Re: Why memory lending is needed for GPU acceleration

Marek Marczykowski-Górecki
2026-04-03T21:24:16Z

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On Tue, Mar 31, 2026 at 09:42:22AM +0000, Teddy Astie wrote:
> XEN_GNTDEV_DMABUF has been designed for GPU use-cases, and more
> precisely for paravirtualizing a display. The only issue I would have
> with it is that grants are not scalable for GPU 3D use cases (with
> hundreds of MB to share).

FWIW we do use grants for graphics buffers already - window composition
buffers specifically. We do run xen with extra options for that:
gnttab_max_frames=2048 gnttab_max_maptrack_frames=4096
And similarly, on domU side:
echo 1073741824 > /sys/module/xen_gntalloc/parameters/limit

--
Best Regards,
Marek Marczykowski-Górecki
Invisible Things Lab

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