Re: [PATCH v06 27/36] uapi xen/gntdev.h: include xen/privcmd.h and define grant_ref_t

From: Juergen Gross
Date: Mon Aug 21 2017 - 09:33:15 EST


On 06/08/17 18:44, Mikko Rapeli wrote:
> Both are needed to compile <xen/gntdev.h> in userspace. Fixes these
> userspace compile errors:
>
> xen/gntdev.h:151:4: error: unknown type name âgrant_ref_tâ
> grant_ref_t ref;
> ^
> xen/gntdev.h:153:4: error: unknown type name âdomid_tâ
> domid_t domid;
> ^
>
> Signed-off-by: Mikko Rapeli <mikko.rapeli@xxxxxx>
> Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
> Cc: Juergen Gross <jgross@xxxxxxxx>
> Cc: xen-devel@xxxxxxxxxxxxxxxxxxxx
> ---
> include/uapi/xen/gntdev.h | 6 ++++++
> include/xen/interface/grant_table.h | 6 +-----
> 2 files changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/include/uapi/xen/gntdev.h b/include/uapi/xen/gntdev.h
> index d0661977667e..f208706b07c9 100644
> --- a/include/uapi/xen/gntdev.h
> +++ b/include/uapi/xen/gntdev.h
> @@ -34,6 +34,12 @@
> #define __LINUX_PUBLIC_GNTDEV_H__
>
> #include <linux/types.h>
> +#include <xen/privcmd.h>
> +
> +/*
> + * Reference to a grant entry in a specified domain's grant table.
> + */
> +typedef __u32 grant_ref_t;
>
> struct ioctl_gntdev_grant_ref {
> /* The domain ID of the grant to be mapped. */
> diff --git a/include/xen/interface/grant_table.h b/include/xen/interface/grant_table.h
> index 7fb7112d667c..29b3724aec2c 100644
> --- a/include/xen/interface/grant_table.h
> +++ b/include/xen/interface/grant_table.h
> @@ -29,6 +29,7 @@
> #define __XEN_PUBLIC_GRANT_TABLE_H__
>
> #include <xen/interface/xen.h>
> +#include <uapi/xen/gntdev.h> /* for grant_ref_t */

Hmm, I really don't like this. We import the Xen headers from the Xen
source repository. The Xen specific types shouldn't be taken from
non-Xen headers.

>
> /***********************************
> * GRANT TABLE REPRESENTATION
> @@ -85,11 +86,6 @@
> */
>
> /*
> - * Reference to a grant entry in a specified domain's grant table.
> - */
> -typedef uint32_t grant_ref_t;
> -
> -/*
> * A grant table comprises a packed array of grant entries in one or more
> * page frames shared between Xen and a guest.
> * [XEN]: This field is written by Xen and read by the sharing guest.
>

I'd rather use __u32 instead of grant_ref_t in the uapi headers.

Boris, what do you think?


Juergen