Re: [Qemu-devel] [Xen-devel] [PATCH 2/2] xenfb: Add comment documentation

[David Vrabel <david.vrabel@citrix.com>]

On 22/09/14 10:04, Owen smith wrote:
> Add documentation for page-ref, page-gref and event-channel.
> 
> Signed-off-by: Owen smith <owen.smith@citrix.com>
> ---
>  xen/include/public/io/fbif.h | 25 +++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
> 
> diff --git a/xen/include/public/io/fbif.h b/xen/include/public/io/fbif.h
> index cc25aab..ba3f524 100644
> --- a/xen/include/public/io/fbif.h
> +++ b/xen/include/public/io/fbif.h
> @@ -26,6 +26,31 @@
>  #ifndef __XEN_PUBLIC_IO_FBIF_H__
>  #define __XEN_PUBLIC_IO_FBIF_H__
>  
> +/*
> + * Frontend XenStore Nodes
> + * -----------------------
> + *
> + * page-ref
> + *   Values: <uint64_t>
> + *   Optional, "page-gref" is used if "page-ref" is not set.
> + *
> + *   The MFN of a page of memory for the shared ring structures. If not
> + *   present, "page-gref" must be set.page-ref" overrides "page-gref".

I think you mean GFN here, not MFN.

> + * page-gref
> + *   Values: <uint32_t>
> + *   Only required if "page-ref" is NOT set.
> + *
> + *   A grant reference to the memory page to be mapped for the shared ring
> + *   structures. Must be present if "page-ref" is not present.

Should there be some negotiation for which of page-ref or page-gref is
required/preferred by the backend?

The same applies to kbdif as well.

David