[Intel-gfx] [PATCH v11 0/1] drm/i915/gvt: Dma-buf support for GVT-g

Tina Zhang tina.zhang at intel.com
Wed Jul 12 06:09:41 UTC 2017


v10->v11:
1) rename plane_type to drm_plane_type. (Gerd)
2) move fields of vfio_device_query_gfx_plane to
   vfio_device_gfx_plane_info. (Gerd)
3) remove drm_format_mod, start fields. (Daniel)
4) remove plane_id.

v9->v10:
1) remove dma-buf management
2) refine the ABI API VFIO_DEVICE_QUERY_GFX_PLANE
3) track the dma-buf create and release in kernel mode

v8->v9:
1) refine the dma-buf ioctl definition
2) add a lock to protect the dmabuf list
3) move drm format change to a separate patch
4) codes cleanup

v7->v8:
1) refine framebuffer decoder code
2) fix a bug in decoding primary plane

v6->v7:
1) release dma-buf related allocations in dma-buf's associated release
function.
2) refine ioctl interface for querying plane info or create dma-buf
3) refine framebuffer decoder code
4) the patch series is based on 4.12.0-rc1

v5->v6:
1) align the dma-buf life cycle with the vfio device.
2) add the dma-buf releated operations in a separate patch.
3) i915 releated changes.

v4->v5:
1) fix bug while checking whether the gem obj is gvt's dma-buf when user
change caching mode or domains. Add a helper function to do it.
2) add definition for the query plane and create dma-buf.

v3->v4:
1) fix bug while checking whether the gem obj is gvt's dma-buf when set
caching mode or doamins.

v2->v3:
1) add a field gvt_plane_info in the drm_i915_gem_obj structure to save
the decoded plane information to avoid look up while need the plane info.
2) declare a new flag I915_GEM_OBJECT_IS_GVT_DMABUF in drm_i915_gem_object
to represent the gem obj for gvt's dma-buf. The tiling mode, caching mode
and domains can not be changed for this kind of gem object.
3) change dma-buf related information to be more generic. So other vendor
can use the same interface.

v1->v2:
1) create a management fd for dma-buf operations.
2) alloc gem object's backing storage in gem obj's get_pages() callback.

This patch set adds the dma-buf support for intel GVT-g.
dma-buf is a uniform mechanism to share DMA buffers across different
devices and sub-systems.
dma-buf for intel GVT-g is mainly used to share the vgpu's framebuffer
to other users or sub-systems so they can use the dma-buf to show the
desktop of a vm which uses intel vgpu.

The main idea is we create a gem object and set vgpu's framebuffer as
the backing storage of this gem object. And associate this gem obj
to a dma-buf object then export this dma-buf at the meantime
generate a file descriptor for this dma-buf. Finally deliver this file
descriptor to user space. And user can use this dma-buf fd to do render
or other operations.

Tina Zhang (1):
  vfio: ABI for mdev display dma-buf operation

 include/uapi/linux/vfio.h | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

-- 
2.7.4



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