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Message-ID: <20200908085544.GI2352366@phenom.ffwll.local> Mail-Followup-To: Gerd Hoffmann , dri-devel , Christian =?iso-8859-1?Q?K=F6nig?= , Alex Deucher , David Airlie , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Lucas Stach , Russell King , Christian Gmeiner , Rob Clark , Sean Paul , Ben Skeggs , Sandy Huang , Heiko =?iso-8859-1?Q?St=FCbner?= , Thierry Reding , Jonathan Hunter , Oleksandr Andrushchenko , "open list:RADEON and AMDGPU DRM DRIVERS" , open list , "moderated list:DRM DRIVERS FOR VIVANTE GPU IP" , "open list:DRM DRIVER FOR MSM ADRENO GPU" , "open list:DRM DRIVER FOR MSM ADRENO GPU" , "open list:DRM DRIVER FOR NVIDIA GEFORCE/QUADRO GPUS" , "moderated list:ARM/Rockchip SoC support" , "open list:ARM/Rockchip SoC support" , "open list:DRM DRIVERS FOR NVIDIA TEGRA" , "moderated list:DRM DRIVERS FOR XEN" References: <20200907112425.15610-1-kraxel@redhat.com> <20200907112425.15610-2-kraxel@redhat.com> <20200908054858.um34wojjv6uhi7d3@sirius.home.kraxel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200908054858.um34wojjv6uhi7d3@sirius.home.kraxel.org> X-Operating-System: Linux phenom 5.7.0-1-amd64 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200908_045548_754020_2859B46A X-CRM114-Status: GOOD ( 26.57 ) X-BeenThere: linux-rockchip@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Upstream kernel work for Rockchip platforms List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Heiko =?iso-8859-1?Q?St=FCbner?= , David Airlie , "open list:DRM DRIVER FOR NVIDIA GEFORCE/QUADRO GPUS" , dri-devel , Sandy Huang , Thierry Reding , Oleksandr Andrushchenko , "open list:RADEON and AMDGPU DRM DRIVERS" , Jonathan Hunter , "open list:ARM/Rockchip SoC support" , Ben Skeggs , Russell King , "moderated list:DRM DRIVERS FOR XEN" , Daniel Vetter , "open list:DRM DRIVER FOR MSM ADRENO GPU" , Maarten Lankhorst , "moderated list:DRM DRIVERS FOR VIVANTE GPU IP" , Maxime Ripard , Christian Gmeiner , "open list:DRM DRIVERS FOR NVIDIA TEGRA" , Sean Paul , "moderated list:ARM/Rockchip SoC support" , open list , Rob Clark , Thomas Zimmermann , Alex Deucher , "open list:DRM DRIVER FOR MSM ADRENO GPU" , Christian =?iso-8859-1?Q?K=F6nig?= , Lucas Stach Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-rockchip" Errors-To: linux-rockchip-bounces+linux-rockchip=archiver.kernel.org@lists.infradead.org On Tue, Sep 08, 2020 at 07:48:58AM +0200, Gerd Hoffmann wrote: > On Mon, Sep 07, 2020 at 03:53:02PM +0200, Daniel Vetter wrote: > > On Mon, Sep 7, 2020 at 1:24 PM Gerd Hoffmann wrote: > > > > > > Add drm_device argument to drm_prime_pages_to_sg(), so we can > > > call dma_max_mapping_size() to figure the segment size limit > > > and call into __sg_alloc_table_from_pages() with the correct > > > limit. > > > > > > This fixes virtio-gpu with sev. Possibly it'll fix other bugs > > > too given that drm seems to totaly ignore segment size limits > > > so far ... > > > > > > v2: place max_segment in drm driver not gem object. > > > v3: move max_segment next to the other gem fields. > > > v4: just use dma_max_mapping_size(). > > > > > > Signed-off-by: Gerd Hoffmann > > > > Uh, are you sure this works in all cases for virtio? > > Sure, I've tested it ;) > > > The comments I've found suggest very much not ... Or is that all very > > old stuff only that no one cares about anymore? > > I think these days it is possible to override dma_ops per device, which > in turn allows virtio to deal with the quirks without the rest of the > kernel knowing about these details. > > I also think virtio-gpu can drop the virtio_has_dma_quirk() checks, just > use the dma api path unconditionally and depend on virtio core having > setup dma_ops in a way that it JustWorks[tm]. I'll look into that next. The comment above vring_use_dma_api() suggests that this has not yet happened, that's why I'm asking. If this has happened then I think it'd be best if you remove that todo entry and update it, as part of the overall series to add dma_max_mapping_size and remove the quirks. Otherwise this all is a bit wtf material :-) -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ Linux-rockchip mailing list Linux-rockchip@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-rockchip