On Mon, 6 Nov 2017 10:19:17 +0800
Tina Zhang <tina.zhang@xxxxxxxxx> wrote:
> Add VFIO_DEVICE_QUERY_GFX_PLANE ioctl command to let user query and get
> a plane and its related information. So far, two types of buffers are
> supported: buffers based on dma-buf and buffers based on region.
>
> This ioctl can be invoked with:
> 1) either DMABUF or REGION flag. Vendor driver returns a plane_info
> successfully only when the specific kind of buffer is supported.
> 2) flag PROBE. And at the same time either DMABUF or REGION must be set,
> so that vendor driver can return success only when the specific kind of
> buffer is supported.
>
> Add VFIO_DEVICE_GET_GFX_DMABUF ioctl command to let user get an exposed
> dma-buf fd of a specific dmabuf_id which was returned in VFIO_DEVICE_QUERY
> _GFX_PLANE ioctl command.
>
> The life cycle of an exposed MDEV buffer is handled by userspace and
> tracked by kernel space. The returned dmabuf_id in struct vfio_device_
> query_gfx_plane can be a new id of a new exposed buffer or an old id of
> a re-exported buffer. Host user can check the value of dmabuf_id to see
> if it needs to create new resources according to the new exposed buffer
> or just re-use the existing resource related to the old buffer.
>
> v16:
> - add x_hot and y_hot fields. (Gerd)
> - add comments for VFIO_DEVICE_GET_GFX_DMABUF. (Alex)
> - rebase to 4.14.0-rc6.
>
> v15:
> - add a ioctl to get a dmabuf for a given dmabuf id. (Gerd)
>
> v14:
> - add PROBE, DMABUF and REGION flags. (Alex)
>
> v12:
> - add drm_format_mod back. (Gerd and Zhenyu)
> - add region_index. (Gerd)
>
> v11:
> - rename plane_type to drm_plane_type. (Gerd)
> - move fields of vfio_device_query_gfx_plane to vfio_device_gfx_plane_info.
> (Gerd)
> - remove drm_format_mod, start fields. (Daniel)
> - remove plane_id.
>
> v10:
> - refine the ABI API VFIO_DEVICE_QUERY_GFX_PLANE. (Alex) (Gerd)
>
> v3:
> - 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. (Gerd)
>
> Signed-off-by: Tina Zhang <tina.zhang@xxxxxxxxx>
> Cc: Gerd Hoffmann <kraxel@xxxxxxxxxx>
> Cc: Alex Williamson <alex.williamson@xxxxxxxxxx>
> Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
> ---
> include/uapi/linux/vfio.h | 68 +++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 68 insertions(+)
>
> diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
> index ae46105..6c55668 100644
> --- a/include/uapi/linux/vfio.h
> +++ b/include/uapi/linux/vfio.h
> @@ -502,6 +502,74 @@ struct vfio_pci_hot_reset {
>
> #define VFIO_DEVICE_PCI_HOT_RESET _IO(VFIO_TYPE, VFIO_BASE + 13)
>
> +/**
> + * VFIO_DEVICE_QUERY_GFX_PLANE - _IOW(VFIO_TYPE, VFIO_BASE + 14,
> + * struct vfio_device_query_gfx_plane)
> + *
> + * Set the drm_plane_type and flags, then retrieve the gfx plane info.
> + *
> + * flags supported:
> + * - VFIO_GFX_PLANE_TYPE_PROBE and VFIO_GFX_PLANE_TYPE_DMABUF are set
> + * to ask if the mdev supports dma-buf. 0 on support, -EINVAL on no
> + * support for dma-buf.
> + * - VFIO_GFX_PLANE_TYPE_PROBE and VFIO_GFX_PLANE_TYPE_REGION are set
> + * to ask if the mdev supports region. 0 on support, -EINVAL on no
> + * support for region.
> + * - VFIO_GFX_PLANE_TYPE_DMABUF or VFIO_GFX_PLANE_TYPE_REGION is set
> + * with each call to query the plane info.
> + * - Others are invalid and return -EINVAL.
> + *
> + * Return: 0 on success, -ENODEV with all out fields zero on mdev
> + * device initialization, -errno on other failure.
> + */
> +struct vfio_device_gfx_plane_info {
> + __u32 argsz;
> + __u32 flags;
> +#define VFIO_GFX_PLANE_TYPE_PROBE (1 << 0)
> +#define VFIO_GFX_PLANE_TYPE_DMABUF (1 << 1)
> +#define VFIO_GFX_PLANE_TYPE_REGION (1 << 2)
> + /* in */
> + __u32 drm_plane_type; /* type of plane: DRM_PLANE_TYPE_* */
> + /* out */
> + __u32 drm_format; /* drm format of plane */
> + __u64 drm_format_mod; /* tiled mode */
> + __u32 width; /* width of plane */
> + __u32 height; /* height of plane */
> + __u32 stride; /* stride of plane */
> + __u32 size; /* size of plane in bytes, align on page*/
> + __u32 x_pos; /* horizontal position of cursor plane */
> + __u32 y_pos; /* vertical position of cursor plane*/
> + __u32 x_hot; /* horizontal position of cursor hotspot */
> + __u32 y_hot; /* vertical position of cursor hotspot */
> + union {
> + __u32 region_index; /* region index */
> + __u32 dmabuf_id; /* dma-buf id */
> + };
> +};
> +
> +#define VFIO_DEVICE_QUERY_GFX_PLANE _IO(VFIO_TYPE, VFIO_BASE + 14)
> +
> +/**
> + * VFIO_DEVICE_GET_GFX_DMABUF - _IOW(VFIO_TYPE, VFIO_BASE + 15,
> + * struct vfio_device_gfx_dmabuf_fd)
> + *
> + * Retrieve dmabuf_fd of an exposed guest framebuffer referenced by dmabuf_id
> + * which is returned from VFIO_DEVICE_QUERY_GFX_PLANE as a token of the
> + * exposed guest framebuffer.
> + *
> + * Return: 0 on success, -errno on failure.
> + */
> +struct vfio_device_gfx_dmabuf_fd {
> + __u32 argsz;
> + __u32 flags;
> + /* in */
> + __u32 dmabuf_id;
> + /* out */
> + __s32 dmabuf_fd;
> +};
> +
> +#define VFIO_DEVICE_GET_GFX_DMABUF _IO(VFIO_TYPE, VFIO_BASE + 15)
> +
I thought we had agreed to make this behave similar to
VFIO_GROUP_GET_DEVICE_FD, the ioctl would take a __u32 dmabuf_id and
return the file descriptor as the ioctl return value. Thanks,
Alex
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