Re: [PATCH] vfio: re-arrange vfio region definitions

[Auger Eric <eric.auger@redhat.com>]

Hi Connie,

On 7/17/19 1:49 PM, Cornelia Huck wrote:
> It is easy to miss already defined region types. Let's re-arrange
> the definitions a bit and add more comments to make it hopefully
> a bit clearer.
> 
> No functional change.
> 
> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
> ---
>  include/uapi/linux/vfio.h | 19 ++++++++++++-------
>  1 file changed, 12 insertions(+), 7 deletions(-)
> 
> diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
> index 8f10748dac79..d9bcf40240be 100644
> --- a/include/uapi/linux/vfio.h
> +++ b/include/uapi/linux/vfio.h
> @@ -295,15 +295,23 @@ struct vfio_region_info_cap_type {
>  	__u32 subtype;	/* type specific */
>  };
>  
> +/*
> + * List of region types, global per bus driver.
> + * If you introduce a new type, please add it here.
> + */
> +
> +/* PCI region type containing a PCI vendor part */
>  #define VFIO_REGION_TYPE_PCI_VENDOR_TYPE	(1 << 31)
>  #define VFIO_REGION_TYPE_PCI_VENDOR_MASK	(0xffff)
> +#define VFIO_REGION_TYPE_GFX                    (1)
> +#define VFIO_REGION_TYPE_CCW			(2)
>  
> -/* 8086 Vendor sub-types */
> +/* 8086 vendor PCI sub-types */
>  #define VFIO_REGION_SUBTYPE_INTEL_IGD_OPREGION	(1)
>  #define VFIO_REGION_SUBTYPE_INTEL_IGD_HOST_CFG	(2)
>  #define VFIO_REGION_SUBTYPE_INTEL_IGD_LPC_CFG	(3)
>  
> -#define VFIO_REGION_TYPE_GFX                    (1)
> +/* GFX sub-types */
>  #define VFIO_REGION_SUBTYPE_GFX_EDID            (1)
>  
>  /**
> @@ -353,20 +361,17 @@ struct vfio_region_gfx_edid {
>  #define VFIO_DEVICE_GFX_LINK_STATE_DOWN  2
>  };
>  
> -#define VFIO_REGION_TYPE_CCW			(2)
>  /* ccw sub-types */
>  #define VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD	(1)
>  
> +/* 10de vendor PCI sub-types */
>  /*
> - * 10de vendor sub-type
> - *
>   * NVIDIA GPU NVlink2 RAM is coherent RAM mapped onto the host address space.
>   */
>  #define VFIO_REGION_SUBTYPE_NVIDIA_NVLINK2_RAM	(1)
>  
> +/* 1014 vendor PCI sub-types*/
>  /*
> - * 1014 vendor sub-type
Maybe the 10de vendor sub-type and 1014 vendor sub-type could be put
just after /* 8086 vendor PCI sub-types */

More generally if it were possible to leave the subtypes close to their
parent type too, this would be beneficial I think.

Besides that becomes sensible to put all those definitions together.

Thanks

Eric
> - *
>   * IBM NPU NVlink2 ATSD (Address Translation Shootdown) register of NPU
>   * to do TLB invalidation on a GPU.
>   */
>