Matthew Auld d755887f8e drm/xe/dma_buf: stop relying on placement in unmap
The is_vram() is checking the current placement, however if we consider
exported VRAM with dynamic dma-buf, it looks possible for the xe driver
to async evict the memory, notifying the importer, however importer does
not have to call unmap_attachment() immediately, but rather just as
"soon as possible", like when the dma-resv idles. Following from this we
would then pipeline the move, attaching the fence to the manager, and
then update the current placement. But when the unmap_attachment() runs
at some later point we might see that is_vram() is now false, and take
the complete wrong path when dma-unmapping the sg, leading to
explosions.

To fix this check if the sgl was mapping a struct page.

v2:
  - The attachment can be mapped multiple times it seems, so we can't
    really rely on encoding something in the attachment->priv. Instead
    see if the page_link has an encoded struct page. For vram we expect
    this to be NULL.

Link: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/4563
Fixes: dd08ebf6c3 ("drm/xe: Introduce a new DRM driver for Intel GPUs")
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: <stable@vger.kernel.org> # v6.8+
Acked-by: Christian König <christian.koenig@amd.com>
Link: https://lore.kernel.org/r/20250410162716.159403-2-matthew.auld@intel.com
2025-04-16 09:59:24 +01:00
2024-09-01 20:43:24 -07:00
2025-02-04 11:27:45 -05:00
2025-03-09 13:45:25 -10:00

Linux kernel
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In order to build the documentation, use ``make htmldocs`` or
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There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
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