Re: [virtio-dev] [PATCH 2/2] drm/virtio: add iommu support.

[Jiandi An]

On 09/18/2018 11:46 PM, Gerd Hoffmann wrote:
>   Hi,
> 
>> buffer.  I tried to put a dma_sync_sg_for_device() on virtio_gpu_object obj->pages-sgl
>> before VIRTIO_GPU_CMD_TRANSFER_TO_HOST_2D is sent.  This fixes the kernel console path.
> 
> That should be the right place.
> 
>> Once display manger is kicked off for example (sudo systemctl start lightdm.service) and
>> resource id 3 gets created from user space down, it still gives a blank black screen.
> 
> Hmm.  I'd suspect there is simply a code path missing.  Can you send the
> patch you have?
> 
> cheers,
>   Gerd
> 

I sent the patch.  For now it does dma_sync_sg on the pages in 
TRANSFER_TO_HOST_2D/3D when use_dma_api is true.

https://lore.kernel.org/lkml/20180919070931.91168-1-jiandi.an@xxxxxxx/

- Jiandi