Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:8 as permitted sender) client-ip=2620:137:e000::3:8;
Message-ID: <612d1b7e7ebb01cb8a975d68a8f9b763187610eb.camel@linux.intel.com>
Subject: Re: [PATCH drm-misc-next v6 3/6] drm/gpuvm: add an abstraction for
 a VM / BO combination
From:   Thomas =?ISO-8859-1?Q?Hellstr=F6m?= 
        <thomas.hellstrom@linux.intel.com>
To:     Danilo Krummrich <dakr@redhat.com>, airlied@gmail.com,
        daniel@ffwll.ch, matthew.brost@intel.com, sarah.walker@imgtec.com,
        donald.robson@imgtec.com, boris.brezillon@collabora.com,
        christian.koenig@amd.com, faith@gfxstrand.net
Cc:     dri-devel@lists.freedesktop.org, nouveau@lists.freedesktop.org,
        linux-kernel@vger.kernel.org
Date:   Fri, 13 Oct 2023 14:33:23 +0200
In-Reply-To: <20231008233212.13815-4-dakr@redhat.com>
References: <20231008233212.13815-1-dakr@redhat.com>
         <20231008233212.13815-4-dakr@redhat.com>
Organization: Intel Sweden AB, Registration Number: 556189-6027
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
User-Agent: Evolution 3.46.4 (3.46.4-1.fc37) 
MIME-Version: 1.0
Precedence: bulk

On Mon, 2023-10-09 at 01:32 +0200, Danilo Krummrich wrote:
> Add an abstraction layer between the drm_gpuva mappings of a
> particular
> drm_gem_object and this GEM object itself. The abstraction represents
> a
> combination of a drm_gem_object and drm_gpuvm. The drm_gem_object
> holds
> a list of drm_gpuvm_bo structures (the structure representing this
> abstraction), while each drm_gpuvm_bo contains list of mappings of
> this
> GEM object.
>=20
> This has multiple advantages:
>=20
> 1) We can use the drm_gpuvm_bo structure to attach it to various
> lists
> =C2=A0=C2=A0 of the drm_gpuvm. This is useful for tracking external and e=
victed
> =C2=A0=C2=A0 objects per VM, which is introduced in subsequent patches.
>=20
> 2) Finding mappings of a certain drm_gem_object mapped in a certain
> =C2=A0=C2=A0 drm_gpuvm becomes much cheaper.
>=20
> 3) Drivers can derive and extend the structure to easily represent
> =C2=A0=C2=A0 driver specific states of a BO for a certain GPUVM.
>=20
> The idea of this abstraction was taken from amdgpu, hence the credit
> for
> this idea goes to the developers of amdgpu.
>=20
> Cc: Christian K=C3=B6nig <christian.koenig@amd.com>
> Signed-off-by: Danilo Krummrich <dakr@redhat.com>
> ---
> =C2=A0drivers/gpu/drm/drm_gpuvm.c=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0 | 332 +++++++++++++++++++++--
> --
> =C2=A0drivers/gpu/drm/nouveau/nouveau_uvmm.c |=C2=A0 64 +++--
> =C2=A0include/drm/drm_gem.h=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 |=C2=A0 32 +--
> =C2=A0include/drm/drm_gpuvm.h=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 | 177 ++++++++++++-
> =C2=A04 files changed, 521 insertions(+), 84 deletions(-)

Forgot to mention, there are a couple of checkpatch.pl --strict issues
with this patch that might need looking at.

Thanks,
Thomas