SR-IOV broken in Ubuntu 20.04.2 LTS

[gijs van der velden]

SR-IOV does not work since Ubuntu Server 18.04.2 LTS, once the HWE kernel (4.18.0-15 generic x86_64)) has been installed on that version. Please also see ticket: https://bugs.launchpad.net/ubuntu/+source/linux-hwe/+bug/1818400

This bug report was created for Ubuntu 20.04.02 LTS, since the kernel for the previous bug report is no longer being supported and a developer requested us to make a new bug report for the new Ubuntu version...

Environment:
Windows Server 2019
Fresh Hyper-V generation 2 VM (configuration version 9.0)
SR-IOV enabled on the virtual switch (Intel I350-T2 physical network adapter)
SR-IOV enabled on the virtual network card of the VM

Steps to reproduce:
Install Ubuntu Server 20.04.2 LTS
Verify SR-IOV is enabled in the Networking tab of the Hyper-V manager

Check SR-IOV status in the Networking tab of the Hyper-V manager. It will show status degraded (SR-IOV not operational)

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: linux-image-5.8.0-1033-azure 5.8.0-1033.35~20.04.1
ProcVersionSignature: Ubuntu 5.8.0-1033.35~20.04.1-azure 5.8.18
Uname: Linux 5.8.0-1033-azure x86_64
ApportVersion: 2.20.11-0ubuntu27.18
Architecture: amd64
CasperMD5CheckResult: pass
Date: Wed Jun 23 23:00:26 2021
InstallationDate: Installed on 2020-09-15 (281 days ago)
InstallationMedia: Ubuntu-Server 20.04.1 LTS "Focal Fossa" - Release amd64 (20200731)
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: linux-signed-azure-5.8
UpgradeStatus: No upgrade log present (probably fresh install)

[Marcelo Cerri (mhcerri)]

Hi, Gijs. Thank you for your report.

Can you provide the full output of dmesg from the Ubuntu VM?

Thank you

[gijs van der velden (gijsvandervelden)]

Certainly, see the attached file.

[Marcelo Cerri (mhcerri)]

Does the problem happen when using the 5.11 provided by linux-azure-edge? This kernel can be installed with `apt-get install linux-azure-edge`.

The 5.11 kernel is scheduled to become the default linux-azure kernel soon.

[gijs van der velden (gijsvandervelden)]

Hi Marcelo,

Thank you for following up on this.
Unfortunately, even with the 5.11 kernel the problem still exists.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.