The412Banner a132a6de97 Map 32-bit games' GPU memory below 4 GiB on Qualcomm ...

32-bit DXVK titles failed every vkMapMemory with
VK_ERROR_OUT_OF_HOST_MEMORY: the Qualcomm driver maps above 4 GiB, which
WoW64 Wine rejects unless the device offers VK_EXT_map_memory_placed.

The bridge's placed-memory layer emulates that extension, but its
OPAQUE_FD path made every exportable resource external. This driver
reports OPAQUE_FD export as dedicated-only: external buffers and images
bind only to dedicated exported memory and cannot use the cached
host-visible type, so DXVK's first image bind failed with
VK_ERROR_INVALID_EXTERNAL_HANDLE.

0015-placed-memory-dedicated-export.patch adds a mode for such drivers:
resources stay native and each host-visible allocation that is not
dedicated already is dedicated to a hidden buffer of its size and
exported. The driver binds other resources to that memory, and the
dma-buf mapped at Wine's placed address is coherent with the GPU (probe
on the Pocket FIT: CPU writes through the low mapping, GPU copy, read
back). With a locally built layer, AIO's 32-bit DX11 cube ran 15 s at
142.8 FPS average.

Qualcomm sessions now load the layer with
DROIDDECK_EXPERIMENTAL_PLACED_MEMORY=1; it only acts for devices that
request VK_EXT_map_memory_placed.

2026-10-26 07:18:10 +00:00

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usr

Map 32-bit games' GPU memory below 4 GiB on Qualcomm

2026-10-26 07:18:10 +00:00