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punktfunk/crates/pf-zerocopy/Cargo.toml
T
enricobuehler 7c82a72ecd fix(zerocopy): find the NVIDIA render node instead of assuming renderD128
The EGL importer — the head of the CUDA/NVENC zero-copy path — opened
`/dev/dri/renderD128` and hoped. On a single-GPU host that is the
NVIDIA node and it always worked. On a hybrid laptop the iGPU is bound
first, so renderD128 is Intel: we built a GBM device on Mesa, asked it
for a pbuffer-capable OpenGL config, got none (Mesa's GBM platform
advertises only window-capable ones — gbm_surface is the point of that
platform there), and reported

    zerocopy worker init failed: no EGL config for OpenGL

on a machine whose NVIDIA EGL stack was demonstrably fine, naming
neither the device nor the reason. `PUNKTFUNK_RENDER_NODE` was no
escape either: this path never read it.

Pick the node by what it is — the first `/dev/dri/renderD*` whose
sysfs PCI vendor is 0x10de, the same identification the crate's Vulkan
bridge already uses for its physical device. A local scan rather than a
`pf_gpu` dependency, because this crate is a leaf whose worker is its
own process, and `pf_gpu::linux_render_node` answers a different
question anyway: it follows the operator's GPU *preference*, which may
legitimately name the iGPU. What is needed here is not which GPU to use
but where CUDA is. `PUNKTFUNK_ZEROCOPY_RENDER_NODE` overrides, and no
NVIDIA node found keeps the historical guess — sysfs may just not be
mounted, and the CUDA context is what properly fails on a host with no
NVIDIA at all.

Then stop the config query being able to fail this way: retry without
the surface-type constraint, which is honest because we never create an
EGLSurface — `eglMakeCurrent` runs surfaceless. And name the node in
every error and in the ready line, so the next hybrid host diagnoses
itself.
2026-07-25 15:13:11 +02:00

37 lines
1.9 KiB
TOML

# The Linux GPU zero-copy plumbing (plan §9 / §W6), extracted into a leaf crate so the shared
# frame vocabulary (pf-frame `FramePayload::Cuda`), the encode backends (CUDA copies/context),
# and the capture import machinery can all reach it WITHOUT the host orchestrator in between.
# Content is Linux-only; the crate compiles to an empty lib elsewhere so dependents can carry a
# plain (non-target-gated) dependency.
[package]
name = "pf-zerocopy"
version.workspace = true
edition = "2021"
# Inherit the workspace MSRV: clippy keys MSRV-gated lints off it (without this, e.g.
# `manual_is_multiple_of` fires on code the host crate compiles clean).
rust-version.workspace = true
license = "MIT OR Apache-2.0"
description = "punktfunk host Linux zero-copy GPU plumbing: CUDA context/buffers, EGL/Vulkan dmabuf import, the isolated import worker, and dmabuf implicit-fence sync."
publish = false
[target.'cfg(target_os = "linux")'.dependencies]
anyhow = "1"
tracing = "0.1"
libc = "0.2"
# `libcuda.so.1` is dlopen'd at runtime (NOT link-time) so one Linux binary runs on NVIDIA
# (zero-copy via CUDA) AND on AMD/Intel (VAAPI, no NVIDIA driver present) — see `cuda::ffi`.
libloading = "0.8"
# EGL imports the PipeWire dmabuf, CUDA maps it (`dynamic` = load the NVIDIA libEGL at runtime).
khronos-egl = { version = "6", features = ["dynamic"] }
# Vulkan bridge for LINEAR dmabufs (gamescope): VK_EXT_external_memory_dma_buf import,
# GPU-copy into an exportable allocation, export OPAQUE_FD → cuImportExternalMemory.
ash = "0.38"
# The isolated import worker's control protocol: small serde_json blobs over a Unix socket
# (SCM_RIGHTS carries the fds; pixels never cross the socket).
serde = { version = "1", features = ["derive"] }
serde_json = "1"
# Linux-only like the code under test: the render-node scan is exercised against a fixture tree.
[target.'cfg(target_os = "linux")'.dev-dependencies]
tempfile = "3"