GPU Support

[amrragab8080]

Public facing api doesnt seem to have support yet for passthrough pci devices, namely gpu is this technically feasible?

[goswamig]

That would be super helpful to have support for GPU.

[acatangiu]

GPU support in Firecracker is very hard/tricky at the moment. With current GPU hardware, there's two major problems:

1. To do device pass-through implies pinning physical memory which would remove our memory oversubscription capabilities.
2. We can only run 1 customer workload securely per physical GPU, and switching between customer workloads takes a long enough time to make it impractical.

As a result there is no known path to supporting GPUs in Firecracker.

[raduweiss]

@amrragab8080, we'll be looking at this as part of #1179.

[normtown]

To do device pass-through implies pinning physical memory which would remove our memory oversubscription capabilities.

Why do you want to maintain the ability to oversubscribe memory?

[raduweiss]

Oversubscription is a core part of makes Firecracker a great way to isolate serverless workloads; that's why we took on a tenet around it [1].

[1] https://github.com/firecracker-microvm/firecracker/blob/master/CHARTER.md