Comment 4 for bug 2008883

just following up on my last comment when we implemented
https://specs.openstack.org/openstack/nova-specs/specs/ussuri/implemented/vgpu-multiple-types.html
the spec linked to the fact that the Nvidia grid drivers at the time did not support multiple mdev types in the same pyhical gpu.
https://docs.nvidia.com/grid/10.0/grid-vgpu-user-guide/index.html#homogeneous-grid-vgpus

that changed in a100 with the introduction of mig

i think what we ended up merging in ussuri was support for multiple vgpus types with one vgpu type per physical GPU and i suspect mig support is not enough with novas current implementation to model different GPU types on the same card.