Comment 5 for bug 1981631

Thanks Sylvain. Just to clarify, are you suggesting that we could specify a subset of the PCI addresses in the vgpu_type group in nova.conf to supply placement with the correct inventory? (i.e. instead of using custom traits to workaround the issue)
e.g.
enabled_vgpu_types=nvidia-471

[vgpu_nvidia-471]
device_addresses = 0000:41:00.4,0000:a1:00.4

I had initially tried that, but it didn't work. It seems that when specifying a single enabled_vgpu_type on the host then it is assumed that all discovered gpu devices are of the enabled type and any pgpu_type_mapping is ignored. As a result, all of the gpu pci addresses are added as inventory in placement rather than the subset specified in device_addresses.
The attached patch seems to fix the issue. I've only tested an equivalent patch on victoria. We're unable to test against master with this hardware currently, though the issue still appears to exist in the code in master. Happy to send up a review if that looks sane.