Thread

1. mjg59 · 1790230761 · focus · HN ↗

   Hrm, something of a lack of discussion about what level of access the card has to the host in the absence of IOMMU-restricted passthrough.

   1. orphereus · 1790231063 · focus · HN ↗

      I am very sceptical about this. I have some experience in GPU virtualization and passthrough with Nvidia GPUs and they are really not designed to be able to share them with multiple guests/host without Nvidia's blessing (licenced drivers).

      1. WanjohiRyan · 1790231531 · focus · HN ↗

         Yes they are not... we run the Nvidia drivers unmodified. Only thing we have done is make the guest driver think it's running on the host, talking to the host's GPU kernel.

         It works really well with a ~2% performance penalty. Nvproxy by google/gvisor has been doing this for years.

         You should try running it yourself and see how it goes :D

         1. orphereus · 1790233192 · focus · HN ↗

            So you can share the GPU between multiple VMs? I can have 4 VMs simultaneously do work on the GPU?

            And each one would have its own Nvidia driver? How do they not interfere with each other? I mean I am by no means an expert in GPU architecture or anything similar, but I thought the problems with sharing a GPU come from the differences between GPU vs CPU architecture. On the other hand, multiple processes on a host can run on the same GPU, but that is all using the same kernel. I am just very confused.

            1. madushan1000 · 1790234473 · focus · HN ↗

               This has been a thing for AMD, Intel, and Qualcomm GPUs for a few years now. Search for "DRM native context". The only difference here is that you had to use mesa drivers before and now someone made it work with the Nvidia drivers.

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