:39:59 2021] i40e 0000:d8:00.1: Setting MAC fa:16:3e:1b:2f:cd on VF 19
[Wed Jul  7 10:39:59 2021] i40e 0000:d8:00.1: Reload the VF driver to make this change effective.

Our question :
- Is Red Hat recommending disabling the i40evf driver from the compute side?
- Is Red Hat recommending disabling the iavf (if the kernel provides the iav driver) driver from the compute side?