Messages in this thread | | | Subject | Re: [Intel-gfx] [PATCH v9 5/7] vfio: Define vfio based dma-buf operations | From | Gerd Hoffmann <> | Date | Wed, 21 Jun 2017 13:03:31 +0200 |
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On Wed, 2017-06-21 at 09:20 +0000, Zhang, Tina wrote: > Thanks for all the comments. I'm planning to cook the next version of > this patch set
How about posting only this patch instead of the whole series until we've settled the interfaces?
> Could the following two works? > #define VFIO_DEVICE_FLAGS_DMABUF (1 << 5) /* vfio-dmabuf > device */
VFIO_DEVICE_FLAGS_GFX_DMABUF?
> 2. vfio_device_gfx_plane_info > struct vfio_device_gfx_plane_info { > __u64 start;-> offset > __u64 drm_format_mod; > __u32 drm_format; > __u32 width; > __u32 height; > __u32 stride; > __u32 size; > __u32 x_pos; > __u32 y_pos; > }; > > Does it make sense to have a "generation" field in the plane_info > > struct (which gets increased each time the struct changes) ?
> Well, Gerd, can you share more details about how to use this field > in user mode, so that we can figure out a way to support it? Thanks.
generation would be increased each time one of the fields in vfio_device_gfx_plane_info changes, typically on mode switches (width/height changes) and pageflips (offset changes). So userspace can simply compare generation instead of comparing every field to figure whenever something changed compared to the previous poll.
> > 3. vfio_device_query_gfx_plane > struct vfio_device_query_gfx_plane { > __u32 argsz; > __u32 flags; > #define VFIO_GFX_PLANE_FLAGS_REGION_ID (1 << 0) > #define VFIO_GFX_PLANE_FLAGS_PLANE_ID (1 << 1) > struct vfio_device_gfx_plane_info plane_info; > __u32 id; > __u32 plane_type; > }; > So far, dmabuf use id for DRM_PLANE_TYPE_PRIMARY or > DRM_PLANE_TYPE_CURSOR.
> If the newly added plane_type is used for this, the id field may be > useless in dmabuf usage. Do you have any idea about the usage of this > id field in dmabuf usage?
plane_type should be DRM_PLANE_TYPE_PRIMARY or DRM_PLANE_TYPE_CURSOR for dmabuf.
Given that nvidia doesn't support a separate cursor plane in their region they would support DRM_PLANE_TYPE_PRIMARY only.
I can't see yet what id would be useful for.
Likewise I can't see yet what the VFIO_GFX_PLANE_FLAGS_* are good for.
cheers, Gerd
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