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| author | Jiri Pirko <jiri@nvidia.com> | 2026-04-07 12:26:17 +0300 |
|---|---|---|
| committer | Marek Szyprowski <m.szyprowski@samsung.com> | 2026-04-10 15:20:01 +0300 |
| commit | 15818b2cd42df3cc886f4cc46acfab4d072dcacc (patch) | |
| tree | ffa6f2c542041a4014d8e24619d7aae75ba446c7 | |
| parent | 78b30c50a7ac9b8fbec678d71f81dec80bf8eed6 (diff) | |
| download | linux-15818b2cd42df3cc886f4cc46acfab4d072dcacc.tar.xz | |
dma-buf: heaps: system: document system_cc_shared heap
Document the system_cc_shared dma-buf heap that was introduced
recently. Describe its purpose, availability conditions and
relation to confidential computing VMs.
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: T.J.Mercier <tjmercier@google.com>
Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20260407092617.635223-1-jiri@resnulli.us
| -rw-r--r-- | Documentation/userspace-api/dma-buf-heaps.rst | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/Documentation/userspace-api/dma-buf-heaps.rst b/Documentation/userspace-api/dma-buf-heaps.rst index 05445c83b79a..f56b743cdb36 100644 --- a/Documentation/userspace-api/dma-buf-heaps.rst +++ b/Documentation/userspace-api/dma-buf-heaps.rst @@ -16,6 +16,13 @@ following heaps: - The ``system`` heap allocates virtually contiguous, cacheable, buffers. + - The ``system_cc_shared`` heap allocates virtually contiguous, cacheable, + buffers using shared (decrypted) memory. It is only present on + confidential computing (CoCo) VMs where memory encryption is active + (e.g., AMD SEV, Intel TDX). The allocated pages have the encryption + bit cleared, making them accessible for device DMA without TDISP + support. On non-CoCo VM configurations, this heap is not registered. + - The ``default_cma_region`` heap allocates physically contiguous, cacheable, buffers. Only present if a CMA region is present. Such a region is usually created either through the kernel commandline |