The same exposure of Mellanox hardware issue occurs on Photon OS as well. Having installed the Mellanox Firmware Tools (MFT), mst status throws 'no MST devices were found'.
mst start
Starting MST (Mellanox Software Tools) driver set
Loading MST PCI module - Success
Loading MST PCI configuration module - Success
Create devices
Unloading MST PCI module (unused) - Success
Unloading MST PCI configuration module (unused) - Success
mst status -v
MST modules:
------------
MST PCI module is not loaded
MST PCI configuration module is not loaded
No MST devices were found or MST modules are not loaded.
You may need to run 'mst start' to load MST modules.
/dev/mst is empty, nevertheless lsipci -nnn presents
aca4:00:02.0 Ethernet controller [0200]: Mellanox Technologies MT27500/MT27520 Family [ConnectX-3/ConnectX-3 Pro Virtual Function] [15b3:1004]
b75a:00:02.0 Ethernet controller [0200]: Mellanox Technologies MT27500/MT27520 Family [ConnectX-3/ConnectX-3 Pro Virtual Function] [15b3:1004]
The content in /sys/bus/pci/devices/b75a\:00\:02.0/ is
ari_enabled current_link_speed driver local_cpus modalias pools resource subsystem_device
broken_parity_status current_link_width driver_override max_link_speed msi_bus power resource2 subsystem_vendor
class d3cold_allowed enable max_link_width msi_irqs remove resource2_wc uevent
config device irq mlx4_port1 net rescan revision vendor
consistent_dma_mask_bits dma_mask_bits local_cpulist mlx4_port1_mtu numa_node reset subsystem
It seems the links are down
cat /sys/bus/pci/devices/b75a\:00\:02.0/current_link_width
0
cat /sys/bus/pci/devices/b75a\:00\:02.0/current_link_speed
Unknown speed
The underlying hardware of the study lab is a MS Azure setup. Accelerated Networking, for the network adapter presentation, and IP forwarding, aka the prerequirement ESXi promiscuous mode for nested virtualization, both setting are enabled.