Exporting Virtual Memory as dmabuf
Talkat Embedded Linux Conference + OpenIoT Summit North America 2017 · on Wednesday, 2017-02-22· at 16:20· Atrium Ballroom·
summary
A kernel character driver called vm_m_export walks process page tables in software to convert any user virtual address into a scatter‑gather list of physical pages, pins those pages and returns a DMA-BUF FD via simple ioctls, enabling malloced, RTOS/“artists” or CMA buffers to be shared with Linux importers like DRM, Wayland and GStreamer. Implemented against 4.4, it works but currently does not trigger page faults automatically, so pinning, alignment, continuity and security checks remain important.
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chapters (9)
- 0:00Introduction
- 0:35Presentation Outline
- 2:12Typical Use Case
- 4:40What is DMF
- 18:57Page table
- 25:05Buffers
- 32:23Generic Use Cases
- 34:47Memory Sharing
- 42:41Security Concerns
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