[Intel-gfx] [PATCH v2 0/5] drm/i915/gvt: Dma-buf support for GVT-g

[Xiaoguang Chen]

v2->v1:
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.
User need to create a fd(for intel GVT-g dma-buf support it is a:dma-buf
management fd) then user can use this fd to query the plane information
or create a dma-buf. The life cycle of this fd is managed by GVT-g user
do not need to care about that.

We have an example program on how to use the dma-buf. You can download
the program to have a try. Good luck :)
git repo: https://github.com/01org/igvtg-qemu branch:kvmgt_dmabuf_example.

Xiaoguang Chen (5):
  drm/i915/gvt: Extend the GVT-g architecture to support vfio device
    region
  drm/i915/gvt: OpRegion support for GVT-g
  drm/i915/gvt: Frame buffer decoder support for GVT-g
  drm/i915/gvt: Dmabuf support for GVT-g
  drm/i915/gvt: Adding interface so user space can get the dma-buf

 drivers/gpu/drm/i915/gvt/Makefile     |   3 +-
 drivers/gpu/drm/i915/gvt/display.c    |   2 +-
 drivers/gpu/drm/i915/gvt/display.h    |   2 +
 drivers/gpu/drm/i915/gvt/dmabuf.c     | 321 ++++++++++++++++++++++
 drivers/gpu/drm/i915/gvt/dmabuf.h     |  44 +++
 drivers/gpu/drm/i915/gvt/fb_decoder.c | 487 ++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/gvt/fb_decoder.h | 166 ++++++++++++
 drivers/gpu/drm/i915/gvt/gvt.c        |   2 +
 drivers/gpu/drm/i915/gvt/gvt.h        |   7 +
 drivers/gpu/drm/i915/gvt/kvmgt.c      | 207 ++++++++++++++-
 drivers/gpu/drm/i915/gvt/opregion.c   |  12 +-
 include/uapi/drm/i915_drm.h           |  29 ++
 include/uapi/linux/vfio.h             |  12 +
 13 files changed, 1287 insertions(+), 7 deletions(-)
 create mode 100644 drivers/gpu/drm/i915/gvt/dmabuf.c
 create mode 100644 drivers/gpu/drm/i915/gvt/dmabuf.h
 create mode 100644 drivers/gpu/drm/i915/gvt/fb_decoder.c
 create mode 100644 drivers/gpu/drm/i915/gvt/fb_decoder.h

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1.9.1