Comment 20 for bug 1650058

A quick test on the kernel in comment #14:
Mellanox CX3 VF device is not showing up when booting up with this test kernel: 4.4.0-64-generic.
Looks like this is a regression from 4.4.0-63-generic. In 4.4.0-63-generic, the VF presented correctly.

1. Boot with this test kernel: 4.4.0-64-generic; then VF is not listed in lspci:

root@ubuntu1604-client:~# uname -r
4.4.0-64-generic
root@ubuntu1604-client:~# lspci
00:00.0 Host bridge: Intel Corporation 440BX/ZX/DX - 82443BX/ZX/DX Host bridge (AGP disabled) (rev 03)
00:07.0 ISA bridge: Intel Corporation 82371AB/EB/MB PIIX4 ISA (rev 01)
00:07.1 IDE interface: Intel Corporation 82371AB/EB/MB PIIX4 IDE (rev 01)
00:07.3 Bridge: Intel Corporation 82371AB/EB/MB PIIX4 ACPI (rev 02)
00:08.0 VGA compatible controller: Microsoft Corporation Hyper-V virtual VGA
00:0a.0 Ethernet controller: Digital Equipment Corporation DECchip 21140 [FasterNet] (rev 20)

2. Then boot the same VM with same configuration on: 4.4.0-63-generic, VF shows up.

root@ubuntu1604-client:~# uname -r
4.4.0-63-generic
root@ubuntu1604-client:~# lspci
0000:00:00.0 Host bridge: Intel Corporation 440BX/ZX/DX - 82443BX/ZX/DX Host bridge (AGP disabled) (rev 03)
0000:00:07.0 ISA bridge: Intel Corporation 82371AB/EB/MB PIIX4 ISA (rev 01)
0000:00:07.1 IDE interface: Intel Corporation 82371AB/EB/MB PIIX4 IDE (rev 01)
0000:00:07.3 Bridge: Intel Corporation 82371AB/EB/MB PIIX4 ACPI (rev 02)
0000:00:08.0 VGA compatible controller: Microsoft Corporation Hyper-V virtual VGA
0000:00:0a.0 Ethernet controller: Digital Equipment Corporation DECchip 21140 [FasterNet] (rev 20)
99b2:00:02.0 Ethernet controller: Mellanox Technologies MT27500/MT27520 Family [ConnectX-3/ConnectX-3 Pro Virtual Function] <=== this is the VF device