Running ONNX Runtime WebGPU Tests Locally on Linux (No GPU)

Reusable knowledge for exercising the WebGPU execution provider on a Linux box with no physical GPU.

Scope: Linux ORT WebGPU only. macOS uses the Metal backend and a real GPU; this skill is the off-Mac story for running WebGPU EP kernels in CI-less dev loops.

1. Why software Vulkan is enough

On Linux, ORT's WebGPU EP runs on Dawn with the Vulkan backend. Vulkan does not require a hardware GPU — Mesa lavapipe is a software (CPU) Vulkan adapter that Dawn enumerates like any other device. For EP correctness tests this is sufficient because: