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Fri, 3 Apr 2026 17:24:09 -0400 (EDT) Date: Fri, 3 Apr 2026 23:24:07 +0200 From: Marek =?utf-8?Q?Marczykowski-G=C3=B3recki?= To: Teddy Astie Cc: Val Packett , Demi Marie Obenour , Xen developer discussion , dri-devel@lists.freedesktop.org, linux-mm@kvack.org, Ariadne Conill Subject: Re: Why memory lending is needed for GPU acceleration Message-ID: References: <84462c4b-7813-4ad1-aeb2-862ae4f3a627@gmail.com> <0bbf0349-1006-485f-a2db-6c8b795b4242@invisiblethingslab.com> <1de15ce0-9f7e-4253-80a7-ecd94caa4325@vates.tech> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="4Ae0y7aT9vuqArIi" Content-Disposition: inline In-Reply-To: <1de15ce0-9f7e-4253-80a7-ecd94caa4325@vates.tech> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" --4Ae0y7aT9vuqArIi Content-Type: text/plain; protected-headers=v1; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Date: Fri, 3 Apr 2026 23:24:07 +0200 From: Marek =?utf-8?Q?Marczykowski-G=C3=B3recki?= To: Teddy Astie Cc: Val Packett , Demi Marie Obenour , Xen developer discussion , dri-devel@lists.freedesktop.org, linux-mm@kvack.org, Ariadne Conill Subject: Re: Why memory lending is needed for GPU acceleration 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=3D2048 gnttab_max_maptrack_frames=3D4096 And similarly, on domU side: echo 1073741824 > /sys/module/xen_gntalloc/parameters/limit --=20 Best Regards, Marek Marczykowski-G=C3=B3recki Invisible Things Lab --4Ae0y7aT9vuqArIi Content-Type: application/pgp-signature; name=signature.asc -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEhrpukzGPukRmQqkK24/THMrX1ywFAmnQL/gACgkQ24/THMrX 1yxbGQf+OgsupCAnm7yeXU50i8UAUbaCxLl6LTgomVWE8BqqFLLzbd1uZRBaxgwi 08KM6UwaNDnWYrJjTzzuVajjgvb364NRxaCcDQMU1gg9QaScwe0rvqNXjTCyyZIZ KcGYITuyNobu6TEOlxjMZCYe09hjh5Tv6YIAjNytG/v4Wj0BeLd6dpU3y/K79rsz k5Q2KuSQNJBm0DrX1xHtYDI34Ecs8kMi+QNmTxBNirLjkzswlCpewSvOONNsy8Ff 8k+hGeZuhbRQMidzb/toBQpk5p82359YvtUwGWz6rn/YnryTk6+3x3Vr1octMvgz 5SPKxfVNDvikjgpYpZpWowiX1sDLHw== =Aya7 -----END PGP SIGNATURE----- --4Ae0y7aT9vuqArIi--