uPCIe: user-space PCIe libraries

uPCIe is a set of header-only C libraries for user-space PCIe device interaction on Linux. It provides hugepage-backed DMA, MMIO accessors, PCI discovery and BAR mapping, VFIO wrappers, dma-buf helpers, and a minimalist NVMe driver, with no dependencies beyond the Linux UAPI headers.

It started as a way to explore the boundary between safe and unsafe user-space PCIe practices. It targets both the IOMMU-protected path (vfio-pci) and the raw-physical path (uio_pci_generic with hugepages). The companion tooling lives in its own repositories: devbind, hugepages, and iommu.

Design goals

• Header-only
• Idiomatic, with a consistent error and ownership model
• Zero-dependency, beyond the Linux UAPI headers
• Minimalistic
• Low-coupling
• C11

Topics of interest

• Mapping PCIe BAR spaces via vfio-pci and uio_pci_generic
• IOMMU-protected memory for safe DMA
• Hugepages for raw-physical DMA with uio_pci_generic
• PCIe driver binding and unbinding
• Interrupts and how to handle them

Documentation

The documentation is published at https://safl.dk/upcie. The sources live under docs/ and build locally with:

make -C docs deps
make -C docs html      # output in docs/_build/html