Re: [PATCH 1/2] vfio: ABI for setting mdev display flip eventfd

[Alex Williamson]

On Mon, 27 May 2019 16:43:11 +0800
Tina Zhang <tina.zhang@xxxxxxxxx> wrote:

> Add VFIO_DEVICE_SET_GFX_FLIP_EVENTFD ioctl command to set eventfd
> based signaling mechanism to deliver vGPU framebuffer page flip
> event to userspace.
> 
> Signed-off-by: Tina Zhang <tina.zhang@xxxxxxxxx>
> ---
>  include/uapi/linux/vfio.h | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
> index 02bb7ad6e986..27300597717f 100644
> --- a/include/uapi/linux/vfio.h
> +++ b/include/uapi/linux/vfio.h
> @@ -696,6 +696,18 @@ struct vfio_device_ioeventfd {
>  
>  #define VFIO_DEVICE_IOEVENTFD		_IO(VFIO_TYPE, VFIO_BASE + 16)
>  
> +/**
> + * VFIO_DEVICE_SET_GFX_FLIP_EVENTFD - _IOW(VFIO_TYPE, VFIO_BASE + 17, __s32)
> + *
> + * Set eventfd based signaling mechanism to deliver vGPU framebuffer page
> + * flip event to userspace. A value of -1 is used to stop the page flip
> + * delivering.
> + *
> + * Return: 0 on success, -errno on failure.
> + */
> +
> +#define VFIO_DEVICE_SET_GFX_FLIP_EVENTFD _IO(VFIO_TYPE, VFIO_BASE + 17)
> +
>  /* -------- API for Type1 VFIO IOMMU -------- */
>  
>  /**

Why can't we use VFIO_DEVICE_SET_IRQS for this?  We can add a
capability to vfio_irq_info in the same way that we did for regions to
describe device specific IRQ support.  Thanks,

Alex